Thèses sur le sujet « Protein feed »

Thesis (M.S.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on January 16, 2008) Includes bibliographical references.

Feed intake is a key factor affecting pig performance; thus, the objective of these studies was to assess a variety of factors that could potentially affect intake in pigs in different production stages. Studies were conducted to determine the effects of flavor and diet complexity, Appetein™ (an alternative protein source), and graded levels of salt on swine feed intake and feed preference. Two newly developed flavors were used in nursery pig diets. The use of the two flavors did not increase feed intake (P > 0.05). Nursery pigs actually showed a preference for the control diet. Complex diet formulation does increase feed intake (P < 0.03) in nursery pigs when diets are not over-formulated. When flavor was added to lactation diets sow feed intake did not change compared to the control. The flavor did not affect litter performance (P > 0.05). When Appetein™ was added to lactation diets at 0.5%, pig weight and litter weight were numerically greater for the sows fed Appetein™ but not significantly so. Appetein™ did not affect feed intake. When nursery pigs were fed graded levels of salt (0.1, 0.5, and 0.8%) feed intake increased (P < 0.01) as salt level increased. Nursery pigs also preferred (P < 0.05) 0.8% salt over other levels the first two weeks after weaning when given a choice among diets.

The studies reported in this thesis were carried out to evaluate the effects of enzyme treatment on the nutritive value of three lupin species (L. luteus, L. albus and L. angustifolius) and evaluate their suitability as a source of protein for growing broilers. Some preliminary in vitro work on the effect of quinolizidine alkaloids on bacteria from poultry excreta was carried out. Furthermore the use of near infrared spectroscopy (NIRS) as an alternative technique for assessing the chemical composition and nutritive value (such as metabolizable energy and digestibilities) was investigated. Compositional analyses of the various lupins, fractions and diets were conducted. The chemical composition of the lupin seeds used in this study showed a high crude protein content and a variable content in ether extract and neutral detergent fibre. The alkaloid content of the seeds was determined and allowed the classification of the lupin into bitter (L. luteus cv Cardiga), semi-sweet (L. albus cv Estoril) and sweet (L. albus from France and L. angustifolius from Australia) seeds. Alkaloids from lupins decrease feed consumption and may affect the digestive capacity of the animal. A preliminary study on the effects of sparteine and alkaloids extracted from L. luteus seeds on bacteria from poultry excreta indicated that extracts of alkaloids from L. luteus had an inhibitory effect on coliform growth that was not, however, as great as that of sparteine. Sparteine, essentially prevented growth of coliforms at concentrations of 10 g dm-3. Lactobacilli were apparently not directly affected by the lupin extract of alkaloid or the isolated sparteine. This in vitro work suggests that it may be possible to influence the gut microflora in a beneficial manner by using the appropriate concentration of the appropriate alkaloids. A set of tube feeding experiments (by gavage) were carried out to evaluate the effect of different enzymes on the nutritive value of L. luteus (cv. Cardiga) and L. albus (cv. Estoril) seeds. The first experiment was a preliminary one which allowed the modification of the tube feeding assay in order to suit the characteristics of the test materials used in this study. The following six experiments tested the effects of pre-incubation, as a wet mash, of a polygalacturonase, five proteases, a pectinase and an [Special character omitted]-galactosidase at variable levels, on the nutritive value of L. luteus (cv Cardiga) and L. albus (cv. Estoril). The nutritive value of the lupin seeds was evaluated essentially by measuring metabolizable energy (ME) and amino acid (AA) digestibilities. Results indicated that L. albus seeds, irrespective of enzyme treatment, had a higher ME expressed as TMEn than L. luteus seeds. Carbohydrase containing enzyme preparations, caused variable improvements in the ME value of lupin seeds. Polygalacturonase caused a significant increase in the ME of L. luteus seeds, which may have been mediated by an increase in protein digestibility as shown by improvements in the AA digestibility. Increased concentrations of pectinase tended to be more effective in the improvement of ME of L. albus, while increasing concentrations of a-galactosidase were so for L. luteus. The fact that the carbohydrases acted differently upon the two lupin species was probably due to their different concentration in constituent carbohydrates. Pre-incubation with exogenous proteases decreased the ME of the lupin seeds. The reasons for the depression were not clear, however high concentrations of proteases, expressed as U kg-1 of lupin seeds, may have interfered with the gastro intestinal tract and also with the endogenous enzymes of the bird resulting in reduced utilisation of the pre-incubated material. A growth experiment was design to investigate the effects of the inclusion of L. luteus (cv. Cardiga), L. albus (from France) or L. angustifolius (from Australia) as the main or secondary source of protein in diets for growing broilers. Lupin seeds were either pre-incubated as a wet mash, or the lupin containing diets were supplemented with a carbohydrase, a protease or a mixture of both. Diets were fed to the animals over a three week period. The results obtained tended to support the hypothesis that the enzymes had little effect on the other dietary ingredients but had their main effects on the lupins in the diets.

A series of experiments were conducted to measure the mode of action by which fishmeal exerts its effect on milk composition of dairy cows. Production Study One measured the effect of increased fishmeal intake on milk production and milk composition in dairy cattle. Milk fat percentage and yield were decreased by increased fishmeal intake. This decrease was not associated with changes in ruminal fermentation patterns. Plasma long-chain n-3 polyunsaturated fatty acids were increased with increased fishmeal intake. Mammary slices from lactating bovine mammary gland were incubated with eicosapentaenoic acid. Changes in ¹⁴C-acetate metabolism were measured. Acetate oxidation and incorporation into milk lipid were not changed by eicosapentaenoic acid. However, tissue from mammary gland of cows milked 6 to 8 h prior to slaughter had 2 fold higher activity than tissue milked 1 h before slaughter. Disappearance of dry matter, crude protein, and lipid in fish meal from undegradable bags in the rumen was measured. Dry matter and crude protein degradation of fish meal were similar to published values. Lipid escaped rapidly with greater than 70% removed by 8 h. A subsequent fish oil infusion study revealed that intraruminal fish oil treatment did not significantly alter ruminal fermentation, or change fatty acid profiles in duodenal digesta, plasma, or milk. Duodenal infusion increased plasma concentrations of n-3 fatty acids but did not affect milk lipid fatty acid composition. A second production study compared the effects of fish meal versus fish oil on milk production and composition, and changes in fatty acids in plasma and milk. Fish meal significantly increased plasma n-3 fatty acids compared to the fish oil treatment. Residual fatty acids contained in fish meal seemed to be protected from rumen degradation and probably remained intact for digestion and absorption since plasma n-3 fatty acid concentrations increased. No changes in milk yield or composition were due to the experimental treatments. Fat in fish meal and fish oil source differed significantly in their ability to alter milk composition and plasma fatty acid profiles.
Ph. D.

Attempts to improve upon the crude protein feeding system have strived to characterize feedstuffs with respect to ruminal protein degradability. In vitro an in situ procedures fall short of this goal by not accounting for ruminal turnover. Six lactating cows, fitted with ruminal and duodenal cannulae, were utilized for in vivo determination of protein degradability by employing a double-marker system. Treatments were corn silage-based diets supplemented with 2:1 soybean meal:fish meal nitrogen (SF) or 1:2 soybean meal:fish meal nitrogen (FS) at levels of 15. 9 and 16.0 percent protein. Ruminal cobalt ethylenediaminetetraacetic acid (CoEDTA) infusions marked liquid phase (LP) digesta and Yb-soaked hay was used as a solid phase (SP) marker. Duodenal digesta was separated into SP and LP at 3000xg. Least squares means of LP flows did not differ for total, precipitable protein, or microbial nitrogen, for SF and FS. Total solid phase flow of dry matter was higher for FS (9.06 kg/d) than for SF (7.97 kg/d), although intakes did not differ. Milk composition and yield did not differ for FS and SF. Average daily gain was 0.12 kg/d for SF and 1:26 kg/d for FS. Whole-tract digestibilties were not different although rumen digestibility of dry matter was 24.9% for FS and 35.7% for SF, and duodenal recovery of N was 93.8% for SF and 107.5% for FS. Inclusion of a higher level of fish meal in the diet increased the proportion of feed proteins delivered to the small intestine, increasing weight gain while having no effect on milk production.
Master of Science

The goal of this work was to contribute to the fed-batch process optimisation task by deriving parameters that have considerable impact on productivity as well as product quality The chosen parameters were I) the design of the glucose feed profile, II) the choice of induction strategy, with respect to the method of addition, and III) the time of the induction, with respect to the specific glucose consumption rate.

The present fed-batch experiments using the lacUV5-promoter, for production of b-galactosidase, have shown that a high glucose feed rate gives a specific production rate, q_p, that is twice as high, after induction, compared to a feed rate that is 2.5 times lower. The constant accumulation of lacZ-mRNA indicates that the translational capacity is initially limiting the synthesis machinery, but after four hours of maximum specific production and a corresponding drop in lacZ-mRNA production, the cultivation is likely to be transcription limited. The high feed-rate system resulted in high accumulation of β-galactosidase, corresponding to 40% of total cellular proteins.

By design of feed profiles in a fed-batch process the detrimental effects of overflow metabolism, giving acetic acid formation, can be avoided. However, the results show that a one-dose addition of isopropyl-β-D-galactopyranoside (IPTG), provokes a non-growth associated production of acetic acid. This response can be alleviated by; lowering the inducer concentration (in this case to below 165 μM), by further reducing the feed rate of glucose or by using alternative induction methods. The use of a stepwise addition or a feed of IPTG thus delayed and reduced the level of acetic acid accumulation. It was also shown that a small change in the time-point of induction lead to large variability, regarding both productivity and acetic acid accumulation, in a fed-batch cultivation,

In order to further investigate the protein quality two additional proteins were studied in fed-batch cultivations using high and low glucose feed. The aim was to prove the hypothesis that the feed related change in the rate of synthesis of the nascent polypeptide controls the product quality. For the two proteins: Zb-MalE (wt) and Zb-MalE31 (mutant), the transcription rate, in terms of amount of IPTG, and translation rate, in terms of changes in feed rate, influences the percentage of inclusion body formation and degradation of nascent polypeptide. The data show a higher rate of inclusion body formation for the model protein Zb-MalE31 during high feed rate cultivations, as well as at high levels of inducer. Furthermore, the rate of proteolysis was significantly higher for a high feed rate. The high feed rate thus results in a higher rate of synthesis but a lower corresponding quality, for the model proteins studied.

In the present investigation of fed-batch cultivations using several different expression vectors, it was found that the central alarmone guanosine tetraphosphate (ppGpp) was formed at both high and low feed rates upon induction. It could be shown, however, that by secretion of Zb-MalE to the periplasm, the stringent response could be avoided. This might be due to the decreased burden on the host where the secretion of product further seems to make the cell able to redirect the carbon flux from overflow metabolism, since no acetic acid was produced. The secretion also demonstrates that the growth arrest could be aborted, which is otherwise gained in the P_malK production system.

A novel fed-batch process based on the promoters for the universal stress proteins A and B (P_uspA, P_uspB) was designed to make use of these powerful promoters in an industrial production context. It was concluded that the process had to start from a high specific growth rate and induction was performed once a limiting feed started. This was done to purposely induce the stringent response and/or acetic acid accumulation since this was required for induction. In the suggested system, induction has to be performed and maintained at continuous substrate feeding, whilst avoiding exceeding the cellular capacity, since the stationary phase starvation alone did not lead to production. In conclusion, a new stress induction based production system was achieved resulting in high accumulations of product protein without any detected metabolic side effects.

Protein upgrading of orange peel waste was carried out by Solid Substrate Fermentation using an Aspergillus sp. inoculum in a waste peel mixture containing peel waste, potassium dihydrogen orthophosphate (KH2 PO4), ammonium sulphate [(NH4)2SO4] and molasses. Fermentation lasted 72 hours at 30C. after which crude protein level in the substrate increased from 5% to 13%. Factors found to be important in determing the efficiency of the fermentation process included fermentable sugar content of the medium, nitrogen and mineral levels, initial temperature, PH, moisture, agitation of the medium, and size of particles constituting the substrate. Protein quality of the fermented peel was evaluated by PEP assay and a PER value of 0.78 was recorded. It is suggested that a low level of total amino acids is the major contributory factor to this low PEP value. Total amino acid level measured 5.75g per 100g fermented peel waste.
Master of Science (Hons)

Thesis (M.Sc.) -- Hawkesbury Agricultural College, 1985.
"A thesis submitted to Hawkesbury Agricultural College in partial fulfilment of the requirements for the degree of Master of Applied Science."

A study was conducted to evaluate the use of Leucaena leucocephala leaf meal (LLM) as a protein supplement for pigs. In addition, an evaluation of detoxifying LLM, by sun-drying, water-soaking, or treating with ferrous sulphate (FeS04) solution was undertaken. The research involved two experiments; a growth study and a metabolic study. In the growth study sixteen, 12 weeks old Large White x Landrace pigs (average body weight 22.9 ± 2.12 kg) were fed four experimental rations; a commercial grain-based grower /finisher ration (control); or a ration containing 20% of either sun-dried LLM, water-soaked LLM, or FeS04-treated LLM, replacing the basal diet. There was a significant (P<0.05) decrease in liveweight gain, feed intake and feed conversion efficiency in pigs fed the ration containing sun-dried LLM. Growth rate, feed intake and feed conversion efficiency were not affected by the addition of water-soaked and FeS04-treated LLM to the basal diet. Triiodothyronine (T3) and thyroxine (T4) levels in the blood plasma were not affected by the dietary treatments. However, addition of FeS04-treated LLM to the basal diet significantly (P<0.05) decreased the back fat thickness of the pigs. In the metabolic study, the digestible dry matter (DDM) and digestible CP (DCP) were measured as well as mimosine, 3-hydroxy-4-(1H) pyridone (3,4-DHP) and 2,3DHP output in the faeces and urine.Addition of water-soaked LLM to the diet significantly (P<0.05) lowered the DDM of the diet, whereas addition of FeS04-treated LLM significantly (P<0.05) reduced the DCP. Sun-drying, water-soaking and treatment of LLM with FeS04 solution, did not enhance the output of mimosine or 3,4-DHP in the urine and faeces. The results suggest that water soaking or treatment with FeS04 solution reduces the antinutritional factors (presumably including mimosine) and therefore improves the nutritional quality of LLM containing diets for pigs.

Thesis (MSc)--Stellenbosch University, 2000.
ENGLISH ABSTRACT: South Africa, like many other developing countries throughout the world, has a rapidly growing human population, resulting in a consequent increased demand for food. Ironically, this increased food supply has to be produced on a smaller area of available agricultural land, which means that agricultural production processes have to become more efficient. Furthermore, the majority of the people in these countries are unschooled and poverty is a common phenomenon. Therefore, animal scientists are faced with the challenge and the responsibility to provide affordable, high quality food to these people. One way of reaching this objective is to improve the utilisation of low-quality, high roughage feedstuffs like crop residues and dry natural grass pastures. In the winter rainfall area of South Africa alone, about 460 000 ha of wheat straw are annually available. The ruminant animal has the ability to utilise the relatively unavailable energy (cellulose, hemi-cellulose and pectin) in the fibre component of these low-quality forages. Unfortunately, various factors, of which a N deficiency is the pre-dominant one, limit the utilisation of these feedstuffs. If the ability of the ruminant to utilise low-quality, fibrous energy sources is improved, these abundantly available and relatively inexpensive crop residues and natural pastures can be converted into high quality protein food for human consumption. Therefore, in order to rectify the N deficiency caused by these low-quality forages, the supplemental N requirement to optimise the fermentation and digestive processes of the ruminant animal has to be determined. The first study was conducted to determine the supplemental rumen degradable protein (RDP) requirement, to maximise the digestible organic matter intake (DOMI) of Dohne Merino sheep fed wheat straw. Keeping the high cost of natural protein supplementation in mind, the purpose of the second study was to determine the amount of true protein that can be replaced by nonprotein nitrogen (NPN) in RDP supplements fed to Dohne Merino sheep consuming wheat straw. In both trials animals had ad libitum access to low-quality wheat straw (3.2% CP; 74.2% NDF) and water. In the first trial, RDP (calsium caseinate: 90% CP; 100% rumen degradable) was intraruminally administered at 07hOOand 19hOO,at the following levels: 0, 40,80, 120 and 160 gld. Intake, fermentation and digestion were monitored to determine the RDP requirement to maximise DOM!. Digestible organic matter (OM) intake displayed a quadratic increase with elevated amounts of RDP (P < .01), and was maximised at an estimated 3.15 g RDPlkg BW·75 or 11.6% of DOM. Forage OM intake tended to increase quadratically (P = .15) with higher RDP levels. Microbial nitrogen (MN) flow to the duodenum and microbial efficiency increased quadratically (P ~ .04) and fluid dilution rate tended to increase in a quadratic manner (P = .15) with increased RDP supplementation levels. Rumina! ammonia nitrogen (NH3-N) and total volatile fatty acid (VFA) concentrations increased linearly (P ~ .07), while rumen pH exhibited a variable response to increased RDP levels (cubic; P = .08). Increasing RDP supplementation to Dohne Merino wethers consuming wheat straw, generally enhanced forage utilisation and DOM!. In the second trial, urea replaced different levels of casein N on an isonitrogenous basis, ranging from 0 - 100%. Since true protein is much more expensive than urea, the purpose of this study was to determine the maximum natural protein level that can be replaced by urea in RDP supplements, without adversely affecting intake and/or fermentation and digestive processes. The control treatment provided all of the RDP in the form of calcium caseinate (90% CP; 100% rumen degradable). The percentages of supplemental RDP from urea in the other treatments were 25, 50, 75 and 100%. The 100% urea treatment was balanced with maize starch to contain 40% CP and all other treatments received the same amount (150 gld) of starch. Intake of forage OM showed a weak decreasing trend (linear; P = .16) with increasing urea levels. Ruminal digestibilities of OM and NDF were not affected (P ;;::.:18) by urea level. Increasing urea levels resulted in linearly reduced total tract OM and NDF digestibilities (P ~ .10). As a result, DOMI declined (linear; P < .01) with increasing proportions of urea. Effects of increasing urea proportions on duodenal N flow, microbial efficiency and fluid dilution rate were minimal. Ruminal NH3-N tended to increase quadratically with increasing urea levels (P = .l4). Total VFA concentration decreased linearly (P = .03), while rumen pH increased in a linear manner (P = .08) with increasing urea proportions. Branched-chain volatile fatty acids (BCVFA's) and valerate decreased linearly (P ~ .05) with increasing urea levels, while other VFA's and the acetate:propionate ratio were generally not affected by treatment (P ;;:::.16). It appears as though ruminal and total tract OM and NDF digestibility criteria, as well as DOMI reached maximum values at substituting 25% of casein for urea. It is therefore concluded that replacing 25% of casein with urea in RDP supplements, will maintain effective utilisation of low-quality forages by sheep.
AFRIKAANSE OPSOMMING: Ontwikkelende lande, insluitend Suid-Afrika, word gekenmerk deur 'n vmmge bevolkingsaanwas. Dit lei tot 'n verhoogde vraag na voedsel, wat op 'n gevolglik kleinerwordende beskikbare kommersiële lanbbou-area geproduseer moet word. Die doeltreffendheid van produksieprosesse in die landbousektor moet dus noodgedwonge verbeter word. Die oorgrootte meerderheid van die bevolkings in ontwikkelende lande is ongeletterd en armoede en hongersnood is soms 'n algemene verskynsel. Veekundiges word dus gekonfronteer met die uitdaging en verantwoordelikheid om bekostigbare, hoë kwaliteit voedsel aan hierdie mense te voorsien. Een van die mees doeltreffende metodes om hierdie probleem aan te spreek, is om die benutting van lae kwaliteit, hoë-vesel voerbronne, bv. oesreste en droë grasweidings te verhoog. In die winterreënstreek van Suid-Afrika alleen, is 460 000 ha koringstrooi jaarliks beskikbaar. Herkouers beskik oor die besondere vermoë om die relatief onbeskikbare energie (sellulose, hemi-sellulose en pektien) in die veselkomponent van hierdie lae kwaliteit voere te benut. Verskeie faktore, waarvan 'n N-tekort die mees prominente is, beperk egter die benutting van hierdie voerbronne. Die uitdaging is dus om die herkouer se vermoë om hierdie voere te benut, te optimaliseer. Sodoende word 'n geredelik beskikbare, onderbenutte en relatief goedkoop voerbron omgeskakel in hoë kwaliteit proteïen vir menslike gebruik. Die N-aanvullingsbehoefte om die fermentasie- en verteringsprosesse van die herkouerdier te optimaliseer moet dus bepaal word, sodat die N-tekort in herkouers, wat soortgelyke weidings benut, reggestel kan word. Gevolglik was die doel met die eerste proef om die behoefte aan rumen degradeerbare proteïen-(RDP)-aanvulling, vir die maksimum inname van verteerbare organiese materiaal (VOM) van Dohne Merino skape wat koringstrooi ontvang, te bepaal. Weens die hoë koste van natuurlike proteïenaanvulling, was die doel met die tweede proef om die hoeveelheid ware proteïen in RDP-aanvullings, vir Dohne Merino skape wat koringstrooi ontvang, wat met nie-proteïen stikstof (NPN) vervang kan word, te bepaal. In beide eksperimente het die diere ad libitum toegang tot koringstrooi (3.2% RP; 74.2% NBV) en water gehad. In die eerste proefis RDP (kalsiumkaseïnaat; 90% RP; 100% rumen degradeerbaar) teen 07hOOen 19hOOintraruminaal toegedien, teen die volgende peile: 0, 40, 80, 120 en 160 gld. Inname, fermentasie en vertering is gemonitor om die RDP behoefte vir die maksimum inname van VOM te bepaal. Verteerbare OM-inname het 'n stygende kwadratiese tendens (P < .01) getoon met verhoogde RDP-peile en het 'n maksimum bereik by 'n aanvullingspeil van 3.15 g RDPlkg metaboliese liggaamsmassa (LM·75 ) of 11.6% van VOM. Organiese materiaalinname vanaf koringstrooi het geneig om kwadraties toe te neem (P = .15) met verhoogde RDP-peile. Mikrobiese stikstof-(MN)-vloei na die duodenum en mikrobiese effektiwiteit het kwadraties toegeneem (P :::;.;04) en vloeistof deurvloeitempo het 'n neiging vir 'n kwadratiese toename (P = .15) met verhoogde RDPpeile getoon. Rumen-ammoniakstikstof (NH3-N) en vlugtige vetsuur-(VVS)-konsentrasies het lineêr toegeneem (P :::;.;07), terwyl rumen pH 'n wisselende reaksie (kubies; P = .08) met stygende RDP-peile getoon het. Verteerbare OM-inname en benutting van koringstrooi is verbeter deur stygende peile van RDP aanvulling by Dohne Merino hamels. In die tweede proef is kaseïen op 'n iso-stikstof basis met verskillende ureumpeile, vanaf o - 100%, vervang. Omdat ureum baie goedkoper is as natuurlike proteïen, was die doel van die tweede proef om die hoeveelheid natuurlike proteïen in RDP-aanvullings te bepaal wat met ureum vervang kan word, sonder om inname, fermentasie en vertering te benadeel. Die kontrolebehandeling het 100% van die RDP in die vorm van kalsiumkaseïnaat (90% RP; 100% rumen degradeerbaar) voorsien, terwyl ureum in die ander behandelings onderskeidelik 25, 50, 75 en 100% van die kaseïen-N vervang het. Die 100% ureumbehandeling is met mieliestysel tot 40% RP gebalanseer en dieselfde hoeveelheid stysel (150 gld) is by al die ander behandelings ingesluit, om moontlike effekte van stysel op rumenfermentasie te elimineer. Organiese materiaalinname vanafkoringstrooi het 'n swak dalende tendens getoon met stygende ureum insluitingsvlakke (lineêr; P = .16). Rumenverteerbaarheid van OM en neutraal bestande vesel (NBV) is nie deur die ureumpeil beïnvloed nie (P ;;:: .18). Toenemende ureumpeile het gelei tot 'n lineêre afname in totale kanaal OM en NBVverteerbaarheid (P ~ .10). Gevolglik het VOM inname lineêr afgeneem (P < .01) met stygende ureum insluitingspeile. Die effek van behandeling op duodenale N-vloei, mikrobiese effektiwiteit en vloeistof deurvloeitempo was minimaal. Rumenammoniakstikstof-( NH3-N)-konsentrasie het 'n stygende kwadratiese tendens getoon (P = .14) met toenemende ureum peile. Totale vlugtige vetsuur-(VVS)-konsentrasies het lineêr gedaal (P = .03), terwyl rumen pH lineêr toegeneem het (P = .08) met stygende ureum insluitingsvlakke. Vertakte ketting VVS' e en valeriaansuurkonsentrasies het lineêr gedaal (P ~ .05) met stygende ureumpeile, terwyl die ander VVS' e en die asynsuur:propioonsuurverhouding oor die algemeen nie deur behandeling beïnvloed N; nie (P ;;:: .16). Dit blyk asof VOM inname, sowel as rumen- en totale kanaal verteerbaarheidsmaatstawwe, by 25% vervanging van kaseïen-N met ureum-N 'n maksimum bereik het. Die gevolgtrekking is gemaak dat die doeltreffende benutting van lae kwaliteit ruvoere deur skape, gehandhaaf sal word deur 25% van die ware proteïen in RDP-aanvullings met ureum te vervang.

In Venezuela, four sheep fitted with rumen cannulas were fed the toxin-containing legumes Leucaena leucocephala (sun dried leaves and stems) and Canavalia ensiformis (grains). L. leucocephala did not have any apparent toxic effects on the animals, in spite of the presence of the toxic compounds 3,4 DHP and 2,3 DHP in the rumen. There were no significant effects on the rumen pH, concentrations of VFAs, microbial counts, rate of rice straw degradation or in the rumen outflow of liquids and solids. However, there was an increase in the concentration of ammonia in the rumen, and in the number of Gram negative rods isolated from the rumen of sheep when L. leucocephala was added to the diet. When C. ensiformis was supplemented the presence of canavanine in the rumen was confirmed. Sheep did not show signs of toxicity. There was no effect on rumen pH, microbial counts, degradation of rice straw or rates of outflow of liquids and solids from the rumen. There was a decrease in the rumen concentrations of valerate and ammonia and an increase in the numbers of Gram negative bacteria isolated from the rumen of sheep as the dietary inclusion of Canavalia increased. Several pure cultures capable of mimosine, 2,4 DHP and (in fewer cases) 3,4 DHP wre isolated. One of them, a Gram variable spore-forming rod, presumably a new species of Clostridium, was characterised. The presence of degraders of mimosine and DHP in the rumen presumably accounted for the lack of toxicity of L. leucocephala in Venezuela. The effect of canavanine on the growth and products of fermentation of pure cultures was independent of the Gram staining reaction and the results of experiments using media containing either peptides and amino acids or free amino acids alone suggest that canavanine may have an effect on peptide hydrolysis.

The overall hypothesis of this research was that silage biomass and protein yields would be higher in corn-soybean intercrops than in monocrops on the same land area. Yields, European corn borer infestation and N transfer were tested over tall and dwarf corn hybrids, nodulating and nonnodulating soybean genotypes and at 0, 60 and 120 kg N ha$ sp{-1}$. Land Equivalent Ratios ranged from 0.97 to 1.23, but most were higher than 1.10. Protein concentrations of corn-soybean silage, up to 10.76%, were on average 9.24% vs. 7.41% in corn silage. A general trend of higher protein yield ha$ sp{-1}$ in intercrops compared to corn monocrops was significant in 1986. Corn-soybean intercrops at 60 kg N ha$ sp{-1}$ and three population densities were $132 to $261 ha$ sp{-1}$ more cost effective than monocropped tall corn at 120 kg N ha$ sp{-1}$. European corn borer infestation was reduced by intercropping and was higher at 120 kg N ha$ sp{-1}$ than at 60 or 0 kg N ha$ sp{-1}$. Under normal rainfall, dwarf corn had higher protein and yield levels when intercropped with nodulating rather than nonnodulating soybean. On N-depleted soil, N transfer was detected from nodulating soybean to nonnodulating soybean and to corn by the $ sp{15}$N dilution method, and to corn by direct $ sp{15}$N labelling of nodulating soybean.

Optimum feed ration was determined for riffleshell mussels (Epioblasma spp.) held in captivity. Mussels were fed one of four rations (0.49, 0.72, 1.28, or 1.73 mg dry wt/l) of algae Neochloris oleoabundans for 2-h trials in spring, summer, fall, and winter. The test ration resulting in the most feed absorbed per hour (net absorption rate, mg/h) was determined to be the optimum feed ration. Mussels absorbed the greatest amount of food when fed the highest ration. Suggested feed rations for captive adult Epioblasma species are 1.73 mg/l when held at moderate temperatures (i.e., 15-19C), and 1.28 mg/l when held at cool temperatures (i.e., near 11C).

Seasonal utilization of protein by oyster mussel (E. capsaeformis) and rainbow mussel (V. iris) was examined with O:N ratios. Ratios were determined for mussels fed a low or high-protein diet (0.11, or 0.31 mg protein/mg dry algal feed), and for mussels held in a hatchery or in the Clinch River, in spring, summer, and winter. Significant differences in O:N ratios were not observed between mussels fed a low or high-protein diet (p > 0.05). The O:N ratios were significantly highest in spring and summer, and lowest in winter (p < 0.05). Mussels primarily utilized protein in spring and summer, and conserved protein in winter. A diet high in energy was suggested in spring and summer, and a diet high in protein was suggested in winter.
Master of Science

Lack of affordable feeds is one of the major constraints facing small-scale fish farmers in Tanzania. This study evaluated the suitability of moringa leaf meal (MLM), cassava leaf meal (CLM) and cassava root meal (CRM) as novel ingredients in Nile tilapia, Oreochromis niloticus diets. Each of the ingredients was processed in an attempt to remove the most significant antinutritional factor. A series of five experiments was conducted in a recirculation system using juvenile O. niloticus. The fish were fed isonitrogenous (30g 100g-1), isolipidic (10g 100g-1) and isoenergetic (18 kJ g-1) diets containing graded levels of the processed ingredients to their apparent appetite but not exceeding 10% of their body weight for a period of 8 weeks. Processing led to the removal of 0.3% of saponin from MLM and 60% and 90% of hydrogen cyanide from CLM and CRM respectively. The contents of other inherent antinutritional factors such as phenols, tannins and phytic acid were little affected. Processed MLM, CLM and CRM had 31.1/29.0/1.5g 100g-1 of crude protein, 5.9/10.2/2.4g 100g-1 of crude fibre and 20.1/19.7/15.8k Jg-1 of gross energy. The content of sulphur amino acids was higher in CLM (0.47%) than in MLM (0.23%). Digestibe protein and digestible energy was higher in MLM (25.71g 100g-1/15.44kJ g-1) than in CLM (12.71g 100-1/9.16kJ g-1). CRM had a digestible energy content of 13.5kJ g-1. Inclusion of either of the leaf meals, even at the lowest level of 15g 100g-1 of total dietary protein, led to a significant reduction in feed intake, growth and feed utilisation. Liver and small intestine did not show any histopathological changes which could be linked to dietary treatment. Conversely, cassava root meal could replace up to 75% of wheat meal in the diet without significantly affecting performance. The performance of leaf meals was marginally improved by a combination of blending and feeding stimulants, whereby a blend containing 1 part MLM and 2 parts CLM could provide up to 20g 100g-1 of dietary protein without significantly reducing performance. Biological and economic performance of practical diets containing 30-50g 100g-1 of dietary protein from moringa and cassava blends (LMB) with feeding stimulants was significantly lower than a fishmeal-meal based diet (FM) but comparable to a soybean meal-based diet (SBM). The suitability of MLM and CLM as novel protein sources in O. niloticus diets will depend on 1) improving reduction/removal of inherent antinutritional factors in MLM and CLM as well as improving digestibility of CLM. On the other hand, the suitability of CRM as a carbohydrate energy source will depend on the availability of cost effective protein sources due to its low protein content.

A study was conducted to evaluate the use of Leucaena leucocephala leaf meal (LLM) as a protein supplement for pigs. In addition, an evaluation of detoxifying LLM, by sun-drying, water-soaking, or treating with ferrous sulphate (FeS04) solution was undertaken. The research involved two experiments; a growth study and a metabolic study. In the growth study sixteen, 12 weeks old Large White x Landrace pigs (average body weight 22.9 ± 2.12 kg) were fed four experimental rations; a commercial grain-based grower /finisher ration (control); or a ration containing 20% of either sun-dried LLM, water-soaked LLM, or FeS04-treated LLM, replacing the basal diet. There was a significant (P<0.05) decrease in liveweight gain, feed intake and feed conversion efficiency in pigs fed the ration containing sun-dried LLM. Growth rate, feed intake and feed conversion efficiency were not affected by the addition of water-soaked and FeS04-treated LLM to the basal diet. Triiodothyronine (T3) and thyroxine (T4) levels in the blood plasma were not affected by the dietary treatments. However, addition of FeS04-treated LLM to the basal diet significantly (P<0.05) decreased the back fat thickness of the pigs. In the metabolic study, the digestible dry matter (DDM) and digestible CP (DCP) were measured as well as mimosine, 3-hydroxy-4-(1H) pyridone (3,4-DHP) and 2,3DHP output in the faeces and urine.
Addition of water-soaked LLM to the diet significantly (P<0.05) lowered the DDM of the diet, whereas addition of FeS04-treated LLM significantly (P<0.05) reduced the DCP. Sun-drying, water-soaking and treatment of LLM with FeS04 solution, did not enhance the output of mimosine or 3,4-DHP in the urine and faeces. The results suggest that water soaking or treatment with FeS04 solution reduces the antinutritional factors (presumably including mimosine) and therefore improves the nutritional quality of LLM containing diets for pigs.

La present tesi ha servit per avaluar estratègies per tal de redissenyar els sistemes d’engreix intensiu de vedells, amb l’objectiu de millorar-ne els resultats econòmics i disminuir-ne l’impacte mediambiental. A més, se n’ha determinat el vincle amb la microbiota ruminal, fent èmfasi en el concepte de rusticitat. Les estratègies testades van ser: la reducció del contingut de proteïna bruta de la dieta del 14 % al 12 % (sobre matèria seca); la substitució de la palla de cereal per un farratge de més qualitat (fenolatge de civada o de veça); i la millora de l’eficiència alimentària dels animals. Es va observar que les tres estratègies estudiades tenen efectes sobre els resultats productius, la ingestió d’aliment, les característiques de la fermentació ruminal i la composició i interaccions de la microbiota ruminal; concloent que són estratègies viables per tal de redissenyar el sistema d’engreix intensiu de vedells.
En la presente tesis se evaluaron estrategias para rediseñar los sistemas de engorde intensivo de terneros, con el objetivo de mejorar sus resultados económicos y disminuir su impacto medioambiental. Además, se determinó su vínculo con la microbiota ruminal, haciendo hincapié en el concepto de robustez. Las estrategias testadas fueron: la reducción del contenido de proteína bruta de la dieta del 14 % al 12 % (sobre materia seca); la substitución de la paja de cereal por un forraje de más calidad (henolaje de avena o veza); y la mejora de la eficiencia alimentaria de los animales. Se observó que las tres estrategias testadas tenían efectos sobre los resultados productivos, la ingestión de alimento, las características de la fermentación ruminal y la composición e interacciones de la microbiota ruminal, concluyendo que son estrategias viables para rediseñar el sistema de engorde intensivo de terneros.
The present thesis aimed at identifying and assessing strategies to redesign beef cattle intensive fattening systems in order to increase their profitability and decrease their environmental burden. Moreover, the potential role of ruminal microbiota in the outcome of the tested strategies was evaluated, focusing on their link with ruminal microbiota robustness. The strategies tested were: the reduction of dietary crude protein content from 14 % to 12 % (on a dry matter basis); the replacement of cereal straw by a quality forage (oats or vetch haylage); and the improvement of animals’ feed efficiency. It was observed that the three studied strategies had an impact on performance, feed intake, ruminal fermentation parameters and ruminal microbiota composition and interactions, concluding that they are feasible options to redesign intensive beef cattle production.

Broiler breeding companies continue to analyse the recommended nutrient levels of broiler diets due to the short production cycle and continuous genetic development of broilers. Modern broilers reach marketable weights very early, often at an immature body weight and without achieving maximum genetic potential in terms of absolute quantities, for example daily growth. As broilers age, their daily feed intake increases and nutrients are deposited in body tissue, mainly as protein and fat. An imbalance of energy or protein cause for excess fat deposited in carcasses due to excessive feed intake to satisfy a nutritional requirement. The cost of feed contributes substantially to the total production expenses, with energy alone contributing approximately 70% of the total cost of poultry diets. Therefore, the focus of feed companies remain to determine the energy and protein requirements of broilers, in order to feed a balanced diet, delivering a bird with an optimal carcass composition. Two experiments of identical design were conducted in floor pens to evaluate the effect of metabolisable energy levels as well as crude protein levels on broiler performance. The first trial was an energy dose-response trial and the second trial a protein dose-response trial. Each study was conducted over a period of five weeks where five thousand seven hundred and sixty Hubbard Flex (mixed sex as hatched) broilers were housed in 60 pens. Ninety six (96) chicks were randomly allocated in a pen at a stocking density of 16 birds/m2. Each treatment was repeated once within a block, totalling to 10 replications/treatment. Water and feed were provided ad libitum. In the energy dose-response experiment two iso-protein basal feeds were formulated and manufactured, one containing a high energy (HE) level, the other a low energy (LE) level. These basal diets were further diluted into four diets containing various percentages of energy (80% LE: 20% HE; 60% LE: 40% HE; 40% LE: 60% HE and 20% LE: 80% HE). The crude protein and amino acid balance was kept constant across all treatments. Six dietary treatment combinations were implemented in a 4-phase feeding programme: Pre-starter (0 to 10 d), Starter (11 to 18 d), Grower (19 to 28 d) and Finisher (29 to 35 d of age). Body weight (BW) and average daily gain did not show any significant difference between LE and HE treatments. A weekly numerical difference was recorded for BW between LE and HE treatments; where birds fed the HE diet weighed heavier on Day 35, at 1939.97 g compared to the 1898.10 g of birds fed the LE diet. FI increased as the energy concentration increased from the LE to HE treatments; and although the differences in FI was non-significant (NS), birds fed HE diets consumed 2882.11 g/bird by Day 35 and birds fed LE diets, only consumed 2830.90 g/bird in total. No significant difference was recorded for cumulative feed conversion ratio (CFCR) among treatments by Day 35 and birds fed the LE diet ended with 1.53 points compared to 1.52 points for birds fed HE diet. Despite the dietary energy increase in energy level from the LE diet to the HE diet, there was no significant effect on daily mortalities; birds fed the LE diet showed 5.10% mortality compared to 5.41% mortality for birds fed the HE diet. In the protein dose-response trial two isocaloric basal feeds were formulated and manufactured, one containing a high protein (HP) level, the other a low protein (LP) level. These basal diets were further diluted into 4 diets containing various percentages of protein (80% LP: 20% HP, 60% LP: 40% HP, 40% LP: 60% HP and 20% LP: 80% HP). The dietary metabolisable energy (ME) was kept constant across all treatments. Birds fed the HP diet showed the greatest BW at Day 21 with 900.97 g compared to birds fed the LP diet on 858.85 g; and weighed 1937.48 g at Day 35 compared to 1869.80 g for birds fed LP diet. Cumulative feed intake (CFI) decreased as the protein content in the feed increased. Although the results from Day 28 only approached significance, birds fed the HP diet consumed significantly less feed (2840.29 g/bird) than birds fed the LP diet (2913.66 g/bird) by Day 35. CFCR for HP was 1.50 points by Day 35 compared to 1.59 points for LP. The increase in protein content from LP to the HP diet, did not cause a significant increase in mortalities; although a numerical increase can be seen of 6.24% for birds fed on the LP diet compared to 9.06% mortality in birds fed the HP diet.
Dissertation (MSc)--University of Pretoria, 2015.
Animal and Wildlife Sciences
MSc
Unrestricted

One of the major problems facing aquaculture in Ghana is the non-availability of quality and affordable fish feeds. The present study investigated the nutritional suitability and cost-effectiveness of some Ghanaian oilseed by-products, soybean meal (Glycine spp), cottonseed meal (Gossypium spp), groundnut cake (Arachis hypogaea L.) and groundnut husk, as alternative protein sources to fishmeal (FM) in the diet of Nile tilapia (Oreochromis niloticus L.). The oilseed meals were used individually, as mixtures, as mixtures enriched with methionine and mixtures detoxified by heat processing (autoclaving) and/or addition of supplements (viz. phytase and ferrous sulphate) intended to reduce levels of the most important antinutritional factors (ANFs). Diets, containing the oilseed meals at inclusion levels from 25% to 75% dietary protein, were formulated to be isonitrogenous (320 g.kg-1), isolipidic (100 g.kg-1) and isoenergetic (18 KJ.g-1) and fed to juvenile Nile tilapia at 4-10% of their body weight for a period of eight weeks. Proximate analysis showed that soybean meal (SBM), cottonseed meal (CSM), groundnut cake (GNC) and groundnut husk (GNH) had 500.3, 441.4, 430.5 and 205.6 g.kg-1 crude protein, 38.2, 89.5, 12.8 and 89.2 g.kg-1 crude fibre and 20.19, 19.61, 23.17 and 22.18 kJ.g-1 gross energy respectively. Generally the oilseed meals had good essential amino acid (EAA) profiles with the exception of GNH. The EAA profile of SBM compared very well with FM but methionine and threonine were low (0.73 and 1.50 % of protein respectively) and the same was true for CSM and GNC with even lower levels. Analyzed ANFs in SBM, CSM, GNC and GNH were 17.54, 31.64, 14.86 and 3.99 g.kg-1 phytic acid, 14.09, 1.24 and 2.34 g.kg-1 trypsin inhibitors and 5.80, 6.50, 8.01 and 10.08 g.kg-1 saponin respectively and in CSM 5.6 g.kg-1 gossypol. Nutrient digestibility of these oilseed proteins suggested that Nile tilapia may be able to utilize SBM, CSM and GNC efficiently as dietary protein sources due to high apparent protein digestibility of 94.50%, 84.93% and 90.01% respectively. However, GNH may not be suitable because of very low apparent protein digestibility (27.67%). These protein sources when used individually were shown to cause depressed growth and feed efficiency when substituting more than 50% of the FM protein in diets. This may be attributed to high levels of ANFs, high fibre content and poor EAA profile. However, the use of mixtures of these meals was found to be marginally more effective than that of single sources. This may have been as a result of lower levels of ANFs and improvement in essential amino acid profile due to mixing. Supplementing the mixtures with methionine led to improvement in feed utilization but without significantly improving the nutritive value compared with FM. Heat processing was effective in reducing heat labile trypsin inhibitors in SBM, CSM and GNC by almost 80%, but not phytic acid and saponins, which remained virtually unaffected. Use of meals detoxified by heat processing with/without supplements at 50% inclusion improved growth and feed utilization compared to the unprocessed meals and performance was generally not significantly different from FM. Cost effectiveness analysis revealed that diets containing single feedstuffs or mixtures, particularly those containing equal proportions of oilseed meals and higher proportion of CSM replacing between 50% - 75% FM protein, were more profitable than FM diet. Similarly, the use of heat processed meals at 50% replacement of FM protein yielded greater profit than all other diets including the FM diet. However, essential amino acid supplementation of the meals was less profitable compared to the control. Generally, fish fed diets with oilseed meals would take longer to attain harvest size compared with FM and this could lead to an increase in production costs or a decrease in the number of production cycles which could be achieved within a year. It can be concluded that there is nutritional and economic justification for using SBM, CSM and GNC as partial replacement for FM in diets of Nile tilapia. Based on growth performance, nutrient utilization and economic benefits the diet with heat processed oilseed meal mixtures (containing equal proportions of 16.67% each) at 50% inclusion has the best prospects for replacing FM protein in diets of O. niloticus.

In recent years, there has been a growing interest in feeding phytogenic products to poultry for their growth and health benefits. The objective of this experiment was to determine the effects of a phytogenic feed additive on turkey poult performance and digestive physiology over a 6-week brooding period. In total, 864 male Hybrid Converter turkey poults were obtained from a local commercial hatchery on day-of-hatch and placed into floor pens with clean pine shavings. The treatments were randomly assigned including an industry-type corn-soybean meal positive control (PC), a similar diet with a 1.5% reduction in crude protein and key amino acids (NC), or the NC with the addition of Digestarom® (PFA) included at a rate of 1 g/kg. Body weight gain (BWG), feed intake (FI), feed efficiency (FE), and mortality were recorded throughout the experiment. On day 14 poults fed the PFA had significantly higher BWG compared to the PC and NC fed birds. By day 42 birds fed the PC and PFA diets had significantly higher BWG compared to the NC, and the PC had significantly higher FE compared to the NC and PFA fed birds. No differences in FI or mortality were observed throughout the experiment. There were no significant differences in AMEn, crude protein digestibility, or nutrient transporter or pancreatic enzyme mRNA expression among treatments. However, aminopeptidase activity tended to be lower in the ileum of poults fed the PC or PFA diets compared to the NC, suggesting that the PFA may be improving protein utilization.
Master of Science

Four studies were conducted to determine the effect of synchronization of protein and starch degradation on nutrient utilization, microbial protein synthesis and milk production in dairy cows. In Experiment 1, five cereal grains and five protein supplements were compared for extent of solubility and degradability of their starch and nitrogen fractions. Results indicated large differences which permitted their ranking from high to low degradability as follows: grains, oats > wheat > barley > corn > milo protein supplements, soybean meal > cottonseed meal, (CSM) > corn gluten meal > brewers dried grains, (BDG) > blood meal. In Experiment 2, the five grains were incubated for varying times in vitro (with added amylase) or in situ to determine rate and extent of degradation of dry matter, crude protein and starch. Results showed that rate of starch degradation followed a similar, but slightly different trend than in trial 1 (wheat > barley > oats > corn > milo). Rates for DM and CP degradation were similar than those for starch. In Experiment 3, high (barley, HS) and low (milo, LS) degradable starch sources were combined with a high (CSM, HP) and a low (BDG, LP) degradable protein sources to formulate four diets; HSHP, HSLP, LSHP and LSLP. Diets were fed to 32 cows, starting two to four weeks postpartum, for a 60-d milk production and digestibility study. Apparent digestibility was calculated using chromium oxide. Organic matter digestibility was higher (P < .05) was found in nutrient output to the small intestine among diets and microbial CP synthesis was higher (P > .05) for barley diets.

Lysine is one of the more limiting amino acids in protein sources for chickens. Since lysine is also an essential amino acid for animals, it is an important component of animal dietary formulation. Therefore, an accurate pre-determination of bioavailable lysine in feedstuffs is important. An optical density (OD) based microbiological assay for lysine determination using E. coli lysine auxotroph has been previously developed. However, because the assay is based on bacterial growth response to extracellular lysine measured as OD, it can be relatively time consuming (10-12h). Therefore, more rapid assays are needed if pre-formulation estimates are required. In this dissertation whole cell fluorescent biosensors for the quantification of bioavailable and total lysine in feed protein sources were developed. The biosensor for quantification of bioavailable lysine was based on the growth response of E. coli to an external source of lysine and lysinecontaining small peptides. Green fluorescent protein (GFP) was inserted in the genome of E. coli lysine auxotroph as a part of a mini-Tn5- transposon by conjugation. Bacterial growth response to external lysine and small peptides was monitored and recorded by measuring the fluorescence emitted by GFP. The second type biosensor developed was designed for the quantification of total lysine. It was based on the measurement of a promoter activity, which was induced and modulated by extracellular concentration of lysine. Cad promoter was amplified from E. coli K-12 genome and was cloned into promoterless gfp plasmid. The construct was electroporated into electrocompetent E. coli cells. The promoter activity was induced under the conditions of low pH and graded concentrations of lysine. Lysine-dose response was measured by the fluorescence of GFP. Both methods were characterized as having a high potential for practical application.

Durante la fermentación ruminal de los piensos, se producen grandes cantidades de gases de efecto invernadero (GEI) que hace en el ganado uno de los productores de gases de efecto invernadero más importantes. La Organización de las Naciones Unidas para la agricultura y la alimentación (FAO, 2006) informó que el sector ganadero representa aproximadamente el 18% del metano (CH4) y el 9%de las producciones de dióxido de carbono (CO2). Se han hecho muchos intentos para mitigar la emisión de ch4 de rumiantes, incluyendo la inclusión de levaduras (Elghandour et.al., 2017), sal de ácidos orgánicos, enzimas exógenas y aceites esenciales con resultados prometedores.

Kelp is widely used as feed in the abalone aquaculture industry in South Africa, and farmers have reported different feed quality between the two dominant kelp species occurring along the west and southwest coasts with Ecklonia maxima reported as having a better Food Conversion Ratio (FCR) than Laminaria pallida. Total protein content and other nutritional components (Carbon, Nitrogen and moisture content) of two kelp species, E. maxima and L. pallida were investigated. The kelps were collected from Kommetjie (borderline of west and southwest coasts). Seasonal total protein content of E.maxima from a commercially-harvested kelp bed in Jacobsbaai (west coast) was compared with crude protein levels (measured as %N x 6.25). Total protein was extracted and quantified using the Bradford method. No significant difference in carbon content was found between seasons for E. maxima but there was a significant difference in average carbon content between E. maxima (30.79 %) and L. pallida (27.79 %). No seasonal pattern was observed in the nitrogen content, and hence crude protein content, of E. maxima (seasonal crude protein averaged 7.8% of dry weight) and there was no significant difference found between E. maxima and L. pallida (crude protein averaged 9. 05% of dry weight). There was no significant seasonal difference in total protein (averaged 0.99% of dry weight) and no significance found between species. The reported better FCR in abalone feed comprised of E. maxima rather than L.pallida, if correct, is likely to be related to higher carbohydrate content (measured here as carbon) and not to higher protein content. E. maxima differs from L. pallida with regards to carbon storage, but not protein content

Thesis (MScAgric)--University of Stellenbosch, 2000
ENGLISH ABSTRACT: A flock of 500 Hybro broiler breeders were employed to study the effect of different levels of protein and energy on production and body composition. The daily lysine intake of the birds were 900, 1050, 1200 and 1350 mg respectively, each fed in diets with a daily energy intake of 1800 and 2000 kJ ME to provide a 4 x 2 factorial design. Lysine was used as the reference amino acid in the experiment and all other amino acids were kept in a constant ratio in every experimental diet. The total production was divided into 3 periods of 13 weeks each (week 23 - 35; week 36 - 48 and week 49 - 61) to determine the effect of the treatments over time. Production was evaluated by hen day production; egg weight (g/egg); egg mass (g/day); fertility; hatchability; chicks/hen/week; feed conversion and day old chick weight. Hen day production was significantly (P < 0,05) lower at the high energy intake for period week 49 to 61. Energy and protein levels significantly increased egg weight. Effect of protein was consistent during all three periods of production. Egg mass output had a significant (P < 0,05) response to increasing levels of protein for the total period of production. The birds on the high energy diet produced a significant higher egg mass per hen during the first period of production (week 23 - 35). Hatchability was reduced (P < 0,05) by the higher energy intake for the total period of production and this effect was very significant (P < 0,01) during the final period of production. Similar to hen day production, the higher energy had a significant (P < 0,05) negative effect on the amount of chicks produced. The well-known correlation between egg weight and chick weight was confirmed with the regression equation: Chick weight = 10,5 + 1,22 x Egg weight. Both energy and protein had a significant (P < 0,01) positive effect on chick weight. The feed conversion was lower at increasing levels of amino acid intake (P < 0,01). Higher energy intake significantly (P < 0,05) increased hen weight and protein had a very significant effect during the first period of production (P < 0,01). The isotope dilution technique (tritiated water) was used to estimate the body composition of the breeders. This was done at 5 different periods (week 27, 35, 43, 52 and 61) of the production period to establish changes in requirements over time. Significant correlation were found between carcass moisture and waterspace (R2 = 0,76); fat % and carcass moisture (R2 = 0,78); protein % and waterspace (R2 = 0,35) and fat % and waterspace (R2 = 0,46). The regression equations obtained from these correlation were employed to determine excess energy and lysine consumed at different ages. Energy requirements were calculated according to the effective energy (EE) system and the conventional ME system. According to effective energy the lower energy intake was not sufficient and the maximum requirement was calculated to be 1942 kj EE/day. The metabolizable energy calculations indicated sufficient intakes at every treatment with the maximum requirement 1746 kj ME/day. The lysine requirement was found to be in excess of 1050 mg lysine per day. The recommendation for daily lysine intake is 1200 mg/day and the energy intake of breeders should be 1900 to 2000 kj ME/day from week 23 to 35 and can be reduced to 1800 kj ME/day in the final period of production.
AFRIKAANSE OPSOMMING: Om die effek van verskillende vlakke energie en proteïen op produksie en liggaamsamestelling te ondersoek is 'n trop van 500 Hybro braaikuiken teelouers gebruik. Die daaglikse lisien inname van die henne was onderskeidelik 900, 1050, 1200 en 1350 mg, wat elk by 'n daaglikse energie inname van 1800 en 2000 kJ ME verskaf is, in 'n 4 x 2 faktoriale ontwerp. Alle aminosure is in 'n konstante verhouding met die verwysings aminosuur lisien in die rantsoen ingesluit. Om te evalueer of daar veranderinge oor 'n tydperk plaasvind weens die verskillende behandelings is die produksie periode in drie periodes van 13 weke elk verdeel (week 23 - 35; week 36 - 48 en week 49 - 61). Die produksie standaarde wat gemeet is, is hen dag produksie, eiergewig (g/eier), eiermassa (g/dag), vrugbaarheid, uitbroeibaarheid, kuikens/hen/week, voeromset en dagoud kuikenmassa. Hen dag produksie was betekenisvol (P < 0,05) laer by die hoër energie innames in die laaste periode van 49 tot 61 weke. Energie en proteïen het eiergewig betekenisvol (P < 0,01) verhoog. Die effek van hoër vlakke proteïen was konstant in alle produksie periodes. Die daaglikse eiermassa (g/dag) het ook saam met stygende vlakke proteïen verhoog en hierdie effek was vir die totale periode van produksie. Energie het die eiermassa in die eerste periode van produksie (week 23 - 35) verhoog. Uitbroeibaarheid is verlaag (P < 0,05) vir die totale periode van produksie deur die hoër energie inname en die effek was selfs groter (P < 0,01) in die finale periode van produksie. In ooreenstemming met die hen dag produksie is die aantal kuikens geproduseer negatief beïnvloed deur die hoër energie inname (P < 0,05). Die korrelasie wat bestaan tussen eiermassa en kuikenmassa is bevestig deur die regressie: Kuikenmassa = 10,5 + 1,22 x Eiermassa. Energie en proteïen het kuikenmassa betekenisvol (P < 0,01) verhoog. Voeromset was laer by stygende vlakke van proteïen inname (P < 0,01). Die hoër energie inname het henmassa ook betekenisvol (P < 0,05) verhoog en proteïen het dieselfde effek slegs in die eerste periode van produksie gehad (P < 0,01). Die liggaamsamestelling van teelhenne is bepaal met behulp van die isotoop verdunnings tegniek (tritium water). Dit is bepaal op 5 verskillende stadiums in die produksie periode (week 27, 35, 43, 52 en 61) om die moontlike verandering in behoeftes oor tyd vas te stel. Betekenisvolle korrelasies is gevind tussen karkasvog en die waterspasie (RZ= 0,76); vet % en karkasvog (R2 = 0,78); proteïen % en waterspasie (R2 = 0,35) en vet % en waterspasie (R2 = 0,46). Die regressie vergelykings van hierdie korrelasies is gebruik om die hoevelheid surplus energie en lisien ingeneem te bepaal. Die" effective energy" sisteem en die konvensionele ME sisteem is gebruik in die bepaling van energie behoeftes. Volgens die " effective energy" was die energie inname nie voldoende by die laer energie innames nie en die maksimum behoefte is bereken as 1942 kJ EE/dag. Die maksimum energie behoefte volgens metaboliseerbare energie is bereken as 1746 kj ME/dag. Die lisien behoefte moet hoër as 1050 mg/dag wees. Die aanbeveling van die daaglikse lisien inname is 1200 mg/dag en die energie inname moet 1900 tot 2000 kj/dag wees tot 35 weke produksie en kan daarna verlaag word na 1800 kJ ME/dag.

Thesis (MScAgric)--Stellenbosch University, 2001.
ENGLISH ABSTRACT: The goat is a significant domestic animal throughout the world today. With an estimated world goat population of 590 million goats in 1991 (FAO, 1991 as citied by Haenlein, 1996) it is impossible to consider the goat as insignificant. The need for milk, and it seems particularly goat’s milk, is obvious if one considers the increase in dairy goat populations over the past 20 years. Across the globe the dairy goat population has increased by 52% while in developing and developed countries, there has been an increase of 56% and 17%, respectively (Haenlein, 2000). The goat dairy industry in South Africa is still very underdeveloped, yet it holds tremendous potential for the entrepreneur willing to take the risk and do the job correctly. With the present South African financial situation the opportunities that exist for exporting value added products to countries with stronger currencies is a market with extraordinary potential. In New Zealand, the national herd consists of approximately 16000 dairy goats and 90% of the milk produced is turned to powdered milk and then exported to the East, a valuable source of foreign currency. In South Africa, the same potential exists and with some vision and hard work the dairy goat industry can make a valuable contribution to generating foreign currency. Research into the protein requirements and particularly protein degradability requirements of dairy goats is scarce, yet in recent years there has been an increased interest in the effect of protein supplementation to lactating animals (Mishra & Rai, 1996). In the work of Mishra & Rai (1996) there were benefits obtained from the use of different rumen degradable proteins for lactating dairy goat does. The does on the highly degradable protein diet had a better feed intake while the does on the low degradable protein diet gave a higher milk production. Other research on this field of study has also delivered positive results with more than one species of lactating animal that had increased levels of UDP in the diet (Robinson et al., 1991 and Christensen et al., 1993). Loerch et al. (1995) suggested that improved production by making use of rumen undegradable proteins would have no effect if crude protein were not a limiting factor in production. Pailan & Kaur (1995) and Mishra & Rai (1996) did research on lowered CP levels with increased UDP levels in lactating dairy does. They used of three diets, with the one having a 20% lower CP value but an increased level of UDP (40-45% of total CP). From this work it was concluded that a decreased CP level and an increased level of UDP is able to sustain production when compared with diets with a higher CP value. The current study consists of two trials. In the first trial the effect of weaning age and dietary protein degradability on the growth of Saanen kids was investigated. In the second trial the effect of dietary protein degradability on the production of lactating Saanen does was investigated. Fifty-eight Saanen kids were divided into groups to determine the effect of weaning age (42 vs. 70 days) on animal performance. Within the weaning day treatments, the kids were again divided into two dietary treatments. One group received a low UDP creep diet (LC) and the other a high UDP creep diet (HC). The two creep diets were formulated with rumen degradable: undegradable protein (RDP : UDP) ratios of 70:30 and 60: 40, referred to as LC and HC, respectively. However, the results from the degradability trial indicated no difference in RDP: UDP ratios for the low and high creep (72:28 and 73:27 respectively) diets. At 15.66 ± 3.09 kg the kids were taken off the creep diet and put on the growth diet. At this transition, the kids in each of the 4 established treatments were again randomly divided into two dietary treatments, a high or a low UDP growth diet, resulting in a total of eight treatments for the trial. The two growth diets were formulated with RDP: UDP ratios of 70:30 and 60:40, referred to as low growth (LG) and high growth (HG) respectively. Results from the degradability trial indicated RDP: UDP ratios for the LG and HG of 73:27 and 68:32 respectively. The growth trial was conducted over 140 days and feed intake, bodyweight change and feed conversion efficiency were compared for each of the 8 treatments. From the trial with the Saanen kids it was concluded that weaning dairy goat kids at 42 days of age when feed intake was 240 g/day resulted in similar growth rates when compared with weaning at 70 days. The two creep diets did not differ in RDP: UDP ratios and thus no conclusion can be made regarding the influence of the creep diets on the growth of Saanen kids from 20 to 80 days of age. The two growth diets did in fact differ from one another, in terms of RDP: UDP however, protein degradability had no influence on the performance of the Saanen kids from 80 to 140 days of age. Twenty-one lactating Saanen does were randomly assigned to one of three experimental diets. The treatments had two RDP: UDP ratios and two crude protein (CP) levels. Treatments were formulated to be 1) RDP: UDP = 70:30, CP = 20 % 2) RDP: UDP = 62:38, CP = 20% and 3) RDP: UDP = 62:38, CP = 18.3%. In the production trial the does were milked for 120 days, during which milk yield, milk composition, bodyweight change, feed intake and feed conversion efficiency were compared between the treatments. In the digestibility and nitrogen metabolism trial, 18 does varying from 84 to 110 days in lactation, were used to compare the experimental diets. Furthermore, the experimental diets were compared in a degradability and rate of passage trial using cannulated Dohne merino wethers. Results from the degradability trial indicated that the low UDP, low protein high UDP and high UDP diets had RDP: UDP ratios of 82:18, 78:22 and 79:21 respectively, and that the dietary protein degradability did not differ significantly between diets. Results from the production trial indicated that there was a significant difference in feed intake, dry matter (DM) intake and bodyweight. The does on the low UDP diet had significantly higher feed intakes and DM intakes and were significantly heavier at the end of the trial period. As the diets didn’t differ in protein degradability other factors must have influenced the intakes between diets. Palatability may have influenced feed and DM intake, as the low protein high UDP and high UDP diets both contained higher levels of fishmeal. No significant differences in milk production, milk composition or milk production efficiency were observed. Besides the fact that the diets did not differ in effective protein degradability, large variations in milk production between animals and low numbers of animals per treatment limited the ability to measure a difference between the treatments. Results from the digestibility trial varied between diets with the low UDP diet having a significantly lower digestibility overall than the other two diets. Reasons for the difference in digestibility could be due to the difference in rate of passage (low UDP = 0.064/hour versus the 0.044- 0.045/hour of the low protein and high UDP diets respectively) and the high ADF value of the low UDP diet. Because no difference in effective protein degradability existed between the diets it is not possible to make an accurate conclusion on whether or not the dietary protein degradability had an influence on production parameters tested in this trial.
AFRIKAANSE OPSOMMING: Huidiglik is die bok ‘n belangrike gedomestikeerde dier dwarsoor die wereld. Aangesien die wereldwye bokpopulasie in 1991 op 590 miljoen geraam is (FAO, soos aangehaal deur Haenlein, 1996), is dit onmoontlik om die bok as onbelangrik te beskou. Die behoefte aan melk, en dan veral bokmelk, is duidelik as mens die toename in bokpopulasies oor die afgelope 20 jaar in ag neem. Wereldwyd het die melkbokpopulasie met 52% toegeneem, terwyl dit in ontwikkelende en ontwikkelde lande met 56% en 17% onderskeidelik, toegeneem het (Haenlein, 2000). Ten spyte van die feit dat die bokmelk-industrie in Suid-Afrika nog baie onderontwikkel is, is daar geweldige potensiaal vir die entrepeneur wat bereid is om ‘n risiko te loop en die taak korrek aan te pak. Binne die huidige Suid-Afrikaanse finansiele situasie bestaan daar veral geleenthede om waardetoegevoegde produkte na lande waarvan die wisselkoers sterker is, uit te voer. In Nieu Zeeland is die nasionale kudde ongeveer 16000 melkbokke en 90% van die geproduseerde melk word verwerk na poeiermelk en uitgevoer na die Ooste. In Suid-Afrika bestaan dieselfde potensiaal en met die korrekte visie en harde werk kan die melkbok-industrie ‘n belangrike bydra lewer om buitelandse valuta te verdien. Alhoewel navorsing aangaande die proteien-degradeerbaarheidsbehoeftes van melkbokke skaars is, bestaan daar die afgelope paar jaar ‘n toenemende belangstelling in die effek van proteien supplementering aan lakterende diere (Mishra & Rai, 1996). In die werk van Mishra & Rai (1996) is die voordele om verskillende rumen degraderende proteTenvlakke in lakterende melkbokke te gebruik, aangetoon. Ooie op ‘n hoogs degradeerbare prote'fen-dieet het beter voerinnames getoon, terwyl die ooie op ’n laag degradeerbare prote'fen-dieet hoer melkproduksies gelewer het. Navorsing van hierdie aard op ander lakterende spesies het ook positiewe resultate met ‘n toename in verbyvloeiprote'ien in die dieet gelewer (Robinson et al., 1991 en Christensen et al., 1993). Loerch et al. (1995) het voorgestel dat ‘n verbeterde produksie, deur gebruik te maak van verbyvloeiprote'fn, geen effek sal he as ruprote'fen (RP) nie ‘n beperkende faktor i.t.v produksie is nie. Beide Pailan & Kaur (1995) & Mishra en Rai (1996) het navorsing gedoen op die invloed van verlaagde RP-vlakke en verhoogde nie-degradeerbare protein (NDP) vlakke in die diete van lakterende melkooie. Daar is gebruik gemaak van drie diete, waarvan die een dieet ‘n 20% laer RPinhoud, maar ‘n verhoodge NDP-vlak (40-45% van totale RP) gehad het. Vanuit hierdie werk is die gevolgtrekking gemaak dat ‘n verlaging in RP-vlak en ‘n verhoging in NDP-vlak dieselfde produksie kan onderhou, soos met ‘n hoer RP-inhoud. Die huidige navorsing bestaan uit twee proewe. In die eerste proef is die effek van speenouderdom en dieet-prote'fen-degradeerbaardheid op die groei van Saanen-lammers ondersoek. In die tweede proef is die effek van dieet-proteien-degradeerbaardheid op die produksie van lakteerende Saanen melkbokke ondersoek. Agt-en-vyftig Saanen-lammers is verdeel in twee speenouderdom-behandelings, nl. ‘n 42 dae (42) en ‘n 70 dae (70) speenouderdom. Binne hierdie speenouderdom-behandelings is die lammers verder verdeel in twee dieet-behandelings. Die een groep het ‘n lae NDP kruiprantsoen (LK) en die ander ‘n hoe NDP kruiprantsoen (HK) ontvang. Die twee kruiprantsoene was geformuleer om rumen degradeerbare proteien (RDP): NDP verhoudings van 70:30 (LK) en 60:40 (HK) te bevat, maar die resultate van die degradeerbaarheidsproef het aangetoon RDP: NDP verhoudings van 77:23 (LK) en 78:22 (HK). Die lammers is vanaf die kruipdieet oorgeplaas op ‘n groeidieet by ‘n gemiddelde lewende massa van 15.99±3.09 kg. Tydens hierdie oorplasing is die lammers van die vier bestaande behandelings verdeel in ‘n verdere twee dieetbehandelings, nl. ‘n hoe of ‘n lae NDP groei-dieet (LG en HG onderskeidelik), met die gevolg dat ‘n totaal van agt behandelings in hierdie proef bestaan het. Die twee groeidiete is geformuleer met RDP: NDP verhoudings van 70: 30 (LG) en 60: 40 (HG) onderskeidelik, maar die resultate van die degradeerbaarheidsproef het aangetoon RDP: NDP verhoudings van 78:22 (LG) en 72:28 (HG). Die groeiproef is uitgevoer oor 140 dae en voerinname, verandering in liggaamsgewig en voeromsettingsdoeltreffendheid (VOD) is vergelyk tussen die agt behandelings. Uit die lammerproef is die gevolgtrekking gemaak dat boklammers wat op 42 dae gespeen is, wanneer voerinname 240g/dag is, soortgelyke resultate i.t.v. groeitempo lewer as lammers wat op 70 dae gespeen is. Die twee kruiprantsoene het nie van mekaar in RDP: NDP verskil nie en dus kan geen gevolgtrekking gemaak word omtrentdie invloed van dieet-protel'en-degradeerbaarheid op die groei van Saanen boklammers van 20 tot 80 dae ouderdom. Die twee groei diete het van mekaar verskil in RDP: NDP maar dieet-proteien-degradeerbaardheid het geen invloed op die groei van die Saanen boklammers van 80 tot 140 dae ouderdom gehad nie. Een-en-twintig lakterende Saanen-ooie is ewekansig in drie groepe. Die behandelings het twee RDP: NDP-verhoudings en twee ruprotei'en (RP) -peile ingesluit. Behandelings was 1) RDP: NDP = 70:30, RP = 20% 2) RDP: NDP = 62:38, RP = 20% en 3) RDP: NDP = 62:38, RP = 18.3%. Tydens hierdie produksieproef is die ooie vir 120 dae gemelk en die melkopbrengs, melksamestelling, verandering in liggaamsgewig, voerinname en VOD bepaal en vergelyk tussen behandelings. In die verterings- en stikstofmetabolismeproef is 18 ooie gebruik om die diete te vergelyk. Verder is die diete ook vergelyk in ‘n degraderings- en deurvloeitempoproef met gekannuleerde Dohne merino hamels. Dieet-proteien-degradeerbaardheid waardes verkry uit die degradeerbaarheidsproef het aangedui dat die bepaalde RDP: NDP verhoudings was 82:18, 78:22 en 79:21 vir die lae NDP, lae prote'fen hoe NDP en hoe NDP diete, en dat daar geen verskil in dieet-prote'fen-degradeerbaardheid was tussen die drie rantsoene. Resultate van die produksieproef dui daarop dat daar verskille in voerinname, droematerialinname, en liggaamsgewig tussen die drie rantsoene was. Die ooie op die laer NDP rantsoen het ‘n hoe voer en DM inname gehad en was swaarder na 120 dae in die proef as die ooie in die ander twee behandelings. Redes vir hierdie verskille is nie as gevolg van dieet-proteiendegradeerbaarheid nie. Die smaaklikheid kon dalk ‘n rol gespeel het omdat dat die twee hoe NDP rantsoene hoer vlakke van vismeel gehad het. Daar was geen verskil in melkproduksie, melksamestelling en melkproduksiedoeltreffenheid tussen die drie behandelings. Resultate van die verteringsproef het tussen die laer NDP-rantsoen en die ander twee rantsoene gevarieer. Die rede vir die verskil in verteerbaarheid mag wees a.g.v. verskillende deurvloeitempo’s (laer NDP = 0.064/uur teenoor 0.044 - 0.045/uur vir die laeproteien en hoe-proteienrantsoene) en die ADF waarde wat van die lae NDP rantsoen verskil het van die ander twee rantsoene. Omdat die resultate van die degradeerbaarheidsproef aangedui het dat daar geen verskil in dieet-proteiendegradeerbaardheid was nie is dit nie moontlik om ‘n gevolgtrekking te maak random die invloed van dieet-proteien-degradeerbaardheid op die produksie van lakterende Saanen melkbokke nie.

The nutritional value of novel yeast products were evaluated for warmwater fish species. A yeast co-product (yeast protein concentrate unrefined (YPCU)) obtained from a bio-ethanol process using wheat was tested using iso-nitrogenous (38% crude protein) and iso-lipidic (8%) diets for juvenile mirror carp (Cyprinus carpio). The fishmeal (FM) protein component of a basal diet was replaced by (YPCU) at 7.5, 15, 20, and 50% of total dietary protein. After an 8 week feeding trial, all fish fed YPCU yielded better growth performance than the control fed fish, with diets containing 15% and 20% YPCU being optimal. Whole body composition was unaffected by dietary treatment, however, ash levels were elevated in fish fed >15% YPCU. Hepatic alanine amino transferase (ALAT) and aspartate amino transferase (ASAT) were measured as bio-indicators of liver function in carp. Only ASAT activity was significantly lower for carp fed 20% and 50% YPCU. Additionally, histological assessment of liver and intestinal tissues gave no indication of impairment, but high YPCU inclusion (>15%) elevated the number of goblet cells present in the posterior intestine. Molecular microbiological analysis using DGGE revealed no definitive changes in intestinal microbial communities. In a second study, bio-ethanol yeast (refined YPCR and unrefined YPCU) and dried distillers grain with solubles (DDGS) a co-product of the bio-fuel process and distillery yeast from potable alcohol (whisky) production (YPCPA) were evaluated as before for carp. FM was replaced with 30% of YPCU, YPCR and YPCPA and 15, or 30 % DDGS with a combination of 10% YPCR. Weight gain, and Apparent Net Protein Utilization (ANPU%) were higher in fish fed YPCU 30%, equivalent for fish fed FM, YPCR 30%,DDGS 15% and DDGS 30%, and lower in fish fed YPCPA 30% diets. Feed conversion ratio was significantly increased in carp fed YPCU 30% and decreased for carp fed DDGS 30% and YPC PA 30% compared with the control group. A significant improvement of net mineral retention was seen for carp feed the yeast supplementation diets compared to the fishmeal control group. The YPCU 30% diet produced the highest mineral retention in fish fed yeasts and the YPCPA 30% gave lowest retention. The microvilli density of the intestinal tract decreased for carp fed YPCR 30%, but microvilli length significantly increased in fish fed YPCU 30% compared with other groups, thus indicating changes in gut integrity. In the third study, four diets were formulated to replace 0, 10, 20 and 30% of the fishmeal with refined yeast protein concentrate (YPCR) for Nile tilapia (O. niloticus) of mean weight 12.39g. Growth performance and feed efficiency were not affected with up to 20% replacement with YPCR. There were no obvious changes in the liver structure, but high yeast inclusion showed higher numbers of intestinal goblet cells with increasing YPCR dietary inclusion suggesting enhanced intestinal integrity. Microvilli density and length was significantly (P = 0.025) improved with up to 10% and 30% YPCR inclusion in comparison to other dietary treatments. It was generally concluded that YPC co-products were effectively viable for both juvenile carp and tilapia offering an option for partial fish meal replacement.

This investigation was conducted in the rural community of Cuambo, located in the northeast of Imbabura province, in the Mira river basin of Salina parish, at 1530 meters above sea level and with an average temperature of 19 C. The principal objective of this investigation was to evaluate the effect of four levels of substitution of fish meal for earthworm meal in broiler chicken diets. The fieldwork occurred in two stages over the course of 20 months: A. Creation of the feed: This step lasted from the installation of an earthworm culturing area through the cultivation, harvest, and drying of the worms until obtaining the flour and then the feed with the respective formulas and acquisition of primary materials. B. Cultivation of broiler chickens: This was carried out in a community member's house adapted to function like a chicken coop that had been previously prepared to receive the chicks. The study lasted 7 weeks. A completely random design (CRD) was used with five treatments and five repetitions per treatment, with five chickens per experimental unit. ANOVA, Tukey analysis at 5%, and orthogonal polynomial analysis were used to evaluate the data. The factor under study was the percentage of earthworm flour in a basic diet. The treatments were as follows: T0: Control (Pronaca commercial feed) T1: 100% earthworm meal T2: 75% earthworm meal T3: 50% earthworm meal T4: 25% earthworm meal Analyzed variables: Weekly weight gain, Weekly food conversion, Accumulated food conversion, Total food consumption, Efficiency index, Yield, Organoleptic analysis, Economic analysis. From the results obtained, we conclude that treatment 0 (T0) is the best because it gave the best results in weight gain, food conversion, efficiency index, yield, and cost of production. In the organoleptic analysis T4 received the most points for appearance and flavor; T3 received the most for color, smell, and texture. The treatment with greatest acceptability was T4, with the most points. In production costs, the least expensive was T1, but it is not recommended for use because the chickens had poor results in the studied variables.

O estudo consistiu de dois experimentos com o objetivo de avaliar o efeito metabólico, custos e viabilidade econômica de dietas com diferentes fontes nitrogenadas e teores proteicos. No primeiro experimento avaliou-se o efeito de dois teores de proteína bruta (PB) (130 e 148g/kg de MS) e duas fontes nitrogenadas (farelo de algodão 38 e grão de soja cru integral) na dieta de vacas leiteiras com cana de açúcar como volumoso, sobre as frações nitrogenadas do leite, balanço de nitrogênio e perfil metabólico. Foram utilizadas 12 vacas da raça Holandesa com 155 (±65) dias em lactação, agrupadas em três quadrados latinos 4x4 contemporâneos, com período experimental de 21 dias, sendo 14 dias para adaptação às dietas e os sete últimos para a realização das coletas. As vacas foram alojadas em baias individuais e alimentadas ad libitum. As amostras de leite para análise do balanço nitrogenado e frações nitrogenadas foram coletadas no 15° dia de cada período. O consumo e balanço de nitrogênio foram maiores para vacas alimentadas com dietas com 148 g PB/kg de MS. Por outro lado, vacas alimentadas com dietas contendo farelo de algodão apresentaram maior excreção de nitrogênio no leite do que vacas alimentadas com grão de soja cru integral. A relação entre caseína e proteína verdadeira no leite foi maior em vacas alimentadas com grão de soja cru integral. Houve interação entre fonte nitrogenada e teor de PB da dieta sobre as concentrações de nitrogênio ureico no leite (NUL) e nitrogênio não proteico (NNP). A concentração de NUL foi maior em vacas alimentadas com farelo de algodão e com maior teor de PB, em contrapartida houve menor excreção de NUL em vacas alimentadas com grão de soja com maior teor proteico. Não houve efeito das dietas sobre os teores de proteína do leite, nitrogênio não caseinoso (NNC), caseína e proteína do soro. Conclui-se que o uso de dietas com 130g de PB/Kg na MS não altera o balanço de nitrogênio e de composição do leite de vacas leiteiras em comparação com teores de 148g/Kg de PB na MS, e resultam em menor excreção de nitrogênio no ambiente. No segundo experimento foram calculados os custos e margens totais de dietas com cinco fontes nitrogenadas principais (ureia, farelo de soja, farelo de algodão, grão de soja cru integral e farelo de glúten de milho) e cinco teores proteicos (130, 145, 148, 157 e 160 g/kg de MS) com cana de açúcar como volumoso para vacas em lactação. Os dados foram provenientes de três estudos conduzidos com a finalidade de coleta de dados produtivos e respostas metabólicas. A análise econômica foi realizada com base nos preços históricos deflacionados (corrigidos do efeito da inflação) praticados durante o período 2002 a 2012, e no cálculo dos custos de alimentação, em função do consumo de alimento, da produção de leite e do teor de proteína bruta no leite. Dietas com cana de açúcar com teor proteico de 14,5% com ureia como fonte nitrogenada principal apresentaram a maior margem bruta (diferença entre a receita da venda do leite e do custo da dieta) com valor médio anual de R$1,85.vaca-1.dia-1. A dieta com 14,8% de PB com grão de soja cru integral apresentou a menor margem bruta de R$ 2,16.vaca-1.dia-1.
The study consisted of two experiments to evaluate the N balance and economical analysis of diets with different nitrogen sources and crude protein levels. On the first experiment it was evaluated the effect of two crude protein (CP) levels (130 e 148 g/kg DM) and two nitrogen sources (cottonseed meal 38% and whole raw soybean) in diets of dairy cows using sugar cane as forage on nitrogen in milk, nitrogen balance and metabolic parameters. Twelve Holstein cows with 155 (±65) days in lactation were distributed into three contemporary 4x4 Latin squares, with experimental period of 21 days, 14 days for diet adaptation and the remaining seven days for sampling. The cows were housed in individual pens and fed ad libitum. Milk samples for nitrogen balance and milk nitrogen fractions analysis were collected on the 15th day of each experimental period. Nitrogen intake and nitrogen balance were higher for the cows fed diets with 148 g CP/kg DM. However cows fed diets with cottonseed meal had higher nitrogen excretion in milk than cows fed diets with whole raw soybean. The casein: true milk protein ratio was higher in cows fed diets with whole raw soybean. There was interaction between the nitrogen source and the diet CP content on the milk urea nitrogen and non-protein nitrogen. Milk urea nitrogen was higher in cows fed diets with cottonseed meal and higher CP concentrations, however lower milk urea nitrogen was observed in cows fed diets with whole raw soybean and higher CP concentration. The concentration of crude protein, noncasein protein, casein and whey protein in milk did not differ between diets. In conclusion the use of low concentrations of protein (130g/Kg in MS) does not affect the performance of dairy cows and provides lower excretion of nitrogen in the environment. On the second experiment, the costs and the gross margin were calculated for diets formulated with five nitrogen sources (urea, soybean meal, cottonseed meal, whole raw soybean and corn gluten meal) and five protein levels (130, 145, 148, 157 e 160 g/kg DM) using sugar cane as forage. Performance data were obtained from three experiments conducted previously. Economical analysis were performed based on historical prices adjusted for the effect of inflation during the period between 2002 and 2012 and based on the feed costs, cow intake, milk prodution and milk protein levels. The higher gross margin (difference between the income from milk sale and diet costs) were obtained for 145 g/kg of CP in DM diets and urea as main nitrogen source, with mean of R$1,85.vaca-1.dia-1. The lower gross margin were observed in the 148 g/kg of CP in DM diet and whole raw soybean as nitrogen source, with mean of R$ 2,16.vaca-1.dia-1.

Large White turkey breeder hens were used to examine the effect of duration of feed restriction, prebreeder protein content, and nesting material on subsequent growth and reproductive performance. Day old poults were raised following standard commercial practices with feed and water for ad libitum consumption until 6 wk of age (WOA). At this time, hens were equally divided among six grower feeding regimens. The treatments were as follows: a) a control group fed standard commercial diets for ad libitum consumption (CON); b) a second control group like (a) but fed plain white oats from 19 through 26 wk (OATS). In contrast, the 4 remaining treatment groups were feed restricted beginning at 6 WOA to achieve body weights 45% less than the full-fed CON at 16 WOA. Birds were kept at this level of restriction until either 17.0 (R17.0), 18.3 (R18.3), 19.6 (R19.6), or 20.9 (R20.9) WOA. Thereafter, feed allowance was gradually increased to achieve a predetermined minimum target BW of 10.8 kg at photostimulation. An additional prebreeder protein treatment was superimposed from 27 to 31 WOA. Treatments reduced BW but none of the four quantitatively restricted groups achieved the target BW of 10.8 kg at photostimulation. Feed restriction reduced feed consumption and improved feed conversion. There were no differences in flock uniformity, sexual maturity, mortality, body composition at photostimulation, and total egg production. The R18.3 treatment achieved the highest peak production. The quantitative restriction treatments exhibited low laying persistency. There were no differences in number of large yellow follicles, egg weight, fertility, or hatchability, but poult weight was reduced in the R18.3 treatment. Dietary protein influenced the proportions of multiple follicle sets and percentage misshaped eggs.Three nesting materials were compared and were as follows: 1) all nests filled with shavings (S), 2) all nests filled with paper chips (P), and 3) two nests filled with shavings and two nests with paper chips (S/P). There were significant differences in percentage floor and broken eggs. Nesting materials did not affect total egg production, fertility, or hatchability. The data suggest, if restriction is too severe and is continued too near to the time of conventional photostimulation, BW recovery and egg production will be depressed. Oat feeding was the easiest treatment to implement and resulted in equivalent reproductive performance. Dietary protein content may affect proportions of multiple follicle sets. Turkey breeder hens can and do distinguish between nesting materials and this may affect floor laying. Combinations of various types of nesting materials within the same breeder unit should be avoided. (Key words: turkey breeder hens, feed restriction, prebreeder protein, egg production, body composition, nesting material)
Ph. D.

Five experiments were conducted to investigate the effects of early feed restriction on body weights, feed conversion, organ weights, fat deposition, carcass and muscle composition, plasma lipids, lipogenesis, lipolysis, and muscle tissue DNA and RNA in broiler chickens. In Experiments 1 and 2, broiler chicks were reared in litter pens for 49 days, while Experiments 3,4, and 5 were conducted in battery cages for 28 days. Feed restriction in all experiments was induced by providing male broiler chicks with 40 kcal/bird/day for 7 (Experiments 1 and 2) or 6 (Experiments 3, 4, and 5) days, starting at 4 days of age. Feed restriction (40 kcal/bird/day) for broiler females in Experiment 1 was imposed from 4 to 9 days of age. Ad libitum feeding was resumed after the restriction periods and continued to the conclusion of each experiment. Broilers fed ad libitum for the entire experimental period were used as controls in each study. Broilers under early feed restriction had significantly (P s .05) lower mean body weights than ad libitum fed controls, for all ages measured. However, feed to gain ratios for restricted birds were Significantly lower at 28 (Experiments 1 through 4) and 49 (Experiments 1 and 2) days of age than for birds fed ad libitum. Total pen body weights for restricted and ad libitum fed groups were similar at 49 days of age in Experiments 1 and 2 which, reflected a significant reduction in the rate of mortality observed in the early restricted groups. Significantly higher levels of lipogenic activity, plasma triglycerides and lipoproteins (VLDL + LDL), and significantly larger abdominal fat pads were observed in restricted broilers than in ad libitum fed controls at 28 days of age (Experiment 4). No significant differences were found in organ weights, carcass composition, lipolysis, and muscle tissue DNA/RNA levels, and muscle composition between early restricted and unrestricted broilers. Results from these studies indicate that restricted broilers were not able to attain body weights comparable to ad libitum fed birds at 49 days of age. In contrast, early feed restriction resulted in consistently better feed efficiency in restricted birds when compared to controls. Furthermore, it appears that early feed restriction altered lipid metabolism early in life; however, organ weights, fat deposition, muscle composition, and carcass composition were only minimally affected by this procedure.
Ph. D.

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 26, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Monty Kerley. Vita. Includes bibliographical references.

Excessive dietary protein may affect MP use because of energetic costs of excreting excess N. Amino acids also may influence post-ruminal digestion. Therefore, two experiments were designed to evaluate the effects of MP intake and post-ruminal flow of AA on growth performance and pancreatic digestive enzymes. In experiment 1, treatments supplied different amounts of MP intake to cattle and the effects on growth performance and feeding behavior were evaluated. In experiment 2, duodenal infusion of glutamate or casein was examined and the effects on pancreatic enzymes were measured. Experiment 1 suggests that feeding steers 906 g MP/d in finishing diets supplied enough MP for the greatest growth performance and carcass characteristics. Interestingly, MP intake caused different responses on feeding behavior with greater effects on steers fed 626 and 1444 g MP/d. In experiment 2, casein infusion increased α-amylase activity but not trypsin activity. Glutamate did not influence pancreatic digestive enzymes.

Mestrado em Engenharia Zootécnica - Produção Animal - Instituto Superior de Agronomia / Faculdade de Medicina Veterinária
The effect of different standardized ileal digestible tryptophan:lysine ratios, in diets with low crude protein on the zootechnical performances of pigs between 20 and 40 kg, was studied using 120 pigs in a five week trial. The 120 pigs were allotted to four experimental diets, 30 animals per diet and placed in cages in groups of 3 pigs per cage. Diet 1 was the control diet, with a level of 16,5% crude protein and standardized ileal digestible tryptophan:lysine ratio of 20,7%; diets 2, 3 and 4 were diets with a low crude protein level (14,5%) and the standardized ileal digestible tryptophan:lysine ratios were 17,4%, 20,5% and 23,5%, respectively. The average daily feed intake and the average daily gain decreased in pigs fed diet 2 compared to pigs fed diet 1 (P=0,0432; P=0,0187, respectively). The average daily feed intake, average daily gain and feed conversion ratio were not significantly different between diets 1 and 3 and between diets 3 and 4. These results suggest that it is possible to reduce the level of crude protein in two percentage points, as long as balance is maintained in the standardized ileal digestible tryptophan:lysine ratio at 20,5%