Literatura científica selecionada sobre o tema "Sheep Feed utilization efficiency"

Growth and metabolic studies were conducted with 32 sheep (16 rams and 16 ewes) to evaluate Ficus leaves (Ficus thonningia) as substitute for Hyparrhenia rufa (Hyparrhenia) in the diets of sheep. Ficus replaced 0, 25, 50 and 75% of grass and was offered at 3% of animal body weight as DM. all the sheep received concentrate at 1% of body weight as supplement. Digestibilities of DM, NDF, ADF and N were similar (P > 0.05)lower. Nitrogen retention was positive and the values increased with dietary level of Ficus up to 50% and then declined. Differences were not however, significant. Intake of ficus was significant (P < 0.001) and positively related to both total feed intake of (r=0.99) and daily liveweight gains (r=0.55). Average daily liveweight gains (LWG) was 28.75, 33.75, 47.50 and 36.25 g/day for sheep on 25, 50 and 75% dietary level of FIcus. Feed efficiency was 11.35, 21.67, 31.84 and 27.87 (g feed DM/g LWG) for sheep on dietary levels of ficus. The results showed that sheep on diet containing 50% Ficus gained 47.50g/day which represented an increase of about 65.22% higher than value obtained for those on the control diet (0% Ficus) but at lower feed conversion efficiency

SUMMARYVarious physiological characteristics of castrate male sheep fed ad libitum were studied between 1986 and 1987 in Australia. The sheep were between 20 and 45 kg live weight (LW) before and during fattening. Sequential data on body composition, estimated from TOH space (starting at 10 kg), established that the weight gain contained 19% fat and 13% protein below c. 26 kg LW and 55% fat and 10% protein above. For a given feed intake, the rate of fat gain was constant but the rate of body protein gain was 45% lower above 26 kg LW. Voluntary feed consumption per unit weight peaked at 26 kg LW and declined thereafter. There was an increase at 45 kg LW in weight of rumen digesta per unit feed intake and in digestibility; metabolizable energy (ME) per kg feed was increased as a result by 6–9%. Efficiency of use of ME, determined by calorimetry, increased from 44% in the lower weight range to 53% in the higher; utilization of nitrogen decreased from 37 to 28%. Partition of ME and energy gain suggested that the energetic efficiency of neither fat nor protein deposition changed between the two weight ranges. Change in the amount of DNA (‘cell number’) rather than g tissue/mg DNA (‘cell size’) accounted for weight change in three muscles and most digestive organs. Exceptions were the rumen, in which cell number and size both contributed to gain and the large intestine, in which cell size diminished during growth. It was concluded that fattening in sheep reflects diminution of the protein content of weight gain due to a decrease in the efficiency of protein utilization at the tissue level.

Energy utilization is affected by protein-energy balance in the feed. The purpose of this study<br />was to determine the optimum balance of crude protein (CP) and total digestible nutrients (TDN) in a feed efficiency on the native sheep, by looking at the ability of the utilization of energy from the feed. 24 male native sheep with an average of initial body weight around 18±3.1 kg (CV=17.15%), were used and designed with a completely randomized design (CRD) into 6 dietary treatments of complete feed: Treatment 1 (CP 18.84% and 61.56% TDN), Treatment 2 (CP 16.29% and 66.51% TDN), Treatment 3 (CP 19.94% and 60.29% TDN), Treatment 4 (CP 19.40% and 67.31% TDN), Treatment 5 (CP 20.88% and 60.47% TDN), Treatment 6 (CP 20.12% and 63.05% TDN). Data were analyzed by analysis of variance. Results of DM intake between treatments were not significantly different (P>0.05). The average intake of DM of the study was 775.6 g/day. Energy intake in each treatment was not significantly different (P>0.05) (14.27±1.7 MJ/day). Different ratio of CP and TDN on digested amount of energy in each treatment were not significantly different (P>0.05). Average metabolized energy in native sheep in this study was 6.28 ± 0.9 MJ/day (P>0.05). Conclusion from this research is the different balance of CP and TDN in this study do not have any impact on energy utilization and body weight gain (ADG) of native sheep.<br />Key words: sheep, ratio of CP and TDN, energy feed utilization

Energy utilization is affected by protein-energy balance in the feed. The purpose of this study<br />was to determine the optimum balance of crude protein (CP) and total digestible nutrients (TDN) in a feed efficiency on the native sheep, by looking at the ability of the utilization of energy from the feed. 24 male native sheep with an average of initial body weight around 18±3.1 kg (CV=17.15%), were used and designed with a completely randomized design (CRD) into 6 dietary treatments of complete feed: Treatment 1 (CP 18.84% and 61.56% TDN), Treatment 2 (CP 16.29% and 66.51% TDN), Treatment 3 (CP 19.94% and 60.29% TDN), Treatment 4 (CP 19.40% and 67.31% TDN), Treatment 5 (CP 20.88% and 60.47% TDN), Treatment 6 (CP 20.12% and 63.05% TDN). Data were analyzed by analysis of variance. Results of DM intake between treatments were not significantly different (P>0.05). The average intake of DM of the study was 775.6 g/day. Energy intake in each treatment was not significantly different (P>0.05) (14.27±1.7 MJ/day). Different ratio of CP and TDN on digested amount of energy in each treatment were not significantly different (P>0.05). Average metabolized energy in native sheep in this study was 6.28 ± 0.9 MJ/day (P>0.05). Conclusion from this research is the different balance of CP and TDN in this study do not have any impact on energy utilization and body weight gain (ADG) of native sheep.<br />Key words: sheep, ratio of CP and TDN, energy feed utilization

A complete pellet feed was developed using 40 % roughage (Rice straw) and 60 % concentrate (Rice polish 50 %, Maize crush 16 %, Soybean meal 20 %, Molasses 10 %, Salt 2 %, DCP 1 %, Vitaminmineral premix 0.5 %, Pellet binder 0.5 %) for commercial sheep production under stall feeding system. To know the effect of complete pellet feed on animal performances, both on-station and on-farm trials were conducted in growing sheep. The results of the experiment demonstrated that in the traditional system of rearing; only 22.42 g daily weight gain was observed. While, feeding of complete pellet feed achieved 84.98 g, and 100.67 g daily weight gain at on-farm and on-station condition respectively suggesting that pelleting enhanced the efficiency of utilization of feed. However, no differences were observed for the feed cost per kg weight gain, feed conversion ratio (FCR) and benefit-cost ratio (BCR) among the pellet feeding group and other group. But results suggest that complete pellet feed would be more economical for commercial sheep production under the stall-fed condition and farmers would be more benefited using complete pellet feed compared to conventional grass or urea molasses straw (UMS) and concentrate based feeding system. No disease or clinical symptoms were observed in the animals during the experimental period, suggesting that pellet feeds are well accepted by the sheep and results in better growth rate.
 SAARC J. Agri., 18(2): 157-166 (2020)

In the tropical area, productivity of ruminant has not optimized caused by the low quality of nutrition that leads to low-efficiency metabolism at the level of ruminal fermentation, post rumen digestibility, and intermediary metabolism. The study aimed to analyze effect of methionine hydroxy analog (MHA) on ruminal fermentation profiles of indigenous sheep specifically in the increase of ruminant productivity. In vitro utility test was conducted using rumen fluid of the indigenous sheep and sample of rational ration having a proportion of grass and concentrate 30%:70%, dry matter basis. The treatments implemented were three levels of MHA supplementation; T0: 0 g/day, T1: 3 g/day, and T2: 6 g/day. Variables measured were dry matter digestibility (DMD), organic matter digestibility (OMD), production of VFA, NH3, as well as total protein, and molar proportion of partial VFA of rumen fluid. Data were analyzed using analysis of variance (ANOVA) in a completely randomized design (CRD). The 0.2% MHA supplementation increased OMD with the highest production of total protein was from 28.57 mg/g (T0) to 40.49 mg/g (T2) (P<0.05). Meanwhile, the lowest ratio of acetate : propionate was from 2.74 (T0) to 2.33 (T2) (P<0.05). Supplementation of MHA up to 6 g/day concentrate increased the performance of fermentation and/or feed utility.

The cost of feed is the highest expenditure on animal husbandry management. One solution to reduce the high cost of feed is by utilizing local feed ingredients or abundant horticulture waste. Waste from bananas namely banana peel can be used as small ruminant animal feed so that feed efficiency can be achieved both in terms of cost, nutrition and feed formulation. Abundant banana skin waste that has not been used optimally so that it is feared can cause environmental pollution. To prevent the accumulation of horticultural waste, one of which is by giving cattle as feed used in the dry season. The method used in the first community service program is to approach, interview and deepen problems and find solutions to problems later. Secondly, learning methods by using teaching media in the form of a book of community service activities and ways of fermented kepok banana peels, giving brochures or leaflets and demonstration using media aids and banners that attract farmers' interests. The results that have been achieved have shown that increasing farmers' knowledge and income related to fermentation technology as animal feed by utilizing agricultural waste

This study is targeted at evaluating whether C. deserticola addition promotes digestion, nitrogen and energy use, and methane production of sheep fed on fresh forage from alfalfa/tall fescue pastures. The sheep feeding trial was conducted with four addition levels with C. deserticola powder, and a basal diet of fresh alfalfa (Medicago sativa) and tall fescue (Festuca arundinacea). Addition levels of 4% and 6% improved average body weight gain (BWG) by 215.71 and 142.86 g/d, and feed conversion ratio (FCR) by 0.20 and 0.14, respectively. Digestibility of dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), and ether extract (EE) was 62.25%, 65.18%, 58.75%, and 47.25% under the addition level of 2%, which is greater than that in the control group. C. deserticola addition improved energy utilization efficiency, while addition levels of 2% and 4% increased nitrogen intake and deposited nitrogen. Overall, C. deserticola has the potential to improve growth performance, digestion of sheep, so it has suitability to be used as a feed additive.

Thesis (MScAgric)--University of Stellenbosch, 2001.<br>ENGLISH ABSTRACT: One of the reasons why meat supply does not meet human demand is that man has concentrated on utilising relatively few animal species as a source of meat. Development of unconventional livestock, such as goats, is advocated as a means of increasing global meat production and consumption. Although South Africa possesses large numbers of domestic ruminants, meat consumption has been limited mainly to sheep and cattle. Goats are used to a lesser extent. This is partly attributed to a general belief that goat meat is inferior to mutton and beef. Numerous contradictions regarding comparative goat and sheep growth, carcass characteristics and meat composition exist in literature. Concepts involved with most of the contradictions includes average daHy gain (ADG), dressing percentage, carcass weight distribution and organoleptic characteristics, especially tenderness, juiciness and flavour, particularly as pertaining to animals reared/grown under intensive/feedlot conditions. Therefore this project was undertaken to obtain more information on the growth, carcass and organoleptic characteristics, as well as meat chemical compositions of Boer goat (BG) kids in comparison with South African Mutton merino (MM) lambs, reared under feedlot conditions. Thirty-two BG kids and 32 MM lambs were used for this investigation. All the animals were castrated and weaned before entering the feedlot. Two pelleted diets (fed to 16 animals/species) with either a low (LE; 8.9 MJ/kg OM) or a high (HE, 10.9 MJ/kg OM) metabolisabie energy level were fed individually, ad lib for either 28 or 56 days. Feed and water intake, ADG and feed conversion efficiencies (FCE) were monitored. During the last week of the feeding trial, 12 BG kids and 12 MM lambs were used to evaluate the digestibility of the two diets. After either 28 or 56 days, the animals were slaughtered and the carcasses dissected into South African commercial cuts. The m. semimembranosus and 8-9-10-rib cut of each carcass was dissected for determination of chemical composition, drip loss, cooking loss, shear force values and colour measurement. The m. gracilis was dissected from the hind leg of the carcass and used for sensory evaluation. MM's had significantly higher AOG's than BG's (e.g. MMHE56: 0.281; BGHE56: 0.162 kg/day). Within a diet there was no difference (P>0.05) in FCE between BG's and MM's and only the MM's FCE differed between the LE and HE diet (e.g. BGLE28: 7.65; BGHE28: 6.37; MMLE28: 8.73; MMHE28: 5.56 kg feed/kg weight gain). BGLE digested dry matter (OM), crude protein (CP) and energy more efficiently and had a higher energy retention than MMLE. The two diets had the same ME-value for the goats, which confirms that goats perform equally well on a lower quality feed as their contemporaries on a higher quality feed. Neither species, nor diet affected nitrogen retention. The BG had a 49 % lower (P<0.01) water intake per kg weight gain than the MM on both the high and low energy diets. Both species had a lower (P<0.01) water intake on the high than on the low energy diet. Furthermore, the BG had a daily water intake of only 171 ml/kgo.75 compared to the 302 ml/kgo.75 of the MM. The weight of the liver, empty stomach, head and feet (as a percentage of empty body weight) were higher in goats than in sheep. The MM's had significantly heavier skins, probably due to wool growth. Both kidney fat and gastro-intestinal tract (GIT) fat increased with age. The animals slaughtered after 56 days in the feedlot had significantly longer and deeper carcasses than their contemporaries slaughtered after 28 days. Within a diet and slaughter age, the MM had significantly broader and deeper carcasses than the BG's. BG's had significantly less weight per unit carcass length, and thus more slender carcasses than MM's. Diet had no significant influence on the carcass weight distribution of the goats. However, MM's had heavier carcasses (LE: 19.87 vs. 15.28 kg; HE: 24.01 vs. 17.05 kg) and proportionally heavier ribs and buttocks than BG's. Neither diet nor slaughter age influenced the proximate analysis of the m. semimembranosus, but MM's had significantly lower moisture values than BG's. In the 8-9-10-rib cuts BG's had significantly more moisture and protein and lower fat and energy values than MM's. OM, fat and energy values increased with an increase in slaughter age in both species. BG's had significantly higher concentrations of 11 of the 18 measured essential amino acids in their 8-9- 10-rib cuts than the MM's. Gaat carcasses had higher Ca, K, Mg, Na and P-Ievels than sheep carcasses, regardless of the diet fed. There was a tendency for goat's m. semimembranosus to have a lower Fe-content than that of sheep. BG carcasses had a lower carcass cholesterol content than that of lamb (66.77 vs. 99.28 mg/100g, respectively). Palmitic (C16:0), stearic (C18:0) and oleic (C18:1 n9) acid comprised the greatest proportions of fatty acids in both the m. semimembranosus and 8-9-10-rib cut for both species. On a LE-diet there was no significant difference between the saturated fatty acid (SFA) to unsaturated fatty acid (UFA) ratio of goat meat and lamb. However, on the HEdiet, lamb had a significantly higher SFA:UFA ratio than chevon (m. semimembranosus: 0.842 vs. 0.689; 8-9-10-rib cut: 1.407 vs. 0.892). Organoleptically, a difference was noted between chevon and lamb. Each has a specific species flavour, which was not influenced by energy level of the diet. BG meat was perceived to be stringier than that of the MM, but there was no significant difference in Warner-Bratzler shear force values. Tenderness declined with age in both species and there was also a tendency for goat meat to be less juicy than lamb. Chevon had a more pronounced aftertaste than lamb. No objective differences could be distinguished between the colour of the cooked chevon and lamb. There was a tendency for fresh lamb to have a higher a*-value (redness) than chevon. Although diet did not influence drip loss, drip loss increased with an increase in slaughter age. Only after 56 days did the MM's m. semimembranosus have a significantly higher drip loss than the BG's (LE: 4.84 vs. 3.43%; HE: 4.72 vs. 3.32%). In the m. semimembranosus of both species, cooking loss increased with an increase in slaughter age. Since diet did not influence the growth, carcass weight distribution, water holding capacity, colour, shear force values or organoleptic qualities of chevon, BG's may be finished on a diet with a lower ME-value than that usually formulated for sheep, without a reduction in performance. This may render a direct economic advantage for BG feedlot finishing. Meat from young feedlot goats is not inferior to that of lamb and it has a higher protein percentage and lower fat percentage. Therefore, it can be considered as a healthy food commodity, especially among low-income groups or people wishing to consume a low calorie diet.<br>AFRIKAANSE OPSOMMING: 'n Vergelykende analise van nutriëntverbruik en vleiskwaliteisparameters van Boerbokke en Suid-Afrikaanse Vleismerino's: Een van die hoofredes waarom die vraag na vleis die aanbod oorskrei, is die feit dat die mens tot op hede net op 'n paar dierspesies as bron van vleis gekonsentreer het. Benutting van niekonvensionele spesies, soos bokke, kan aanbeveel word ten einde die globale vleisproduksie en -verbruik te verhoog. Ten spyte van die feit dat Suid-Afrika oor baie gedomestikeerde herkouerspesies beskik, is vleisverbruik in die verlede tot hoofsaaklik skape en beeste beperk. Bokke is tot 'n mindere mate gebruik. Dit kan gedeeltelik toegeskryf word aan die algemene siening dat bokvleis ondergeskik aan skaap- en beesvleis is. Verskeie teenstrydighede ten opsigte van vergelykings tussen bokke en skape se groei, karkaseienskappe en vleissamestelling bestaan in die literatuur. Teenstrydige resultate ten bpsigte van gemiddelde daaglikse toename (GOT), uitslagpersentasie, karkasgewigverspreiding en organoleptiese eienskappe (veral taaiheid, sappigheid en geur) van diere afgerond onder intensiewe/voerkraal-toestande, kom veral voor. Hierdie projek is vervolgens uitgevoer ten einde meer inligting ten opsigte van die groei, karkas- en organoleptiese eienskappe, sowel as die chemiese samestelling van die vleis van Boerbok (BB) lammers in vergelyking met Suid-Afrikaanse Vleismerino (VM) lammers, onder voerkraal-toestande grootgemaak, te verkry. Twee-en-dertig BB lammers en 32 VM lammers is vir hierdie studie gebruik. AI die diere is gekastreer en gespeen voor hulle in die voerkraal geplaas is. Twee verpilde diëte (gevoer aan 16 diere/spesie) met óf 'n lae (LE, 8.9 MJ/kg DM) óf 'n hoë (HE, 10.9 MJ/kg DM) metaboliseerbare energievlak is individueel, ad lib, vir óf 28 óf 56 dae aan die diere gevoer. Voer- en waterinname, GOT en voeromsettingsdoeltreffendheid (VOD) is gemonitor. Gedurende die laaste week van die voedingsproef is 12 BB'e en 12 VM's gebruik ten einde die verteerbaarheid van die twee diëte te bepaal. Na 28 of 56 dae is die diere geslag en die karkasse in Suid-Afrikaanse kommersiële snitte verdeel. Die m. semimembranosus en 8-9-10-rib snit van elke karkas is verwyder vir bepaling van chemiese samestelling, drupverlies, kookverlies, skeurwaardes en kleurbepaling. Die m. gracilis is uit die agterbeen uitgehaal en vir sensoriese evaluering gebruik. VM's het betekenisvolle hoër GOT's as BB'e (bv. VMHE56: 0.281; BBHE56: 0.162 kg/dag) gehad. Binne 'n dieet was daar geen verskille (P>0.05) in VOD tussen BB'e en VM's nie en net die VM's se VOD het tussen die LE- en HE-dieet verskil (bv. BBLE28: 7.65; BBHE28: 6.37; VMLE28: 8.73; VMHE28: 5.56 kg voer/kg gewigstoename). BBLE het die droë materiaal (DM), ruproteïen (RP) en energie meer effektief verteer en het 'n hoër energieretensie as VMLE gehad. Die twee diëte het dieselfde ME-waarde vir die bokke gehad, wat bevestig dat bokke net so goed op 'n laer kwaliteit voer presteer as op 'n dieet van 'n hoër kwaliteit. Stikstofretensie is nie deur spesie of dieet beïnvloed nie. Die BB het 'n 49% laer (P<0.01) waterinname per kg massatoename op beide die HE- en LE-dieet gehad. Beide spesies het 'n laer (P<0.01) waterinname op die hoë as die lae energie dieet gehad. Verder het die BB ook 'n daaglikse waterinname van slegs 171 ml/kg075 gehad in vergelyking met die 302 ml/kgO.75van die VM. Die gewig van die lewer, leë pens, kop en pote (as persentasie van leë liggaamsgewig) was hoër vir bokke as vir skape. Die VM's se velle was betekenisvol swaarder, waarskynlik as gevolg van wolgroei. Beide niervet en kanaalvet het toegeneem met 'n toename in slagouderdom. Die diere wat na 56 dae in die voerkraal geslag is, het betekensivol langer en dieper karkasse gehad as dié na 28 dae. Binne 'n dieet en slagouderdom, het die skape breër en dieper (P<0.05) karkasse as die bokke gehad. BB'e het betekenisvol minder gewig per eenheid karkaslengte en dus maerder karkasse as VM's gehad. Dieet-energievlak het geen betekenisvolle effek op die verspreiding van karkasgewig by bokke gehad nie. VM's het egter swaarder karkasse (LE: 19.87 vs. 15.28 kg; HE: 24.01 vs. 17.05 kg) en proporsioneel swaarder ribbes en boude as BB'e gehad. Dieet of slagouderdom het nie 'n betekenisvolle effek op die chemiese samestelling (vog, vet, proteïen en as) van die m. semimembransous gehad nie, maar VM's het laer (P<0.05) vogwaardes as BB'e gehad. In die 8-9-10-rib snit het BB'e betekenisvolle hoër vog en proteïen, maar laer vet- en energiewaardes as VM's gehad. In beide spesies het DM, vet en energiewaardes toegeneem met 'n toename in slagouderdom. BG'e het 'n betekenisvolle hoër konsentrasie in 11 van die 18 gemete essensiële aminosure in hul 8-9-10-rib snitte gehad in vergelyking met VM's. Bokkarkasse het ook hoër Ca, K, Mg, N en P-vlakke as skaapkarkasse gehad, ongeag die dieet. Daar was 'n neiging vir die bok m. semimembranosus om 'n laer Fe-inhoud as dié van die skaap te hê. BB-karkasse het 'n laer cholesterol-inhoud as skaapkarkasse (66.77 vs. 99.28 mg/100g, onderskeidelik) gehad. Palmitiensuur (C16:0), steariensuur (C18:0) en oleïensuur (C18:1n9) het die grootste proporsies van die vetsure in beide die m. semimembranosus en 8-9-10-rib snit van beide spesies uitgemaak. Op 'n LE-dieet was daar geen verskil tussen die versadigde (SFA) tot onversadigde (UFA) vetsuur-verhouding van bok- en skaapvleis nie. Op 'n HE-dieet het skaapvleis egter 'n betekenisvol hoër SFA:UFA-verhouding as bokvleis gehad (m. semimembranosus: 0.842 vs. 0.689; 8-9-10-rib snit: 1.40 vs. 0.892, onderskeidelik). Organolepties is 'n verskil tussen bok- en skaapvleis gevind. Elkeen het 'n spesifieke spesiegeur, wat onafhanklik van die dieet was. Bokvleis is waargeneem as meer veselrig as skaapvleis, maar daar was geen verskil in Warner-Bratzler skeurwaardes nie. In beide spesies het sagtheid afgeneem met 'n toename in ouderdom en daar was 'n neiging vir bokvleis om minder sappig as lamsvleis te wees. Bokvleis het ook 'n meer pertinente nasmaak as lam gehad. Geen objektiewe verskil kon tussen die kleur van gekookte skaapen bokvleis onderskei word nie. Daar was egter 'n tendens vir vars lamsvleis om 'n hoër a*- waarde (rooiheid) as bokvleis te hê. Alhoewel dieet nie 'n invloed op drupverlies gehad het nie, het drupverlies toegeneem met 'n toename in slagouderdom. Slegs na 56 dae het die VM se m. semimembranosus 'n hoër (P>0.05) drupverlies as dié van die BB getoon (LE: 4.84 vs. 3.43%; HE: 4.72 vs. 3.32%, onderskeidelik). In die m. semimembranosus van beide spesies het kookverlies toegeneem met 'n toename in slagouderdom. Aangesien dieet nie 'n effek op die groei, karkasgewig-verspreiding, waterhouvermoë, kleur, skeurwaardes of organoleptiese eienskappe van bokvleis gehad het nie, kan BB'e op 'n dieet met 'n laer ME-waarde as wat normaalweg vir skape geformuleer word, afgerond word, sonder om 'n verlaging in produksie te verwag. Dit mag 'n direkte ekonomiese voordeel vir afronding van BB'e in die voerkraal inhou. Vleis van jong voerkraalbokke is nie minderwaardig teenoor die van skape nie e-n dit het 'n hoër proteren- en laer vetpersentasie. Dus kan bokvleis as 'n gesonde voedselbron gesien word, veralonder lae-inkomste groepe of mense wat 'n lae kalorie-dieet wil inneem.

Includes bibliographical references (leaves 290-309) Investigates aspects of the intake and utilization of barley grain and grain legume supplements by sheep fed low quality pasture hay and when grazing mature summer pastures.

Carnosine and methionylglycine (using ³⁵S-methionylglycine as a representative marker) absorption and transfer across ruminal and omasal epithelia collected from four (carnosine) and seven (methionylglycine) sheep were studied using parabiotic chambers that were repeatedly sampled over a 240-min incubation. The quantity of dipeptide absorbed or transferred was linearly (P < .01) dependent on substrate concentration. Carnosine was transferred intact across both tissues. More carnosine was absorbed (P < .02) and transferred (P < .01) by the omasal epithelia. Methionylglycine was transferred intact across both tissues, but less (P < .01) remained intact in serosal buffer after 240 min incubation with omasal epithelium than with ruminal epithelium. The amount of methionylglycine that accumulated in each tissue was similar. Methionylglycine accumulation in tissues plus transfer after 240 min was greater (P < .01) for omasal tissue. The ability of sheep ruminal and omasal epithelia to absorb and transfer carnosine and methionylglycine in parabiotic units was demonstrated. Dipeptide translocation across forestomach epithelial tissues, which has not been reported previously, may be an important route for supplying dietary amino acids to the ruminant.<br>Master of Science

Thesis (MSc)--Stellenbosch University, 2000.<br>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.<br>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.

[Truncated abstract] Saltbush is one of the few types of forage that will grow on salt affected land but, sheep struggle to maintain weight when grazing saltbush mainly because of its high salt content. Therefore, a strategy to improve salt tolerance of sheep would be beneficial to the profitable use of revegetated saline land. This could be done by manipulating the dietary salt load of pregnant or lactating ewes which could 'program', or permanently alter the physiology of their offspring to allow them to cope better with a high-salt diet as adults. When rat dams consume a high amount of salt during pregnancy, the salt balance mechanisms of their offspring are 'programmed' due to suppression of the offspring's renin-angiotensin system in early development. If this occurs in offspring from ewes grazing saltbush, beneficial adaptations may be programmed in these offspring which could allow them to better cope with the high-salt content of saltbush. I tested the general hypothesis that offspring born to ewes that consumed a high-salt or saltbush diet from mid-pregnancy to early lactation would have an increased capacity to cope with salt that would allow them gain weight when grazing saltbush in later life. To test this hypothesis, I pair-fed ewes either a high-salt diet (14% NaCl) or control diet (2% NaCl) in an animal house from day 60 of gestation until day 21 of lactation. During the same period, I also conducted a field experiment where ewes grazed on saltbush (supplemented with barley) or on pasture (supplemented with lupins). ... This led to the high-salt offspring retaining more salt than control animals. In contrast, the renin activity of saltbush was consistently lower than pasture offspring which allowed them to excrete salt more rapidly. In experiment three, the saltbush offspring gained tissue weight after grazing saltbush for 8 weeks, whereas the offspring in the other three treatments lost weight. High-salt and saltbush offspring also had higher greasy fleece weights at 22 months of age than their respective control groups. Feeding saltbush to ewes from mid-pregnancy to early lactation induces physiological adaptations in their offspring that allow them to cope better with salt and gain weight when grazing saltbush as adults, supporting my hypothesis. However, contrary to expectations, the high-salt offspring did not gain weight when grazing saltbush because their physiological adaptations, such as salt retention, did not allow them to cope better with a salt load. The reason that saltbush offspring showed different adaptations to highsalt offspring is likely to be because saltbush contains not only NaCl but also high amounts of other minerals such as potassium, and other plant compounds, which may influence the adaptive responses of the offspring. This research has direct implications for farmers because it shows they could utilize otherwise unproductive saltland by grazing pregnant ewes on saltbush to 'program' their offspring to gain weight when they graze saltbush later in life.

Bibliography: leaves 122-138. Investigates the use of microbial inoculants to prevent the onset of acidosis in acutely grain fed animals; and, the most effective combination of virginiamycin and lactic acid utilising bacteria (selenomonas ruminantium subsp. lactilytica and Megasphaera elsdenii) in controlling lactic acid accumulations in vitro.

Includes bibliographical references (leaves 290-333). Describes research into the nutritional value of aquatic plants as novel or non-conventional feedstuffs for ruminants in general and for sheep in particular, with especial reference to those which are available in high amount in southern Australia, such as the seagrass, Posidonia australis.

<p>Two experiments were conducted with sheep to determine the nutritional value of 'Lathco' flatpea (Lathyrus sylvestris) hay. In experiment 1, a finishing trial was conducted with 50 group fed crossbred lambs (25 ewes and 25 wethers) fed diets consisting of 70% chopped forage and 30% ground corn grain for 70 d. Five pens of five wethers and five pens of five ewes were selffed diets in which the forage consisted of 100:0, 75:25, 50:50, 25:75, and 0:100 proportions of alfalfa (Medicago sativa L.) and flatpea hay. Feed efficiencies decreased linearly (P<.05) as flatpea increased in the diet. Linear decreases (P<.05) were obtained in kidney and pelvic fat, backfat, leg conformation, and yield grade with increased flatpea in the diet. Blood urea-N (BUN), ruminal pH and NH3-N increased (P<.005) as proportion of flatpea increased. Total volatile fatty acid (VFA) and acetate concentration decreased linearly (P<.005) and propionate, isovalerate, and valerate levels increased linearly (P<.01) with increased proportions of flatpea hay. In experiment 2, 30 wether lambs were fed diets consisting of 100:0, 75:25, 50:50, 25:75 and 0:100 proportions of chopped alfalfa and flatpea hays in a digestion trial. Neutral detergent fiber (NOE), acid detergent fiber (ADE), cellulose, hemicellulose and energy digestibilities decreased linearly (P<.Ol) with increased levels of flatpea hay. Nitrogen retention was not different between sheep fed the different diets. Apparent absorbtion and retention of Ca decreased linearly (P<.05) with increased level of flatpea hay Ruminal pH and NHa-N, and BUN increased linearly (P<.OOl) as flatpea was increased in the diet. Ruminal total VEA, acetate and acetate to propionate ratio decreased linearly (P<.001) and propionate, isobutyrate, isovalerate, and valerate levels increased linearly (P<.001) as level of flatpea increased.</p><br>Master of Science

Two metabolism trials were conducted with 15 wethers surgically equipped with duodenal and ileal cannulas to study the absorption of P and certain other minerals from swine waste and broiler litter. The effect of source and level of P on rumen cellulytic bacterial populations was also determined. Animals were fed a low P basal diet until serum inorganic P averaged 5.5 mg/dl, then randomly assigned to the following diets: low P basal alone, or supplemented with swine waste, broiler litter, dicalcium phosphate, or soybean meal. Trials consisted of a 7-d preliminary period, a 7-d collection of urine and feces and a 6-d sampling of duodenal and ileal digesta, and feces. Animals fed the waste diets tended to absorb more P than those fed the conventional supplements. Calculated by difference, sheep absorbed more P from swine waste and broiler litter than from dicalcium phosphate and soybean meal (P< .1). Less Ca was absorbed from the waste diets than from the conventionally supplemented diets (P< .05). Expressed as g/d, there was no difference in Mg absorption between waste and conventional diets. Sheep fed waste tended to digest more dry matter and a higher percentage of ADF in the large intestine. Lignin was primarily digested in the large intestine of all sheep. More cellulytic bacteria were isolated from the rumen of sheep fed the supplemented diets (P< .05). Both P intake and P recycling appear to be important influences on cellulytic bacteria in the rumen. Both broiler litter and swine waste appear to be good sources of P and Mg for ruminants.<br>Ph. D.

The increasing demand of meat requires the adoption of sustainable intensification livestock systems, applying nutritional strategies to reduce any negative contribution from beef cattle to global warming and, at the same time, to increase animal performance and productive efficiency. The pasture management practices and feed supplementation, mainly using non-edible feed with less costs, could minimize environmental and social impacts, resulting in higher productivity with less inputs utilization. Tropical grass submitted to grazing management according to plant height present high soluble protein and low levels of indigestible neutral detergent fiber contents. Energy or rumen undegradable protein supplementation, associated to alternative additives to antibiotics effects, such as probiotics, tannin, essential oils and saponin, can help to fully exploit the animal genetic potential and nutrient utilization efficiency, which decreases greenhouse gases emissions and improves animal performance. Hence, more information about these tools can make the livestock systems in tropical pasture more efficient and eco-friendlier.

The research is based on the tasks of applied research on the topic: «Development of a complex of energy-efficient and resource-saving equipment and promising technologies for feeding farm animals of the AIC of Ukraine», state registration number 0121U108589. The authors’ research is aimed at solving current problems of technological renewal and development of the agro-industrial complex of Ukraine.The mechanism of action of probiotics is that they interfere with the development of pathogenic microflora, and can also synthesize biologically active substances (BAS – vitamins, amino acids, enzymes), while increasing digestibility and nutrient utilization. Probiotic microorganisms create a physical barrier between the cells of the intestinal epithelium and its contents. In addition, probiotic bacteria produce short-chain fatty acids, which leads to lower pH levels.In the conditions of the scientific farm of the Faculty of Technology of Production and Processing of Livestock and Veterinary Products of Vinnytsia National Agar University, research was conducted on the use of probiotic feed additives of natural origin in feeding broiler chickens. Rational use of biologically active substances in animal feed makes it possible to significantly increase the rate of absorption of feed nutrients, productivity and conservation of poultry. The article presents the results of research on the use of feed additives of natural origin in the feeding of broiler chickens. Broiler chickens, compound feed, meat, and blood were used as the object of the study. It has been established that the probiotic in the compound feed has a positive effect on the intensity of growth by increasing the digestibility of the main nutrients of the feed. It was found that the additive under study improves the quality of poultry meat due to the higher content of essential amino acids. New data have been obtained on the effect of feed additives on the availability of amino acids and the retention of mineral elements. For the first time, the dependence of physicochemical parameters, amino acid, fatty acid and mineral composition of the pectoral and femoral muscles on the ratio of different doses of the probiotic was found. An increase in the slaughter rates of broiler chickens under the action of a probiotic supplement has been established. The influence of the studied additive on the morphological, biochemical parameters of poultry blood was studied. Studies have shown a positive effect on the productivity, growth and quality of broiler meat.

Methane gas has a very significant contribution to the increase in greenhouse gases (GHG) globally. The livestock sector, especially ruminants, causes the issue of increasing GHG concentrations. The chapter presents the issue of reducing methane gas production from cattle. Various experiments to reduce methane gas production from ruminants have been carried out and have shown varying results. This series of results of the author\'s research on reducing methane gas production in livestock in beef cattle based on agriculture by-product to animal feed is addressed with this background. Agriculture by-products such as oil palm fronds and rice straw can be used to feed beef cattle in Indonesia. However, agriculture by-product as animal feed can reduce feed efficiency and increase methane gas production due to the high lignin content. Therefore, various alternatives are carried out to optimize the utilization of this plantation waste. One of them is the use of feed additives and methanogenesis inhibitors. The author\'s series of research using feed additives (direct-fed microbial) and various methanogenesis inhibitors (plant bioactive compounds and dietary lipids) were tested to determine their effect on nutrient digestibility and methane gas production in feed based on plantation waste. Experiments were carried out in vitro and in vivo on various types of ruminants. Plant bioactive compounds such as tannins are proven to reduce methane production through their ability to defaunate in the rumen. Tannins may also have direct effect on methanogens and indirectly by reducing fiber digestion. In addition, direct-fed microbial (DFM) feed additives such as Saccharomyces cerevisiae, Bacillus amyloliquifaciens, and Aspergillus oryzae can be used in ruminants to increase livestock productivity. Furthermore, virgin coconut oil as a dietary lipid contains medium-chain fatty acids, mainly lauric acid, which can inhibit the development of ciliates of protozoa and methanogenic bacteria that produce methane in the rumen.

A review of the latest research on the addition of humic substances (HSs) in the drinking water or feed of farm animals including poultry, pigs, dairy cows and calves, goats, and rabbits was carried out. The results reinforces the promoted protective action of HS on the digestive mucosa, their antioxidant properties, immunomodulatory, and anti-inflammatory attributes, the suggested microbial shift to a probiotic-type bacteria in the gut, including antiparasitic and antifungal effects, as well as their influence on the higher efficient of minerals, proteins, and lipids utilization within the body. The outstanding improvements in health, productivity, and meat and milk quality obtained from animals supplemented with HS are common features in the majority of available research. The main benefits in the gastrointestinal tract stem from the formation of protective barriers on the epithelial mucosa due to its colloidal properties and stimulation of mucin production. HS also promotes the development of probiotic microbiota and positive changes in bacterial fermentation patterns, which results in improved intestinal health and integrity. As a result, a cascade of benefits is derived within the body, reinforcing antioxidant protection responses, immunomodulation, and anti-inflammation mechanisms, as well as improving nutrient utilization efficiency. However, the truly molecular mechanisms of action of HS in the intestine and throughout the body remain unknown.

Eimeria spp. are parasites specialized in invade and replicate in the intestine, causing coccidiosis, an enteric disease of major economic importance worldwide. The disease causes losses in production and high morbidity ranging from bloody enteritis, with high mortality, to being subclinical silent but affecting feed intake and efficiency. However, intestinal lesions of the infection vary, depending on the species of coccidia. The most important Eimeria species in poultry are: E. tenella, E. acervulina, E. maxima, E. necatrix, E. mitis, E. praecox and E. brunetti. All those species affect different anatomic sites of the intestine. Thus, they alter the homeostasis of the host reducing nutrient absorption and utilization. Nutritional factors are key players in several steps of the coccidiosis disease. Firstly, as a susceptibility or protection factor, secondly, during the process of infection and pathogenesis, and thirdly, in the recovery and compensatory growth of the bird. Otherwise, coccidiosis also triggers immune response in the intestine. To counter these complicated effects, there are nutritional strategies (including formulation of key amino acids, vitamins, short and medium chain fatty acids, prebiotics, enzymes, among others) that can be utilized to reduce the infection, alleviate the signs, and boost the compensatory growth after infection. This chapter review the impacts of coccidiosis in nutrition and discuss about of strategies to mitigate these risks.

The article presents the results of the evaluation of the breeding value of Romanov sheep of the Yaroslavl region population by fertility, type of birth and live weight at the first lambing. It was found that the indicators of phenotypic variability by type of birth and fertility by the first lambing were at the level of average values, which indicates the possibility of selecting individuals with desirable phenotypes. When evaluating animals using breeding value indices according to the proposed models, the genetic improvement in live weight will be 0.7–1.7 kg, in fertility — 0.03–0.06 heads. The economic effect of using genotype estimation models by live weight will be 150–340 rubles, by fertility — 480–882 rubles per head per year.

The article presents the results of a study on the cost-effectiveness of breeding of Kazakh fat tail sheep, Edilbaev and Aktogay semi-coarse sheep in harsh climatic conditions, poor feed conditions with year-round grazing in the desert zone of Central Kazakhstan. It has been established that in this zone, the most profitable, both from the point of view of obtaining the highest, higher quality products, and economic efficiency, is the breeding of Aktogai populations of semi-coarse fat tail sheep.

A number of studies on digestion of the ruminants have shown the process of synthesis of all the essential amino acids in the rumen (Abu Fadel, 2004; Trukhachev, V., Zlidnev, N. 2008). However, according to some researches, microbial protein is deficient in methionine and lysine. This assumption also proves the need for further study of the influence of balanced amino acids to these diets on the growth, development and productive performance of the ruminants. Scientific approbation of the issues related to establishing the requirements of young sheep in lysine and methionine with cystine and development of recommendations for their proper balance in animal rations have been conducted along with a series of physiological, scientific and practical experiments. For this purpose, we used the following research methods: preparative, analytical, measuring and calculating. Zootechnical evaluation of young sheep’s diet with different levels of lysine and methionine with cysteine has been conducted, and influence of these components on growth, development, metabolism, the use of amino acids and wool productivity have been studied. The importance of studying the content of amino acids in plasma is evident because they are the indicators of protein metabolism in the animals’ organism and represent themselves the exchange fund when used in the biochemical transformations in the process of updating the protein of the body tissues and the synthesis of animal products. Increase in young sheep’s diet of lysine and methionine can improve their productivity, reduce the cost of feed energy and improve biochemical indexes of meat, taking into account the optimization of its amino acid composition. Efficiency increase of young sheep during the process of the individual development is linked to conditions of feeding and in particular the usefulness of a protein food, which is primarily determined by sufficient intake of essential amino acids - lysine and methionine with cystine. Thus, the inclusion in the diet of growing young sheep some amount of synthetic amino acids – 6–8 grams of lysine and 3–4 g of methionine per 1 fodder unit, enhances oxidation-reduction processes, increase productivity, i.e. wool yield and other indicators. The content of free amino acids in plasma directly depends on their availability in feed. The use of synthetic amino acids (lysine, methionine and cystine) contributed to the increase of their content in a free state in the blood serum, indicating their increased demand in sheep. With the use of different doses of synthetic amino acids (lysine, methionine, cystine) in the diets of young sheep it has been found that the organization of optimum conditions of feeding, care and management of sheep in winter season help to avoid abrupt changes in the structure of the skin, to ensure the normal development of the histological structure and morphogenetic processes.)

The world’s first 1000MW double reheat ultrasupercritical unit has been in operation since September 25th, 2015 in Taizhou, China. The thermal efficiency at turbine heat-rate acceptance (THA) condition is around 51%, which is the highest among all condensing units in coal-fired power plants around the world. However, the resultant superheat degree of the extraction steam is relatively high, leading to a large temperature difference in heat transfer process in the regenerative system, thereby a great exergy loss. In order to utilize the superheat of turbine bleeds more effectively, we present a scheme by employing an outer steam cooler (OSC) after the last high pressure heater in series to use the superheat to heat the feed water. Based on the newly installed unit in Taizhou, we examine the energy saving effect of the superheat utilization of different bleeds and their possible combinations respectively. The influencing factors of the mass flow rate, superheat, and effective superheat of the extraction steam are studied. Thermodynamic analyses revealed that the second extraction steam has not only high effective superheat, but also large mass flow rate, so in the overall efficiency improvement it ranks first and the third extraction steam ranks second. Although the fourth extraction steam has the largest superheat, it ranks third as the result of relatively lower mass flow rate. It was found that at nominal load, by adopting OSC’s to utilize the superheat of the second to sixth extraction steam, temperature of the feed water can increase by 8.1 °C, 3.5 °C, 2.6 °C, 1.1 °C, and 1 °C respectively, and the net coal consumption reduces by 0.73g/kWh, 0.47g/kWh, 0.40g/kWh, 0.21g/kWh and 0.22g/kWh accordingly. Consequently, three possible schemes are recommended for future design: one is to adopt one OSC to utilize the superheat of the second extraction steam, in return of 8.1°C increment in feed water temperature and 0.73g/kWh reduction of the net coal consumption; the second is to adopt two OSC’s to utilize the superheat of the second and third extraction steam at the same time, in return of 11.4 °C increment in feed water temperature and 1.21g/kWh reduction of the net coal consumption; and the last is to apply three OSC’s to utilize the superheat of the second to the fourth extraction steam simultaneously, to achieve 13.9°C increment in feed water temperature, and 1.62g/kWh reduction of the net coal consumption.

The simulation work presented herein characterizes the performance of a recuperated gas turbine (GT) hybrid systems in response to different levels of fuel utilization (Uf) by the SOFC. The SOFC performance was compared with and without anode recycle (AR), operating at 90% total stack Uf (Uf.stack). A study at 65% Uf was also considered as a reference case for the hybrid power system without anode recycle, i.e. using single-pass cell fuel utilization (Uf.cell). All three cases in this paper were evaluated at design points for a 550 MW hybrid system using coal-derived syngas feed with zero methane. A previously developed one-dimensional (1D) fuel cell model was used to simulate the distributed profile of thermal and electrochemical properties along the fuel cell length. Fuel cell total current density, average solid temperature, and cathode inlet temperature were maintained identical at each fuel utilization to avoid confounding the results with the impacts of SOFC degradation. The maximum system efficiency of 71.1% was achieved by SOFC/GT non-recycle systems at 90% Uf.cell (with 90% Uf.stack). The case at 65% Uf.cell (with 65% Uf.stack) demonstrated 70.7% total efficiency, only 0.4% point lower than at 90% Uf.cell. However, integrating anode recycle to the system significantly reduced the maximum total efficiency to 55.5%. Although the distributed SOFC performance across the cell length for 65% Uf.cell with AR at 90% Uf.stack was similar to the 65% Uf.cell (with 65% Uf.stack), recycling anode off-gas resulted in lower fuel cell Nernst potential that caused further drop in both stack and total system efficiency.

An anode gas recycle system using an ejector for 1 kW solid oxide fuel cells (SOFCs) was developed to increase the electrical efficiency of combined power generation. We call this an AGR-SOFC (anode gas recycle-solid oxide fuel cell). The effects of recirculation ratio, externally steam feed rate, and fuel utilization were determined experimentally on the AGR-SOFC performance (i.e., output power, stack temperature and gas composition) using a variable flow ejector and a recirculation ratio of 0.55–0.62, overall fuel utilization of 0.72–0.84, and steam feed rate of 0–1.5 g/min. A quadrupole mass spectrometer was used to identify the recirculation ratio, the gas composition of reformed gas at the AGR-SOFC inlet, and that of the recycle gas at the outlet. Compared to one-path SOFC systems i.e. without an anode gas recycle, the AGR-SOFC was stable and generated about 15 W more electricity when the overall fuel utilization was 0.84 and the recirculation ratio was 0.622 with no steam supply. This improved performance was due to the reduced H2O concentration in the anodic gas. In addition, although the recirculation ratio did not affect the AGR-SOFC performance, a high recirculation ratio can provide steam produced via the electrochemical reaction to the injected fuel for the steam reforming process.

Ruminants provide human society with high quality food from non-human-edible resources, but their emissions negatively impact the environment via greenhouse gas production. The rumen and its resident microorganisms dictate both processes. The overall goal of this project was to determine whether a causal relationship exists between the rumen microbiome and the host animal's physiology, and if so, to isolate and examine the specific determinants that enable this causality. To this end, we divided the project into three specific parts: (1) determining the feed efficiency of 200 milking cows, (2) determining whether the feed- efficiency phenotype can be transferred by transplantation and (3) isolating and examining microbial consortia that can affect the feed-efficiency phenotype by their transplantation into germ-free ruminants. We finally included 1000 dairy cow metadata in our study that revealed a global core microbiome present in the rumen whose composition and abundance predicted many of the cows’ production phenotypes, including methane emission. Certain members of the core microbiome are heritable and have strong associations to cardinal rumen metabolites and fermentation products that govern the efficiency of milk production. These heritable core microbes therefore present primary targets for rumen manipulation towards sustainable and environmentally friendly agriculture. We then went beyond examining the metagenomic content, and asked whether microbes behave differently with relation to the host efficiency state. We sampled twelve animals with two extreme efficiency phenotypes, high efficiency and low efficiency where the first represents animals that maximize energy utilization from their feed whilst the later represents animals with very low utilization of the energy from their feed. Our analysis revealed differences in two host efficiency states in terms of the microbial expression profiles both with regards to protein identities and quantities. Another aim of the proposal was the cultivation of undescribed rumen microorganisms is one of the most important tasks in rumen microbiology. Our findings from phylogenetic analysis of cultured OTUs on the lower branches of the phylogenetic tree suggest that multifactorial traits govern cultivability. Interestingly, most of the cultured OTUs belonged to the rare rumen biosphere. These cultured OTUs could not be detected in the rumen microbiome, even when we surveyed it across 38 rumen microbiome samples. These findings add another unique dimension to the complexity of the rumen microbiome and suggest that a large number of different organisms can be cultured in a single cultivation effort. In the context of the grant, the establishment of ruminant germ-free facility was possible and preliminary experiments were successful, which open up the way for direct applications of the new concepts discovered here, prior to the larger scale implementation at the agricultural level.

Feed inputs represent the largest variable cost of producing meat and milk from ruminant animals. Thus, strategies that improve the efficiency of feed utilization are needed to improve the global competitiveness of Israeli and U.S. cattle industries, and mitigate their environmental impact through reductions in nutrient excretions and greenhouse gas emissions. Implementation of innovative technologies that will enhance genetic merit for feed efficiency is arguably one of the most cost-effective strategies to meet future demands for animal-protein foods in an environmentally sustainable manner. While considerable genetic variation in feed efficiency exist within cattle populations, the expense of measuring individual-animal feed intake has precluded implementation of selection programs that target this trait. Residual feed intake (RFI) is a trait that quantifies between-animal variation in feed intake beyond that expected to meet energy requirements for maintenance and production, with efficient animals being those that eat less than expected for a given size and level of production. There remains a critical need to understand the biological drivers for genetic variation in RFI to facilitate development of effective selection programs in the future. Therefore, the aim of this project was to determine the biological basis for phenotypic variation in RFI of growing and lactating cattle, and discover metabolic biomarkers of RFI for early and more cost-effective selection of cattle for feed efficiency. Objectives were to: (1) Characterize the phenotypic relationships between RFI and production traits (growth or lactation), (2) Quantify inter-animal variation in residual HP, (3) Determine if divergent RFIphenotypes differ in HP, residual HP, recovered energy and digestibility, and (4) Determine if divergent RFI phenotypes differ in physical activity, feeding behavior traits, serum hormones and metabolites and hepatic mitochondrial traits. The major research findings from this project to date include: In lactating dairy cattle, substantial phenotypic variation in RFI was demonstrated as cows classified as having low RMEI consumed 17% less MEI than high-RMEI cows despite having similar body size and lactation productivity. Further, between-animal variation in RMEI was found to moderately associated with differences in RHP demonstrating that maintenance energy requirements contribute to observed differences in RFI. Quantifying energetic efficiency of dairy cows using RHP revealed that substantial changes occur as week of lactation advances—thus it will be critical to measure RMEI at a standardized stage of lactation. Finally, to determine RMEI in lactating dairy cows, individual DMI and production data should be collected for a minimum of 6 wk. We demonstrated that a favorably association exists between RFI in growing heifers and efficiency of forage utilization in pregnant cows. Therefore, results indicate that female progeny from parents selected for low RFI during postweaning development will also be efficient as mature females, which has positive implications for both dairy and beef cattle industries. Results from the beef cattle studies further extend our knowledge regarding the biological drivers of phenotypic variation in RFI of growing animals, and demonstrate that significant differences in feeding behavioral patterns, digestibility and heart rate exist between animals with divergent RFI. Feeding behavior traits may be an effective biomarker trait for RFI in beef and dairy cattle. There are differences in mitochondrial acceptor control and respiratory control ratios between calves with divergent RFI suggesting that variation in mitochondrial metabolism may be visible at the genome level. Multiple genes associated with mitochondrial energy processes are altered by RFI phenotype and some of these genes are associated with mitochondrial energy expenditure and major cellular pathways involved in regulation of immune responses and energy metabolism.