Academic literature on the topic 'PHYTATE LINES'

AbstractThe objective of the current experiment was to determine the effects of high-concentration phytase (5000 FTU/kg) feeding to diverse lines of chickens fed phosphorus (P) adequate maize–soybean meal diets (4.5 g/kg non-phytate P) on the performance and intestinal immune function. Performance was measured for outbred broiler (Ross 308) and inbred Fayoumi lines over 0–21 days, and duodenum and ileum were harvested for the determination of mucin-2, interleukin (IL)-1βand IgA mRNA by quantitative reverse transcription polymerase chain reaction. Over the 0–7-day period, there was a significant line × diet interaction, as high phytase supplementation increased broiler average daily gain (ADG), but had no effect on Fayoumi ADG. Treatment of diets with phytase increased expression of the mucin-2 gene in the duodenum mucosa. There were significant interactions between line and age, and line, diet and age on duodenal expression of the IL-1βgene as phytase supplementation of the broiler line reduced IL-1βin comparison to control fed broilers without change in the Fayoumi line. Overall, the addition of a high concentration of phytase to broilers fed adequate concentrations of non-phytate P resulted in improved growth performance early with a reduction in this effect over time. Mucosal mucin-2 expression was increased with high-concentration phytase feeding across both lines, but IL-1βmRNA expression was reduced in the duodenum of broilers fed high concentrations of phytase, suggesting that the increased performance noted might be related to decreased inflammation.

Inositol phosphates from barley low-phytate grain mutants and their parent variety were analysed by metal-dye detection HPLC and NMR. Compound assignment was carried out by comparison of retention times using a chemical hydrolysate of phytate [Ins(1,2,3,4,5,6)P6] as a reference. Co-inciding retention times indicated the presence of phytate, D/L-Ins(1,2,3,4,5)P5, Ins(1,2,3,4,6)P5, D/L-(1,2,4,5,6)P5, D/L-(1,2,3,4)P4, D/L-Ins(1,2,5,6)P4 and D/L-Ins(1,4,5,6)P4 in PLP1B mutants as well as the parent variety. In grain extracts from mutant lines PLP1A, PLP2A and PLP3A unusual accumulations of D/L-Ins(1,3,4,5)P4 were observed whereas phytate and the above-mentioned inositol phosphates were present in relatively small amounts. Assignment of D/L-Ins(1,3,4,5)P4 was corroborated by precise co-chromatography with a commercial Ins(1,3,4,5)P4 standard and by NMR spectroscopy. Analysis of inositol phosphates during grain development revealed accumulation of phytate and D/L-Ins(1,3,4,5)P4, which suggested the tetrakisphosphate compound to be an intermediate of phytate synthesis. This assumption was strengthened further by phytate degradation assays showing that D/L-Ins(1,3,4,5)P4 did not belong to the spectrum of degradation products generated by endogenous phytase activity. Metabolic scenarios leading to accumulation of D/L-Ins(1,3,4,5)P4 in barley low-phytate mutants are discussed.

Crop seed phosphorus (P) is primarily stored in the form of phytate, which is generally indigestible by monogastric animals. Low-phytate soybean lines have been developed to solve various problems related to seed phytate. There is little information available on the effects of P fertilization on productivity, physiological characteristics, and seed yield and quality in low-phytate soybeans. To address this knowledge gap, studies were conducted with a low-phytate line and two normal-phytate cultivars from western Japan when grown under high- and low-P fertilization. The whole plant dry weight, leaf photosynthesis, dinitrogen fixation, and nodule dry weight at the flowering stage were higher in the higher P application level, but were not different between the low-phytate line and normal-phytate cultivars. As expected, seed yield was higher in the higher level of P application for all lines. Notably, it was higher in the low-phytate line as compared with the normal-phytate cultivars at both levels of fertilizer P. The total P concentration in the seeds of the low-phytate line was the same as that of the normal-phytate cultivars, but the phytate P concentration in the low-phytate line was about 50% less than that of the normal-phytate cultivars. As a result the molar ratio of phytic acid to Zn, Fe, Mn, and Cu in seed were also significantly lower in the low-phytate line. From these results, it can be concluded that growth after germination, leaf photosynthesis, nitrogen fixation, yield and seed quality were not less in the low-phytate soybean line as compared with two unrelated normal-phytate cultivars currently grown in Japan, and that low-phytate soybeans may improve the bioavailability of microelements.

Phytates are mixed cationic salts of phytic acid formed by sequential phosphorylation of myo-inositol. Phytate is a phosphorus storage molecule essential for cellular and hormonal signalling in plants but exhibits anti-nutrient properties in animals. Low phytate plants have reduced basal resistance towards microbial pathogens and reduced tolerance to environmental stresses resulting in compromised yields. We report that three mutant lines of Arabidopsis thaliana, each with altered expression of myo-inositol-3-phosphate synthase (MIPS) isoforms, show altered susceptibility towards infection by the beet cyst nematode, Heterodera schachtii. Disruption of MIPS2 accompanied by increased MIPS1 expression results in reduced cyst nematode infection. Lack of MIPS3 resulted in a higher proportion of second-stage juveniles in the early phase of infection, suggesting delayed nematode development on mips3 mutants. Reduction in total phytate by down-regulation of the inositol polyphosphate kinase gene (IPK1) resulted in higher susceptibility to cyst nematode infection but a reduced average size of adult females. However, specific down-regulation of MIPS gene expression reduces susceptibility as myo-inositol is required to feed into the myo-inositol oxygenase pathway, which has an important role in development of the cyst nematode feeding site.

The pollution of surface waters by excessive biogenic elements, especially phosphorus, is a highly topical subject. Fishery management on ponds may be one of the potential sources of phosphorus in waters. Cyprinid fish generally have a very poor digestion of the phosphorus contained in the plant‑based components of feeds. In them, phosphorus is deposited in the form of phytic acid which is almost indigestible for cyprinids. The conducted testing was focused on affecting the digestibility of phosphorus contained in plant‑based feeds. Two of the cereals most frequently grown in the Czech Republic were tested, namely, wheat and barley. Control feeds were varieties commonly grown in our country, i.e. Vánek and Bojos. Furthermore, we used special cereal mutant lines with a decreased content of the phytic acid, JS‑12/IDO 563 and M955. The test results showed that when using the low‑phytate wheat line, the digestibility of phosphorus was increased by up to 11.21 % (P < 0.01); and by 5.89 % (P < 0.05) in the case of barley. Both low‑phytate lines of the cereals used significantly affect phosphorus digestibility and decrease the loading of the environment with phosphorus. When using the low‑phytate wheat line, a significant effect (P < 0.05) was found on the fat content in the fish body compared to the control variety but also compared to the low‑phytate barley line. No significant effect was found comparing both control varieties and comparing the barley varieties mutually.

Phytate is the major storage form of phosphorus in seeds of soybeans. Because phytate chelates mineral cations including calcium, iron, and zinc, these mixed salts are often excreted by non-ruminant animals such as humans, swine, poultry, and fish. While this causes iron and zinc deficiencies, phytate is also considered a water pollutant due to the excess phosphorus excreted in animal waste. These negative environmental and nutritional effects, create a need for low phytate soybeans. While several low phytate soybean lines have been developed, a major drawback is the reduced seedling emergence of these lines resulting in low yields. Therefore, understanding the genetic and molecular bases of the low emergence trait in relation to seed phytate content in major crops such as soybean is of great economic importance. This PhD project worked towards the long term goal of developing low phytate soybean cultivars with good seedling emergence and high-yield. This dissertation focused on metabolomic differences between low and normal phytate lines and how these could relate to the low emergence phenotype. The genetic materials used here include four near isogenic lines that differ in mutations in two multi drug resistance-associated proteins (MRPs). Only the line with both mutations was low phytate. The phytate levels, field- and lab-based emergence rates were determined for these lines, their parents and a control line through replicated field experiments for three consecutive years. The emergence rates of the low phytate lines were not always reduced. This showed that the environment the seeds were produced in is highly important, especially when breeding and commercially growing low phytate lines. A protocol was developed for successful metabolomic discrimination of these closely related soybean lines. The polar and non-polar metabolite profiles were determined using ultra performance liquid chromatography mass spectrometry and metabolomic differences between the low and normal phytate lines were identified. The low phytate double mutant did not contain C22 glucose terminated Group A soyasaponins and almost exclusively contained C22 xylose terminated Group A soyasaponins (A4, A5 and A6). Compared to the normal phytate lines, the low phytate soybean line showed a higher concentration of storage lipids (triacylglycerols and diacylglycerols) and certain phospholipids.
Ph. D.

Los cereales son empleados como dieta complementaria a la lactancia materna a partir del 4º mes ya que suministra nutrientes esenciales (especialmente hidratos de carbono, proteínas, minerales y vitaminas (particularmente tiamina). Los alimentos infantiles elaborados a partir de harinas procedentes de cereales pueden presentar compromiso en la biodisponibilidad de determinados minerales, por ello, es de gran importancia tratar de establecer los tratamientos tecnológicos necesarios para que la utilización de estos nutrientes esenciales sea la máxima. Se ha comprobado que el método más sencillo y eficaz de conseguir la eliminación del ácido fítico, es la adición de fitasa exógena.
Dietary minerals intake is of interest of human beings in general, but particularly for infant and young children in the first year of life, when growth is accelerated. Insuficient mineral intake in this period, mainly of iron, calcium and zinc, is responsible for diseases such as anaemia, rickets, osteoporosis or inmune diseases. Cereals are introduced to infants at the age of four to six months to supplement breastmilk and follow-on formula, since this is a period of rapid growth and development. Phytic acid (myoinositol hexa-phosphoric acid, IP6) is the major phosphorus storage compound of most seeds and cereal grains, and it has a strong ability to chelate multivalent metal ions, specially iron, zinc, and calcium.Based on this knowledge, complete phytate degradation by means of technological treatments is desirable, in order to overcome its negative effects on mineral bioavailability. Food processing-such as cooking, bread-making and fermentation-is known to reduce phytic acid content. However, the bioavailability of minerals can be considerably increased by dephytinization adding an exogenous phytase.

Phytate is the major storage form of phosphorus in crop seeds, but is not well digested by humans and non-ruminant animals. In addition, phytate chelates several essential micronutrients which are also excreted contributing to phosphorus pollution in the environment. This research was aimed at the biochemical and molecular characterization of two low phytate pea mutant lines, 1-150-81 and 1-2347-144 developed at the Crop Development Centre, University of Saskatchewan in collaboration with Dr. Victor Raboy, USDA, Idaho. Low phytic acid (lpa) crops are low in phytic acid and high in inorganic phosphorus (Pi). In Study I, two lpa pea genotypes, 1-150-81, 1-2347-144, and their progenitor CDC Bronco were evaluated in field trials for two years. The lpa genotypes did not significantly differ from CDC Bronco in all agronomic traits assessed except for lower seed weight and grain yield. The concentration of IP6 at 14 DAF was not significantly different among CDC Bronco, 1-150-81 and 1-2347-144. However, the concentrations of IP6 among CDC Bronco, 1-150-81 and 1-2347-144 started to differ significantly from 21 DAF onwards. The lpa genotypes 1-150-81 and 1-2347-144 showed 65% and 60% reduction in IP6, respectively, when compared to their progenitor CDC Bronco at 49 DAF. The Pi concentrations between the lpa genotypes were similar and significantly higher than CDC Bronco from 21 DAF to 49 DAF. At 49 DAF, 1-150-81 and 1-2347-144 were 72 and 84% higher in Pi, respectively, than CDC Bronco. The total P concentration was similar in lpa genotypes and CDC Bronco throughout the seed development. This study elucidated the rate and accumulation of phosphorus compounds in lpa genotypes. In Study II, aiming at understanding the genetic basis of the lpa mutation in pea lines 1-150-81 and 1-2347-144, a 1530 bp open reading frame of myo-inositol phosphate synthase gene (MIPS) was amplified from CDC Bronco and the lpa genotypes. Sequencing results showed no difference in coding sequence in MIPS between CDC Bronco and lpa genotypes. Transcript levels of both MIPS and myo-inositol tetrakisphosphate1-kinase (ITPK1) were relatively lower at 49 DAF than at 14 DAF for CDC Bronco and lpa lines. There was no difference in expression level of both MIPS and ITPK1 between CDC Bronco and the lpa genotypes at 49 DAF. The data demonstrated that mutation in MIPS was not responsible for lpa trait in pea. Study III was aimed at developing a single nucleotide polymorphism (SNP) based genetic linkage map and mapping genomic regions associated with phytic acid-phosphorus (PA-P) concentration using PR-15 recombinant inbred lines (RILs) derived from a cross between a low phytate (lpa) pea genotype, 1-2347-144 and normal phytate pea cultivar CDC Meadow. A total of 163 RILs were genotyped using 1536 SNP markers in an Illumina GoldenGate array. Three hundred and sixty seven polymorphic SNP markers, ordered into 7 linkage groups (LGs), generated a linkage map with a total length of 437.2 cM. The phytic acid locus was mapped on to LG5. A quantitative trait locus (QTL) for iron bioavailability was mapped on to the same location in LG5 as phytic acid concentration. Potential benefits arising out of this research include improved bioavailability of phosphorus, iron and zinc in foods and feeds, less phosphorus excretion and environmental pollution and a saving in feed costs.

Soybean is one of the leading oilseed crops in the world and is showing a remarkable surge in its utilization in formulating animal feeds and supplements. Its dietary consumption, however, is incongruent with its existing industrial demand due to the presence of anti-nutritional factors in sufficiently large amounts. Phytic acid, in particular, raises concern as it causes a concomitant loss of indigestible complexed minerals and charged proteins in the waste and results in reduced mineral bioavailability in both livestock and humans. Reducing the seed phytate level thus seems indispensable to overcome the nutritional menace associated with soy grain consumption. To conceive our objective, we designed and expressed an inositol poly phosphate 6-/3-/5-kinase gene-specific intron-containing self-complementary hairpin RNAi construct in the seeds of Pusa-16 soybean cultivar. Inositol polyphosphate 6-/3 /5-kinase is a multifunctional kinase which catalyzes the formation of inositol pentakisphosphate, the immediate substrate of PA biosynthesis. Due to a broad range of substrate specificity, it plays a pivotal role in regulating the cellular phytic acid turnover and is therefore conceived to be the most appropriate target for effective seed phytate reduction. We subsequently conducted a genotypic, phenotypic, and biochemical analysis of the developed putative transgenic populations and found low phytic acid levels, moderate accumulation of inorganic phosphate and elevated mineral content in some lines. These low phytic acid lines did not show any reduction in seedling emergence and displayed an overall good agronomic performance, thus, proving to be a successful attempt.

Bones are multifunctional passive organs of movement that supports soft tissue and directly attached muscles. They also protect internal organs and are a reserve of calcium, phosphorus and magnesium. Each bone is covered with periosteum, and the adjacent bone surfaces are covered by articular cartilage. Histologically, the bone is an organ composed of many different tissues. The main component is bone tissue (cortical and spongy) composed of a set of bone cells and intercellular substance (mineral and organic), it also contains fat, hematopoietic (bone marrow) and cartilaginous tissue. Bones are a tissue that even in adult life retains the ability to change shape and structure depending on changes in their mechanical and hormonal environment, as well as self-renewal and repair capabilities. This process is called bone turnover. The basic processes of bone turnover are: • bone modeling (incessantly changes in bone shape during individual growth) following resorption and tissue formation at various locations (e.g. bone marrow formation) to increase mass and skeletal morphology. This process occurs in the bones of growing individuals and stops after reaching puberty • bone remodeling (processes involve in maintaining bone tissue by resorbing and replacing old bone tissue with new tissue in the same place, e.g. repairing micro fractures). It is a process involving the removal and internal remodeling of existing bone and is responsible for maintaining tissue mass and architecture of mature bones. Bone turnover is regulated by two types of transformation: • osteoclastogenesis, i.e. formation of cells responsible for bone resorption • osteoblastogenesis, i.e. formation of cells responsible for bone formation (bone matrix synthesis and mineralization) Bone maturity can be defined as the completion of basic structural development and mineralization leading to maximum mass and optimal mechanical strength. The highest rate of increase in pig bone mass is observed in the first twelve weeks after birth. This period of growth is considered crucial for optimizing the growth of the skeleton of pigs, because the degree of bone mineralization in later life stages (adulthood) depends largely on the amount of bone minerals accumulated in the early stages of their growth. The development of the technique allows to determine the condition of the skeletal system (or individual bones) in living animals by methods used in human medicine, or after their slaughter. For in vivo determination of bone properties, Abstract 10 double energy X-ray absorptiometry or computed tomography scanning techniques are used. Both methods allow the quantification of mineral content and bone mineral density. The most important property from a practical point of view is the bone’s bending strength, which is directly determined by the maximum bending force. The most important factors affecting bone strength are: • age (growth period), • gender and the associated hormonal balance, • genotype and modification of genes responsible for bone growth • chemical composition of the body (protein and fat content, and the proportion between these components), • physical activity and related bone load, • nutritional factors: – protein intake influencing synthesis of organic matrix of bone, – content of minerals in the feed (CA, P, Zn, Ca/P, Mg, Mn, Na, Cl, K, Cu ratio) influencing synthesis of the inorganic matrix of bone, – mineral/protein ratio in the diet (Ca/protein, P/protein, Zn/protein) – feed energy concentration, – energy source (content of saturated fatty acids - SFA, content of polyun saturated fatty acids - PUFA, in particular ALA, EPA, DPA, DHA), – feed additives, in particular: enzymes (e.g. phytase releasing of minerals bounded in phytin complexes), probiotics and prebiotics (e.g. inulin improving the function of the digestive tract by increasing absorption of nutrients), – vitamin content that regulate metabolism and biochemical changes occurring in bone tissue (e.g. vitamin D3, B6, C and K). This study was based on the results of research experiments from available literature, and studies on growing pigs carried out at the Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences. The tests were performed in total on 300 pigs of Duroc, Pietrain, Puławska breeds, line 990 and hybrids (Great White × Duroc, Great White × Landrace), PIC pigs, slaughtered at different body weight during the growth period from 15 to 130 kg. Bones for biomechanical tests were collected after slaughter from each pig. Their length, mass and volume were determined. Based on these measurements, the specific weight (density, g/cm3) was calculated. Then each bone was cut in the middle of the shaft and the outer and inner diameters were measured both horizontally and vertically. Based on these measurements, the following indicators were calculated: • cortical thickness, • cortical surface, • cortical index. Abstract 11 Bone strength was tested by a three-point bending test. The obtained data enabled the determination of: • bending force (the magnitude of the maximum force at which disintegration and disruption of bone structure occurs), • strength (the amount of maximum force needed to break/crack of bone), • stiffness (quotient of the force acting on the bone and the amount of displacement occurring under the influence of this force). Investigation of changes in physical and biomechanical features of bones during growth was performed on pigs of the synthetic 990 line growing from 15 to 130 kg body weight. The animals were slaughtered successively at a body weight of 15, 30, 40, 50, 70, 90, 110 and 130 kg. After slaughter, the following bones were separated from the right half-carcass: humerus, 3rd and 4th metatarsal bone, femur, tibia and fibula as well as 3rd and 4th metatarsal bone. The features of bones were determined using methods described in the methodology. Describing bone growth with the Gompertz equation, it was found that the earliest slowdown of bone growth curve was observed for metacarpal and metatarsal bones. This means that these bones matured the most quickly. The established data also indicate that the rib is the slowest maturing bone. The femur, humerus, tibia and fibula were between the values of these features for the metatarsal, metacarpal and rib bones. The rate of increase in bone mass and length differed significantly between the examined bones, but in all cases it was lower (coefficient b <1) than the growth rate of the whole body of the animal. The fastest growth rate was estimated for the rib mass (coefficient b = 0.93). Among the long bones, the humerus (coefficient b = 0.81) was characterized by the fastest rate of weight gain, however femur the smallest (coefficient b = 0.71). The lowest rate of bone mass increase was observed in the foot bones, with the metacarpal bones having a slightly higher value of coefficient b than the metatarsal bones (0.67 vs 0.62). The third bone had a lower growth rate than the fourth bone, regardless of whether they were metatarsal or metacarpal. The value of the bending force increased as the animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. The rate of change in the value of this indicator increased at a similar rate as the body weight changes of the animals in the case of the fibula and the fourth metacarpal bone (b value = 0.98), and more slowly in the case of the metatarsal bone, the third metacarpal bone, and the tibia bone (values of the b ratio 0.81–0.85), and the slowest femur, humerus and rib (value of b = 0.60–0.66). Bone stiffness increased as animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. Abstract 12 The rate of change in the value of this indicator changed at a faster rate than the increase in weight of pigs in the case of metacarpal and metatarsal bones (coefficient b = 1.01–1.22), slightly slower in the case of fibula (coefficient b = 0.92), definitely slower in the case of the tibia (b = 0.73), ribs (b = 0.66), femur (b = 0.59) and humerus (b = 0.50). Bone strength increased as animals grew. Regardless of the growth point tested, bone strength was as follows femur > tibia > humerus > 4 metacarpal> 3 metacarpal> 3 metatarsal > 4 metatarsal > rib> fibula. The rate of increase in strength of all examined bones was greater than the rate of weight gain of pigs (value of the coefficient b = 2.04–3.26). As the animals grew, the bone density increased. However, the growth rate of this indicator for the majority of bones was slower than the rate of weight gain (the value of the coefficient b ranged from 0.37 – humerus to 0.84 – fibula). The exception was the rib, whose density increased at a similar pace increasing the body weight of animals (value of the coefficient b = 0.97). The study on the influence of the breed and the feeding intensity on bone characteristics (physical and biomechanical) was performed on pigs of the breeds Duroc, Pietrain, and synthetic 990 during a growth period of 15 to 70 kg body weight. Animals were fed ad libitum or dosed system. After slaughter at a body weight of 70 kg, three bones were taken from the right half-carcass: femur, three metatarsal, and three metacarpal and subjected to the determinations described in the methodology. The weight of bones of animals fed aa libitum was significantly lower than in pigs fed restrictively All bones of Duroc breed were significantly heavier and longer than Pietrain and 990 pig bones. The average values of bending force for the examined bones took the following order: III metatarsal bone (63.5 kg) <III metacarpal bone (77.9 kg) <femur (271.5 kg). The feeding system and breed of pigs had no significant effect on the value of this indicator. The average values of the bones strength took the following order: III metatarsal bone (92.6 kg) <III metacarpal (107.2 kg) <femur (353.1 kg). Feeding intensity and breed of animals had no significant effect on the value of this feature of the bones tested. The average bone density took the following order: femur (1.23 g/cm3) <III metatarsal bone (1.26 g/cm3) <III metacarpal bone (1.34 g / cm3). The density of bones of animals fed aa libitum was higher (P<0.01) than in animals fed with a dosing system. The density of examined bones within the breeds took the following order: Pietrain race> line 990> Duroc race. The differences between the “extreme” breeds were: 7.2% (III metatarsal bone), 8.3% (III metacarpal bone), 8.4% (femur). Abstract 13 The average bone stiffness took the following order: III metatarsal bone (35.1 kg/mm) <III metacarpus (41.5 kg/mm) <femur (60.5 kg/mm). This indicator did not differ between the groups of pigs fed at different intensity, except for the metacarpal bone, which was more stiffer in pigs fed aa libitum (P<0.05). The femur of animals fed ad libitum showed a tendency (P<0.09) to be more stiffer and a force of 4.5 kg required for its displacement by 1 mm. Breed differences in stiffness were found for the femur (P <0.05) and III metacarpal bone (P <0.05). For femur, the highest value of this indicator was found in Pietrain pigs (64.5 kg/mm), lower in pigs of 990 line (61.6 kg/mm) and the lowest in Duroc pigs (55.3 kg/mm). In turn, the 3rd metacarpal bone of Duroc and Pietrain pigs had similar stiffness (39.0 and 40.0 kg/mm respectively) and was smaller than that of line 990 pigs (45.4 kg/mm). The thickness of the cortical bone layer took the following order: III metatarsal bone (2.25 mm) <III metacarpal bone (2.41 mm) <femur (5.12 mm). The feeding system did not affect this indicator. Breed differences (P <0.05) for this trait were found only for the femur bone: Duroc (5.42 mm)> line 990 (5.13 mm)> Pietrain (4.81 mm). The cross sectional area of the examined bones was arranged in the following order: III metatarsal bone (84 mm2) <III metacarpal bone (90 mm2) <femur (286 mm2). The feeding system had no effect on the value of this bone trait, with the exception of the femur, which in animals fed the dosing system was 4.7% higher (P<0.05) than in pigs fed ad libitum. Breed differences (P<0.01) in the coross sectional area were found only in femur and III metatarsal bone. The value of this indicator was the highest in Duroc pigs, lower in 990 animals and the lowest in Pietrain pigs. The cortical index of individual bones was in the following order: III metatarsal bone (31.86) <III metacarpal bone (33.86) <femur (44.75). However, its value did not significantly depend on the intensity of feeding or the breed of pigs.

Introdução: Espécies do gênero Zanthoxylum (Rutaceae) são conhecidas por apresentarem compostos químicas diversificados de elevado potencial farmacológico. Porém, apresentam dificuldades de propagação devido características recalcitrantes, justificando adotar técnicas de cultura de tecidos, como a micropropagação, para facilitar a propagação de Zanthoxylum tingoassuiba. Objetivos: Avaliar diferentes tipos de explantes, diferentes concentrações e tipos de reguladores de crescimento no desenvolvimento de protocolo para cultivo in vitro de Z.tingoassuiba. Material e Métodos: O experimento foi conduzido no Laboratório de Cultura de Tecido (CCA/UEMA). Como explantes, utilizaram-se sementes, provenientes da região Sul do Maranhão, no qual foram desinfestadas com Lysoform® (20 minutos), seguido de álcool etílico a 70% (2 minutos), hipoclorito de sódio (2% de cloro ativo) adicionando-se duas gotas de Tween® para cada 100mL (15 minutos), seguido de tríplice lavagem em água destilada autoclavada (2 minutos/cada). Após a desinfestação, realizou-se excisão nas sementes, para quebra da dormência física, com posterior inoculação em tudo de ensaio contendo 10mL de meio MS + sacarose (30g.L-1), mio-inositol (100mg.L-1), polivinilpirrolidona (PVP, 400mg.L-1), PPM® (1mL.L-1), glutamina (1g.L-1), arginina (1g.L-1), asparagina (500mg.L-1), e combinações de 6-benzilaminopurina (0, 7,5, 15, 22,5μM) com ácido naftalenoacético (0, 1, 2μM) solidificado com Phytagel® (1,8g.L-1) e pH ajustado para 5,7 antes de autoclavagem. O experimento foi conduzido em Delineamento Inteiramente Casualizado, 12 tratamentos, seis repetições, cada uma com uma semente/tubo. Aos 50 dias foram avaliadas porcentagem de germinação e oxidação. Resultados: Para porcentagem de germinação foi possível observar destaque nos tratamentos MS + 0μM BAP + 1μM ANA (63,33%) e MS + 15μM BAP + 1μM ANA (63,33%), sendo superiores significativamente apenas quando comparado a MS + 15μM BAP + 2μM ANA (23,33%), MS + 15μM BAP + 0μM ANA (13,33%) e MS + 22,5μM BAP + 1μM ANA (3,33%). Para porcentagem de oxidação, a partir dos dez dias foi crescente, chegando a 43,40% aos 50 dias. Conclusão: O meio de cultura mais indicado para induzir a germinação foi MS + 0μM de BAP + 1μM de ANA e MS + 15μM de BAP + 1μM de ANA, porém, a oxidação ao longo da permanência em meio de cultura foi o maior desafio para alcançar sucesso pleno na micropropagação de Z.tingoassuiba.