Morfometria e compactação da cromatina espermática de touros Nelore de acordo com a idade e sua influência na produção de embriões in vitro

Pós-graduação em Medicina Veterinária - FCAV

Uso de extratos vegetais, vitaminas e sua associação sobre o desempenho, temperamento e qualidade de carne de bovinos nelore confinados com dieta de alto grão

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Non-synonymous mutations mapped to chromosome X associated with andrological and growth traits in beef cattle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Association of ADIPOQ, OLR1 and PPARGC1A gene polymorphisms with growth and carcass traits in Nelore cattle

In beef cattle farming, growth and carcass traits are important for genetic breeding programs. Molecular markers can be used to assist selection and increase genetic gain. The ADIPOQ, OLR1 and PPARGC1A genes are involved in lipid synthesis and fat accumulation in adipose tissue. The objective of this study was to identify polymorphisms in these genes and to assess the association with growth and carcass traits in Nelore cattle. A total of 639 animals were genotyped by PCR-RFLP for rs208549452, rs109019599 and rs109163366 in ADIPOQ, OLR1 and PPARGC1A gene, respectively. We analyzed the association of SNPs identified with birth weight, weaning weight, female yearling weight, female hip height, male yearling weight, male hip height, loin eye area, rump fat thickness, and backfat thickness. The OLR1 marker was associated with rump fat thickness and weaning weight (P < 0.05) and the PPARGC1 marker was associated with female yearling weight.

Histologia e histomorfometria do retículo de bovino no período pré-natal

The development of the stomach of ruminants requires further studies because it is a complex process. Therefore, was analyzed the histology and histomorphometry of reticulum at each gestation period. Samples of Nelore fetuses (Bos taurus indicus) was divided in 5 groups: 1 - fetuses at 9 to 15 weeks (8 to 21cm) of gestation, 2 - fetuses at 16 to 22 weeks (23 to 37cm) 3 - fetuses at 23 to 29 weeks (40 to 58cm), 4 - fetuses at 30 to 36 weeks (61 to 77cm) and 5 - fetuses at 37-43 weeks (79 to 88cm). The histological sections were stained with hematoxylin and eosin and Mallory's trichrome and examined by light microscopy. In group 1, the fetuses with 11 cm, showed mucosal projections that eventually become primary crests, lamina propria and submucosa are fused and external and internal muscular and similar. At 16.5 inches, the primary crests had lamina propria and at 18.5 cm, appeared connections between the ridges. In group 2, at 31 cm started epithelial involvement around the crests. In group 3, the fetuses of 42 cm revealed the first secondary papillae and muscular mucosa in the upper portion of the primary crests. Thereafter, it was increased epithelial due to its positioning around the crests, thickening of the lamina propriasubmucosa, muscular layer, especially the internal muscular and serosa. It was concluded that the most visible changes occur in fetuses belonging to the first 3 groups, measurements for the epithelium, muscle layer and total wall were increasing and the other analyzed layers showed variations during fetal development.

Correlações entre escores visuais e características produtivas em prova de ganho de peso de bovinos da raça Nelore Mocha

The objective was evaluate the phenotypic correlations among visual scores, performance traits and scrotal circumference of the polled Nelore cattle performance tests. Animals of the fifth, sixth, seventh official performance test in pasture were analysed. At the end of each test period the following measures were taken: adjusted weight to 550 days, gain weight, visual score (body structure; precocity and muscle) and scrotal circumference. The musculature, precocity and body structure showed significant positive correlations (P <0.01) with gain weight, adjusted average daily weight to 550 days, scrotal circumference and chest circumference. However, only hip height showed a significant positive correlation with muscularity. Therefore, in polled Nelore cattle, regards to performance test in pasture, the visual scores show positive correlation with the performance traits and scrotal circumference, showing that visual scores is important tool in the polled Nelore Cattle performance test.

Desenvolvimento do rúmen de bovinos no período pré-natal

The development of the domestic mammals’ stomach is a complex process, especially in ruminants. The objective of this research was to perform the analysis of structures of this organ during prenatal period. Samples of Nelore fetuses rumen (Bos Taurus indicus) were divided into five groups: 1 - fetuses with 9 to 15 weeks (8 to 21cm) of gestation, 2 - fetuses with 16 to 22 weeks (23 to 37cm), 3 - fetuses at 23 to 29 weeks (40 to 58cm) 4 - fetuses with 30 to 36 weeks (61 to 77cm) and 5 - fetuses with 37 to 43 weeks (79 to 88cm). Sections were stained with Hematoxylin and eosin and Mallory's trichrome and examined at light microscope. In group 1, in fetuses with 11 cm, could be seen all the layers, mucosa with high epithelium and light cells, lamina propria fused with submucosa, the muscular layer was with two thin sublayers similar in thickness and serosa was thin too. With 13.5 cm, was observed the first irregularities in the mucosa with epithelium projections and lamina propria that will lead rumen papillae. With 16.5 cm there was differentiation of the lamina propria to the submucosa. In group 2, in fetuses with 28 cm were observed complete papillae. From this stage, the remaining groups, there was an increase in thickness of the epithelium, lamina propria, submucosal and muscular layer whit the inner sublayer more thicker than the external and serosa. It was concluded that the main variations occur in fetuses of groups 1 and 2, and after this phase, there is increased in thickness of all layers until the end of the pregnancy period.

Development of bovine abomasum in prenatal period

For this purpose, samples of Nelore fetus abomasum (Bos taurus indicus) were classified into five groups: 1 – fetuses with 9 to 15 weeks (8 to 21 cm) of gestation, 2 – fetuses with 16 to 22 weeks (23 to 37 cm), 3 – fetuses at 23 to 29 weeks (40 to 58 cm) 4 – fetuses with 30 to 36 weeks (61 to 77 cm) and 5 – fetuses with 37 to 43 weeks (79 to 88 cm). Histologic sections were stained with Hematoxylin and eosin, picrosirius and Mallory’s trichrome methods and examined under light microscopy. In fetus with 11 cm of length showed deep mucosa, wide folds and villi lined by single cylindrical epithelium, lamina propria, submucosa, muscular sublayers and serosa. Fetus with 13.5 cm, villi were evident and muscular layer of the mucosa was formed. At 16.5 cm, could be seen an increase in mucosa glands size and number. In fetus of 26 cm, showed gastric mucous glands at great number and ramifications. At 29 cm large folds, were observed. At 37 cm, showed glandular epithelium, muscular layer of the mucosa and muscular layer well development. Fetus with 42 cm, showed deep glands with corresponding mucous cells surrounding by thin lamina propria. It was concluded that the histomorphometric values of muscular layer and total abomasum wall were increased for all groups except for groups 4 and 5 which there was a decline of values, without presenting a significant difference and there was no continuous pattern of growth for other components of abomasum wall.

Estudo genômico do nível de infecção por Babesia bovis em bovinos da raça angus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Prospecção de assinaturas de seleção em regiões de QTL associadas com características reprodutivas em novilhas Nelore

Pós-graduação em Genética e Melhoramento Animal - FCAV

Fatty acid composition of the longissimus dorsi muscle in crossbred steers fed different sources of fatty acids

The objective of this study was to evaluate the fatty acid composition of the longissimus dorsi muscle in carcasses of 3/4 Bos taurus taurus 1/4 Bos taurus indicus steers fed different sources of fatty acids. Thirty-six steers aged 14 months, with a mean live weight of 320 kg, were fed the following diets for 96 days:1) control diet, containing no supplemental fat source; 2) CaSFA, diet containing 50 g calcium salts of fatty acids per kg total dry matter; 3) CS diet, containing 210 g cottonseed per kg total dry matter. The fatty acid composition of the longissimus dorsi muscle was determined by gas chromatography. No difference in slaughter weight, carcass weight, backfat thickness, or longissimus dorsi muscle area was observed between animals receiving the diets CaSFA and CS. Animals consuming the two fat-supplemented diets presented higher concentrations of oleic (C18:1), palmitic (C16:0) and stearic (C18:0) acids, corresponding to an average 80.76% of total fatty acids, and higher concentrations of vaccenic acid (C18:1 t11) in the muscle when compared with the control group. Supplementation of the diet of feedlot crossbred steers with CaSFA or cottonseed did not promote significant alterations in the lipid composition of the longissimus dorsi muscle.