Avaliação do desempenho ao primeiro parto de fêmeas Nelore e F1

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação do peso à desmama e do ganho médio de peso de bezerros cruzados, no estado do Mato Grosso do Sul

O objetivo deste trabalho foi comparar o desempenho de bezerros mestiços de diferentes grupos genéticos até a desmama. Informações de 3631 bezerros F1 filhos de vacas Nelore com touros Aberdeen Angus, Brangus, Brangus (pelagem vermelha), Canchim, Gelbvieh, Nelore e Simental foram usadas (Grupo 1). Foram usadas também informações de 1896 bezerros de fêmeas Nelore com touros das raças supracitadas e de fêmeas F1 retrocruzadas com touros Gelbvieh e Nelore (Grupo 2). Os pesos à desmama foram ajustados aos 230 dias (PD230) e aos 240 dias (PD240), para os grupos 1 e 2, respectivamente, e o ganho médio diário até a desmama (GMD), para ambos os grupos, foi determinado. O modelo matemático usado nas análises pelo método de quadrados mínimos incluiu os efeitos fixos de grupo contemporâneo (GC), grupo genético do bezerro (GG) e idade do bezerro e idade da vaca. GC e GG influenciaram as características estudadas em ambos os grupos. A idade do bezerro não influiu significativamente no PD230 e GMD no Grupo 1, mas no Grupo 2 foi significativa para PD240 e GMD. A idade da vaca ao parto influenciou as características estudadas tanto no Grupo 1 como no Grupo 2. Os animais cruzados foram superiores aos puros Nelore em ambos os grupos. Foi obtido, a partir do Grupo 2, um terceiro conjunto de dados, Grupo 3, contendo os produtos do retrocruzamento de fêmeas F1, Nelore-Gelbvieh, com touros Gelbvieh e Nelore, contendo 722 informações de PD240 e GMD. Nesse arquivo foram estimados os efeitos aditivos direto e materno e heterótico individual. Apenas o efeito heterótico individual foi significativo.

Levels of replacing corn by cassava starch on performance and carcass characteristics of bulls finished in feedlot

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Técnica dos isótopos estáveis para determinar o turnover de carbono nas fezes, no sangue e plasma de bovinos jovens confinados

Pós-graduação em Zootecnia - FMVZ

Prospecção de genes relacionados com a resistência ao carrapato Rhipicephalus (Boophilus) microplus em bovinos de corte

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise exploratória de experimentos com bovinos terminados em confinamento

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Consumo e digestibilidade de dietas contendo fontes energéticas associadas ao farelo de girassol ou ureia em novilhos confinados

Objetivou-se avaliar o consumo e a digestibilidade total e parcial de dietas utilizando milho, casca de soja e polpa cítrica associados ao farelo de girassol ou ureia em novilhos confinados. Foram utilizados quatro novilhos ½ Aberdeen Angus vs. ½ Nelore, providos de cânulas no rúmen e duodeno, com 18 meses de idade e 360 kg de peso médio inicial. As dietas foram constituídas por duas fontes energéticas (milho grão e polpa cítrica) associadas a duas fontes nitrogenadas (ureia e farelo de girassol), totalizando quatro tratamentos, numa proporção volumoso:concentrado de 40:60. O delineamento utilizado foi o quadrado latino com quatro tratamentos e quatro períodos de 21 dias cada. O consumo médio diário de matéria seca foi influenciado (p < 0,05) entre as dietas, e o maior valor foi atribuído à dieta milho e farelo de girassol. A digestibilidade aparente de todos os componentes, exceto da proteína bruta, foi maior (p < 0,05) para as dietas com polpa cítrica. Não houve efeito (p > 0,05) entre as dietas para as digestibilidades ruminal e intestinal. A utilização de coprodutos na alimentação animal não prejudicou a digestibilidade das dietas, sendo indicados como ingredientes de elevado potencial de utilização em dietas para bovinos de corte.

Quantitative study of Babesia bovis infection in beef cattle from Sao Paulo state, Brazil

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

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

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Retorno à atividade reprodutiva de touro angus após fimose traumática com obliteração parcial da luz prepucial: relato de caso

The main disturbs affecting the genital segment of bulls are balanitis, phimosis and preputial injuries, abscesses or prolapses, resulting in decreased libido or mating ability. One case of traumatic phimosis with partial obliteration of preputial lumen is reported in Aberdeen Angus bull. During anamnesis, it was reported that the animal was unable to expose the penis and presented increased penile and preputial volume of unknown etiology after being submitted to a libido test. During clinical examination, a firm preputial mass of 15 cm in diameter was observed in the middle third of the prepuce and stenosis of preputial lumen was detected approximately 17 cm from the preputial orifice. Reconstructive surgery was the chosen therapy, with amputation of the affected foreskin portion. A skin segment of about 12 cm and affected mucosal portion were removed. Postoperative therapy consisted of dressing with chlorhexidine digluconate based ointment, povidone iodine and topical insect repellent (cypermethrin and carbamyl), systemic antibiotic therapy with benzathine penicillin (30,000 IU / kg, repeated after 48 hours) and anti-inflammatory therapy with flunixin meglumine (2 , 0 mg / kg SID) for three days. After twenty days, semen was collected by massage of the accessory glands. The ejaculate volume was 3 mL, with 200x106 spermatozoa / mL, white color, "suis generis" odor, 88% of motile sperm, 64% of progressively motile sperm and 82% of rapid sperm. Thus, the chosen surgical treatment was effective to correct the pathology and reintroduce the animal into reproductive activity

Estudo de associação genômica e perfil de expressão gênica de folículos antrais em novilhas das raças nelore e angus, associadas ao fenótipo de alta e baixa população folicular

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

Random regression analyses using B-spline functions to model growth of Nellore cattle

The objective of this study was to estimate (co)variance components using random regression on B-spline functions to weight records obtained from birth to adulthood. A total of 82 064 weight records of 8145 females obtained from the data bank of the Nellore Breeding Program (PMGRN/Nellore Brazil) which started in 1987, were used. The models included direct additive and maternal genetic effects and animal and maternal permanent environmental effects as random. Contemporary group and dam age at calving (linear and quadratic effect) were included as fixed effects, and orthogonal Legendre polynomials of age (cubic regression) were considered as random covariate. The random effects were modeled using B-spline functions considering linear, quadratic and cubic polynomials for each individual segment. Residual variances were grouped in five age classes. Direct additive genetic and animal permanent environmental effects were modeled using up to seven knots (six segments). A single segment with two knots at the end points of the curve was used for the estimation of maternal genetic and maternal permanent environmental effects. A total of 15 models were studied, with the number of parameters ranging from 17 to 81. The models that used B-splines were compared with multi-trait analyses with nine weight traits and to a random regression model that used orthogonal Legendre polynomials. A model fitting quadratic B-splines, with four knots or three segments for direct additive genetic effect and animal permanent environmental effect and two knots for maternal additive genetic effect and maternal permanent environmental effect, was the most appropriate and parsimonious model to describe the covariance structure of the data. Selection for higher weight, such as at young ages, should be performed taking into account an increase in mature cow weight. Particularly, this is important in most of Nellore beef cattle production systems, where the cow herd is maintained on range conditions. There is limited modification of the growth curve of Nellore cattle with respect to the aim of selecting them for rapid growth at young ages while maintaining constant adult weight.

Congenital syndactyly in cattle: four novel mutations in the low density lipoprotein receptor-related protein 4 gene (LRP4)

BACKGROUND: Isolated syndactyly in cattle, also known as mulefoot, is inherited as an autosomal recessive trait with variable penetrance in different cattle breeds. Recently, two independent mutations in the bovine LRP4 gene have been reported as the primary cause of syndactyly in the Holstein and Angus cattle breeds. RESULTS: We confirmed the previously described LRP4 exon 33 two nucleotide substitution in most of the affected Holstein calves and revealed additional evidence for allelic heterogeneity by the identification of four new LRP4 non-synonymous point mutations co-segregating in Holstein, German Simmental and Simmental-Charolais families. CONCLUSION: We confirmed a significant role of LRP4 mutations in the pathogenesis of congenital syndactyly in cattle. The newly detected missense mutations in the LRP4 gene represent independent mutations affecting different conserved protein domains. However, the four newly described LRP4 mutations do still not explain all analyzed cases of syndactyly.

Brain Regulation of Growth in Beef Calves

Small peptide hormones produced in the lower part of the brain (hypothalamus) regulate episodic and basal secretion of hormones from the anterior pituitary gland that affect metabolism and growth in cattle. This study focused on long-term growth in young calves subjected to hypophysectomy (HYPOX), hypophyseal stalk transection (HST), and sham operation control (SOC). Crossbred (Hereford x Aberdeen Angus) and Hereford, and Aberdeen Angus calves were HYPOX (n = 5), HST (n = 5), or SOC (n = 8) at 146 days of age, whereas another group was HST (n = 5) or SOC (n = 7) at 273 days of age. Body weight was determined every 21 days from birth to 1008 days of age. From day 146-1008, growth was arrested (P < 0.001) in HYPOX (0.06 kg/day) compared with SOC (0.50 kg/day) calves. Growth continued but at a significantly lower rate (P < 0.05) in calves HST at 146 days (0.32 kg/day) and 273 days (0.32 kg/day) compared with SOC (0.50 kg/day). Although episodic growth hormone (GH) secretion was abolished and peripheral blood serum GH concentration remained consistently lower in HST calves (2.4 ng/ml) than in the SOC (5.5 ng/ml; P < 0.01), the calves continued to grow throughout 1008 days. Peripheral serum thyroid stimulating hormone (TSH) concentration was less (P < 0.05) in HST compared with SOC calves. There was an abrupt decrease (P < 0.001) in serum thyroxine (T4) (4-fold) and triiodothyronine (T3) (3-fold) concentration after surgery that remained to 360 days in HST compared with SOC calves. At sacrifice, pituitary gland weight was markedly reduced (P < 0.001) in HST (0.18 g/100 kg body weight) compared with SOC (0.55 g/100 kg body weight) calves. Histological examination of pituitary glands from HST calves indicated the persistence of secretory GH and TSH cells in the same areas of the anterior pituitary gland as SOC calves. Coronal sections of the gland revealed GH and TSH secreting cells in HST calves that were similar to the controls. These results indicate that long-term growth continues, but at a slower rate, after hypophyseal stalk transection of immature calves in spite of complete abolition of episodic GH secretion and consistently decreased basal secretion of GH, TSH, T4, and T3 compared with sham-operated animals. Growth was abolished after hypophysectomy of immature calves in which circulating GH and TSH was undetectable.

Gene ... The universal calf,

Revised reprint of a series of articles prepared especially for publication in The Aberdeen-Angus journal.