Fatores genéticos e de meio no intervalo de partos de caprinos leiteiros

The kidding intervals (IDP) of dairy goats raised in Southeastern Brazil were studied to quantify the influence of environmental factors and to estimate genetic parameters by means of least squares (MMQ) and restricted maximum likelihood (REML). The data analyzed were obtained from five farms and three breeds (Alpine, Saanen, and Toggenburg). The overall mean and standard error of IDP, as estimated by MMQ, were 339 +/- 12.70 days. The interaction of year x season of parturition influenced IDP. In two of the years studied, goats kidding at the end of the kidding season showed a shorter IDP when compared to those that were kidding after the end of the season. A quadratic trend of IDP over years was observed across the three kidding periods. For the three seasons. IDP increased from 1986 until mid-1989 and decreased thereafter. The heritability and repeatability of IDP, as estimated by MMQ and REML, were: 0.046 +/- 0.071 and 0.103 +/- 0.043, and 0.00026 and 0.08411, respectively. These estimates indicate that little genetic gain can be expected from selection for this trait.

Desempenho em pastagens e características de carcaça da 16a progênie dos rebanhos Nelore, Guzerá e Caracu de Sertãozinho (sp)

Forty one young bulls of herds selected for 378 day's weight (W378), born in 1996, were finished on pastures of Panicum Maximum (Jacq.), Panicum Maximum (Jaq) cv. Tanzania 1 and Brachiaria brizantha (Hoschst) Stapf cv. Marandu at the Sertaozinho Experimental Station, São Paulo State, Brazil. The samples, representing the W378 mean for each herd, were composed by 11 Nellore Selection (NeS) and by 10 of each one of the groups Nelore Control (NeC), Guzera Selection (GuS) and Caracu (Ca). The slaughter was carried out when the animals were 824 days older, with a body condition score averaging 7.6, in a 1-9 scale. The minimum and maximum adjusted means for the main traits, including all groups, were: average weight daily gain, 406 (NeC) and 501 g (NeS); slaughter weight (SW), 446.8 (NeC) and 544.3 kg (NeS); carcass weight (CW), 249.8 (NeC) and 309.7 kg (NeS); dressing percentage (DP), 54.0 (GuS) and 56.3% (NeC and NeS). In the 9(th) - 11(th) rib section: muscle, 59.6 (NeC) and 65.2% (Ca); fat, 15.6 (Ca) and 21.4% (NeC); bone, 18.9 (NeC) and 20.2% (GuS); fat thickness (FT), 2.0 (Ca) and 4.2 mm (NeC); loin eye area, 65.6 (NeC) and 71.1 cm(2) (NeS and Ca); Warner-Bratzler shear force (SF), 4.5 (Ca) and 6.6 kg (GuS) and total cooking losses (TCL), 22.5 (NeC) and 24.9% (GuS). The selection for weight promoted higher SW and CW in the NeS group, without changing the DP, the physical composition of the rib, SF and TCL in the meat. However, there was lower FT compared to NeC. The GuS animals had intermediates SW and CW, compared to NeS and Ca and lower DP. The Ca animals presented higher muscle percentage, in the rib section, and also higher meat tenderness compared to the meat of the Zebu animals.

Fatores genéticos e de Meio na idade ao primeiro parto de caprinos leiteiros

Data on age at first kidding (IPP) were collected on seven farms in the Brazilian Southeastern region which explored breds. Least squares (LS) were used to evaluate the effects of environmental factors and to estimate variance components, and the derivative-free restricted maximum likelihood (DFREML) method was used to estimate the variance components of IPP and to genetically evaluate the goats used in the southest region of Brazil. The LS mean and standard error of IPP were 607.18 +/- 17.09 days. The interaction of year x kidding season had a significantly influenced IPP, indicating that management conditions varied among the seasons within each specific year, with a direct influence on body weight which is the main criterion adopted by farmers to decide when the animal is ready to breed. The effect of farm-breed combination influenced the IPP. The compararison among levels of farm-breed were done by cluster analysis. The results indicated that the individual goat management within each farm had a greater influence than breed, since goats of different breeds showed high and similar values on those farms having a high mean IPP. Heritability estimates obtained by LS using intraclass correlations among paternal half-sibs and those obtained by REML were 0.220 and 0.369, respectively.

Soroprevalência de Toxoplasma gondii em rebanhos caprinos no Estado de São Paulo

Four hundred forty-two serum samples were collected from dairy goats in seven regions of São Paulo State. These were tested for Toxoplasma gondii antibodies using the indirect immunofluorescent antibody test. Sixty-four (14,5%) serologically positive animals were found from all these goat farms studied.

Metano entérico de bovinos leiteiros em condições tropicais brasileiras

The objective of this work was to quantify methane (CH4) emission using the sulfur hexafluoride (SF6) tracer technique, by dairy cattle on pasture in Brazilian tropical field conditions. Measurements were performed in the rainy season, with Holstein and Holstein x Zebu crossbred, from lactating and dry cows and heifers grazing fertilized Tobiatã grass, and heifers grazing unfertilized Brachiaria grass. Methane and SF6 concentrations were determined by gas chromatograph. Methane emissions by lactating cows varied from 13.8 to 16.8 g/hour, by dry cows from 11.6 to 12.3 g/hour, by heifers grazing fertilized grass was 9.5 g/hour and by heifers grazing unfertilized grass varied from 7.6 to 8.3 g/hour or 66 to 72 kg/head/year. Methane emission per digestive dry matter intake (DMDI) varied from 42 to 69 g/kg DMDI for lactating cows, 46 to 56 g/kg for dry cows, 45 to 58 g/kg for heifers grazing fertilized grass and 58 to 62 g/kg for heifers in unfertilized grass pasture. The CH4 emission measured on dairy cattle feeding tropical grasses was higher than that observed for temperate climate conditions.

Identificação de espécies e genótipos de Cryptosporidium em bovinos leiteiros no Brasil

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

Atividade viral do vírus respiratório sincicial bovino (brsv) em bezerros leiteiros

The purpose of the present study was to evaluate the antimicrobial activity of propolis extracts diluted in different solvents against bacteria from Staphylococcus genus. The study was performed in the Immunology and Microbiology Laboratory from Universidade Federal do Vale do São Francisco. The propolis extracts were prepared using brown propolis diluted in different solvents such as chloroform, methanol, ethyl acetate and grain alcohol. In order to determine the antimicrobial potential of extracts, agar well diffusion method was used, with controls for each diluent. After that, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) methods were used. All tests were performed in triplicate. In the agar well diffusion test, the measurements of the inhibition zone for propolis extract were as follows: grain alcohol and propolis (2.88mm), methanol and propolis (2.41mm), chloroform and propolis (2.40mm) and ethyl acetate and propolis (0.83mm). The MBC of propolis extracts in different solvents were 93.75 μg/mL for grain alcohol, 375 μg/mL for chloroform and methanol and 3,000 μg/ml for ethyl acetate. Statistically significant differences were achieved comparing the inhibition zones of propolis diluted in grain alcohol and ethyl acetate (2.88 and 0.83 mm, respectively). Considering the low cost of therapy and the activity of the propolis against caprine mastitis pathogens, other studies regarding in vivo activity and chemical characterization are necessary, in addition to evaluation of the toxicological aspects of propolis extracts.

Biodigestão anaeróbia de dejetos de bovinos leiteiros submetidos a diferentes tempos de exposição ao ar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estimativas de (co) varância genética de pesos do nascimento até a maturidade em rebanhos da raça Nelore usando modelos de regressão aleatória e de características múltiplas

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

Monitoração da ocorrência do Vírus Respiratório Sincicial Bovino (BRSV) em plantéis leiteiros infectados pelo Herpesvírus Bovino Tipo 1 (BoHV-1)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Prevalência de brucelose bovina entre rebanhos fornecedores de leite de um laticínio no município de Itirapuã, Estado de São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Detecção de anticorpos contra o vírus da diarréia viral bovina (BVD) no soro sangüíneo, no leite individual e no leite de conjunto em tanque de expansão de rebanhos não vacinados

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

Ocorrência e caracterização molecular de Cryptosporidium spp. em bezerros leiteiros da região noroeste do Estado de São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação dos padrões de susceptibilidade antimicrobianas e sorogrupos de cepas de Escherichia coli isoladas de bovinos leiteiros, portadoras e não portadoras dos genes stx1, stx2 e eae

Pós-graduação em Microbiologia Agropecuária - FCAV

Detecção de Escherichia coli shigatoxigênica (STEC) e enteropatogênica (EPEC) isoladas de búfalos leiteiros no Estado de São Paulo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)