The objective of this trial was to investigate correlations among the California Mastitis Test, somatic cells count (SCC), and milk yield. Milk samples were collected from thirty-eight Murrah buffalo cows in the years of 2002 and 2003. Milking management included cleaning teats with individual paper towel followed by attachment of the milk units in cows that were milked once daily. The CMT was done immediately after teat cleaning and collected milk samples were sent to the laboratory for determination of […]

Five lactating Brown-Swiss cows averaging 520 kg of body weight (BW) and 15 kg of milk yield were assigned to a 5 x 5 Latin square to study the effects of replacing sorghum silage (Sorghum bicolor L. Moench) with a columnar cactus known as xiquexique (Pilosocereus gounellei (A. Weber ex K. Schum.) Byl ex Rowl.) on animal performance and apparent digestibility of nutrients. The experimental diets contained (DM basis): 0, 12.5, 25, 37.5, or 50% of xiquexique. Each experimental period […]

Covariance components for test day records and lactation milk yield using 263.390 records of 32.448 first lactation Holstein cows, were estimated using animal models by REML. Besides the lactation model, two alternative repeatability models (RM) were analyzed. Lactation model included fixed effects of herd-year-season and age of cow with linear and quadratic terms, and random effects of animal and error. The first model for test-day yield (RMF) included the same effects, but fixed effect of contemporary group, defined as herd-year-month […]

Breeding values were predicted for test day milk yields of Caracu cows, using univariate model (TDMO) and random regression model (RRM). The ranks were based on traditional 305-day milk yield breeding values (PTA305). For RRM, breeding values were predicted for individual test-day milk yield and for sum of all test-days (RRM305). Spearman correlation were estimated among predicted breeding values from different methodos (TDMO and RRM) and the coincidence of rank of 10% best sires were verified. Genetic lactation curves of […]

The objective of the experiment was to evaluate the biologic efficiency of Charolais (CH) and Nellore (NE) cows nursing CH and ½NE ½CH (produced by CH cows), NE and ½CH ½NE (produced by NE cows) calves, mantained together until weaning, on native pasture (NP) or winter (oat + italian rye grass) and summer (alexander grass) cultivated pasture (CP). Cows and calves were weighted at birth; 14; 42; 70; 98; 126; 154; 182 days; and at weaning. The cows milk yield […]

The relationship between milk somatic cells count (SCC) and milk yield has been the aim of countless researches in several countries; however, in Brazil, the literature related to this subject is scarce. Therefore, the objective of this study is to verify if the losses in milk yield due to SCC increase are proportional to the yield, or absolute (independent of it) and starting from which SCC, the losses become evident. For this study, 13.725 observations were used, collected monthly from […]

Twelve purebred and crossbred Holstein cows were allotted to three 4 x 4 Latin Squares to evaluate the intake, apparent digestibility of nutrients, milk production and composition, ruminal pH and ammonia. The experimental diets were based on corn silage (CS) (AG 1051) with forage:concentrate ratio (F:C) of 60:40, in dry matter (DM) basis, or based on sugar cane (SC) (RB 855536) with F:C of 60:40 with .35 or 1% of urea+ammonium sulfate (AS) mixture or F:C of 50:50 with 1% […]

The objective of this study was to evaluate the effects of feeding alfalfa haylage with microbial inoculat on dry matter intake, milk yield and composition in Holstein cows, at 135 ± 16.4 days in milk. A cross-over design with two periods of sampling was used. Treatments were alfalfa haylage (50.0% DM and 16.5% CP) control or microbially inoculated with Silobac® product (Lactobacillus plantarum and Pediococcus pentosaceus). Each experimental period extended for twenty-one days, the last five used for data collection. […]

Fourteen random regression models were used to adjust 86,595 test-day milk records of 2,155 first lactation of native Caracu cows. The models include fixed effects of contemporary group and age of cow as covariable. A cubic regression on Legendre orthogonal polynomial of days in milk was used to model the mean trend and the additive genetic and permanent environmental regressions. Different structures of residual variances were tried and considered through homogeneous variances or heterogeneous variances, modeled as a step function […]

Genetic parameters for first lactation test-day milk yields and 305 day milk yield (M305) for Caracu cows were estimated. The test-day animal model included additive genetic effect as random and contemporary group and age of cow (quadratic regression) as fixed effects. Two contemporary groups were defined to explain variation, composed by year, week of test and paddock (gc1) or year, week of test and paddock (gc2). Variance components were estimated by Restricted Maximum Likelihood. Phenotypic, residual and genetic additive variances […]