The objective of this study was to evaluate the effect of increased environmental temperature on physiological traits of Morada Nova (MN) and Santa Ines (SI) sheep breeds in the Federal District, Brazil. Two groups (25 MN and 25 SI) were selected for study and included both pregnant (EP) and non-pregnant (EPN) ewes, aged betwen 2 and 4 years. The fifty ewes were recorded, once a month, for six months, at 8 am and 2 pm, and measurements included body weight […]

In this study 9,527 lactations of purebreed Holstein cows, calved between 1988 to 1997, from herds in the Minas Gerais State, were analysed. Two data sets were established: one with first lactations only and another with the first lactation until the third one. Milk and fat 305-day yields were analysed using a multivariate mixed model and restricted maximum likelihood procedure (REML). The milk and fat 305 days yields averages were respectively 5,870 ± 1,662 kg and 199 ± 55 kg […]

The main objective of this work was to evaluate the Nellore breed in Brazil with respect to the phenotypic and genetic variation of the mature size of cows. The observations were taken from 34 herds of eleven different beef cattle production regions in the country. There were considered cows of the horned and polled varieties, raised on pastures, from herds that had at least 50 cows. With these restrictions it was formed a general file with 6,867 cows with valid […]

The objectives of this study were to evaluate the influence of environmental factors on milk production from dairy goats raised in the Brazilian Southeast and to estimate genetic parameters for this trait through least squares. The data originated from seven farms and three breeds (Alpine Brown, Saanen and Toggenburg). Milk yields obtained from 1,336 lactations were initially fitted to a diphasic function, whereby total milk production (TMP) was estimated. The overall mean and standard error for TMP were 635.31±39.75 kg. […]

Data to 53433 of Nellore cattle were used to estimate genetic parameters for standardized weights at 120, 240, and 550 days of age (P120, P240, and P550 respectively), scrotal circumference at 550 days (PE550), days to reach 160 kg (D160), and 240 kg (D240) of live weigh. It was used software the MTDFREML with mixed-model analysis using animal model. Model included fixed effects of contemporary groups (GC) and classes of age-of-dam calving and random direct and maternal genetic effects, the […]

Milk yield adjusted for 305 days and for age of Holtein cows were used to verify the effectiveness of including sire-by-herd interaction in the model of analysis as an adjustment factor for heterogeneous variances between herds. The herds were classified in three classes of phenotypic standard deviation: high, medium and low. Variance component estimates were obtained by Restricted Maximum Likelihood methodology, for classes of phenotypic standard deviation, considering each one as a different trait, using a multiple trait analysis. Two […]

Yield records of Holstein cows were used to verify the interaction effect on accuracy of sire breeding values. The records of milk yield were adjusted to 305 days of lactation and age of the cow. Variance components for milk yield were estimated using restricted maximum likelihood methodology through two animal models, either not fitting or fitting a sire-by-herd interaction term. Likelihood ratio test was used to verify the effectiveness of including a sire-by-herd interaction effect in the model. Average milk […]

Average daily gain from weaning (GMD¾12) to yearling weight (P12M) of Nellore, Guzerá x Nellore (GN), Red Angus x Nellore (RN), and Marchigiana x Nellore (MN) cattle, from a crossbreeding experiment conducted at the IAPAR Paranavaí Experimental Station, produced by artificial insemination, born between 1985 and 1997 within two annual birth seasons (January – April and July – December), were analyzed. The least squares method was utilized to study 634 observations of GMD_D12 and of P12M. Calf’s birth month was […]

Forty-eight female pigs were used to determine tissue growth curves after slaughter of the animals at 50, 60, 70, 80, 90, 100, 110 and 120 kg and dissection of the carcasses. The lean cuts in carcass were made according to that used by Brazilian pork slaughters. In each cut it were separated muscle, fat, bone and skin amounts. The expanded allometric function was used to estimate and to fit the growth curves. The muscle amounts in carcass increased to 41.9% […]

Simulated data were used to verify the effect of the connectedness on the accuracy of progeny and performance tests. The simulated genome was formed from a quantitative trait governed by 500 loci. Significance herd effect (9 herds) by 5% probability F test was simulated. Data sets with 0, 15, 30, 60, 90 and 100% of connectedness for heritabilities 0.10, 0.30 and 0.60 and for different progeny sizes (9, 54 and 90 progenies/sire) were simulated. In each generation nine males were […]