The effect of feeding increasing calcium levels for semi-heavy laying hens during the prelay phase and its effects in the four subsequent weeks were evaluated in this trial. Two hundred and eighty-eight Isabrown birds with 16 weeks of age were allotted to a complete randomized design with four treatments, eight replicates and nine birds per experimental unit. The corn and soybean meal-based diets were formulated to meet the bird nutrient requirements, with the exception of calcium levels. The experiment lasted […]

Thirty crossbred sows averaging 118.18±12.2 kg of BW, backfat thickness of 13.82±1.42 mm and 220 days old were assigned to a completely randomized design in a split plot scheme with 10 replicates and parturition orders included in the plots (3 x 3 factorial arrangement) and CP ingestion levels (10.0, 13.5, and 17.0%) in the sub-plots. The effects of dietary CP ingestion levels on female performance in three complete successive reproductive cycles were evaluated during the pregnancy. Sow weight gain in […]

The experiment was conducted to evaluate the effect of different energy levels and feeding programs on performance of broilers from 42 to 57 days of age. One thousand and six hundred 1-d male chicks (Cobb) were assigned to a completely randomized design with 2 x 4 factorial arrangement (two levels of energy: 3,200 and 3,600 kcal ME/kg and four different feeding programs: amino acid recomendations). From 1 to 41 days of age all birds were fed the same corn and […]

Two trials were conducted to evaluate the apparent digestibility of GE, DM and CP in energy and high protein feedstuffs for adult dogs. Four adult mongrel dogs (two males and two females) averaging of 13.1 ± 2.0 kg were used in both trials, to evaluate each feedstuff. The animals were fed the same amount of food per metabolic weight. The nutritive value of energy feedstuffs was evaluated in the trial 1. In the trial 2, the digestibility coefficients of protein […]

Two trials were carried out to estimate the nutritional requirement and carcass composition of male broiler breeders according to five levels of metabolizable energy (ME) ingestion. Four hundred and fifty females and 75 males of Cobb-500 strain were selected to evaluate body weight, semen volume, spermatic concentration, motility, vigor and fertility of spermatozoa. Thirty males were used for evaluation of carcass chemical composition (DM, CP and crude fat [CF]) as a function of energy intake. The experiment was analyzed as […]

Two trials were carried to estimate the protein requirements and carcass composition of male broiler breeders from 27 to 61 weeks of age. Four hundred and fifty females and 75 males of Cobb-500 strain were selected to evaluate the body weight, semen volume, spermatic concentration, mobility, vigor and fertility of spermatozoa. Thirty males were used for evaluation of carcass chemical composition (DM, CP and crude fat [CF]) as a function of protein intake. The experiment was analyzed as a complete […]

The effects of total excreta collection period length on estimated values of metabolizable energy [apparent (AME) and nitrogen corrected (AMEn)] were evaluated in broiler chickens from 19 to 23 days of age. Five treatments with six replicates were used in a randomized block design, in a total of 300 broiler chicks for the control and 300 broiler chicks for the reference diet. The control replaced 40% of reference diet with corn. After diet adaptation (four days), total excreta collection was […]

Data comprising 39,578 test-day records of 3,766 first lactation Holstein cows calving from 1994 to 2002 was used to estimate genetic parameters for test-day yields (TDY) and 305-day milk yield (MY305) and to compare two selection criteria. Variance components were estimated by restricted maximum likelihood using univariate and bivariate animal models. The TDY models included the additive genetic random effect and the fixed effects of contemporary groups and the regressions of calving age (linear and quadratic effects) and days in […]

The aim of this work was to evaluate arrays of fixed effects and residual covariance structures that best fit the herd and the animal variability to weights at birth, weaning, twelve and eighteen months of 3,690 Canchim animals. Different arrays of fixed effects (contemporary groups and, or the main effects of year, month or season of birth and sex) and different residual covariance structures (considering or not change of variance and of correlation between weights at different ages) were studied. […]

Data from 26.314 animals of Guzerá cattle, weighted every 90 days from birth to 630 days, between 1975 and 2001, were used to estimate covariance components by REML methodology using four different models. The first model was the complete one and included four random components: direct genetic (GA), maternal genetic (GM), maternal permanent environmental (AM) and the residual; model 2 did not include the GM effect; model 3 did not include the AM effect and model 4 did not include […]