Fifty gilts crossbreed (Hampshire, Belgium Landrace, Pietran), with initial average weight of 60.23±0.49 kg and high genetic potential for lean meat deposition, were used to evaluate different lysine levels. A randomized blocks design, with five treatments, five replicates and two animals per experimental unit, was used. The treatments corresponded to a basal diet with 15.8% crude protein, supplemented with five levels of HCl-L-Lisine, resulting in diets with 0.75, 0.85, 0.95, 1.05, and 1.15% of lysine. There was no effect of […]

An experiment was carried out to evaluate the dietary concentrate levels on the intake, total and partial apparent digestibilities of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), total carbohydrates (CHO), neutral detergent fiber (NDF) and non structural carbohydrates (NEC). The effects of samples collections, realized on the day or the night, on the total and partial apparent digestibilities of DM and OM, were studied. Five F1 Simental x Nellore bulls fistulated in the rumen, abomasum […]

This work was conducted with the objective to determine the body composition for fat, protein and ash, the net requirements of energy and protein for weight gain, and the requirements of metabolizable protein of growing lambs. Twenty-two male lambs, sired by Texel males, from crossbreed Texel x Ideal dams were used. Four lambs were slaughtered at the beginning of the experiment (24 hours after birth) and groups of six lambs were slaughtered at weaning, at 28 and 33 kg of […]

Three experiments were carried out to study the performance and digestibility of nutrients and to determine the endogenous enzyme level in grouving swines fed diets supplemented with exogenous enzymes. The experimental diets consisted of corn, soybean meal, vitamins and minerals plus the addition of exogenous enzymes. The mixtures consisted of 25 g of exogenous enzyme per 100 kg of diet. The basic composition of the diets were 18.00% of crude protein (CP) and 3400 kcal/kg of digestible energy (DE). In […]

The objective of this work was to exam the convenience of paying for the genetic value of protein and fat in imported semen using the technique of discounted gene flow, based on economic values derived in a parallel paper and literature biological parameters. In the State Parana, semen of Holstein sires positive for protein and fat could be economic, depending on its cost, while in Minas Gerais such sires would be unprofitable. Genetic trends for protein and fat in Brazilian […]

The objective of the present work was to validate the ruminal and post-ruminal nutrient dynamics and the ruminal microbial growth predictions, by using the equations of the Cornell system. The experiment was carried out during the rainy and dry seasons of the 1996 year, in a natural pasture area situated in the county of Viçosa (MG). Esophageally, ruminally and abomasally cannulated steers were used during two experimental periods within each season, and external markers (Cr2O3 and Eu) were used to […]

The effects of dietary concentrate levels were evaluated on the microbial synthesis efficiency, the nitrogenous compounds balance, the ammonia concentrations and the ruminal fluid pH, the ruminal digesta passage rate and the endogenous losses of nitrogen compounds (N). Five F1 Simental x Nellore bulls fistulated in the rumen, abomasum and ileum, full fed diets with 25.0; 37.5; 50.0; 62.5; and 75.0% of concentrate and allotted to 5×5 Latin square, were used. The ammonia concentrations and the ruminal pH were determined […]

Forty crossbred gilts (Hampshire, Belgium Landrace, Pietran) with initial average weight of 30.1±1.25 kg and high genetic potential for lean meat deposition were used to evaluate different lysine levels. A randomized block experimental design, with four treatments, five replications and two animal per experimental unit, was used. The treatments corresponded to the basal diet with 17.5% crude protein, supplemented with L-lysine-HCl, resulting in diets with 1.00, 1.10, 1.20 and 1.30% of lysine. The diets were supplemented with increasing levels of […]

The objective of this work was to study the effects of the injection of 10 mg buserelin (GnRH) in the presence of an ovarian follicle with ³ 10 mm diameter associated to a dose of 500 mg of cloprostenol six days later, or with two doses of 500 mg of cloprostenol (PGF2a) at the 12th and 26th days postpartum about the follicular dynamic and the reestablishment of cyclic ovarian activity in crossbred Holstein-Zebu cows. Fifteen crossbred Holstein-Zebu cows were randomly […]

Records of 4595 lactations from 2254 cows, daughters of 145 sires and 1618 dams of the Gyr breed, assigned to 18 herds, with calving from 1980 to 1997 were used to study the viability of using production from projected partial lactations, on the evaluation of sires. From 91, 151, 211 or 241 days of lactation, 10, 30, 50 or 70% of the lactations were projected, for the duration of the observed lactation and at 305 days of lactation. The estimated […]