The net requirements of energy for the maintenance of bulls from four Zebu breeds (Gyr, Guzera, Mocho-Tabapuã and Nellore) were estimated with 63 bulls averaging 24 months of age and 366 kg initial LW and (15 Nellore and 16 from the Gyr, Guzera and Macho-Tapabuã). Fifteen animals, four Gyr, Guzera and Mocho-Tabapuã breed and three Nellore breed, were slaughtered at the beginning of the trial and the remaining were allotted to four groups of 12 animals, being three animals from […]

The objective of this work was to evaluate the in situ disappearance of canola meal treated with water (control), in autoclave at 127oC for 30 min (CC), with 15% of Acacia mearnsii tannin (CT) and tannin followed by autoclaving (CTC). The effect of these treatments on in situ disappearance of dry matter (DM) and crude protein (CP) was evaluated by the nylon bag technique, using two rumen fistulated Holstein cows. The estimates of effective degradation of DM for control, CC, […]

The objective of this work was to evaluate the performance, ponderal development of heifers fed sugar cane based diets, supplemented with non protein nitrogen (NPN) sources (urea or broiler litter, in replacement of urea) and, or, probiotics addition (without probiotic, with yeast or with ruminal microbiota). Cost and gross margin of the use of these diets were also evaluated. Twenty-four heifers, with age and average initial weight of 14 months and 247 kg LW, respectively, were maintained in individual stalls […]

Effect of recombinant bovine somatotropin (rBST) on the performance of steers fed diets with different forages was evaluated. Forty crossbred steers, with average 360.2 kg LW and 30 months of age, were used. The animals were fed diets containing different forages (corn silage, sugarcane, corn silage + sugarcane and hydrolyzed sugarcane bagasse), and received an application of 320 mg rBST at every 28 days and were weighed at every 14 days during an experimental period of 84 days. The weight […]

This study was conducted to evaluate the corn (Zea mays L.) AG 1051 and the sorghums (Sorghum bicolor (L.) Moench) AG 2006 and BR 303, for silage production, and the effect of substitution of soybean meal by urea (0,50 and 100%) in the concentrated diets for feedlot cattle. The silages were used in two experiments and the animals were alloted to a completely experimental design. In the first, 72 F1 crossbred Brown Swiss x Nellore bulls, with 20 months of […]

The objective of this work was to evaluate the ingestive behavior of crossbred dairy heifers fed sugar-cane based diets, supplemented with non protein nitrogen [NPN] sources (urea or broiler litter, in replacement of urea) and, or, probiotics addition (without probiotic, with yeast or with ruminal microbiota). Twenty-four heifers, with age and average initial weight of 15 months and 247 kg, respectively, were maintained in individual stalls and ad libitum fed during the experimental period of 84 days. The animals were […]

The effects of different dietary concentrate levels on the intakes of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), ether extract (EE), total carbohydrates (TC), total digestible nutrients (TDN), calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na) and potassium (K) were evaluated. The live weight (LWG) and the empty body gains (EBG), feed:gain ratio (F:G), carcass gain (CG) and the carcass productivity in relation to live weight (LWCP) and to empty body weight (EBW) were also evaluated. Twenty […]

The objective of this work was to study the effects of the concentrate levels of the diet on the microbial efficiency, ruminal ammonia and pH, and endogenous nitrogen (N) losses. Four Nellore bulls, fistulated in the rumen, abomasum and ileum, were full fed diets with 25.0, 37.5, 50.0, 62.5, and 75.0% of concentrate and allotted to a randomized block design. The ruminal ammonia concentrations and pH were measured in the ruminal fluid samples in collections made before and 2, 4, […]

The effects of different dietary concentrate levels on the net requirements of Ca, P, Mg, Na and potassium (K) were studied. Twenty-nine F1 Simental x Nellore bulls, averaging 17 months of age and initial LW of 354 kg, were used. Five animals were slaughtered at the beginning of the experiment as a reference and the remainders were allotted to a completely randomized design, according to the different dietary concentrate levels: 25.0, 37.50, 50,0, 62.5, and 75.0%. The animals were were […]

The effects of five dietary concentrate levels on the body composition and on the net requirements of protein and energy for weight gain were evaluated. Twenty nine F1 Simental Nellore bulls, averaging 17 months of age and initial 354 kg LW, were used. Five animals were slaughtered at the beginning of the experiment, as a reference, to estimate the initial empty body weight (EBW) and the initial concentrations of fat, protein and energy. The remaining animals were allotted to a […]