This trial was conducted to study the effects of pre and postnatal feed restriction on growth and production of Santa Inês lambs from birth to weaning. Sixty-eight lambs were assigned to three treatments as follows: prenatal feed restriction (PRER), postnatal feed restriction (POSTR), and no feed restriction (Control). Average birth body weight of lambs on Control (4.628 kg) and POSTR (4.421 kg) treatments were similar but higher than that of animals on PRER (3.024 kg). Milk replacer intake averaged 1.308, […]

This trial was conducted to study the production and biological efficiency of 48 buffaloes averaging 18 months of age and initial body weight of 330 kg finished in feedlot. Sixteen animals from each of the following breeds were used: Murrah (MUR), Jafarabadi (JAF), and Mediterranean (MED). Within each genetic group, four animals (references) were randomly assigned to initial slaughter in order to determine empty body weight (EBW) and initial carcass. The remaining 12 animals from each genetic group were randomly […]

Twenty-four lactating dairy cows were assigned to a completely randomized block design to compare the effects of isoenergetic diets but different crude protein (CP) levels: P100- 100%, P133- 133% or P166- 166% of the NRC (1989) requirements on the concentrations of urea nitrogen in plasma (PUN) and milk (MUN). Increasing levels of CP were obtained by adding urea to the diet. Feeds, milk, and blood were all collected weekly from 30 days before to 60 days after parturition. Milk yield […]

The objective of this trial was to evaluate the partial replacement of ground corn with soybean hulls or corn germ meal on ruminal microbial protein synthesis and efficiency and ruminal dilution and passage rates. Three crossbreed steers fitted with ruminal and duodenal cannulas were assigned to two 3 x 3 Latin squares. The experimental diets contained: corn silage (60%), sunflower meal and ground corn (GC diet) that was partially replaced with soybean hulls (SBH diet) or corn germ meal (CGM […]

The objective of this trial was to study the in vitro effects of monensin and propolis on ruminal fermentation of amino acids. Ruminal fluid was collected from a steer grazing tropical pasture and after addition of casein hydrolysate was used in the incubations. Treatments consisted of: control-C; monensin-M; and propolis-P. In the first phase of the study, inocula were transferred daily into new tubes until day 10; on the 11th day of incubation, tubes from each of the treatments were […]

Twenty-four castrated Holstein x Zebu bovines averaging 435 kg of initial body weight and 36 months of age were assigned to a randomized complete block design (six replications/treatment) to investigate the effects of sorghum silage with different concentrate levels on intake, apparent total tract digestibility, weight gain, feed conversion, and carcass yield. Animals received the following forage:concentrate ratios: 80:20, 65:35, 50:50, and 35:65 on dry matter basis. Different forage:concentrate ratios did not change significantly intakes of DM, OM, CP, and […]

The energy and protein requirements for gain of Brangus and Nellore bulls were estimated using the comparative slaughter technique, in which the empty body as well as the gain composition were estimated through the 9th -10th -11th rib cut. Twenty-eight animals from each breed were used in this research. At the beginning of the trial four animals from each breed were slaughtered to determine the initial body composition while the remaining bulls had free access to diets containing 20, 40, […]

In this study the net requirements of energy and protein for weight gain were estimated through the comparative slaughter technique using 56 Nellore steers averaging 432 kg of initial body weight. The analytical composition of the 9th-10th-11th ribs was used to estimate empty body (EB) composition. Eight steers were slaughtered at the beginning of the trial to determine the initial body composition while the remaining steers were fed for 70 days diets containing 60% of concentrate (dry matter basis) composed […]

The objective of this study was to economically evaluate feedlot finished steers and young steers from two genetic groups: 5/8Charolais (CH) 3/8Nellore (NE) and 5/8NE 3/8CH. The average age of animals at the end of the experimental period was 22.8 and 15.2 months for steers and young steers, respectively. Animals were maintained in the feedlot until reach the previously established slaughter weight of 430 kg. Animals were fed a diet containing a forage:concentrate ratio of 60:40 with the following chemical […]

The objective of this study was to analyze the situation of the beef cattle industry in Brazil after changes in the production/commercialization system with the Mercosul advent. It was closely investigated not only beef cattle production indexes but also amounts of meat produced, consumed, and exported after 1990. Results showed that Brazil has potential to increase meat exportation but that will depend of actions channeled to improve herd sanitary conditions, political issues, and overall production efficiency.