Two studies were carried out to evaluate individual dry matter intake of group-fed lactating dairy cows. In the first trial, eight cows were housed in individual pens and fed corn silage and 4 kg of concentrate meal. Two external markers (chromium oxide and titanium dioxide) were used to predict individual concentrate intake. Indigestible acid detergent fiber (iADF) was used to estimate individual silage intake. Fecal dry matter output (FDMO) was determined by total collection and also by LIPE®. Chromium oxide […]

The efficiency of fat and protein retention by Bos indicus and its cross-breds was estimated from data obtained in the literature to verify possible differences between these animals and Bos taurus. After estimating the efficiencies, a correction factor was used to discount the metabolizable energy fraction that was spent in the maintenance and support metabolism processes. The efficiencies were then estimated again, assuming that all the remaining energy would correspond to the metabolizable energy available for body mass retention. The […]

The objective of this study was to determine the metabolizable energy requirement for maintenance and net requirements of crude protein, energy and macrominerals for weight gain, and also the conversion efficiency of net protein requirements to metabolizable protein requirements in Nellore cattle. Twenty seven Nellore animals (nine bulls, nine steers and nine heifers) were used. Three animals of each gender were slaughtered at the beginning of the trial and formed the reference group. The remaining 18 animals received concentrated feed […]

The objective of this study was to evaluate the Hankins and Howe equations, to estimate the carcass physical composition, and the Paulino equations, to estimate the empty body weight macromineral composition of Nellore cattle. Twenty seven Nellore animls (9 bulls, 9 steers and 9 heifers) were used, and nine animals (three of each gender) were slaughtered at the beginning and formed the reference group. The 18 remaining animals (6 of each gender) were allotted in two levels of concentrate offer […]

Thirteen male Holstein calves with average age of 14 days were used. Three animals were slaughtered at the beginning of the experiment (reference) and ten others were randomly distributed in two treatments (ground or pelleted feed), and slaughtered at 112 days of age to determine the nutritional requirements. Regression equations of the logarithm of the amount of protein, fat and energy in the body were fitted as a function of the empty of body weight (EBW). The net protein and […]

Thirty mid lactating Holstein cows (159 DIM) were used to evaluate the substitution of ground corn with gluten feed (FGM-21) in total mixed diets containing corn silage as the main forage and citrus pulp as part of the energy source. Treatments were: no FGM-21 and 20% ground corn in total feed DM (FGM 0), 10% FGM-21 and 10% ground corn in total feed DM (FGM 10), and no corn and 20% FGM-21 in total feed DM (FGM 20). The parameters […]

The experiment was carried out to evaluate the ingestive behavior of sheep fed diets containing elephant grass silage with different additives. Twenty sheep non-castrated male kids were used in a randomized complete design, with four treatments and five replications. The treatments were: elephant grass silage (control); elephant grass silage (75%) + coffee hulls (15%); elephant grass silage (75%) + cocoa meal (15%) and elephant grass silage (75%) + cassava meal (15%). The additives were added at ensilage moment was realized […]

A dynamic mathematical model was developed to describe the reproductive process in beef cattle production systems and to simulate individual cow reproductive performance while generating results for the herd, based on the body condition score (BCS) at calving and age at sexual maturity. The model is empiric and dynamic, containing deterministic and stochastic elements. The model was developed based on the relationship between BCS and postpartum interval for lactating cows; for heifers and non-lactating cows, the conception rate was based […]