Two trials were conducted to study the effects of different levels of urea or cottonseed hulls on yield of microbial protein, estimated by the urinary excretion of purine derivatives, concentration of plasma urea, and excretion of urea in steers. In the first trial, 24 crossbred castrated steers averaging 300 kg of initial live weight (LW) were uniformly assigned to four treatments in a complete randomized design as follows: 0, 0.65, 1.30, or 1.95% of urea (% of dry matter) that […]

The objective of this trial was to evaluate ruminal, intestinal, and total tract apparent digestibilities of nutrients as well as metabolism of ruminal and nitrogenous compounds in supplemented finishing cattle during the drought to rainy transition season. Five Holstein x Zebu steers averaging 304 kg of live weight and 24 months of age located in five paddocks (0.34 ha each) of Brachiaria decumbens were used in this trial. The supplements fed (4 kg/animal/day) contained ground corn, whole soybean, urea, ammonium […]

In order to estimate fecal production and digesta flow of cattle, three assays were carried out using indigestible NDF and ADF as internal markers, applying in vitro and in situ incubation procedures, as well as chromium oxide as an external marker. The experiment was a randomized block design in a factorial arrangement. Indigestible NDF and ADF contents exhibited high variation despite the methodology employed (in vitro or in situ). These results indicate that, eventually, 144-h incubation time does not reproduce […]

Equations for predicting elephantgrass (Pennisetum purpureum, Schumack) dry matter intake (DMI) by Holstein x Zebu lactating dairy cows under grazing were developed by stepwise regression analysis. The dataset consisted of results of trials carried out at Embrapa Gado de Leite (Coronel Pacheco, MG, Brazil). The independent variables related to animal factors (days in milk; milk protein, fat and total solids contents and yields; live weight; live weight at calving; milk and fat-corrected milk yield; Holstein x Zebu gene fraction; order […]

Data of 320 animals were obtained from eight comparative slaughter studies performed under tropical conditions and used to estimate the total efficiency of utilization of the metabolizable energy intake (MEI), which varied from 77 to 419 kcal kg-0.75d-1. The provided data also contained direct measures of the recovered energy (RE), which allowed calculating the heat production (HE) by difference. The RE was regressed on MEI and deviations from linearity were evaluated by using the F-test. The respective estimates of the […]

Intake, total apparent digestibility of nutrients and milk production and composition were evaluated in mid lactation cows fed with increasing levels of crude protein (CP) in the concentrate (20, 23, 26 and 29% natural matter-NM). Twelve Holstein crossbred lactating cows were assigned to three latin square (4×4), in four periods of 15 days each (one week of adaptation). The feeding consisted of 70% of corn silage and 30% of concentrate. Intakes and digestibilities of dry matter (DM), organic matter (OM), […]

The intake, total apparent digestibility of nutrients and milk production and composition were evaluated in early lactation cows fed with increasing levels (20; 23; 26 and 29% natural matter – NM) of crude protein (CP) in concentrate. Twelve crossbred Holstein cows were assigned to three latin square (4×4), in four periods of 15 days each (one week of adaptation). The feeding consisted of 60% of cow silage and 40% of concentrate. The intakes of dry matter (DM), CP, neutral detergent […]

Lambs born from Romney ewes and sired by Romney, East Friesian x (Finn x Texel), and Finn x Poll Dorset, under pasture grazing system, were evaluated for meat quality. Animals were slaughtered at two age groups (150 and 300 days), each group with 15 animals of each sire breed, in a total of 90 animals. The meat from Romney lambs was more tenderness than those from the other genotypes. The final pH in semimembranosus muscle of younger lambs was higher […]

Intake and total apparent digestibilities of the nutrients and average daily gains (ADG) by beef cattle fed diets based on concentrate and Brachiaria brizantha cv. Marandu silage in the following proportions: 20:80, 35:65, 50:50 and 65:35, in dry matter basis were evaluated. Twenty-four crossbred (Holstein x Zebu) steers, with initial live weight of 364 kg were allotted to a randomized blocks design. At the ensiling process, an enzyme-bacterial inoculant Nutroeste 50 t was applied to the forage. For the determination […]

Twenty-two animals, eight from genetic improved Nellore breed, six non-improved Nellore and eight from genetic improved Caracu breed, were used to evaluate and to validate the VIÇOSA, CNCPS (level 1 and 2) and NRC (level 1 and 2) systems, for diet formulations. The animals were confined with average live weight of 404 kg to genetic improved Nellore, 345 kg to non-improved Nellore and 434 kg to genetic improved Caracu breed, all with 18 months of age. The forage used was […]