Forty-eight crossbreed beef cattle were used to evaluate four commercial mineral supplements: Treatment A- Salt + protein without urea (20% crude protein); B – salt + protein with urea (52,5 % crude protein), C) mineralized salt; D) mineralized salt with urea (91% crude protein). The animals were distributed into 24 plots of Braquiaria decubens grass, with supplementation of (10.5 kg/an/day) of sugar cane, during 112 days, with 28 days of adaptation and 84 days of data collection. The animals were […]

Thirty two Santa Gertrudis young bulls with an initial weight of 230 kg and 9 months of age were used in a comparative slaughter experiment with a 2 x 2 factorial arrangement with two concentrate levels, 80 and 20%, and two energetic ingredients in the concentrate, corn grain or pelletized citrus pulp. Four animals were slaughtered after the adaptation period for the determination of the initial body composition of lot and those that received diets with 80 and 20% of […]

The experiment was conducted to evaluate the ruminal pH and ammonia concentration (N-NH3) in rumen liquor collected at 3, 6 and 12 hours after feeding using four ruminal fistulated European x Zebu steers. The forage leaves: stems ratio and neutral detergent fiber (NDF) and acid detergent fiber in situ ruminal degradability of the leaflets from three tropical legumes (leucaena, Leucaena leucocephala; pigeon pea, Cajanus cajan; and glycine, Neonotonia wightii) and leaves from two others tropical forages (ramie, Boehmeria nivea and […]

This work, evaluated by means of an economically simulation, the beef production systems with heifers calving by first time at two (“one year” system), three (“two years” system) and four (“traditional” system) years old. In “one year” system, the female calves had three different nutritional systems during 100 days, after weaning in the first autumn/winter, constituted by one of the alternatives: a) continuous grazing on cultivated annual ryegrass – PAST; b) continuous grazing on natural pasture plus diet – CNR; […]

Fifteen Nellore steers were allotted to three treatments, consisting of a basal diet, which will be able to provide gains of about 600 g/day, supplemented (15 or 11 g P/day) or not (5 g P/day) with monoammonium phosphate in order to evaluate the alterations in bone, plasma and fecal measurements due to P deficiency. Rib biopsies were taken at 60 and 250 days of trial, plasma samples were taken every 15 days, and fecal grab samples were analyzed in seven […]

The objective of the present study was to determinate the nitrogenous compounds fractions present in the extrusa of grazing cattle maintained in a natural grassland in the Zona da Mata region, MG. The samples were obtained by using four esophageal fistulated steers in two experimental periods during the rainy season of 1996, and three of these animals were used to take samples in two experimental periods during the dry season of the same year. In order to obtain the nitrogen […]

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 […]

The amount of Ca, P, Mg, K and Na of the soils, and the levels of these elements and S of the forages predominant in the pastures and water, were studied in the North and Northwest regions of Rio de Janeiro State, in the dry (June-July) and rainy (December-January) seasons. Samples were collected from soil, forages and water from 12 different places of the regions, in predominant grazing areas, as showed by satellite photography and according to different soil characteristics. […]

ABSTRACT – A trial was conducted to evaluate the effects of five concentrate levels in the diet on the efficiency of microbial synthesis, balance of nitrogen compounds, ammonia concentrate and pH ruminal fluid. Five rumen, abomasum and ileum fistulated F1 Limousin x Nellore bulls were full fed diets containing 25.0, 37.5, 50.0, 62.5, and 75.0% of concentrate and allotted to a 5 x 5 latin square design. The ammonia concentrations and ruminal pH were determined in ruminal fluid samples collected […]

The objective of this trial was to evaluate the in vitro ammonia (N-NH3) production in fermentation of diets with different protein sources (dry yeast, urea and cottonseed meal) used for ruminants diets. The data relative to the N-NH3 production measured in the first hour of incubation, showed differences between diets with cottonseed meal and dry yeast, compared with diets with urea, with values of 7.52; 8.66; and 29.84 mg N-NH3/100 mL of ruminal fluid, respectively. The same pattern was observed […]