Two hundred and sixteen layers were raised from 39 to 55 weeks of age to study the effects of levels of calcium in the rations on performance and eggs quality of brown commercial layers. A completely randomized experimental design were used with six levels of calcium (3.0; 3.4; 3.8; 4.2; 4.6 and 5.0%) and six replicates of six layers hens. There was no effect of calcium levels on hen performance, however significantly affected the percentage of albumen and egg shell. […]

The experiment was carried out to evaluate addition effects of five urea levels with four ammonization periods on Agave sisalana residue chemical composition in the different storage times. It was used 300 kg of this co-product, equally distributed in 60 black polyethylene bags, which urea was added in the following concentrations: 0, 2, 4, 6 and, 8% over 0, 2, 4 and, 6 weeks storage periods. It was made determinations of dry matter (DM), crude protein (PB), neutral detergent fiber […]

This experiment was carried out to study calcium (Ca) and phosphorus (P) kinetics of growing horses fed diets with different Ca levels: 0.15%, 0.45, and 0.75%, using a deterministic and compartmental model. The information on metabolism and kinetic of Ca and P in tissues was obtained by the isotopic dilution technique. Dietary Ca levels influenced Ca true absorption, showing lower value (4.97 g Ca/day) for the Ca level of 0.15%. The changes of Ca between the blood and digestive tract […]

The effect of four dietary urea levels: 0, 0.65, 1.3 and 1.95% in dry matter (DM), on the microbial protein production by means of the urinary purine derivatives was evaluated by using two collection methodologies in steers of four genetic groups: Holstein in, ½ Holstein-Guzera, ½ Holstein-Gir and Zebu. Animals were fed diets with 50:50 tifton-85 bermudagrass hay to concentrate ratio and assigned to four 4 ´ 4 latin squares (genetic groups): four animals, four experimental periods and four treatments […]

This work was carried out to evaluate the effect of four dietary urea levels (0, 0.65, 1.3, and 1.95% in dry matter – DM) on ruminal pH and ammonia-N, plasmatic urea nitrogen, urea fractional excretion, creatinine and urea excretions, as well as to evaluate endogenous urinary losses, by means of creatinine excretion, in steers of four genetic groups (Holstein, ½ Holstein-Guzera, ½ Holstein-Gir and Zebu). Animals were assigned to four 4 ´ 4 latin squares (genetic groups), with four animals, […]

Two hundred male Ross broiler chicks were raised from 10 to 40 days of age and fed a corn-soy diet with 4% of fresh or oxidized poultry offal fat to evaluate the effects of dietary fat quality on broiler performance and on oxidative stability of frozen thigh meat during storage. Fresh poultry fat, characterized by low concentration of oxidation products determined by specific absorbances of 5.80 and 0.69 at 232 and 270 nm, respectively, was supplied by a local renderer […]

The production cost in cow-calf was designed by a standard methodology that can be able to measure the production cost of calves and, simultaneously to validate the method in a production system. Within this context, the present paper discusses, initially, the relevance of the implementation of methodology in cost centers as a support decision-making, due to the need for a segmented analysis of the processes, specialized in cow-calf production systems. The stages for implementation of this method are described. A […]

This work was carried out with the objective to evaluate the effect of replacement of soybean meal by common bean (Phaseolus vulgaris L.) residue in rations for milking cows on the following variables: intakes and total apparent digestibilities of nutrients, milk production and composition and feeding efficiency. Twelve Holstein cows were randomly assigned to three 4 ´ 4 balanced latin square design. The animals was fed ad libitum total mixed rations, which contained 0; 13; 26 and 39% of raw […]

The objectives of this study were to obtain heritability estimates for number (NBZ10 and NBZT) and kilograms (QBD10 and QBDT) of calves weaned up to ten years of age and during herd life, kilograms of calves weaned per year in herd (QTPR) and their genetic correlations with culling age, ages at first, at second and at third calving, adjusted and unadjusted weights for condition score, body size indexes and condition score at first mating, at first calving and at mature […]

The trial was conducted to evaluate the effects supplementation with ground corn on grazing dairy heifers diurnal ingestive behavior. Six Jersey heifers, aged of 6 to 9 months and weighing 105.65 ± 18.2 kg, were used. Heifers were grouped into three animals “testers”, and kept in an annual ryegrass (Lolium multiflorum Lam.) pasture, under continuous grazing, with variable stocking rate. Two treatments were used, one as control (no supplement) and another supplemented with ground corn being assigned three animals “testers” […]