Intake, nitrogen balance and microbial protein synthesis of steers fed with or without lipid addition

This study investigated the influence of energy supplementation with or without the addition of lipids on microbial production, microbial synthesis efficiency and nitrogen balance. Eight fistulated steers were used with accessible rumens and kept in individual stalls. Their diets consisted of corn silage; corn silage + concentrate; corn silage + concentrate with addition of lipids in the form of soybean oil; and corn silage + concentrate with addition of lipids in the form of soybean grains. Estimates of microbial protein synthesis were obtained based on the urinary excretion of purine derivatives. The concentrations of ammonia in the rumen were determined immediately at 2, 4, 6 and 8 hours after feeding. The diets with concentrate increased (P0.05). Concentrated diets presented higher concentrations of urea nitrogen in the serum and urinary urea excretion (P0.05). Energy supplementation, with or without lipid addition, can be used as a strategy to increase the synthesis of the microbial protein in the cattle fed corn silage

Growth performance and carcass traits of young nellore bulls supplemented with or without addition of lipids

The aim of research was to evaluate the performance and characteristics of the carcasses of Nellore young bulls in grazing supplemented with or without addition of lipids. Twenty–eight young bulls, 301 ± 5.8 kg in body weight, which four constituted the reference group and the twenty-four remnants were used in the experiment and randomly distributed into four groups according to treatment: only Panicum maximum cv. Mombasa grass; Mombasa grass with concentrated supplementation based on soybean meal; Mombasa grass with concentrate containing lipids from soybean oil; and Mombasa grass with concentrate containing lipids derived from soybean grains. The total dry matter intake of the animals fed only Mombasa grass did not differ from the average intake of the three treatments supplemented with concentrate. There were no differences (P>0.05) between Mombasa grass and diets with concentrate, supplementation with or without lipid and lipids sources in the carcass traits, gastrointestinal tract, organs and loin eye area. Nellore bulls receiving concentrate increased subcutaneous fat thickness compared with bulls that received only Mombasa grass. Nellore young bulls fed Mombasa grass only, supplemented with or without addition of lipids were similar regarding growth performance and carcass traits

Performance, body composition and net requirements of protein and energy for weight gain in steers supplemented with or without addition of lipids

This research aimed to evaluate the performance, body composition and net requirements for protein and energy in grazing Nellore steers supplemented with or without addition of lipids. Twenty-eight steers, 301 ± 5.8 kg BW, were used in the experiment. The comparative slaughter method was used, with four steers used as references. The remaining 24 steers were randomly distributed into four groups, during 180 days, according to treatment: only Panicum maximum cv. Mombasa grass; Mombasa grass with concentrated supplementation based on soybean meal; Mombasa grass with concentrate containing lipids from soybean oil; and Mombasa grass with concentrate containing lipids derived from soybean grains. The total DMI of the steers fed only the pasture did not differ (P > 0.05) from the average intake of the treatments with or without addition of lipids. There were no differences (P > 0.05) between treatments for total daily gain, carcass and non carcass for protein, energy and fat. The requirements of protein and energy did not differ (P > 0.05) among the treatments. When the pasture is of good quality, supplementation does not alter the body composition or the net requirements of protein and energy for weight gain. The supplementations with higher concentrations of lipids (oil and grain) were not enough to promote greater gains in fat and energy in carcass