ABSTRACT Vitamin A is listed in the fat-soluble vitamins group, whose absorption, transport, and storage are similar to the lipids. However, the vitamin A functions go beyond those reported in the ocular cells’ metabolism being also described in reproductive functions, growth, and specific tissue maintenance through gene regulation. In ruminants, vitamin A supplementation can be done in different ways. Orally with carotenoids which β-carotene is the main representative, and intramuscularly by injectable applications of synthetic vitamin A. In cows, it […]

ABSTRACT The objective of this study was to assess the effect of corn silage particle size on feeding behavior, blood parameters, fecal characteristics, and growth performance of beef heifers. Corn silage was harvested at 37.9 ± 1.6% dry matter (DM) using a self-propelled harvester containing shredding rolls and set to either a 13-mm theoretical length of cut (TLC), designated as conventional particle size (CPS), or a 24-mm TLC, designated as long particle size (LPS). Ninety-six Nellore heifers (initial shrunk body […]

ABSTRACT The objective of this study was to investigate the potential carryover effect of narasin (NAR) supplementation during the backgrounding phase on subsequent feedlot performance and gastrointestinal morphometrics of finishing Nellore bulls. Ninety-six bulls were used in a 2 × 2 factorial design, evaluating conditional NAR supplementation on the backgrounding phase (control [CON] or NAR) and finishing supplementation (sodium monensin [MON] or NAR), resulting in four treatments as follows: 1) CON+MON, 2) CON+NAR, 3) NAR+MON, and 4) NAR+NAR. During the […]

ABSTRACT The objective of this study was to evaluate in vitro effects on ruminal fermentation of by-product from the production of edible mushroom Pleurotus ostreatus. The following by-products were tested: (I) non-colonized sugarcane bagasse (control); (II) sugarcane bagasse from non-enriched mushrooms; and (III) sugarcane bagasse from selenium-enriched mushrooms. A semi-automatic in vitro system was used. The pH and neutral detergent fiber (NDF) residue were determined at 0, 3, 6, 9, 12, 18, 24, 48, 72, and 96 h of incubation. […]

ABSTRACT This study aimed to assess the productive performance and carcass characteristics of feedlot lambs fed corn grain silage rehydrated with different solutions. Twenty-eight Santa Inês ram lambs, approximately 75 days of age and with an average weight of 17.05±3.75 kg, were randomly assigned to one of four dietary treatments: dried corn grains (control); whey-rehydrated corn grain silage; water-rehydrated corn grain silage; and water + additive-rehydrated corn grain silage. For animal performance, dry matter intake, average daily weight gain, and […]

ABSTRACT This study aimed to assess the ruminal fermentation of various cottonseed (Exp. 1) and peanut (Exp. 2) meals, each processed using different techniques and exhibiting varying levels of rumen undegradable protein (RUP). Six treatments were evaluated for each feed. For Exp. 1 (cottonseed meal): negative control (conventional meal; Ncontrol), microwave-heated (2 min) with 2% xylose, conventional oven-heated (90 min) with 2% xylose, autoclave-heated (8 min) with 2% xylose, tannin treatment (6% inclusion), and a commercial soybean-based product (Pcontrol). For […]

ABSTRACT This study aimed to evaluate the effects of backgrounding supplementation, by increasing the levels of energy-protein supplements during the growing phase on the performance and rumen morphometrics of Nellore bulls intensively finished on pasture. Ninety-six Nellore bulls were blocked according to initial body weight (BW) of 385.6 ± 7.3 kg and randomly assigned to one of 24 paddocks of Urochloa brizantha cv. ‘Piata’ (four animals/paddock). The animals were supplemented during the growing phase as follows: (1) energy-protein supplementation at […]

ABSTRACT This study aimed to evaluate the effects of total replacement of soybean meal and partial replacement of ground corn with licuri cake (LC) in the diet of young Nellore bulls on feed intake, ingestive behavior, nutrient digestibility, nitrogen balance, microbial protein synthesis, animal performance, carcass traits and economic efficiency, including marginal costs and returns. Thirty-two 16-month-old Nellore bulls (346 ± 32.5 kg body weight) were individually evaluated in a completely randomized experimental design with four treatments (0, 7, 14, […]

ABSTRACT Two experiments were carried out aiming to evaluate the effect of copaiba oil on growth performance, apparent digestibility of nutrients, and rumen fermentation in lambs on feedlot. The treatments were: no additive inclusion (negative control); 8 mg/kg of sodium monensin (MS; positive control); and 250, 500, and 750 mg of copaiba oil/kg dry matter added to a diet with 70% concentrate and 30% forage. In experiment I, five lambs (Dorper × Santa Inês) cannulated in the rumen, 8 ± […]

ABSTRACT The objective of this study was to evaluate the effect of castration and days of feed (DOF) on glucose sensitivity and muscle expression of genes related to glucose metabolism, muscle growth, and fat deposition. Thirty-six Nellore bull calves were either surgically castrated or left intact, then harvested at 0, 100, or 200 DOF. Glucose tolerance tests were performed at 100 and 200 DOF. Longissimus dorsi (LD) samples were taken just after stunning for gene expression. Data were analyzed as […]