ABSTRACT Sustainable production of adequate quantities of food to support a growing human population is a worldwide goal. Under current feeding conditions in the United States, dairy cattle convert dietary nitrogen to milk nitrogen with 25% efficiency. The remaining 75% is excreted, which contributes to air and water quality problems and reduces economic performance of the industry. Efficiency could be improved to 29% if protein was given to just meet current NRC requirements. Additional improvements may be achievable, but only […]

The objective of the present study was to evaluate the protein requirement of juvenile Trichogaster lalius, blue variety. The experimental design was of randomised blocks (B1 = initial weight of 1.04±0.05 g and B2 = 1.36±0.02 g), with two replicates within each block and five treatments (230, 270, 310, 350 and 390 g CP/kg diet). The fish were fed to satiation, three times a day for 90 days. The study evaluated: survival rate, weight gain, final length, feed intake, feed […]

The objective of this trial was to determine the protein requirements of Zebu bovines on Brachiaria decumbens Stapf. pasture supplemented with concentrate. It was used 28 non-castrated Zebu steers at an average age of 7 months and 180 kg average weight. Eight baseline animals were slaughtered to determine the initial body composition. The 20 remaining animals were divided in five plots of four animals, in a completely randomized design so each group received one out of the five nutritional plans: […]

The high cost of feed ingredients, the use of non-renewable sources of phosphate and the dramatic increase in the environmental load resulting from the excessive land application of manure are major challenges for the livestock industry. Precision feeding is proposed as an essential approach to improve the utilization of dietary nitrogen, phosphorus and other nutrients and thus reduce feeding costs and nutrient excretion. Precision feeding requires accurate knowledge of the nutritional value of feedstuffs and animal nutrient requirements, the formulation […]

The objective in this trial was to estimate the energy requirements of supplemented Zebu bulls grazing Brachiaria decumbens paddocks. Twenty eight intact males, seven months old and initial body weight 180 kg were used. Eight animals were slaughtered as reference, in different weight ranges. The net energy requirements for weight gain were obtained by regressing the log of the retained energy (RE) on the log of empty body weight (EBW). The net energy requirements for maintenance (NEm) were obtained from […]