Performance, nitrogen balance and microbial efficiency of beef cattle under concentrate supplementation strategies in intensive management of a tropical pasture

Abstract

The objective of this study was to evaluate the effect of concentrate supplementation strategies on the nutritional characteristics of beef cattle in intensive management of tropical pasture. Twenty-four Nellore steer at 250 kg body weight (BW) were used, divided into two plots, with 12 animals in each plot. The experimental area consisted of 32 paddocks with 0.25 ha of Panicum maximum cv. Mombaça. The experiment consisted of 96-day experimental periods, with three periods of 32 days. The strategies studied were P = exclusively on pasture and without concentrate supplementation (control), ES = pasture and supplemented with a concentrate low in protein, PS = pasture and supplemented with high protein content, and PES = pasture and supplementation with balanced protein-energy. There was reduced intake of DM in animals of the treatment P in relation to supplemented pasture, regardless of supplementation. Animals fed on ES showed an intake of more nutrients than the animals on PS. The CP and TDN were also lower in P than in pastures where animals received the additional types of concentrate, and the PS animals showed greater digestibility of CP and TDN than the ES animals. However, the animals exhibited similar weight gains. Animals on P ingested smaller amounts of N and had lower fecal excretion compared to the supplemented animals, but there was no difference between treatments in nitrogen balance. Urea nitrogen and urea from the blood were higher in the supplemented animals than in animals fed on pasture; these levels were also higher in PS animals compared to animals receiving ES. Both the purines absorbed and microbial protein production were similar between treatments. However, the animals fed with concentrate supplementation, independent of the strategy involved, showed higher microbial efficiency compared to animals fed exclusively on pasture.

Improve Pasture or Feed Grain? Greenhouse Gas Emissions, Profitability, and Resource Use for Nelore Beef Cattle in Brazil’s Cerrado and Amazon Biomes

“…The area required to produce one kg of beef carcass in degraded pasture is approximately 320 m 2 but falls to 45-50 m 2 when grazing receives fertilization [14]. Similarly, grain supplementation can improve animal performance, while decreasing GHG emissions [13,17,18].…”

Performance, Digestibility, Nitrogen Balance and Ingestive Behavior of Young Feedlot Bulls Supplemented with Palm Kernel Oil

“…This effect may be mostly related to the lower intake of CP and TDN, also observed in our study, since the intake of these nutrients is related to animal performance [ 31 , 32 ]. The increase in palm kernel oil inclusion promoted a reduction in the intake of crude protein and consequently of nitrogen, contributing to the reduction in the excreted N. The excess excreted nitrogen is a parameter of imbalance in the protein–energy ratio of the diet [ 33 ]. The inclusion of palm kernel oil resulted in a 32.9% decrease in the excretion of N in the animals’ urine, and this reduction is desirable, since this is an expensive nutrient in the animals’ diet and excretion involves energy expenditure, due to the deamination process that takes place in the liver [ 34 ].…”

Protein Supplementation Is Vital for Beef Cattle Fed with Tropical Pasture

“…The potential of utilization of this feed strategy is evident, since animals supplemented with concentrates, regardless of the feeding strategy, demonstrate greater microbial efficiency when compared to the animals fed just pasture [3]. Corroborating with this work, another study was carried out by Batista and colleagues [4] to test whether a protein supplementation of beef cattle fed with tropical low quality pasture improves the efficiency of the use of nitrogen.…”