Rocha Tiago Cunha, Fontes Carlos Augusto de Alencar, da Silva Renata Tavares Soares, Processi Elizabeth Fonsêca, do Valle Felipe Roberto Amaral Ferreira, Lombardi Cláudio Teixeira, Oliveira Ronaldo Lopes, Bezerra Leilson Rocha
School of Veterinary Medicine and Animal Science, Federal University of Bahia, Salvador, Bahia State, Brazil.
Department of Animal Science, State University of North Fluminense Darcy Ribeiro, Campos dos Goytacazes City, Rio de Janeiro State, Brazil.
Trop Anim Health Prod. 2016 Mar;48(3):673-81. doi: 10.1007/s11250-015-0991-4. Epub 2016 Jan 14.
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.
本研究的目的是评估在热带牧场集约化管理中，精料补充策略对肉牛营养特性的影响。使用了24头体重250千克的内洛尔阉牛，分为两个小区，每个小区12头动物。试验区由32个围场组成，种植0.25公顷的巴伊亚雀稗品种蒙巴萨。实验包括96天的实验期，分为三个32天的阶段。研究的策略包括：P = 仅在牧场饲养且不补充精料（对照），ES = 牧场饲养并补充低蛋白精料，PS = 牧场饲养并补充高蛋白精料，PES = 牧场饲养并补充蛋白质 - 能量平衡的精料。无论是否补充精料，处理P组动物的干物质摄入量相对于补充精料的牧场饲养动物均有所减少。采食ES精料的动物比采食PS精料的动物摄入更多营养物质。处理P组的粗蛋白和总可消化养分也低于接受其他类型精料补充的牧场饲养动物，且PS组动物的粗蛋白和总可消化养分消化率高于ES组动物。然而，各处理组动物的体重增加相似。与补充精料的动物相比，处理P组动物摄入的氮量较少，粪便排泄量也较低，但各处理组之间的氮平衡没有差异。补充精料的动物血液中的尿素氮和尿素含量高于牧场饲养动物；PS组动物的这些水平也高于采食ES精料的动物。各处理组之间吸收的嘌呤和微生物蛋白产量相似。然而，与仅在牧场饲养的动物相比，无论采用何种精料补充策略，补充精料的动物微生物效率更高。
