Fernandes Rodolfo Maciel, de Almeida Chafic Mustafé, Carvalho Bruna Caldas, Alves Neto João Alexandrino, Mota Verônica Aparecida Costa, de Resende Flávio Dutra, Siqueira Gustavo Rezende
Universidade Estadual Paulista "Júlio de Mesquita Filho", Faculdade de Ciências Agrárias e Veterinárias, Via de Acesso Professor Paulo Donato Castellane s/n, Jaboticabal, SP, CEP: 14884-900, Brazil.
Agencia Paulista de Tecnologia dos agronegócios, Avenida Rui Barbosa s/n, CX 35, CEP: 14770-000, Colina, SP, CEP: 14.783-226, Brazil.
Trop Anim Health Prod. 2016 Jan;48(1):95-101. doi: 10.1007/s11250-015-0925-1. Epub 2015 Oct 3.
The objective of this study was to evaluate the effect of increasing the supply of protein with different degradation rates on the performance and metabolism of growing Nellore cattle reared on Brachiaria brizantha cv. Marandu pasture during the transition period from the dry to rainy season. The experiment was installed on an area of 34 ha, divided into 12 paddocks with an average area of 2.85 ha. In the performance evaluation were utilized 72 recently weaned, non-castrated Nellore cattle with an initial body weight (BW) of 199 kg (SEM = 16). The following supplements were used: energy protein supplement containing 25% crude protein (CP) (C-25) and energy protein supplements containing 40% CP with one third highly degradable CP and two thirds poorly degradable CP (40-1/3NPN), one half highly degradable CP and one half poorly degradable CP (40-1/2NPN), and two thirds highly degradable CP and one third poorly degradable CP (40-2/3NPN). Higher protein degradation rates reduced supplement intake (P < 0.01). In the first period, animals consuming supplement 40-1/3NPN exhibited higher average daily gain (ADG) (0.30 kg/day), similar to that of animals receiving supplement 40-1/2NPN (P = 0.04). In the second period, supplement 40-2/3NPN resulted in lower ADG (0.19 kg/day less than the other supplements). There was no effect of supplement on animal performance in the third period (P > 0.10), when ADG was 0.56 kg/day. In conclusion, the response to supplementation is associated with interactions with characteristics of the forage canopy. Supplementation with a true protein source will be beneficial only during the early stage of the dry-rainy season transition period.
本研究的目的是评估在从旱季到雨季的过渡期，增加不同降解率蛋白质供应对在臂形草cv. Marandu牧场上饲养的生长内洛尔牛的生产性能和代谢的影响。试验在34公顷的区域内进行，分为12个围场，平均面积为2.85公顷。在生产性能评估中，使用了72头刚断奶的非阉割内洛尔牛，初始体重（BW）为199千克（标准误=16）。使用了以下补充剂：含25%粗蛋白（CP）的能量蛋白补充剂（C-25），以及含40%CP的能量蛋白补充剂，其中三分之一为高降解性CP，三分之二为低降解性CP（40-1/3NPN），二分之一为高降解性CP，二分之一为低降解性CP（40-1/2NPN），三分之二为高降解性CP，三分之一为低降解性CP（40-2/3NPN）。较高的蛋白质降解率降低了补充剂摄入量（P<0.01）。在第一阶段，食用40-1/3NPN补充剂的动物平均日增重（ADG）较高（0.30千克/天），与食用40-1/2NPN补充剂的动物相似（P=0.04）。在第二阶段，40-2/3NPN补充剂导致较低的ADG（比其他补充剂低0.19千克/天）。在第三阶段，当ADG为0.56千克/天时，补充剂对动物生产性能没有影响（P>0.10）。总之，对补充剂的反应与与牧草冠层特征的相互作用有关。仅在旱季-雨季过渡期的早期阶段，补充真正的蛋白质来源才有益。
