Cediel-Devia Diana Carolina, Schaitz Luís Henrique, da Silva Fabiano Ferreira, Santos Laize Vieira, da Silva Ana Paula Gomes, Santos Marceliana da Conceição, Dueñez Wbeimar Yamit Sanchez, Melgar Osman Ronaldo Aguilar, Paixão Tarcísio Ribeiro, Silva João Wilian Dias, de Araújo Thiago Luís Alves Campos, de Lima Júnior Dorgival Morais, Silva Robério Rodrigues
Department of Rural and Animal Technology, Southwest Bahia State University, Primavera Square, Itapetinga 45700-000, BA, Brazil.
Department of Animal Science, Federal University of the Semi-Arid Region, Francisco Mota Street, Costa e Silva, Mossoró 59625-900, RN, Brazil.
Animals (Basel). 2024 Aug 27;14(17):2486. doi: 10.3390/ani14172486.
The study aimed to evaluate the effects of three supplementation strategies on intake, apparent digestibility, feeding behavior, performance, carcass traits, proximate composition, and the fatty acid profile of meat from steers on tropical pasture during the post-weaning and finishing stages. The experiment involved 33 1/2 Holstein × 1/2 castrated Zebu steers weighing 335 ± 42.90 kg, aged 22 ± 2 m. The animals were managed on cv. Marandu using an intermittent grazing system with continuous stocking and variable stocking rates for 310 days. The supplementation strategies were as follows: MS/US (mineral salt/urea supplementation): mineral salt in the rainy season and mineral salt with urea in the dry season; US/PS1 (urea supplementation/protein supplementation): mineral salt with urea in the rainy season and protein supplement at 1 g/kg body weight (BW) in the dry season; and PS1/PS2 (protein supplementation 1/protein supplementation 2): protein supplement at 1 g/kg BW in the rainy season and 2 g/kg BW in the dry season. The dry matter intake did not differ significantly ( > 0.05) between strategies. However, the post-weaning PS1/PS2 strategy resulted in higher ( < 0.05) crude protein intake. The final body weight did not differ ( > 0.05) between the strategies, but the average daily gain in post-weaning and finishing was higher ( < 0.05) for MS/US (restricted) animals. Carcass weight, subcutaneous fat thickness, and lipid content in meat were significantly higher ( < 0.05) for steers in the PS1/PS2 group. Steers finished on MS/US produced meat with a higher content of polyunsaturated fatty acids and ω-3 fatty acids ( < 0.05). Concentrate supplementation at 1 g/kg BW during the rainy season and 2 g/kg BW during the dry season is recommended for post-weaning and finishing steers on tropical pasture.
本研究旨在评估三种补饲策略对断奶后及育肥阶段热带草原阉公牛的采食量、表观消化率、采食行为、生产性能、胴体性状、常规成分以及肉脂肪酸谱的影响。试验选用33头体重为335±42.90千克、年龄为22±2月龄的1/2荷斯坦×1/2海福特阉公牛。这些动物在cv. Marandu草地上采用间歇放牧系统,持续放牧且放牧率可变,为期310天。补饲策略如下:MS/US(矿物质盐/尿素补饲):雨季补饲矿物质盐,旱季补饲矿物质盐加尿素;US/PS1(尿素补饲/蛋白质补饲):雨季补饲矿物质盐加尿素,旱季按1克/千克体重补饲蛋白质补充料;PS1/PS2(蛋白质补饲1/蛋白质补饲2):雨季按1克/千克体重补饲蛋白质补充料,旱季按2克/千克体重补饲蛋白质补充料。各策略间干物质采食量差异不显著(P>0.05)。然而,断奶后采用PS1/PS2策略时粗蛋白摄入量更高(P<0.05)。各策略间最终体重差异不显著(P>0.05),但MS/US(限制补饲)组动物断奶后及育肥期的平均日增重更高(P<0.05)。PS1/PS2组阉公牛的胴体重、皮下脂肪厚度和肉中脂质含量显著更高(P<0.05)。采用MS/US策略育肥的阉公牛所产肉中多不饱和脂肪酸和ω-3脂肪酸含量更高(P<0.05)。建议在热带草原对断奶后及育肥阉公牛在雨季按1克/千克体重、旱季按2克/千克体重补饲精料。