Monção Flávio Pinto, Santana Pedro Felipe, Júnior Vicente Ribeiro Rocha, Ruas José Reinaldo Mendes, Rigueira João Paulo Sampaio, Borges Lucas Daniel Alcântara, de Castro Menezes Gustavo Chamon, Sousa Thais Eleonora Santos, da Costa Maria Dulcinéia, Oliveira Laura Lúcia Santos, de Queiroz Fausto Expedito
Department of Animal Science and Technology, State University of Montes Claros, Avenue Reinaldo Viana, Janaúba, Minas Gerais, 2630, Brazil.
Trop Anim Health Prod. 2020 Jan;52(1):141-149. doi: 10.1007/s11250-019-01994-z. Epub 2019 Jul 12.
The quantitative feed restriction of lactating cows has been used in intensive production systems as a strategy to reduce production costs. However, the effects of this restriction in F1 Holstein/Zebu cows are unclear. The objective of this work was to evaluate the effect of quantitative feed restriction on nutrient intake and digestibility, nitrogen balance, feed efficiency, feed behavior, and productive performance in F1 Holstein/Zebu cows during early lactation. Sixty F1 Holstein × Zebu cows were used at the stage of initial lactation (50 ± 13 days of lactation), and they had an initial body weight (BW) of 482 ± 43 kg. The experimental arrangement adopted was a completely randomized design, with five feed restriction levels (3.39, 2.75, 2.50, 2.25, and 2.00% of BW) and 12 cows in each treatment group. In the short term (63 days), there were reductions of 45.9% and 47.2% in dry matter intake (P < 0.01) and crude protein (P < 0.01), respectively, when the diet supply was limited from 3.39% BW to 2.00% of BW. There were declines in intake of ether extract (P < 0.01) and nonfibrous carbohydrates (P < 0.01), but there was no change in daily milk production (P = 0.44) nor the daily milk production corrected to 3.5% fat (P = 0.12); the averages were 14.01 kg/day and 13.25 kg/day, respectively. Considering the lower body weight loss, feed restriction is recommended up to 2.5% of the BW.
在集约化生产系统中，对泌乳奶牛进行定量限饲已被用作降低生产成本的一种策略。然而，这种限饲对F1荷斯坦/瘤牛的影响尚不清楚。本研究的目的是评估定量限饲对F1荷斯坦/瘤牛泌乳早期营养物质摄入量和消化率、氮平衡、饲料效率、采食行为及生产性能的影响。选用60头处于泌乳初期（泌乳50±13天）的F1荷斯坦×瘤牛，初始体重（BW）为482±43千克。实验采用完全随机设计，设置五个限饲水平（BW的3.39%、2.75%、2.50%、2.25%和2.00%），每个处理组12头牛。在短期内（63天），当日粮供应量从BW的3.39%降至2.00%时，干物质摄入量（P<0.01）和粗蛋白摄入量（P<0.01）分别降低了45.9%和47.2%。乙醚提取物摄入量（P<0.01）和非纤维碳水化合物摄入量（P<0.01）下降，但日产奶量（P=0.44）和校正至3.5%脂肪的日产奶量（P=0.12）均无变化；平均日产奶量分别为14.01千克/天和13.25千克/天。考虑到较低的体重损失，建议限饲至BW的2.5%。
