標題: 標準回腸可消化色氨酸和賴氨酸的比例對保育豬生長性能的影響 [打印本頁] 作者: 畜牧編輯 時間: 2016-4-11 13:34 標題: 標準回腸可消化色氨酸和賴氨酸的比例對保育豬生長性能的影響 2015. J. Anim.Sci. 93(8):3909-3918 標準回腸可消化色氨酸和賴氨酸的比例對保育豬生長性能的影響
M. A. D.Gonçalves, S. Nitikanchana, M. D. Tokach, S. S. Dritz, N. M. Bello, R. D.Goodband, K. J. Touchette, J. L. Usry, J. M. DeRouchey和J. C. Woodworth
Effects of standardized ileal digestible tryptophan: lysine ratio on growth performance of nursery pigs
M. A. D.Gonçalves, S. Nitikanchana, M. D. Tokach, S. S. Dritz, N. M. Bello, R. D.Goodband, K. J. Touchette, J. L. Usry, J. M. DeRouchey and J. C. Woodworth
Two experiments were conducted to estimate the standardized ileal digestible (SID) Trp:Lys ratio requirement for growth performance of nursery pigs. Experimental diets were formulated to ensure that lysine was the second limiting AA throughout the experiments. In Exp. 1 (6 to 10 kg BW), 255 nursery pigs (PIC327 × 1050, initially 6.3 ± 0.15 kg, mean ± SD) arranged in pens of 6 or 7 pigs were blocked by pen weight and assigned to experimental diets (7 pens/diet) consisting of SID Trp:Lys ratios of 14.7%, 16.5%, 18.4%, 20.3%, 22.1%, and 24.0% for 14 d with 1.30% SID Lys. In Exp. 2 (11 to 20 kg BW), 1,088 pigs (PIC337 × 1050, initially 11.2 kg ± 1.35 BW, mean ± SD) arranged in pens of 24 to 27 pigs were blocked by average pig weight and assigned to experimental diets(6 pens/diet) consisting of SID Trp:Lys ratios of 14.5%, 16.5%, 18.0%, 19.5%,21.0%, 22.5%, and 24.5% for 21 d with 30% dried distillers grains with solubles and 0.97% SID Lys. Each experiment was analyzed using general linear mixed models with heterogeneous residual variances. Competing heteroskedastic models included broken-line linear (BLL), broken-line quadratic (BLQ), and quadratic polynomial (QP). For each response, the best-fitting model was selected using Bayesian information criterion. In Exp. 1 (6 to 10 kg BW), increasing SID Trp:Lys ratio linearly increased (P < 0.05) ADG and G:F. For ADG, thebest-fitting model was a QP in which the maximum ADG was estimated at 23.9%(95% confidence interval [CI]: [<14.7%, >24.0%]) SID Trp:Lys ratio. For G:F,the best-fitting model was a BLL in which the maximum G:F was estimated at 20.4% (95% CI: [14.3%, 26.5%]) SID Trp:Lys. In Exp. 2 (11 to 20 kg BW),increasing SID Trp:Lys ratio increased (P < 0.05) ADG and G:F in a quadratic manner. For ADG, the best-fitting model was a QP in which the maximum ADG was estimated at 21.2% (95% CI: [20.5%, 21.9%]) SID Trp:Lys. For G:F, BLL and BLQ models had comparable fit and estimated SID Trp:Lys requirements at 16.6% (95%CI: [16.0%, 17.3%]) and 17.1% (95% CI: [16.6%, 17.7%]), respectively. In conclusion, the estimated SID Trp:Lys requirement in Exp. 1 ranged from 20.4% for maximum G:F to 23.9% for maximum ADG, whereas in Exp. 2 it ranged from 16.6% for maximum G:F to 21.2% for maximum ADG. These results suggest that standard NRC (2012) recommendations may underestimate the SID Trp:Lys requirement for nursery pigs from 11 to 20 kg BW。