肥育猪可消化赖氨酸需要量研究

Determination of Digestible Lysine Requirement in Finishing Pigs

本试验旨在确定70-100 kg猪可消化赖氨酸（DLys）的最佳需要量。选用60头平均体重约70 kg的三元杂交杜长大猪,随机分为5组,每组3个重复。以酶解酪蛋白法（EHC）测定的饲料原料DLys含量为基础按理想蛋白质氨基酸模式（IAAP）配制日粮（等能、等氨基酸模式）,通过测定不同剂量DLys处理组猪生长性能、血液指标及胴体品质,确定70-100 kg猪可消化赖氨酸（DLys）的最佳需要量。结果表明：（1）DLys水平为0.47%-0.59%时,平均日增重（ADG）、无脂瘦肉生长指数（FFLI）随DLys水平的提高而增加,0.59%DLys组达到最大,分别为782 g/d和313.8 g/d（P〈0.05）,之后随DLys水平的提高而下降;（2）料肉比（F/G）随DLys的提高先下降后上升,0.5 9%DLys组最低为3.2 0（P〈0.0 1）;（3）血浆尿素氮（SUN）浓度随DLys水平的升高而显著上升（P〈0.0 5）,眼肌面积也随之显著增大（P〈0.05）,背膘厚则变薄;（4）0.59%DLys组生长激素（GH）水平显著高于其他各组（P〈0.05）。另外,血清总蛋白（TP）、游离甲状腺素T3（FT3）水平各组间无显著差异。综合试验结果表明,70-100 kg猪DLys最佳需要量为0.59%（15.9 g/d）,相应的粗蛋白质为12.96%,以消化能浓度表示则为0.43 g/MJ。

To study the requirement of digestible lysine in finishing pigs, Sixty Duroc × Landrace × Yorkshire pigs with body weight of about 70 kg were randomly assigned to one of 5 treatment groups with 3 duplicates of 4 pigs to investigate the growth performance, blood parameters and carcass quality. The pigs were fed five digestible lysine levels of diets with isoenergetic and same amino acid pattern. The diets were prepared base on ideal amino acids pattern and the true digestibilty of lysine in feedstuff was estimated by enzyme-hydrolyzed casein. The result showed that 1） average daily gain（ADG） and fatfree lean index （FFLI） increased as DLys levels increasing from 0.47% to 0.59%, while decreased as DLys levels decreasing from 0.59% to 0.71%. ADG（782 g/d） and FFLI（313.8 g/d） were highest（P〈0.01） at 0.59% DLys group; 2） feed/Gain decreasd, then increased, and reached a minimum value of 3.20 at 0.59% DLys（P〈0.01）; 3）the concentration of plasma urea nitrogen（SUN） and area of musculi loculi increased with increasing DLys level（P〈0.05）, while fat depth decreased;4） the concentration of growth hormone（GH） at 0.59% DLys group was significantly higher than other groups（P〈0.05）. In addition, serum concentrations of total protein（TP）, free triiodothyronine（FT3） have no significant changes. It indicted that the optimum DLys requirement in finishing pigs with BW of 70 to 100 kg was 0.59% or 15.9 g/d, or 0.43 g/MJ as expressed with digestive energy （DE）. [Chinese Journal of Animal Nutrition, 2007,19（6） ：641-646]