不同饲粮赖氨酸水平对二元母猪生长性能和血清指标的影响

研究不同饲粮赖氨酸水平对70~100kg阶段二元母猪生长性能、血清指标的影响。选用96头体况相似、平均体重为(69.01±4.43)kg的长大二元母猪,随机分成4个组,每组4个重复,根据饲料原料可消化赖氨酸(DLys)和理想蛋白质氨基酸平衡模式(IAAP)配制低蛋白质试验饲粮(等能、等氨基酸平衡模式),设置饲粮DLys水平分别为0.61%(Ⅰ组)、0.66%(Ⅱ组)、0.71%(Ⅲ组)、0.76%(Ⅳ组)。结果表明,Ⅱ组平均日增重(ADG)最高(908.33g),料重比(F/G)最低(2.77);Ⅱ组血清尿素氮(UN)浓度〗显著低于Ⅰ组和Ⅳ组(P0.05),与Ⅲ组差异不显著(P0.05),血清胰岛素(INS)、胰岛素样生长因子-I(IGF-I)浓度随饲粮DLys水平的升高呈现先升高后降低的变化趋势(P0.05);血清赖氨酸(Lys)和苏氨酸(Thr)质量浓度Ⅳ组显著高于Ⅰ组(P0.05),其他血清氨基酸质量浓度呈现随饲粮DLys水平的升高先降低后升高的变化趋势(P0.05),以Ⅱ组较低。综合生长性能和血清指标,在本试验条件下,二元母猪70~100kg阶段饲粮DLys适宜日摄入量为16.57g·d~(-1),即饲粮DLys水平为0.66%,能获得较好的生长性能。

Effects of Lysine Content in Low Protein Fodder on Growth and Serum Biochemistry of Two-line Crossbred Gilts

Effect of lysine content in a low-crude-protein fodder on the growth performance and serum biochemical indices of 70-to-100-kg-class gilts was studied.Ninety-six gilts crossbred between Landrace and Large White with an average body weight of (69.01 ±4.43) kg and similar physical conditions were randomly divided into 4 groups with 4 replicates each for the study.With an equal energy and balanced amino acid design,the digestible lysine (DLys)at 0.61％ (Group Ⅰ),0.66％ (Group Ⅱ),0.71％ (Group Ⅲ) or 0.76％ (Group Ⅳ) in the low protein diets were applied for the feeding.The results showed the gilts in Group Ⅱ had the highest average daily gain at 908.33 g · d-1 and the lowest feed/gain ratio at 2.77 (P＜0.05) among all.The Group Ⅱ gilts also showed a significantly lower serum urea nitrogen than the gilts in Group Ⅰ or Group Ⅳ (P＜0.05),but no significant difference in comparison with Group Ⅲ (P＞0.05).The serum insulin and insulin growth factor-Ⅰ in all test animals increased initially,and then,decreased as DLys increased (P＞ 0.05).The serum lysine and threonine of the Group Ⅰ gilts were significantly lower than those of Group Ⅳ (P＜0.05),while the other amino acids decreased initially and followed by an increase with increasing DLys (P＞0.05),which was lower in Group Ⅱ.Taking all factors into account,a daily DLys intake of 16.57 g · d-1 (or,as in Group Ⅱ,0.66％ DLys in the low-protein diet) would be optimal for the growth of gilts in the weight class.