低氮日粮补充支链氨基酸提高断奶仔猪生长性能和氮的利用效率

Low Protein Diet Supplemented with Branched Chain Amino Acids Improves Growth Performance and Nitrogen Utilization in Weaned Piglet

本试验旨在研究低氮日粮中补充支链氨基酸对断奶仔猪的生长及肠道的氧化性能的影响。选用18头28日龄断奶的杜×长×大杂交仔猪按体重随机分为3组,分别采食对照组(21%CP)、低氮组(17%CP)和低氮补充支链氨基酸(17%CP+BCAA)组日粮,试验期为4周。测试仔猪的空肠过氧化物酶、超氧化物歧化酶等抗氧化指标以及仔猪总体的生长性能和血浆游离必需氨基酸的含量变化。结果表明:降低日粮氮水平会降低日粮蛋白水平,与此同时断奶仔猪的生长性能也极显著降低(P<0.01);在低氮日粮中补充支链氨基酸后,仔猪的生长性能得到提高;日粮中补充的氨基酸提高了仔猪血液中相应的氨基酸水平(P<0.05),两组低氮日粮的血浆尿素氮水平都显著低于对照组(P<0.05);但本试验发现支链氨基酸并未显著影响断奶仔猪空肠的抗氧化功能(P>0.05)。从生长性能、血液游离必需氨基酸以及血浆尿素氮都说明了低氮日粮中补充支链氨基酸不仅能够保证断奶仔猪的生长,还可以提高日粮氮的利用效率,降低氮排放;从蛋白原料的紧缺以及畜禽养殖的环境成本来看,补充氨基酸的低氮日粮具有突出的优越性。

The objective of the current study was to investigate growth performance and plasma amino acids concentration in weaning pigs with branched amino acids supplementation diet. In the study, three treatments, the control treatment （21%CP）, the protein restricted diet （17%CP） and the branched-chain amino acids diet （17%CP＋ BCAA） were designed to offer to 18 crossbred piglets weaned at （28＋_1） d of age. After 28 d trail period, the growth performance, plasma amino acids concentration and antioxidant indexes in intestine were tested. The result showed that the protein restricted treatment had the lowest growth performance （P〈0.01）. Branched-chain amino acids supplemented in the protein restricted group improved all of growth performance significantly. The plasma urea concentration of pigs was declined significantly in the BCAA （P =0.06）, and the supplementation of crystalline amino acids significantly increased plasma concentration of these amino acids, compared with the control group. No effect on tissual antioxidant indexes were observed in the jejunum （P〉0.05）. In conclusion, branched chain amino acids improved the growth performance and efficiency of nitrogen utilization in weanling piglets.