低蛋白小麦型日粮对肉鸡生产性能和氨基酸代谢的影响

Effects of low protein wheat diet on performance and amino acid metabolism of broilers

本试验旨在评估日粮不同粗蛋白质和小麦水平对肉鸡生长性能和氨基酸代谢的影响。试验将672只孵化后14 d的肉仔鸡随机分为6组,每组8个重复,每个重复14只。日粮采用2×3因子设计,其中粗蛋白质水平为215和165 g/kg,但颗粒饲料额外添加0%、12.5%和25.0%的小麦,试验从14 d开始到35 d结束。结果:日粮粗蛋白质水平由215 g/kg降低至165 g/kg时,料重比显著降低4.70%(P<0.05),同时采食量提高2.38%(P=0.06)。降低日粮粗蛋白质水平可使腹脂相对重量显著提高12.2%(P<0.05),肌胃内容物相对重量显著提高19.9%(P<0.05)。日粮小麦水平从0升高至25%时,肌胃相对重量显著提高53.8%(P<0.05),肌胃内容物相对重量显著提高1.2%(P<0.05),肌胃pH从3.62降低到2.76(P<0.05),但腹脂相对重量显著降低14.6%(P<0.05)。日粮小麦和粗蛋白质水平对血清谷氨酰胺和脯氨酸水平的影响具有显著交互作用(P<0.05)。结论:日粮中粗蛋白质和小麦对肠内氨基酸的可获得性有不同的影响,其中日粮中粗蛋白质水平的降低导致肠内氨基酸供应不平衡,从而影响生长性能。

The purpose of this study was to evaluate the effects of different crude protein and wheat levels on growth performance and amino acid metabolism in broilers.672 broilers 14 days after hatching were randomly divided into 6 groups with 8 replicates in each group and 14 replicates in each group.The diet was designed with a 2×3 factor,in which the crude protein levels were 215 and 165 g/kg,but 0%,12.5%and 25.0%of the whole grain wheat were added to the granular feed.The experiment began on day 14 and ended on day 35.Results:when the crude protein level was reduced from 215 g/kg to 165 g/kg,the feed weight ratio was significantly reduced by 4.70%(P<0.05),and the feed intake was increased by 2.38%(P=0.06).The relative weight of abdominal fat was significantly increased by 12.2%(P<0.05)and the relative weight of myogastric contents was significantly increased by 19.9%(P<0.05).When the dietary grain level increased from 0 to 25%,the relative weight of muscle stomach significantly increased by 53.8%(P<0.05),the relative weight of muscle stomach contents significantly increased by 1.2%(P<0.05),the pH value of muscle stomach decreased from 3.62 to 2.76(P<0.05),but the relative weight of abdominal fat significantly decreased by 14.6%(P<0.05).Dietary cereal and crude protein levels had significant interactions on serum glutamine and proline levels(P<0.05).Conclusion:the crude protein and whole grain diets have different effects on the availability of intestinal amino acids,among which the decrease of crude protein level in the diet leads to the imbalance of intestinal amino acid supply,which affects the growth performance.