饲粮蛋氨酸水平对7～8周龄肉鸡生长性能和组织NPY表达的影响

Effect of Dietary Methionine Level on Growth Performance and Tissue Expression of NPY in Broilers from 7 to 8 Weeks of Age

为探索评价饲粮蛋氨酸营养的分子生物学方法,将27只6周龄AA+公鸡随机分成3组,每组9只,饲粮蛋氨酸水平分别为低(0.30%)、适宜(0.41%)和高水平(0.51%)。测定每组平均日采食量(ADFI)和平均日增重(ADG)指标,并用Western blot方法检测各组肉鸡下丘脑和肌肉的神经肽Y(NPY)表达水平。结果表明:与适宜蛋氨酸饲粮组相比,低或高蛋氨酸饲粮组的ADG和ADFI均有降低趋势,且低蛋氨酸组ADG显著降低(P<0.05);高和低蛋氨酸饲粮组下丘脑、十二指肠、空肠、腿肌NPY表达水平均低于适宜蛋氨酸组(P<0.05);下丘脑与其他组织的NPY表达具有协调性,ADG与腿肌NPY表达显著正相关。结果初步表明肉鸡腿肌中NPY与平均日增重之间存在一定的关系,并推测高或低饲粮蛋氨酸水平对肉鸡生长均不利,其可能影响NPY的表达,进而影响采食。

To probe the evaluation method of molecular biology about methionine nutrition in feed, 27 6-week-age AA＋ rooster were randomly divided into three groups, each group had 9 duplicates. The level of dietary methionine nutrition was low （0.30%）,appropriate （0.41%）and high （0.51%）respectively. Average daily feed intake （ADFI）,average daily gain （ADG）and Neuropeptide Y （NPY）expression in hypothalamus and muscle were measured with Western blot. The results were showed as follows：Compared with appropriate methionine group, ADG and ADFI in low or high methionine group had the tendency of decline,and ADG in low methionine group was significantly reduced （P〈0.05）; NPY expression levels of hypothalamus, duodenum, jejunum and leg muscle in low and high methionine groups were lower than those in appropriate methionine group（P〈0.05）;There was a certain extent of harmony between hypothalamus and the other tissues, and ADG had significantly positive correlation with NPY expression level in muscle. The results suggested that NPY expression level in muscle had a relationship with ADG, and high or low dietary methionine had adverse effect on growth of broilers,and could affect NPY expression, even feed intake.