不同蛋白质水平日粮对不同日龄育成期公貂(Mstula vision)生长性能与消化代谢规律的影响

Effect of Dietary Protein on the Growth Performance and the Regularity of Digestibility and Metabolism in Mink at the Period of Development

旨在研究水貂在断奶分窝后至育成前期结束期间,对不同蛋白质水平日粮中营养物质的消化代谢规律及不同营养水平对水貂生产性能的影响。选择健康状况、日龄相近的幼龄雄性水貂60只,按照单因素试验设计随机分成6组,6组饲喂蛋白质水平分别为:28%(Ⅰ组)、30%(Ⅱ组)、32%(Ⅲ组)、34%(Ⅳ组)、36%(Ⅴ组)、38%(Ⅵ组)。在水貂育成期内,进行饲养与消化代谢试验,分析不同日龄水貂的蛋白消化率、脂肪消化率、氮沉积、氮生物学价值等指标,结合饲料转化率及日增体质量,研究水貂在生长过程中对蛋白质、脂肪等营养物质的消化代谢规律。试验结果表明:各组水貂在体质量、蛋白质生物学价值和净蛋白质利用率上存在显著差异(P<0.05),在饲料转化率、干物质消化率、蛋白质消化率、脂肪消化率、食入氮和尿氮指标上差异极显著(P<0.01);各组水貂尿氮排出量随着饲喂日粮的蛋白质含量的提高而增加;育成期水貂的日粮蛋白质含量低于32%时,饲料转化率和日增体质量均显著降低(P<0.05)。育成期水貂日粮蛋白质水平低于32%,水貂的生长速度显著减慢;日粮蛋白质含量达到34%以上能够提高脂肪和干物质的消化率;育成期水貂在50～80日龄之间,适宜的蛋白质水平为36%,80～110日龄间,水貂适宜的蛋白质水平是34%。

The expriment was designed to investigate the regulatory of digestion and metabolism of different dietary protein levels in mink at the period of the growth and development.Sixty young male minks were randomly divided into six groups according to a single-factor test.The trials of feeding and metabolism were used to analyse the digestibility of protein,digestibility of fat,nitrogen deposition and protein biological value,combining with the ratio of feed conversion rate and the average daily gain to deduce the fluctuation regulation of nutrition in mink during the rearing process of the growth and development.The result showed that： the paremeters such as body weight,protein biological value and net protein utilization were significantly different among groups（P0.05）;feed conversion rate,digestibility of dry matters,digestibility of protein,digestibility of crude fat,intake nitrogen and urine nitrogen were greatly significantly different among minks（P0.01）;the more urine nitrogen was drained with the more dietary protein（P0.05）;the percentage of dietary protein was less than 32%,the feed conversion rate and average daily gain of minks were significantly reduced（P0.05）.The content of dietary protein was lower than 32%,the growth rate of mink would be obviously declined（P0.05）;the higher dietary protein level that over 34% promoted the digestibility of crude fat and dry matters;the optimum dietary protein level were 36% and 34% at 50-80 day ages and 80-110 day ages,respectively.