日粮蛋白水平对圩猪生长性能、肉质和血清生化指标的影响

Effect of dietary protein levels on growth performance,meat quality trait and serum biochemical parameters in Wei pigs

【目的】探讨不同蛋白水平日粮对圩猪生长性能、肉质和血清生化指标的影响，确定圩猪适宜的蛋白质营养水平。【方法】选用平均体质量约为35 kg的健康圩猪24头，按照公母比例1∶1的原则随机分为3个处理组，每组8个重复，采用种猪自动饲喂系统饲喂，耗料和体质量实时自动记录。试验期共分为2个阶段（生长期：35～60 kg；肥育期：60～80 kg）饲养，1，2，3组生长期粗蛋白水平分别为180，160和140 g/kg，肥育期粗蛋白水平分别为160，140和120 g/kg。3个处理组除粗蛋白水平不同外，其他营养水平基本一致。试验结束时，对全部试猪前腔静脉采血以进行血液生化指标与部分内分泌激素浓度的测定，同时每组选取4头体质量相近的公猪屠宰，测定其屠宰性能和肉质。【结果】在育肥阶段，日粮中粗蛋白含量最少的试验3组料体质量比极显著高于1组和2组（P＜0.01）。除屠宰后24 h肉样的pH值和亮度（L）值外，各组间肉质性状差异均不显著（P＞0.05）， 1组屠宰后24 h的pH值显著低于2组（P＜0.05），而L值显著高于2组（P＜0.05）； 1组的肌苷酸含量显著高于2组（P＜0.05），不饱和脂肪酸和单不饱和脂肪酸含量极显著高于3组（P＜0.01），但均与2组差异不显著（P＞0.05）。随着日粮蛋白水平的降低，血清尿素氮浓度下降，3组血清尿素氮浓度显著低于试验1组和2组（P＜0.05），〖JP2〗血清甲状腺素T3浓度显著高于2组（P＜0.05）。【结论】在日粮消化能水平为12.77 MJ/kg时，圩猪生长期和肥育期日粮粗蛋白水平均以140 g/kg为宜。

【Objective】This study aimed to investigate the effect of dietary protein levels on growth performance,meat quality and serum biochemical parameter so as to find the suitable dietary protein levels of Wei pigs.【Method】24 healthy Wei pigs with weight of 35 kg were randomly split to 3 groups.The pigs were fed by the automatic feeding system,and the consumption was recorded immediately.The trial was divided into two stages （growing period：35-60 kg and finishing period：60-80 kg）.The crude protein （CP） levels in growing period of treatments 1,2 and 3 were 180,160 and 140 g/kg respectively.The CP levels in finishing period were 160,140 and 120 g/kg respectively.Blood samples of all pigs were drawn by Vacuum tubes to determine the serum biochemical parameters and endocrine hormones.Meanwhile,4 pigs were selected to determine the slaughter performance and meat quality.Three treatments had the consistent contents of other nutrients except the crude protein.【Result】In 60-80 kg stage,F/G of treatment 3 significantly increased to 7.00 when dietary CP level reduced to 120 g/kg.Carcass trait of each group had no significant difference （P〉0.05） except pH and L.pH of 24 h after slaughter of treatment 1 was significantly lower than treatment 2 （P〈0.05）,while L24h value was significantly higher than treatment 2 （P〈0.05）.The IMP content of treatment 1 was significantly higher than that of treatment 2 （P〈0.05）,while the contents of unsaturated fatty acid （UFA） and monounsaturated fatty acid （MUFA） were higher than that of treatment 3 （P〈0.01）.With the decrease of dietary CP level,the content of serum urea nitrogen （BUN） descended.The BUN content of treatment 3 was significantly lower than treatment 1 and treatment 2 （P〈0.05）,while thyroid hormone T3 was significantly higher than treatment 2 （P〈0.05）.【Conclusion】When the dietary digestible energy was 12.77 MJ/kg,the appropriate CP level for Wei Pigs was 140 g/kg.