仔猪初生重影响体蛋白沉积,但不影响蛋白利用效率
发布单位:凯发网站查看次数:7876
时间:2020-07-02
探究猪对蛋白利用效率的影响因素可以促进精准饲喂概念的发展。因此,本试验的目的在于研究公猪初生重对其14周龄时生长猪氮沉积、蛋白利用效率、血和尿中相关代谢物水平的影响。
低初生重组和高初生重组猪的初生重分别为1.11±0.14、1.79±0.12kg。两组各20头猪,单独饲喂在代谢笼中,经过11天适应期后,进行连续两期、每期5天的氮平衡试验。试验日粮分为两种,一种为正常满足蛋白日粮,另一种为限氮日粮(蛋白为正常日粮的70%),能量为维持需要的2.8倍。采集尿和血浆样品进行非靶向代谢组学分析。
数据显示,高初生重组猪只的蛋白沉积速度(g/d)显著高于低初生重组(P<0.01),但是单位体重蛋白沉积速度(g/kg代谢体重·天)和蛋白利用效率(氮沉积/氮摄入)不受初生重影响。高出生重组猪只血浆中胰岛素水平(P=0.08)和胰岛素样生长因子(P=0.05)较高,而α-氨基氮有降低的趋势(P=0.06)。不能根据血浆和尿液代谢组学分析结果区分不同初生重组猪只。限制日粮蛋白供应降低了氮沉积(P<0.001)、氮效率(P=0.07)、氮消化率(P<0.001)和血浆α-氨基氮水平(P<0.001)。日粮处理对血浆和尿中代谢物中影响最多的是氨基酸及其衍生物、三羧酸循环代谢物、葡萄糖醛酸化的化合物,其中绝大部分在正常蛋白组猪只较高。
本试验结果表明初生重影响日氮沉积,但是对生长猪蛋白利用效率无影响。因此,在精准饲喂模式下,仔猪出生重应该作为一个蛋白沉积能力的影响因素,而不是蛋白利用效率的影响因素。
Birth weight affects body protein retention but not nitrogen efficiency in the later life of pigs
Exploring factors that might affect nitrogen (N) efficiency in pigs could support the development of precision feeding concepts. Therefore, an experiment was conducted to determine the effects of birth weight (BiW) on N retention, N efficiency, and concentrations of metabolites in plasma and urine related to N efficiency in male pigs of 14 wk of age. BiW of the low BiW (LBW) and high BiW (HBW) pigs was 1.11 ± 0.14 and 1.79 ± 0.12 kg, respectively. Twenty LBW and 20 HBW pigs were individually housed in metabolism cages and were subjected to an N balance study in two sequential periods of 5 d, after an 11-d adaptation period. Pigs were assigned to a protein adequate (A) or protein restricted (R, 70% of A) regime in a change-over design and fed restrictedly 2.8 times the energy requirements for maintenance. Nontargeted metabolomics analyses were performed in urine and blood plasma samples. The N retention in g/d was higher in the HBW than in the LBW pigs (P < 0.001). The N retention in g/(kg BW0.75·d) and N efficiency (= 100% × N retention / N intake), however, were not affected by BiW of the pigs. Moreover, fecal digestibility of N and urinary concentration of N and urea were not affected by BiW of the pigs. The concentration of insulin (P = 0.08) and insulin-like growth factor-1 (IGF-1;P = 0.05) in blood plasma was higher in HBW pigs, whereas the concentration of α-amino N tended to be lower in HBW pigs (P = 0.06). The LBW and HBW pigs could not be discriminated based on the plasma and urinary metabolites retrieved by nontargeted metabolomics. Restricting dietary protein supply decreased N retention (P < 0.001), N efficiency (P = 0.07), fecal N digestibility (P < 0.001), urinary concentration of N and urea (P < 0.001), and concentration of urea (P < 0.001), IGF-1 (P < 0.001), and α-amino N (P < 0.001) in blood plasma. The plasma and urinary metabolites differing between dietary protein regime were mostly amino acids (AA) or their derivatives, metabolites of the tricarboxylic acid cycle, and glucuronidated compounds, almost all being higher in the pigs fed the A regime. This study shows that BiW affects absolute N retention but does not affect N efficiency in growing pigs. Therefore, in precision feeding concepts, BiW of pigs should be considered as a factor determining protein deposition capacity but less as a trait determining N efficiency.
文章来源:猪营养国际论坛
【免责声明】:文章来源于网络,我们对文中陈述观点判断保持中立,并不对文章观点负责。仅供读者参考。版权属于原作者。