仔豬初生重影響體蛋白沉積，但不影響蛋白利用效率

發(fā)布單位:天津瑞孚農(nóng)牧科技集團有限公司

查看次數(shù)：7869

時間：2020-07-02
探究豬對蛋白利用效率的影響因素可以促進精準(zhǔn)飼喂概念的發(fā)展。因此，本試驗的目的在于研究公豬初生重對其14周齡時生長豬氮沉積、蛋白利用效率、血和尿中相關(guān)代謝物水平的影響。
低初生重組和高初生重組豬的初生重分別為1.11±0.14、1.79±0.12kg。兩組各20頭豬，單獨飼喂在代謝籠中，經(jīng)過11天適應(yīng)期后，進行連續(xù)兩期、每期5天的氮平衡試驗。試驗日糧分為兩種，一種為正常滿足蛋白日糧，另一種為限氮日糧（蛋白為正常日糧的70%），能量為維持需要的2.8倍。采集尿和血漿樣品進行非靶向代謝組學(xué)分析。
數(shù)據(jù)顯示，高初生重組豬只的蛋白沉積速度（g/d）顯著高于低初生重組（P＜0.01），但是單位體重蛋白沉積速度（g/kg代謝體重·天）和蛋白利用效率（氮沉積/氮攝入）不受初生重影響。高出生重組豬只血漿中胰島素水平（P=0.08）和胰島素樣生長因子（P=0.05）較高，而α-氨基氮有降低的趨勢（P=0.06）。不能根據(jù)血漿和尿液代謝組學(xué)分析結(jié)果區(qū)分不同初生重組豬只。限制日糧蛋白供應(yīng)降低了氮沉積（P＜0.001）、氮效率（P=0.07）、氮消化率（P＜0.001）和血漿α-氨基氮水平（P＜0.001）。日糧處理對血漿和尿中代謝物中影響最多的是氨基酸及其衍生物、三羧酸循環(huán)代謝物、葡萄糖醛酸化的化合物，其中絕大部分在正常蛋白組豬只較高。
本試驗結(jié)果表明初生重影響日氮沉積，但是對生長豬蛋白利用效率無影響。因此，在精準(zhǔn)飼喂模式下，仔豬出生重應(yīng)該作為一個蛋白沉積能力的影響因素，而不是蛋白利用效率的影響因素。

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.

文章來源：豬營養(yǎng)國際論壇
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