日糧銅水平和來源對斷奶仔豬銅的代謝和氧化應(yīng)激的影響

畜牧編輯

　　2015. J. Anim. Sci. 93(6): 2948-2955

　　日糧銅水平和來源對斷奶仔豬銅的代謝和氧化應(yīng)激的影響

　　Y. L. Huang, M. S. Ashwell, R. S. Fry, K. E Lloyd, W. L. Flowers和J. W. Spears

　　本試驗研究了短時間飼喂不同水平和來源的銅對48頭斷奶閹公豬銅代謝、十二指腸氧化應(yīng)激、盲腸揮發(fā)性脂肪酸（VFA）比例的影響。在21日齡時將斷奶仔豬按體重分組（平均體重7.03±1.20kg），隨機分為以下三組：1）對照組，日糧中添加5mg/kg銅，以硫酸銅形式；2）225mg/kg銅，硫酸銅；3）225mg/kg銅，堿式氯化銅TBCC。每圈飼養(yǎng)2頭，飼喂全價日糧11-12天后屠宰。屠宰時，收集膽囊、肝臟分析礦物元素，并在肝臟樣品中分析銅調(diào)節(jié)蛋白mRNA的表達。收集十二指腸、空腸前段、回腸的食糜，分析可溶銅含量。刮取十二指腸、空腸前段和回腸的黏膜，分析黏膜銅含量和銅調(diào)節(jié)蛋白mRNA的表達，還有丙二醛（MDA）的含量。日糧中添加高水平銅可以顯著提高十二指腸、空腸前段和回腸黏膜中銅含量（P＜0.0001）。硫酸銅組比堿式氯化銅組豬只十二指腸黏膜中銅含量更高（P=0.003）。硫酸銅組豬只十二指腸丙二醛含量高于對照組（P=0.003），與堿式氯化銅組豬只相比有提高的趨勢（P=0.06）。與對照組相比，高銅組豬只十二指腸抗氧化物1（Atox1）mRNA表達量顯著降低（P＜0.01），不同銅源之間無顯著差異。添加高銅日糧組豬只肝臟和膽汁中銅水平更高（P＜0.001）。并且堿式氯化銅組肝臟中銅含量高于硫酸銅組。高銅提高了肝臟銅轉(zhuǎn)運β-多肽ATP酶（Atp7b）酶活（P=0.02），并且不同添加形式?jīng)]顯著差異。高銅組豬只盲腸內(nèi)容物乙酸:丁酸比大大高于對照組。在銅添加量為225mg/kg時，堿式氯化銅組豬只氧化應(yīng)激比硫酸銅組更少。斷奶仔豬飼喂高銅日糧能調(diào)節(jié)十二指腸Atox1和肝臟Atp7b水平。

　　Effect of dietary copper amount and source on copper metabolism and oxidative stress of weanling pigs in short-term feeding

　　Y. L. Huang, M. S. Ashwell, R. S. Fry, K. E Lloyd, W. L. Flowers and J. W. Spears

　　Forty-eight weanling barrows were used to determine the effects of amount and source of dietary Cu on Cu metabolism, oxidative stress in the duodenum, and VFA ratios in the cecum of weanling pigs in short-term feeding. At 21 d of age, newly weaned pigs were stratified by BW (7.03 ± 1.20 kg) and equally assigned to 1 of the following dietary treatments: 1) control (5 mg supplemental Cu/kg diet from CuSO4), 2) 225 mg supplemental Cu/kg diet from CuSO4, or 3) 225 mg supplemental Cu/kg diet from tribasic Cu chloride (TBCC). Pigs were housed 2 pigs per pen and were fed a complex diet until harvest on d 11 and 12. During harvest, bile and liver were obtained for mineral analysis, and liver samples were obtained for analysis of mRNA expression of Cu regulatory proteins. Digesta of duodenum, proximal jejunum, and ileum were collected for soluble Cu analysis. Mucosal scrapings of duodenum, proximal jejunum, and ileum were obtained for analysis of mucosal Cu concentration and mRNA expression of Cu regulatory proteins. Duodenal mucosal scrapings were also collected for analysis of malondialdehyde (MDA). Pigs fed high Cu had markedly greater (P < 0.0001) Cu concentrations in the duodenal, proximal jejunal, and ileal mucosa than controls. Copper in the duodenal mucosa was greater (P = 0.003) in CuSO4 than TBCC pigs. Duodenal MDA concentrations were greater (P = 0.003) in CuSO4 vs. control pigs and tended (P = 0.06) to be greater than in TBCC pigs. Duodenal antioxidant 1 (Atox1) mRNA was downregulated (P < 0.01) in pigs fed high Cu compared to controls and was not affected by Cu source. Compared with control pigs, those fed CuSO4 and TBCC had greater (P < 0.001) liver and bile Cu concentrations. Liver Cu was also greater (P = 0.0007) in TBCC than CuSO4-fed pigs. Hepatic Cu transporting β-polypeptide ATPase (Atp7b) was upregulated (P = 0.02) in the Cu-supplemented pigs compared with controls and did not differ among Cu sources. The acetate:propionate ratio in cecal contents was much greater in pigs supplemented with 225 mg Cu/kg diet than in controls. When fed at 225 mg Cu/kg diet, TBCC may cause less oxidative stress in the duodenum than CuSO4. Feeding weanling pigs increased Cu resulted in modulation of duodenal Atox1 and liver Atp7b at the transcription level。

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