文献类型： 外文期刊

作者： Liu, Q. ¹ ; Wang, C. ¹ ; Yang, W. Z. ¹ ; Dong, Q. ¹ ; Dong, K. H. ¹ ; Huang, Y. X. ¹ ; Yang, X. M. ³ ; He, D. C. ³ ;

作者机构： 1.Shanxi Agr Univ, Coll Anim Sci & Vet Med, Taigu 030801, Shanxi, Peoples R China

2.Agr & Agri Food Canada, Res Ctr, Lethbridge, AB, Canada

3.Shanxi Acad Agr Sci, Inst Anim Sci, Taiyuan 030032, Shanxi, Peoples R China

关键词： Acetic acid;Ammonia;Beef;Degradability;Detergents;Dietary supplements;Diets;Digestibility;Digestion;Dry matter;Enzymes;Ethers;Excretion;Fermentation;Fibers;Lactic acid;Malic acid;Microorganisms;Organic matter;Propionic acid;Rumen;Volatile fatty acids;pH effects;purines

期刊名称：ANIMAL （ 影响因子：3.24； 五年影响因子：3.223 ）

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收录情况： SCI

摘要： The objective of this study was to evaluate the effects of malic acid (MA) supplementation on rumen fermentation, urinary excretion of purine derivatives (PDs) and whole gastro-intestinal tract feed digestibility in steers. Eight ruminally cannulated Simmental steers (465 plus or minus 13 kg) were used in a replicated 4 4 Latin square design. The treatments were: control (without MA), LMA (MA-low), MMA (MA-medium) and HMA (MA-high) with 0.0, 7.8, 15.6 and 23.4 g MA per kg dry matter (DM), respectively. Diets consisted of corn stover and concentrate (60/40, DM basis). DM intake was approximately 9 kg per day, which was 90% of ad libitum intake including 5.4 kg corn stover and 3.6 kg concentrate. Ruminal pH (range of 6.91 to 6.56), ratio of acetate to propionate (range of 3.88 to 3.25), ammonia N (range of 9.03 to 6.42 mg/100 ml) and lactate (range of 91.25 to 76.31 mg/100 ml) decreased linearly as MA supplementation increased, whereas total volatile fatty acid (VFA) concentration (range of 55.68 to 61.49 mM) linearly (P < 0.05) increased with increase in MA supplementation. In situ ruminal neutral detergent fiber (aNDF) degradation of corn stover was improved but the crude protein (CP) degradability of concentrate mix was decreased with increasing the dose of MA. Urinary excretion of PDs was quadratically (P < 0.01) changed with altering MA supplementation (67.88, 72.74, 75.81 and 73.78 mmol/day for control, LMA, MMA and HMA, respectively). Similarly, digestibilities of DM, organic matter (OM), NDF and acid detergent fiber (ADF) in the total tract were also quadratically increased with increasing MA, and no differences in terms of CP and ether extract digestibility were observed. The results indicate that MA supplementation has the potential to improve rumen fermentation and feed digestion in beef cattle. The MA stimulates the digestive microorganisms or enzymes in a quadratic response. In the experimental conditions of this trial, the optimum MA dose was 15.6 g MA per kg DM.