文献类型： 外文期刊

作者： Jiang, Fu-Gui ¹ ; Lin, Xue-Yan ¹ ; Yan, Zhen-Gui ¹ ; Hu, Zhi-Yong ¹ ; Wang, Yun ¹ ; Wang, Zhong-Hua ¹ ;

作者机构： 1.Shandong Agr Univ, Coll Anim Sci & Technol, Ruminant Nutr & Physiol Lab, Tai An, Shandong, Peoples R China

2.Shandong Acad Agr Sci, Inst Anim Sci & Vet Med, Jinan, Shandong, Peoples R China

3.Shandong Key Lab Anim Dis Control & Breeding, Jinan, Shandong, Peoples R China

关键词： chewing activity; forage source; particle size; ruminal pH; saliva

期刊名称：ANIMAL SCIENCE JOURNAL （ 影响因子：1.749； 五年影响因子：1.909 ）

ISSN： 1344-3941

年卷期： 2019 年 90 卷 3 期

页码：

收录情况： SCI

摘要： The present study investigated the effects of dietary forage source (quality) and particle size on chewing activity, saliva secretion, and ruminal pH. Twelve multiparous lactating Holstein cows, four of which were ruminally cannulated, were used in a replicated 4 x 4 Latin square experimental design with a 2 x 2 factorial arrangement of treatments. Cows fed wild-rye hay diets had longer daily eating times than cows fed oaten hay diets. Treatments had no effect on ruminating time; therefore, resting time varied inversely to eating time. Neither the rate nor the amount of saliva secretion while eating, ruminating, or resting was affected by diet, resulting in similar total daily saliva secretions across treatments (231 L/day). Total volatile fatty acids (VFAs) in the ruminal fluid from animals fed oaten hay diets were higher than those from animals fed wild-rye hay diets; further, VFAs increased with decreasing forage particle size (FPS). Consistent with elevated VFA concentrations, reducing FPS and including oaten hay in the diet decreased mean ruminal pH and increased the daily time of ruminal pH under 5.8. Results of this study suggest that forage source and particle size affect ruminal pH might be via variations in VFA production rather than increased salivary recycling of buffering substrates.