Acta Veterinaria et Zootechnica Sinica ›› 2022, Vol. 53 ›› Issue (5): 1475-1485.doi: 10.11843/j.issn.0366-6964.2022.05.015

• ANIMAL NUTRITION AND FEEDS • Previous Articles     Next Articles

Study on Relieving Effect and Mechanism of Yeast on Subacute Ruminal Acidosis in Sheep

HAN Guohao1, GAO Xiaosha1, DUAN Jinwei1, ZHANG Huiqin1, ZHENG Yan1, HE Jinxin1, DING Jian’an2, HUO Nairui1, PEI Caixia3, LI Hongli1, GU Shaopeng1*   

  1. 1. College of Veterinary Medicine, Shanxi Agricultural University, Taigu 030801, China;
    2. Department of Biological Engineering, College of Shuozhou Vocational and Technology, Shuozhou 036002, China;
    3. College of Animal Science, Shanxi Agricultural University, Taigu 030801, China
  • Received:2021-08-09 Online:2022-05-23 Published:2022-05-25

Abstract: This study was designed to explore the alleviating effect and mechanism of a strain of Saccharomyces cerevisiae and two strains of Diutina rugosa from rumen on subacute ruminal acidosis (SARA) in sheep. In order to provide strains and a theoretical basis for developing probiotics to prevent SARA in sheep. Sixty two-month-old weaned Dubo sheep (♂)×Hu sheep (♀) F1 generations were selected as experimental animals. SARA was successfully induced in forty sheep by gradually increasing the diet concentrate-to-roughage ratio. SARA sheep were divided into 4 groups (n=10):SARA group;Saccharomyces cerevisiae ACCC 21162 (SC) group;Diutina rugosa N09 (DR1)group; Diutina rugosa N07 (DR2)group. All four groups were fed a diet with a concentrate to roughage ratio of 90:10. And SC,DR1 and DR2 groups were respectively gavaged with 100 mL Saccharomyces cerevisiae ACCC 21162,Diutina rugosa N09 and Diutina rugosa N07 after morning feeding.The control group (CON, n=10) was fed 50:50 diet at all times. The ruminal pH was measured on the 1, 3, 7, and 10 d after adding yeasts, respectively. On 10 d after adding yeasts, rumen microflora, abnormal metabolites, and blood gas were measured. The results showed that:1) Ruminal pH in the yeast groups was significantly higher than that in the SARA group on the 3rd day (P<0.05), and SARA was effectively relieved in yeast groups. 2) The optimum bacteria in SC and CON groups were Lactobacillus and unidentified Prevotellaceae, respectively, while in the other groups it was unidentified Ruminococcaceae. In the yeast groups, SC group had the highest richness index and DR2 group had the highest diversity index. 3) The rumen and blood lactic acid and rumen histamine in the yeast groups were significantly lower than those in the SARA group (P<0.05). 4) Blood pH and base excess in SC and DR2 groups were extremely significantly higher than those in the SARA group (P<0.01). The blood carbon dioxide partial pressure, total carbon dioxide, and bicarbonate concentration in the yeast groups were significantly higher than those in the SARA group (P<0.05). 5) There was a significantly positive correlation between ruminal pH and actual bicarbonate in the blood (P<0.05), and a significant negative correlation between rumen lactic acid and Chao 1 index of rumen microflora (P<0.05). These results indicated that three yeasts had the effects on improving the abundance of rumen microflora, reducing rumen and blood lactic acid, alleviating rumen inflammation and body acidosis.

Key words: subacute ruminal acidosis, yeast, rumen microbial community, inflammation

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