Effects of enzymatically hydrolyzed yeast supplementation on blood attributes, antioxidant status and gene expression of cytokines in vaccinated dairy cows

Abstract

This study was done to assess the effects of hydrolyzed yeast on blood cells counts, antioxidant status and gene expression of pro-inflammatory and anti-inflammatory cytokines of vaccinated dairy cows. Twenty Holstein lactating dairy cows were randomly divided into four groups received basal diet without (control) and with 10, 20 and 30 g/d/head of hydrolyzed yeast. Cows were vaccinated against foot and mouth disease virus at day 10 and blood samples were taken 10 days after. Cows received hydrolyzed yeast at doses of 20 and 30 g/d/head had the lowest and those in the control group had the highest malondialdehyde concentration. Cows received hydrolyzed yeast at dose of 20 g/d/head had the highest lymphocyte and the lowest neutrophil/lymphocyte ratio. IL-1β and TNF-α downregulated and INF-γ up-regulated in cows received different doses of hydrolyzed yeast. The lowest expression of IL-1β and TNF-α and the highest expression of INF-γ was for cows received hydrolyzed yeast at dose of 20 g/d/head. The highest titers against foot and mouth disease virus were for cows received hydrolyzed yeast at dose of 20 g/d/head and the lowest titer was for the control group. Supplementation of 20 g/d/head hydrolyzed yeast recommended in vaccinated cows.

Keywords:

• Interferon
• interleukin
• lymphocyte
• malondialdehyde
• neutrophil

Acknowledgments

The authors thank the Section of Animal Science, Kimia Behan Enzyme Co. (Tehran, Iran) for providing hydrolyzed yeast samples and the Nuclear Agriculture School and Dr Parvin Shawrang for their generous cooperation and assistance in carrying out this research project. This paper was elicited from PhD thesis (M. Nikkhah) of Islamic Azad University, Science and Research Branch, Tehran, Iran.

Disclosure statement

No potential conflict of interest was reported by the author(s).