Abstract
The objective of this study was to assess the effects of auto-lysed yeast and yeast extract on performance and immune responses of cows in hot climate in the early lactation period. Twenty five lactating dairy cows randomly assigned to 5 groups and 5 replicates. Cows received basal diet with or without auto-lysed yeast (20 or 40 g/d/head) or yeast extract (20 or 40 g/d/head) as on top-dressed. There were no differences for daily dry matter intake, milk production milk fat and the counts of red blood cells and white blood cells among treatments (p > 0.05). There were significant differences among treatments for immunoglobulin G (IgG) level, lymphocyte and neutrophil percentages. Yeast extract had no effect on IgG level, but auto-lysed yeast increased IgG level and neutrophil percentage and decreased lymphocyte percentage (p < 0.05). The highest relative interleukin-2 gene expression was for cows received auto-lysed yeast at the level of 40 g/d/head. Yeast extract had no significant effect on interleukin-2 gene expression as compared to the control group. It was concluded that auto-lysed yeast at the level of 40 g/d/head had no effect on performance, but it could positively influence on immune response of lactating dairy cows in hot climate during early period of lactation.
Highlights
In the late gestation and early lactation periods, dairy cows encounter with a stressful condition, as they rapidly increase milk production, while losing body condition
A low fiber and high starch ration leads to ruminal subclinical acidosis, which resulting in loss of appetite and lower feed intake and milk production, lower fertility rate and weaker immune responses to pathogens (Wankhade et al, 2017)
It has been claimed that β-glucan of live and hydrolyzed yeast could enhance the immune response in dairy cows (Broadway, Carroll, & Burdick Sanchez, 2015; Nocek et al, 2011; Liu et al, 2014), sheep (Khalkhane, Abbasi, Zadeh, & Arian, 2013; Zabek et al, 2013), horse (Jacobs, Gordon, Felippe, & Raub, 2017) and cell cultures (Raa, 2015; Wojcik, 2014)
Summary
In the late gestation and early lactation periods, dairy cows encounter with a stressful condition, as they rapidly increase milk production, while losing body condition. Feed management during this period is important as dry matter intake is low and nutrients demand is very high (Nocek, Holt, & Oppy, 2011). Many farmers fed their cows high concentrate ration during this period. It has been claimed that β-glucan of live and hydrolyzed yeast could enhance the immune response in dairy cows (Broadway, Carroll, & Burdick Sanchez, 2015; Nocek et al, 2011; Liu et al, 2014), sheep (Khalkhane, Abbasi, Zadeh, & Arian, 2013; Zabek et al, 2013), horse (Jacobs, Gordon, Felippe, & Raub, 2017) and cell cultures (Raa, 2015; Wojcik, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
