Effect of seasonal thermal stress on oxidative status, immune response and stress hormones of lactating dairy cows

Abstract

This study aimed to assess the impact of seasonal thermal stress on oxidative stress, immune response, and stress hormones of lactating dairy cows in subtropical regions with different levels of temperature-humidity index (THI). A total of 32 healthy lactating Holstein dairy cows experienced 4 seasons (8 cows/season). The physiological parameters were categorized into low THI (LTHI, THI = 42.97 ± 0.95) in winter, moderate THI (MTHI, THI = 61.84 ± 0.42) in spring and autumn, and high THI period (HTHI, THI = 86.09 ± 0.23) in summer. The blood samples were collected twice in each season to measure oxidative stress, inflammatory and hormonal parameters. Our results showed THI had a positive correlation with the rectal temperature ( R 2 = 0.821, P < 0.001) and respiratory rate ( R 2 = 0.816, P < 0.001). Dry matter intake, milk yield and fat percentage also significantly differed among groups ( P < 0.05). Compared with the MTHI group, the LTHI group exhibited a significant increase in malondialdehyde (MDA) level ( P < 0.001), and the HTHI group displayed a significant increase in levels of cortisol, interleukin (IL)-10, IL-1β and tumor necrosis factor-α ( P < 0.001). Opposite changes in serum endotoxin and immunoglobulin G levels were observed with the increasing THI ( P < 0.001). LTHI notably increased the triiodothyronine level, although the thyroxine level was reduced by LTHI and HTHI compared with the MTHI group. In conclusion, LTHI and HTHI conditions may induce different degrees of oxidative stress, inflammation response, and stress hormone imbalances on lactating dairy cows, therefore environmental management is necessary for the health of dairy cows in extreme weather conditions.

Heart Rate and Heart Rate Variability Change with Sleep Stage in Dairy Cows

“…The NZ recordings were made outdoors over winter with average an average daytime temperature of 10.2 • C (range 2-18 • C) and overnight average of 8.4 • C (range 2-14 • C). Seasonal thermal stress has been found to affect behaviour, stress and immune response in dairy cows [32,33], and increasing temperature humidity index has been associated with decreased HRV measures in sheep and goats [34]. Although the cows in the winter conditions in NZ had higher HR and lower HRV than cows in summer conditions in Scotland, the environmental conditions could have affected the HR and HRV activity in this study.…”

Correlation of oxidative stress‐related indicators with milk composition and metabolites in early lactating dairy cows

“…There were few reports on the effect of l ‐isoleucine and l ‐methionine supplementation on lactation performance of dairy cows under oxidative stress. However, it was reported that unhealthy cows (such as with inflammation or oxidative stress) need multiple nutrients to repair damage and indirectly lose some of their lactation properties (Li et al., 2021 , Memon et al., 2019 , Sordillo & Raphael, 2013 , Zahrazadeh et al., 2018 ).…”

“…However, it was reported that unhealthy cows (such as with inflammation or oxidative stress) need multiple nutrients to repair damage and indirectly lose some of their lactation properties (Li et al, 2021, Memon et al, 2019, Sordillo & Raphael, 2013, Zahrazadeh et al, 2018.…”

Sub-Clinical Mastitis and Reproduction: Season, Parity and Stage of Lactation Effects on Conception Rate and Milk Somatic Cell Count

“…In this study, we show that the pregnancy rate in cows with subclinical mastitis in summer in the second lactation and in winter in the second and third lactations was lower than in cows without subclinical mastitis; while, there was no signi cant difference in the other seasons. Heat stress in summer and high humidity combined cold stress in winter could be responsible for reducing the pregnancy rate (Li et al 2021). In the mid lactation, only in the spring, high SCC was leading to high service per conception.…”