Effect of lactation stage, season and parity on milk cortisol concentration in Holstein cows

Michiru Fukasawa, Hideharu Tsukada, Takami Kosako, Akihisa Yamada

研究成果: Article査読

22 被引用数 (Scopus)

抄録

This experiment was designed (1) to study the effects of lactation stage, season, and parity on milk cortisol concentrations in Holstein cows, and (2) to elucidate the relationships between milk yield, quality, and milk cortisol concentration. Subjects of this study were 24 dairy cows kept in a free stall barn. Milk samples were taken on test day in May, August, November, and February. Data of milk yield, quality, and cortisol concentration were collected. Random effects of animals and fixed effects of lactation stage, test day, and parity on milk yield, quality, and cortisol concentration were analyzed using mixed models. We estimated the best linear unbiased prediction of each trait (BLUP) which was an animal-specific value. Correlation among milk yield, quality, and cortisol concentration was calculated using raw data and BLUP. The effect of the lactation stage on milk cortisol concentration was significant: the value observed in early lactation was higher than in other stages. However, the correlation between milk yield and cortisol concentration was low. The beginning of lactation might be a strong stressor for every cow. Calculated with raw data, milk cortisol concentration had respectively significant negative correlation with milk protein contents and solid not-fat contents. Calculated with BLUP, milk cortisol concentration showed a significant and negative correlation with milk protein contents. The lactation stage and milk protein contents should be considered for measurement of milk cortisol concentrations.

本文言語English
ページ(範囲)280-284
ページ数5
ジャーナルLivestock Science
113
2-3
DOI
出版ステータスPublished - 2008 2
外部発表はい

ASJC Scopus subject areas

  • 動物科学および動物学
  • 獣医学(全般)

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