Association between rumination behavior, hyperketonemia and milk production in early lactation

Abstract

Increased blood beta-hydroxybutyrate (BHB), also known as hyperketonemia (HYK), is a common metabolic disorder in dairy cows, that occurs during first and second week postpar­tum, defined by elevated blood concentration of BHB ( ≥ 1.2 mmol/L). HYK is associated with impaired health, decreased performance, and decreased milk production. Nonetheless, ele­vated BHB concentrations in early lactation are not detrimental to all cows. Past studies from our group found that cows with HYK that had high milk production had similar performance (pregnancy rates and herd removal risk) to non-hyperketone­mic cows that also had high milk production. Moreover, there are reports showing that rumination time in the first week post­partum and milk production are positively correlated, with ani­mals that have a high rumination time producing more milk. For these reasons, our objective was to evaluate whether rumi­nation behavior modified the association between blood BHB concentration during the first week postpartum and milk yield during the first 3 herd tests.