Association between hyperketolactia and production in early-lactating dairy cows

Area of Science:

• Dairy Cattle Metabolism
• Ruminant Nutrition
• Animal Production Science

Background:

• Hyperketolactia (HYKL) is a metabolic condition in dairy cows characterized by elevated ketone bodies in milk.
• Understanding the distinct roles of milk acetone (mACE) and β-hydroxybutyrate (mBHB) in HYKL is crucial for managing dairy herd health and productivity.

Purpose of the Study:

• To investigate the associations between different types of hyperketolactia (HYKL) and milk production traits in Holstein dairy cows.
• To differentiate the impact of elevated milk acetone (mACE) and β-hydroxybutyrate (mBHB) on milk yield and composition during early lactation.

Main Methods:

• Analysis of approximately 5.0 million milk samples collected from Holstein dairy cows over a 5-year period (2014-2019).
• Quantification of milk acetone (mACE) and β-hydroxybutyrate (mBHB) using Fourier-transform infrared spectroscopy (FTIR).
• Categorization into four ketolactia groups: normoketolactia (NKL), HYKL_BHB, HYKL_ACE, and HYKL_ACEBHB, based on defined thresholds.
• Statistical analysis using a linear model to assess the effects of ketolactia group, days in milk (DIM), parity, and their interactions on production outcomes.

Main Results:

• 31.2% of milk samples were classified as HYKL, with HYKL_ACEBHB being the most prevalent subtype (52.6%).
• HYKL_ACEBHB cows exhibited the lowest milk yield, while HYKL_BHB and HYKL_ACE cows showed varied effects on milk yield compared to NKL cows throughout lactation.
• Significant differences in milk composition were observed across ketolactia groups, including altered milk fat (MF), milk protein (MP), and milk lactose (ML) content, particularly in HYKL_ACEBHB and HYKL_BHB cows.

Conclusions:

• Hyperketolactia (HYKL) is significantly associated with altered milk production and composition in dairy cows across all parities.
• The impact of HYKL on production is dependent on the specific ketone profile, involving either acetone (ACE), β-hydroxybutyrate (BHB), or both.
• Further research is warranted to elucidate the biochemical pathways underlying HYKL, especially concerning elevated mACE alone or in combination with mBHB during early lactation.