Prepartum nutritional strategy affects reproductive performance in dairy cows

Area of Science:

• Animal Science
• Reproductive Biology
• Dairy Cattle Nutrition

Background:

• Negative energy balance in early postpartum dairy cows is linked to reduced reproductive efficiency.
• Optimizing prepartum nutrition is crucial for mitigating negative energy balance and enhancing fertility.

Purpose of the Study:

• To investigate the association between prepartum energy feeding regimens and reproductive performance in dairy cows.
• To determine if controlled-energy (CE) or high-energy (HE) diets influence days to pregnancy (DTP).

Main Methods:

• A pooled analysis of 7 studies (1993-2010) involving 408 cows.
• Assessed reproductive performance using DTP, with prepartum diets classified as CE (≤100% NEL) or HE (>100% NEL).
• Utilized Cox proportional hazard models to analyze DTP and associated metabolic indicators.

Main Results:

• CE diets during the close-up (CU) dry period resulted in shorter DTP (median 157 d) compared to HE diets (median 167 d).
• CE-fed cows exhibited less body condition score loss postpartum and lower nonesterified fatty acids (NEFA) concentrations.
• Higher plasma glucose concentrations in early lactation were associated with shorter DTP.

Conclusions:

• Feeding controlled-energy diets during the close-up dry period improves dairy cow reproductive performance.
• CE diets may enhance fertility by increasing postpartum net energy for lactation (NEL) intake, reducing disease incidence, and improving metabolic status.
• Reduced body condition score loss and better glucose profiles contribute to improved reproductive outcomes.