Periódicos Brasileiros em Medicina Veterinária e Zootecnia

Prepartum and postpartum nutritional management to optimize fertility in beef cattle

Meteer, Wynnton ChanceShike, Daniel WilliamCardoso, Felipe Cardoso de

Background: The cow-calf sector of the beef industry has a constant challenge to provide cattle with the proper nutritional profile to optimize reproductive performance. Reproduction and nutrition are the two most important factorswhen considering profitability in this sector of cattle production. Feed costs account for 63% of the total annual cowcost, and, thus, it is evident that nutritional management plays a major role in the financial viability of beef enterprises.Female infertility and other reproductive diseases account for an estimated yearly cost between $441 and $502 millionfor beef producers.Review: There is evidence suggesting that prepartum nutrition affects subsequent postpartum reproduction in beef cattle.The energy balance of the cows and energy profile of their diet are crucial to reproductive success. Prepartum nutritionis important in ensuring cows remain in a positive energy balance and return to estrus efficiently. Cows grazing nativerange grass pastures and supplemented (0.3 kg of 41% Crude Protein cottonseed meal) to lose body weight (BW) for5 months during gestation, had reduced pregnancy rates (29.5% lower) when compared with cows that were fed (1.4kg of 41% Crude Protein cottonseed meal) to maintain BW. This result suggests that cows that lose weight and energyreserves during gestation may suffer from reduced reproductive performance and pregnancy rates when compared withcows that maintain BW and body condition score (BCS). Postpartum nutrition is an important factor in reducing thepostpartum interval to pregnancy and increasing reproductive efficiency in beef cows. When cattle enter a negativeenergy balance during gestation, they tend to mobilize energy reserves and consequently suffer a reduction in BCS. Ithas been shown that when cows calve at a poor BCS (4 or less on a 9 point scale), increasing postpartum dietary energycan decrease the interval from calving to pregnancy and increase conception rates...(AU)

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