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How much dietary fat should growing prepubertal dairy heifers be fed?
Diets for growing dairy heifers have, historically, been forage-based with very low fat concentrations. Supplemental fat has been considered uneconomical to feed to dairy heifers, and therefore, it has become an often overlooked nutrient in dairy heifer rations. However, with the increased interest in the use of biofuel co-products, which are higher in fat content than traditional feeds, and the high price of corn, this nutrient deserves a second look. Additionally, dietary energy sources need to be reconsidered when heifers are fed using alternative feeding strategies, like precision-feeding. Literature searches on feeding dietary fat to dairy heifers yield very limited findings. These findings, often lead to more questions than answers on how fat will affect growth and development of growing heifers. In contrast, there is a relative abundance of research on feeding fat to mature dairy cows, dairy calves, and beef cattle, on which most of the current recommendations for heifers are based. This presentation will describe key findings from research and suggest how to best utilize dietary fat as a nutrient for growing dairy heifers. Positive effects of feeding fat such as increased feed efficiency, changes in metabolic profile, and reproductive performance, will be weighed against the negative effects such as over conditioning, and decreased fiber utilization. From this literature review, recommendations on feeding fat will be made and potential areas for future research will be discussed.
Keywords:
dairy heifers, dietary fat