Recent Applications of Liquid Feed Supplements in Rations for Lactating Dairy Cows

Abstract

Abstract Liquid feed supplements (LFS) have traditionally been used in lick tanks as a source of nonprotein nitrogen and energy for dairy replacement heifers and dry cows. Recent applications of LFS in rations for lactating dairy cows were reviewed along with the corresponding research data available in the scientific literature. Liquid feed supplements offer an alternative delivery vehicle for supplemental fat, undegraded intake protein, and rumen-fermentable carbohydrates in total mixed rations for lactating dairy cows. In general, the experiments reviewed did not show a lactation performance advantage to the dietary addition of animal-fat or animal-protein by-products in liquid compared with dry feed supplements. Lactation performance benefits from the feeding of molasses or sugar were not well- substantiated by the literature data, and controlled research is needed to evaluate this aspect of the use of LFS in diets for lactating dairy cows. University and field trials suggest that sorting of total mixed rations fed to lactating dairy cows can occur. Addition of LFS to total mixed rations to reduce sorting of diet components is a new practice on commercial dairy operations, but controlled research trials evaluating the efficacy of LFS for ameliorating a sorting problem are lacking. Advantages of LFS in convenience and uniformity of ingredient and nutrient delivery can be evaluated relative to cost differences between liquid and dry feed supplements since lactation performance differences between them were minimal.