Liquid Supplements for Lactating Cows Based on Liquid Streptomyces Solubles and Cane Molasses With or Without Condensed Molasses Solubles

Abstract

Four groups of 6 Holstein and Brown Swiss cows were used, 2 groups following each treatment sequence of a double-reversal experiment with three 28-day periods. Treatment A employed a liquid supplement of 80% liquid streptomyces solubles and 20% cane molasses, and treatment B, a modification of the same to include 10% condensed molasses solubles (CMS). These were provided free choice to the groups for about 6 hours daily, and replaced an equivalent amount of solid concentrate dry matter (DM), thus reducing individual concentrate allowances, which otherwise were 1 kg per 2.5 kg of milk produced above 5 kg daily. At night all the animals grazed together in pastures of moderate quality. Acceptance of both liquid supplements was excellent and intakes increased throughout the experiment. Overall means (weighing period 2 data doubly) of daily DM intake from supplements A and B were 3.15 and 3.22 kg. Solid concentrate allowances decreased progressively and corresponding mean intakes were only .82 and .83 kg. Milk production declined more rapidly than normal, reflecting a probable oversubstitution of liquid supplements and suboptimal intakes of digestible protein. Respective over-all weighted means for daily milk production were 11.80 and 11.65 kg; and for milk fat percent, 4.11 and 3.99. Various criteria of partial feed conversion efficiency, such as milk/supplemental DM, all slightly favored treatment A (ex., 3.11 vs. 2.96). Cost of total supplements/kg milk was about 8 cents for each treatment. None of the differences between treatments in any of the criteria studied was significant. The addition of 10% CMS to this type of liquid supplement would be a useful method of disposal of this waste product.