Liquid Streptomyces Solubles and Condensed Molasses Solubles as Feed Supplements for Cows at Pasture

Abstract

On the basis of the lactational, partial feed conversion and liveweight responses observed, LSS and SCM are judged satisfactory as liquid supplements in partial substitution for concentrates for cows at pasture. However, their animal acceptance is suboptimal. Four groups of 7 cows each, some Holstein and some Brown Swiss were used in an experiment for two 5-week periods, to test four treatments in a design consisting of two single reversals of treatments. Treatments A, LSS supplementation, and B, a control, were tested in a Latin square design; and C, CMS supplementation, and D, a control, were tested in a similar design. Dally individual concentrate allowances were reduced by an amount equivalent in dry matter (DM) to that consumed in liquid supplements in treatments A and C. These were offered free choice to cows in groups for 5 or 6 hours daily. At night all cows grazed together in fair quality pastures. Over-all means and SD were as follows: daily milk production, 11.25 ± 4.05 kg; milk fat, 3.67 ± .66%; milk solids not fat (SNF), 8.79 ± .61%; milk total solids (TS), 12.46 ± .98%. Treatments had no significant effects on these characteristics. LSS consumption did not result in detectable antibiotic activity in the milk. Daily consumptions of DM from LSS in periods 1 and 2 and overall were .64, .18 and .41 kg, respectively. Corresponding figures for CMS were .44, 1.36 and .89 kg. Ratios of milk and of fat corrected milk (FCM) produced/total supplemental DM consumed were as follows in the four treatments; A, 4.15 and 4.10; B, 4.03 and 3.81; C, 3.74 and 3.47; D, 3.77 and 3.51.