Use of soybean silage to partially substi tute balanced concentrate and its effects on dairy milk production and quality, in the wet tropics of Costa Rica

Abstract

Partial substitution (0, 13.6 and 27.2 %) of grain mixture (GM) by soy bean silage with 8% molasses and inoculated with Lactobacillus brevis 3, (SS), in daily rations of Holstein cows, and its effect on milk production and quality, was evaluated. Treatments were assigned to 12 first-lactation cows with an average body weight of 550 kg and an average daily production of 18±3 kg, arranged in a “cross over“ experimental design. Substitution of 13.6% GM by SS did not affect dry matter (DM) intake nor milk production, but decreased the feed cost in 7%. Substitution of 27.2% GM for SS reduced DM intake and the average milk production by 1.6 kg cow-1 day-1 (P≤ 0.05). The inclusion of the SS in the diet did not affect fat nor total solids content, but reduced (P≤ 0.05) milk protein and lactose content. These results indicate that the use of SS as a partial substitute of GM is a feasible alternative to reduce milk production cost in the tropics.