Use of soyabean silage to partially substitute balanced concentrate and its effects on dairy milk production and quality in the wet tropics of Costa Rica.

摘要

The partial substitution (0, 13.6 and 27.2%) of grain mixture (GM) by soyabean silage with 8% molasses and inoculated with Lactobacillus brevis 3 (SS) in the daily rations of Holstein-Friesian cows and its effect on milk production and quality were evaluated. Treatments were assigned to 12 first-lactation cows with an average body weight of 550 kg and an average daily production of 18+or-3 kg, arranged in a crossover experimental design. It was shown that substitution of 13.6% GM by SS did not affect dry matter (DM) intake nor milk production but decreased the feed costs by 7%. Substitution of 27.2% GM for SS reduced DM intake and the average milk production by 1.6 kg/cow/day (P<=0.05). The inclusion of the SS in the diet did not affect milk fat or total solids content but reduced (P<=0.05) milk protein and lactose contents. 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.