Productive response of crossbred cows grazing Brachiaria decumbens pasture to supplementation of Saccharomyces cerevisiae

Abstract

The objective of study was to evaluate the productive response of crossbred cows grazing on Brachiaria decumbens pasture to supplementation with an experimental concentrates (CEXP) with or without addition of Saccharomyces cerevisiae (SC). Four milking Brown Swiss × Zebu cows were utilized 4×4 Latin square design. Treatments were T1= 3 kg of CEXP; T2= 2 kg of CEXP; T3= 2 kg of CEXP + 10 g of SC; and T4= 3 kg of commercial concentrate as control treatment. CEXP was 63% ground maize, 25% canola meal, 10% molasses and 2% urea. All cows received 3 kg of maize silage plus free access to grazing Brachiaria decumbens. Experimental periods consisted of 21 days each. Chemical analysis was performed on Brachiaria decumbens grass, maize silage and the concentrate supplements. Variables evaluated were milk yield, protein and fat content in milk, live weight and body condition score (BCS). Mean milk yield was 6.6 kg/cow/day, with no differences among treatments, nor there were differences in live weight or BCS. However, significant differences were found in protein and fat in milk, with lower values for these components in T2 and T3 than in T1 and T4. The addition of different levels of inclusion had no effect on milk yield, live weight and body condition, as well as fat and protein in milk.