Performance of dairy cows fed rations produced with sugarcane silages treated with additives or fresh sugarcane

An experiment was performed aiming at evaluating the performance of dairy cows fed sugarcane silages treated with additives compared to cows fed fresh forage. Twenty-four Holstein cows were grouped in blocks of three cows, according to parity order and milk production level, in multiple 3 x 3 Latin Square design to evaluate three types of ration (63% roughage and 37% concentrate in dry matter - DM): ration with silage treated with urea (5.0 g/kg of fresh forage - FF) + sodium benzoate (0.5 g/kg FF); ration with silage inoculated with Lactobacillus buchneri (5 x 10(4) cfu/g FF); ration with fresh sugarcane. Each evaluation period consisted of two weeks for adaptation and one week for data collection. Cows fed rations with silages treated with urea + benzoate and L. buchneri showed lower DM intake (18.5 vs 21.4 kg/day) and lower milk production (17.4 vs 18.6 kg/day) in comparison to those fed fresh forage ration. Fat content was higher in the milk of cows fed silage inoculated with L. buchneri compared to cows in the fresh forage group resulting in similar 3.5% fat corrected milk (FCM) among cows in both groups. Cows fed ration with silage treated with urea + benzoate presented intermediate fat content in milk but inferior FCM production compared to animals fed fresh sugarcane. Feed efficiency (kg FCM/kg DMI) was higher for cows fed ration produced with the inoculated silage (0.95), intermediate for cows that received silage treated with the combination of chemical additives (0.91) and lower for cows fed the ration with fresh sugarcane (0.83)