Valor alimenticio da silagens de milho e de sorgo sua influência no desempenho de vacas leiteiras

The effect of feeding grain sorghum silage, sweet sorghum silage, and corn silage on intake, milk production, milk composition, and nutrient digestibility of lactation dairy cows was evaluated. Twenty-four Prim' Holstein (PO) cows were used, forming three groups of eight cows each. The experimental treatments were: 1) corn silage; 2) grain sorghum silage; and 3) sweet sorghum silage, fed ad libitum, with two commercial concentrates, distributed following the cow milk production. Grain sorghum silage promoted greater DM intake (22.98 kg/day) compared to corn silage (21.95 kg/day), and sweet sorghum silage (19.43 kg/day). Dry matter intake was greater for corn silage than for sweet sorghum silage. Water intake (L/cow/day) was similar for the animals fed corn silage (71.91) and grain sorghum silage (76.30), and both were greater than the water intake of animals fed sweet sorghum silage (56.95). Total milk production (28.81; 24.69 and 24.14 kg/day), 4% fat corrected milk (30.65; 25.63 and 26.10 kg/day), and milk chemical composition was greater for cows fed corn silage when compared to the ones receiving grain sorghum silage and sweet sorghum silage. Cows fed sweet sorghum silage, but showed higher milk fat percentage (4.56%) compared to cows fed corn silage (4.39%) or grain sorghum silage (4.31%). Milk protein concentration was higher for cows fed corn silage (3.25%), intermediate for cows fed sweet sorghum silage (3.05%), and lower for the ones fed grain sorghum silage (2.97%). Nutrient digestibility coefficients were greater for cows fed sweet sorghum silage compared to other silages.