SUBSTITUTION OF FISH FLOUR AND UREA FOR KUDZU (Pueraria phaseoloides) IN THE PRODUCTION OF MILK.

Abstract

Using a double reversion balanced design, three treatments were studied to determine the substitute effect of crude protein of fish meal and urea by crude protein of kudzu in milk production diets; T₀, control diet based on fish, meal, urea, molasses and a low quality hay of Digitaria swazilandensis; T₁ substitution of the crude protein provided from the fish meal in T₀ by kudzu hay; and T₂, partial substitution of equivalent crude protein of urea in T₁ by kudzu hay. All diets were isonitrogenated and isoenergetic. The kudzu was obtained from a bank of protein which was cultivated after 90 days of repose. Six Holstein-Cebu cows with a lactation period of 60 to 90 days were fed in confinement and milked twice a day without the calf. The levels of substitution of total crude protein of the control diet (T₀) were 20.6% in T₁ and 51.2% in T₂. In all treatments the intake of crude protein and metabolizable energy were higher than the production requirements of cows. The production of milk decreased (P<0.10) when fish meal was substituted by kudzu; the averages, adjusted for the effect of the treatments, were 8.1, 7.8 and 7.7 lt/cow/day for T₀, T₁ and T₂, respectively. There was not effect (P>0.15) of kudzu hay on the corrected milk production (4% fat), milk composition and body weight change. As the level of kudzu hay increased in the diet, the apparent digestibility of the dry material and protein decreased (P<0.10). Also, the feeding cost disminished but the partial net income increased as the level of kudzu hay increased in the diet.