The objectives of this work were to determine the total diet dry matter (TDDM) intake, milk production and milk composition, net energy for lactation (TNE) and total digestible nutrients (TDN) of elephant grass in the total diet. The elephant grass subjected to chemical (CF) and organic (OF) fertilization was mixed to the concentrate, at levels of 400, 500 and 600 g, in dry matter basis (DM). The treatments were arranged in a 6 x 6 Latin square, in a 2 x 3 factorial design (fertilizer x concentrate level). The average TDDM contents, in fed basis, and NDF, CP, Ca and P of the total diet, in DM basis, were different (P<.05) for the different concentrate levels. The TDDM and nutrient intakes increased (P<.05) with increasing concentrate levels, except for NDF (P>0,05). Concentrate levels did not influence digestion of TDDM, MO and PB of total diet. NDF digestion decreased (P<.05) with increasing concentrate levels. Digestion of DM, OM and CP, and of FDN of total diet with elephant grass subjected to OF were higher than total diet with elephant grass subjected to CF. Milk production and milk composition did not change with increasing concentrate levels. The energy value (ELL and NDT) of elephant grass decreased (P<.05) an average of 15% with increasing concentrate levels and did not change with the different fertilizers. The efficiency of microbial protein synthesis in relation to the CP in the total diet consumed was best at 400 g of concentrate, showing the lowest feed: gain ratio.
Crossbred cows; intake; yield performance
