Nutritional value of babassu cake as a substitute for sugarcane in feeding heifers¹

The aim of this study was to evaluate intake, digestibility and performance in dairy heifers fed diets containing increasing levels of babassu cake (0, 100, 200 and 300 g kg(-1) dry matter - DM) as a substitute for sugarcane treated with calcium oxide. Twenty-four heifers with an initial mean weight of 190.8 + 40.8 kg were used, distributed in a completely randomised design. The dry matter intake (DMI), neutral detergent fibre intake (NDFI) and acid detergent fibre intake (ADFI), as %BW and g BW-0.75 , showed an increasing linear response. The organic matter intake (OMI) showed a linear increase of 40 g day(-1), 0.017%BW and 0.66 g BW-0.75 for each 10 g kg(-1) increase in babassu cake in the diet. The apparent digestibility of the dry matter (ADDM) and organic matter (ADOM) showed a quadratic response (P < 0.05), with a minimum of 493 g kg(-1) DM for 150 g kg(-1) DM and 526.5 g kg(-1) DM for 320 g kg(-1) DM as a substitute for the sugarcane, respectively. The final mean weight was not altered, presenting a value of 299.7 + 45.5 kg. Daily weight gain (DWG) showed a quadratic response, with the highest value at a substitution level of 190 g kg(-1) DM. The feed conversion rate of the DM was not affected by the addition of babassu cake, with an average of 4.6 + 0.74 kg DM kg(-1) in weight gain. Babassu cake can substitute hydrolysed sugarcane in heifer diets up to 300 g kg(-1) DM, with the greatest weight gain seen at a substitution level of 190 g kg(-1) DM.