LAUSR

ABSTRACT Research on the use of heart of palm by-product (HPB) as a feed for dairy cattle is needed since it is a low-cost alternative in addition avoiding environmental contamination. The objective of this study was to evaluate intake, digestibility, milk yield and composition from cows fed HPB. Sixteen Holstein cows were used. Treatments consisted of fresh sugarcane replacement (dry matter basis – DM) of HPB at levels 0%, 7.5%, 15% and 22.5%. Experimental design was randomized blocks with measures repeated in time, and data were compared by linear, quadratic and cubic contrasts. A decreasing linear effect of HPB was observed on DM, organic matter (OM), crude protein and non-fibrous carbohydrates intakes and on digestibility of DM and neutral detergent fibre. A quadratic effect was observed for metabolizable energy intake and OM digestibility. Milk yield and composition were not affected by levels of HPB added to the diet. A cubic effect was detected for fat-corrected milk (FCM) and energy-corrected milk (ECM). HPB is detrimental to intake and digestibility, but the 7.5% replacement level of HPB is recommended depending on the milk production level, since rumen environment was improved, leading to greater FCM and ECM yields at lower production costs.