This study was developed to evaluate the intake and apparent digestibility of nutrients in dairy heifers fed diets containing sugar cane treated with calcium oxide (CaO). It was also evaluated the prediction efficiency of dry matter intake and food energy value. Twenty Holstein-zebu crossbred dairy heifers, at 200 kg average initial body weight were used, distributed in a completely randomized design, with four diets and five repetitions. The diets were formulated to be isoprotein and to supply 14% crude protein and they were composed of 71% sugar cane treated with 0; 0.75; 1.5 or 2.25% calcium oxide (in natural matter basis) corrected with 1% of urea and ammonium sulfate (9:1) and 29% of concentrate. Intakes of dry matter (DM), organic matter (OM), ether extract (EE), neutral detergent fiber (NDF), neutral detergent fiber corrected for ash and protein (NDFap), indigestible neutral detergent fiber (iNDF), total carbohydrates (TC), non-fibrous carbohydrates corrected for ash and protein (NFCap) and total digestible nutrients (TDN) (% BW) were linearly reduced with calcium oxide doses. Digestibilities of OM, NDF, NDFap, total carbohidrates and NFCap and TDN content in the diets were not affected. However, hydrolyses of sugar cane with calcium oxide caused reduction in the digestibility of DM and CP. The equations proposed by National Research Council underestimated intakes of DM and TDN and digestible CP and NFC and overestimated intakes of digestible NDF. Hydrolyses of sugar cane with calcium oxide do not improve intake of nutrients neither digestibility of nutrients in dairy heifers. The equations proposed by National Research Council are not efficient to estimate the DM intake and food energy value in experimental conditions.
chemical additive; dry matter; nutritive value
