Intake, nutrient digestibility and nitrogen balance in lactating dairy cows fed diets containing sunflower cake

Resumo

The objective of this study was to evaluate the effect of different levels of sunflower cake (SC) inclusion in the diets of lactating dairy cows on dry matter (DM) intake, the apparent digestibility of dietary nutrients and nitrogen balance. Eight Holstein-Zebu cows with a milk yield of 20 ± 2 kg/day were allotted to a 4 × 4 replicated Latin square design, where were tested the effects of four levels of SC inclusion (0, 7, 14 and 21% of DM basis). Tifton-85 (Cynodon dactylon) hay was used as roughage in a 60:40 roughage:concentrate ratio. The SC inclusion had no effect on dry matter, crude protein, organic matter (OM) or total carbohydrate (TC) intake (kg/day). However, a quadratic effect (P < 0.05) was detected on neutral detergent fiber and non-fibrous carbohydrate (NFC) intake (kg/day). There were no effects of SC inclusion on OM, TC and NFC digestibility, as well as, for nitrogen balance. It was observed a linear effect for the basal endogenous nitrogen (g/day). Sunflower cake can be recommended as an ingredient in the rations of lactating dairy cows.