Effect of grape pulp silage feeding on fattening performance of Holstein calves

This study was designed to investigate the effect of feeding different levels of white grape pulp silage (WGPS) on the diet of finishing calves. In a completely randomized block design, with 4 treatments and 6 replications, twenty four male Holstein calves with initial weight of 234.4±24.67 kg were used in 90 days experiment. Four iso-caloric and iso-nitrogenous rations were formulated in which, WGPS was included in amount of 0.0 (control), 12, 24 and 36% (DM basis). Results showed that the daily feed intake was increased by inclusion of WGPS in the diets (p< 0.05) so that the calves fed 35% WGPS had the highest (9.31kg) but those received control diet had the lowest (8.19kg) DM intake throughout the experiment. During the first month of the experiment, animals received control diet, had the highest weight gain than the other groups and a linear decreasing in body weight gain was found by increasing the WGPS in the diets (p<0.05). However, at the end of the experiment, the highest amount of weight gain was found in the animals fed diet contained 12% WGPS. Furthermore, the feed conversion ratio (FCR) was affected by the diets (p<0.05) where it was increased linearly as the percentage of WGPS was increased in the diets. In conclusion, the white grape pulp could be ensiled, as usual for the common forages, and used in the diet of ruminants up to 12 percent.