Effect of feeding ensiled mixture of pomegranate pulp and drier feeds on digestibility and milk performance in dairy cows

Abstract

Based on a previous ensiling study in glass silos of various pomegranate pulp (PP) mixtures, fresh pomegranate pulp (PP) was mixed with drier feeds including soy hulls and corn silage (40:35:25 on DM basis) and ensiled in 32 pressed bales (700 kg each) wrapped with stretch polyethylene film. This ensiled pomegranate pulp mixture (PPM) was included in lactating cow total mixed ration (TMR) at a level of 20% of DM (PPM-TMR). Performance and digestion experiment was conducted with two groups of 21 milking cows each, fed individually one of the two TMR: 1. Control TMR without ensiled PPM; 2. Experimental TMR which contained 20% ensiled PPM, including 8% PP as corn grain replacer. Voluntary DM intake of cows fed the control TMR was 5·04% higher than that of the PPM cows. In vivo digestibility of DM, OM, NDF, CP and fat were significantly higher in the control cows compared with the PPM group, but methane production in the rumen fluid was 25% lower in the PPM cows. A slightly higher milk yield (by 2·2%) observed in the control cows; however, milk fat content was 5·9% higher in the PPM cows. This was reflected in similar yield of energy corrected milk (ECM) and 3·97% increase in production efficiency (ECM/DM intake) of the PPM cows compared with the control ones. Welfare of the cows, as assessed by length of daily recumbence time, was in the normal range for both groups. Body weight gain was also similar in both groups. Data suggest that the level of 8% PP in the PPM-TMR used in this study was probably too high for lactating cows and should be lowered to 4% in order to achieve better performance.