Effect of complete feed block on nutrient utilisation and rumen fermentation in Barbari goats

Abstract

Fifteen Barbari goats (average BW 13 kg) were randomly divided into three groups of five animals each. All animals were fed complete diets consisting of natural grass hay and concentrate mixture in the ratio of 60:40 on the DM basis. In the concentrate mixture, 15% (T 2) or 30% (T 3) CP of mustard cake was replaced with Leucaena leaf meal (LLM). The diet of the control group (T 1) was offered as such, whereas T 2 and T 3 diets were offered in the form of blocks. The bulk density of the complete feed block was 550–600 kg/m 3. Densification of complete diets increased the bulk density 3.2–3.9 times. Total VFA concentration in the rumen was similar in the three groups. Ammonia N concentration was significantly ( P<0.05) higher in the mash-fed goats (T 1) than in the block-fed animals (T 2 and T 3). The rumen anaerobic fungal population was slightly higher in T 2 and T 3 than in T 1 as a result of the proportionate intake of roughage and concentrate from the block form of the diet. The total protozoa population ranged from 7.47×10 4 to 8.65×10 4 ml −1 of strained rumen liquor (SRL). Voluntary feed intake was similar in T 1 (431 g per day), T 2 (409 g per day) and T 3 (415 g per day). Digestibility coefficients (%) of DM, OM, CP, CF and NFE among treatment groups did not differ significantly. Inclusion of Leucaena leaf meal by replacing mustard cake did not affect the N balance in Barbari goats. DCP and TDN intake were sufficient for maintenance. Blood glucose, protein and urea-N were within normal physiological ranges in all groups. It was concluded that Leucaena leaf meal can be incorporated by replacing mustard cake safely and inexpensively without affecting nutrient utilisation in Barbari goats. Further, the process of block making from low bulk density roughage resources substantially reduces the storage space and transportation cost.