Effect of feeding graded levels of Prosopis cineraria leaves on rumen ciliate protozoa, nitrogen balance and microbial protein supply in lambs and kids

The investigation was carried out to assess the effect of feeding graded levels of tannin-containing Prosopsis cineraria leaves in a complete feed mixture (CFM) on the rumen ciliate protozoa, nitrogen metabolism, microbial protein supply and wool yield (in lambs only). Eighteen lambs and 18 kids of Malpura and Marwari breed, respectively of similar age (90 days) and body weight (11.0 kg), were randomly distributed in to three groups of six each. Each group was offered complete feed mixtures (CFM) ad lib. in feeding troughs under group feeding system for 90 days. The concentrate component of CFM was from the commercial feed in mash form containing whole maize, soybean meal, wheat bran and de-oiled rice bran. Sun dried Prosopis leaves were ground to pass through a 4 mm sieve before being thoroughly mixed with required quantity of concentrate mash. CFMs contained graded levels of Prosopis cineraria leaves. The proportion of Prosopis leaves was 250, 500 and 750 g/kg DM of diet, respectively for treatments T1, T2 and T3 and the concentrate mixture was 750, 500 and 250 g/kg DM of diet, respectively for treatments T1, T2 and T3. The lambs and kids were randomly allotted either one of the diets. Difference (P < 0.01) was observed in rumen spirotrichs between the groups in lambs and kids. Maximum number of spirotrichs was recorded in T1 > T2 and T3 in both species. However, holotrichs were not detected in lambs; but were detected in T3 kids. Nitrogen metabolism recorded differences (P < 0.001) between treatments in both species. Urinary purine derivatives excreted, absorbed and microbial protein supply was highest in T1 and T2 > T3 (P < 0.01) lambs, while they remained unaffected in kids. Wool yield was higher (P < 0.01) in T1 (596.21 g/animal) than in T3 (311.33 g/animal). It is concluded from the results that Prosopis tannins could be included in the diets of lambs and kids at 23 and 45 g/kg DM, respectively to have higher microbial protein supply. (c) 2006 Elsevier B.V. All rights reserved.