Effect of feeding tamarind kernel powder extract residue on digestibility, nitrogen availability and ruminal fermentation in wethers

Objective: This study was to examine in vivo digestibility, nitrogen balance and ruminal fermentation of tamarind (Tamarind indica) kernel powder extract residue (TKPER) compared to soybean products and by-products in wethers. Methods: Four wethers with initial body weight (BW) of $51.6{\pm}5.5kg$ were assigned in a $4{\times}4$ Latin square design to investigate nutritional characteristics of TKPER, dry heat soybean (SB), dry soybean curd residue (SBCR) and soybean meal (SBM) feeding with ryegrass straw (R) at a ratio of 1:1 at 2% of BW in dry matter (DM) on a daily basis. Results: The digestibility of DM, crude protein, and ether extract (EE) of TKPER-R diet were 57.0%, 87.0%, and 86.0%, respectively. Higher non-fiber carbohydrates digestibility was observed in TKPER-R diet (83.2%) than in SB-R diet (73.9%, p<0.05). Wethers fed the TKPER-R diet had lower retention of nitrogen (N) and ruminal ammonia nitrogen ($NH_3-N$) contents at 4 h after feeding than those fed the SBM-R diet (p<0.05), which had values similar to the SB-R or SBCR-R diet. The TKPER feeding had higher propionate (C3) and lower butyrate content, as well as lower acetate to propionate ratio (C2:C3) in rumen fluid than SBM feeding at 4 h after feeding (p<0.05). Conclusion: TKPER did not bring any side effect to the wethers although it was lack of fiber, and could be used as a high protein and energy ingredient in concentrate with appropriate roughage to meet the fiber requirement for ruminants.