Effects of Streblus asper Lour foliage on digestibility, rumen fermentation, and nitrogen balance of growing goats.

Eighteen crossbred (Thai native x Anglo-Nubian) goats were chosen from a Suranaree University of Technology's farm on the basis of similar bodyweight (15.5 ± 3.5 kg). The goats were randomly allocated to three treatments in randomized complete block design. Each goat was given urea-treated rice straw as roughage plus the respective treatment diets. The diets were iso-nitrogenous and iso-energetic containing cassava pulp, molasses, urea, and commercial mineral and vitamin mix. The experimental treatments were (1) soybean meal (SBM), (2) partial substitution of SBM with Streblus aspe Lour foliage, or (3) partial substitution of SBM with Leucaena (Leucaena leucocephala) foliage. Nutrient intakes, ruminal characteristics (pH, ammonia nitrogen, and volatile fatty acids), nitrogen balances, and plasma urea nitrogen were not significantly different among treatments. The present results indicate that protein foliages from locally grown shrubs and trees can substitute imported feedstuffs concentrate (e.g., SBM) as protein supplement for goat production.