Feed is the most expensive component in goat production. Hence, lowering it is crucial to increasing producer profitability. The microbial community in rumen is vital for nutritional digestion and absorption in ruminants. Live yeast and yeast-based products generated from the strain Saccharomyces cerevisiae (commercial strain) are actively being used and investigated. The purpose of this study was to investigate the effects of substituting soybean meal (SBM) in concentrate diets with yeast-fermented palm kernel cake protein (YFPKCP) on dry matter intake, digestibility, blood markers, and nitrogen balance. Five crossbred Thai Native-Anglo-Nubian goats (50% Thai Native goats with 50% Anglo-Nubian goats) weighing an average of 27 ± 2 kg were randomly allocated to one of five diets using a 5 × 5 Latin square design: 0, 25, 50, 75, and 100% YFPKCP replacement for SBM. Plicatulum hay (Paspalum plicatulum Michx.) was provided ad libitum. There were no significant differences in dry matter (DM) intake among treatments, but the apparent digestibility of DM, crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) were affected (p < 0.05) by including YFPKCP in diets. They also tended to be slightly lower for goats fed the diet containing 100% YFPKCP replacement for SBM compared to other treatments. Ruminal pH, ammonia-nitrogen (NH3-N), blood glucose, and packed cell volume were equivalent among treatments. On the other hand, replacement YFPKCP reduced digestibility and N absorption by up to 75% (p < 0.05). Furthermore, there was no difference in total volatile fatty-acid concentration among goats fed YFPKCP as a substitute for SBM. According to the results of this study, the level of YFPKCP in the concentrate replacement of SBM for goats fed plicatulum hay should be 75%.
Keywords: goats; nutrient utilization; palm kernel cake protein; rumen fermentation; yeast.