Nutrient digestibility, fermentation pattern, blood biochemical level and inflammatory response of nulliparous dairy goats fed with various levels of oil palm fronds
This study was conducted to investigate the effect of oil palm frond (OPF) inclusion in total mixed ration (TMR) diets on nutrient digestibility, fermentation pattern, blood biochemical level and inflammatory response in nulliparous dairy goats. Three nulliparous female dairy goats (Saanen x Thai native, 33.88±1.78 kg) were randomly assigned in a 3x3 Latin square design. The diets consisted of 0% OPF (CON), 20% OPF (LOPF) and 40% OPF (HOPF) on a dry matter (DM) basis. The inclusion of OPF in the diets significantly increased the DM and nutrient intake of the dairy goats (p<0.05). There was no significant difference in the digestibility of DM, organic matter and crude protein of LOPF and HOPF, (p>0.05) but those were significantly higher than CON (p<0.05). Dietary OPF did not affect the digestibility of EE and ADF. No significant difference was observed in rumen pH, NH3-N, individual VFA proportions, C2:C3 ratio, C2,C4:C3 ratio, and CH4 production (p>0.05). However, dietary OPF altered the total production of VFA at 0 h before feeding (p<0.05). Total N intake, N absorption, and N retention significantly increased (p<0.05) as the level of OPF inclusion increased. Goats receiving CON diet showed a negative N balance. The results indicate that dietary HOPF lowered the TNF-α level (p<0.05). However, there was no significant difference in the level of IL-6, IL-1β and blood biochemistry (p>0.05). In conclusion, the inclusion of 40% OPF in a TMR-based diet enhanced nutrient intake, nutrient digestibility and lowered the secretion of TNF-α in nulliparous dairy goats.