Supplementation of Yeast Fermented Liquid (YFL) and Coconut Oil on Rumen Fermentation Characteristics, N-balance and Urinary Purine Derivatives in Beef Cattle
Four rumen-fistulated beef cattle were randomly assigned according to a 2x2 factorial arrangements in a 4x4 Latin square design to study effects of Yeast Fermented Liquid (YFL) and Coconut Oil (CO) on rumen fermentation patterns and nutrient digestibility. Two factors were used; Factor A-Source of protein; Soy Bean Meal (SBM), Cassava Hay (CH) and factor B-non-heating of YFL+CO (YCOH) and heating of YFL+CO (at 50°C) (YCOH). Animals received four dietary treatments as follows: T1 = SBM+YCO; T2 = SBM+YCOH; T3 = CH+YCO; T4 = CH+YCOH. The animals were offered with Total Mixed Ration (TMR) containing 60% roughage (Rice Straw (RS) as a roughage source) and 40% concentrate. Four experimental periods were employed and each period lasted for 21 days. In each period, the animals were adjusted for 14 days to feed and voluntary feed intake was measured then followed by total collection method during the last 7 days. Samples of gas, rumen fluid and blood from jugular vein were collected on the last day of each period. Rumen pH and temperature were measured immediately after rumen fluid was sampled. The results showed that factors A and B have no effects on voluntary feed intake but CH fed group was slightly higher (p>0.05) than SBM fed group. Digestibilities of DM, OM, EE, NDF were not different (p>0.05) while digestibilities of CP and ADF in CH fed group was increased (p<0.05). Moreover, CH fed group showed higher ruminal pH (p<0.01), NH3-N, total VFA, C3, total population of bacteria and fungi than SBM fed group (p<0.05). C2/C3, protozoal population and methane production in CH fed group were decreased (p<0.05). NH3-N and BUN in YCO fed group were increased (p<0.05). However, factors A and B have no effects on microbial protein synthesis (p>0.05) but Efficiency Microbial Nitrogen Synthesis (EMNS) in CH fed group was higher (p<0.05) than SBM group and the value of EMNS in CH+YCO fed group was highest. Based on these results, supplementation of YFL and coconut oil with diets containing cassava hay can improve rumen ecology by decreasing protozoal population and increasing bacterial and fungi population. This study provided new findings for using local feed resources as a protein and energy supplement to improve rumen fermentation and livestock production efficiency.