Ruminal fermentation, production and fatty acid quality of milk of late lactation dairy goat fed pufa-diet supplemented with Yeast and C. xanthorrhiza Roxb.

Abstract

In order to meet milk demand nationally and at the same time to improve milk quality, in this case fatty acid of lactating ruminants such as dairy goat; it is required a nutritional improvement in the ration. Based on previous research results that have been applied to either dairy goat or dairy cows with supplementations of yeast, fermented cassava- curcuma (C. xanthorrhiza roxb), Tabut block, and lactating concentrate were reported to increase milk yield and milk quality. Therefore, three experiments, evaluating nutrient contents during storage of the polyunsaturated fatty acid or PUFA- concentrate, analyzing fermented PUFA- diet in vitro, and applying PUFA- diet in vivo had been conducted. Diet containing PUFA- concentrate (PUFA sources consisted of roasted ground corn, roasted soybean meal, and corn oil) supplemented with yeast and curcuma had been applied in late lactation dairy goats. The first experiment was to evaluate the nutritive values of PUFA- concentrate supplemented with yeast and curcuma stored in 2-6 weeks. There were four PUFA- concentrates, namely, no supplement (PC0), 0.5% yeast (PCY), 2% curcuma powder (PCC), and a mixture of 0.5% yeast with 2% curcuma (PCM). Yeast (containing 3.6 x 107 cfu/g) and curcuma powder (containing 0.8% curcumin) were self made. These concentrates were evaluated for nutrition and fatty acid contents during 2 and 6 weeks of storage. Results showed that moisture and Saccharomyces cereviseae (20.68 x 106 cfu/g) increased significantly (P<0.05) in 6 weeks of storage; whereas, dry matter (DM) and organic matter (OM), crude fiber (CF), nitrogen free extract (NFE) decreased significantly (P<0.05). The total PUFA (P), P/S, monounsaturated fatty acid (MUFA), and long chain fatty acid (LCFA) contents were found higher in PUFA- concentrate with 2% curcuma powder. Whereas, the PUFA- concentrate with 0.5% yeast and 2% curcuma powder was higher in unsaturated (U) fat and the ratio of U/S. Based on all nutrient values during the storage of 2- 6 weeks, the PUFA- concentrate with 0.5% yeast and 2% curcuma powder was considered nutritionally reasonable. The second experiment, in vitro, was conducted to evaluate the ruminal performances of PUFA-diet (containing PUFA-concentrate with soybean byproduct and King grass) supplemented with yeast and curcuma. Experimental design applied was Randomized Complete Block of 4 ruminal liquor derived from four slaughtered goats and 4 treatments (PD0, PDY, PDC, PDM ), in 3 replications. Variables analyzed were pH, N-NH3, total and partial VFA, TPC, and CH4. Results showed that in spite of having the lowest organic and dry matter digestibilities as well as N- NH3; however, supported by low protozoa population and high VFA production in the goat rumen fluid, the PUFA- diet with a mixture of yeast and curcuma additives was considered the most potential diet to improve nutrient metabolism in rumen. The third experiment, in vivo, was to evaluate milk production and health of dairy goat fed PUFA-diet supplemented with yeast of curcuma. The were 20 crossbred Ettawa goats in the late lactation selected based on their production levels and grouped them in Randomized Block design to receive 5 treatments of no supplement (PD0), 3 tablets of Asifit (PDA), 0.5%/d yeast (PDY), 2%/d curcuma (PDC), and a mix of 0.5%/d yeast and 2%/d curcuma (PDM) in diets containing concentrate with PUFA sources (roasted ground corn, roasted soy bean meal, and corn oil), soybean by-product, and King Grass. The variables evaluated were milk yield, milk composition, mastitis status, nutrient digestibility, and blood metabolites. Milk yield was recorded daily pre, during, and post treatment. The PDC had lower ether extract than that of mix diet and showed higher crude fiber but lower ADF; diet with yeast had lower crude protein; and mix diet showed lower P content. Milk yield during treatment was higher in PDA and PDY. Post treatment, these milk yields were higher (P<0.05) than those in PDY and PDC; while the PDM was in between. There were tendencies that mix diet (PDM) had lower milk fat, 4% FCM, % protein and weight, fat: protein ratio, dry matter, and solid non fat, but it showed higher lactose and Ca percentage. Mastitis indicators and blood metabolites were not affected by treatments. However, PDM showed lowest SCC, higher Hb, PCV, and glucose but had lower prolactin and triglyceride. In PDM, nutrient intake of ether extract was the highest (P<0.05), while nutrient digestibilities were mostly affected significantly (P<0.05 or P<0.05). The PDC had the lowest DM, OM, CP, EE, and GE; whereas PDY and PDM showed higher digestibilities. As conclusion, a mix supplement of 0.5%/d dried yeast and 2%/d curcuma powder was considered reasonable since it showed a better recovery in milk yield after treatment with progressing lactation in dairy goat. Results dealing with fatty acid demonstrated some consistencies in diet containing polyunsaturated fatty acid (PUFA) supplemented with 0.5% yeast and 2% curcuma (C. xanthorrhiza Roxb) that were high in total fatty acid, MCFA, LCFA, and PUFA. Milk fatty acid of goat fed with this diet showed high in LCFA and MUFA; while it was low in SCFA, n6/n3 ratio, and atherogenicity index. These milk qualities were optimally considered good in terms of healthier product. Therefore, the PUFA- diet with 0.5% yeast and 2% curcuma was a reasonable choice to be applied for dairy goat.