Chemical Composition, In situ Digestion Kinetics and Feeding Value of Oat Grass (Avena sativa) Ensiled with Molasses for Nili-Ravi Buffaloes

다국어 초록 (Multilingual Abstract)

This study examined the effect of cane molasses and fermentation time on chemical composition and characteristics of oat grass silage (OGS) and its in situ digestion kinetics, intake, digestibility, milk yield and composition in buffaloes (Bubalus bubalis). Oat grass (OG) harvested at 50-days of age was ensiled in laboratory silos with cane molasses at the rate of 0, 2, 4 and 6% of OG dry matter (DM) for 30, 35 and 40 days. Silage pH was decreased while lactic acid content increased with increasing level of cane molasses and fermentation time. Dry matter (DM), crude protein (CP) and true protein (TP) content of OGS were (p<0.05) significantly higher with higher cane molasses levels. However, they were not affected by the fermentation time. Similar trends were observed for neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose, acid detergent lignin and ash content of OGS. The OG ensiled for 30-days with 2% molasses was screened from laboratory study and used to determine comparative in situ DM and NDF digestion kinetics of OG and its silage. In situ DM and NDF digestibilities of OG were significantly (p<0.05) higher than OGS. Ruminal DM and NDF lag time, rate and extent of digestion of OG and its silage were similar. Two experimental diets of OG and OGS were formulated using 75:25 forage to concentrate ratio on a DM basis. Dry matter and CP intakes were similar in lactating buffaloes fed either OG- or OGS-based diets. However, NDF intake was higher in buffaloes fed the OG-compared with OGS-based diet. Apparent DM, CP and NDF digestibilities were similar in lactating buffaloes fed either OG- or OGS-based diets. Milk yield (4% FCM) was similar in buffaloes fed either OG-(10.3 kg/d) or OGS-(9.95 kg/d) based diets. Milk fat, total solids and true protein content were higher with OG compared with the OGS diet. Solids not fat and CP content were similar in milk of buffalo fed either OG or OGS. The results of this study indicate that OG ensiled with 2% molasses could safely replace 75% DM of green oat fodder in the diets of lactating buffaloes without negatively affecting intake, digestibility, milk yield and composition.