PSII-5 Chemical composition, in vitro dry matter digestibility, gas production and methane emission of maintenance, growth and production diets/rations of buffaloes
Abstract Ten types of diets were prepared to meet the nutrient requirements of buffaloes for maintenance (MD1 to MD10), growth (GD1 to GD10) and production/lactation (PD1 to PD10). A total of 30 diets were evaluated for chemical composition, in vitro gas and methane production, and dry matter (DM) disappearance using buffalo rumen liquor. The CNCPS was used to estimate the carbohydrate and protein fractions. Protein fractions PB1 and PB2 of maintenance diets were lower (P < 0.05) than growth and production diets, while protein fractions (PB3) and Pc were (P < 0.05) higher in maintenance than in growth and production diets. Mean values of PA was (P < 0.05) higher in growth diets (136.9) than production (114.8) and maintenance diets (105.6 g/kg DM). Maintenance diets had (P < 0.05) higher structural carbohydrate contents (586.2 g/kg DM) than production diets (513.0 g/kg DM). Carbohydrate fraction (CB1) was highest (P < 0.05) in production diets (187.2 g/kg DM) followed by growth (129.5 g/kg DM) and maintenance diets (96.1 g/kg DM). In vitro gas production at different time periods (12, 24 and 48 h) was similar for maintenance (63.04, 51.98 and 48.15 ml/g DM), growth (63.83, 52.73 and 48.250) and production diets (63.51, 52.54 and 47.21 ml/g DM). Cumulative methane production was numerically lower for maintenance (28.40 ml/g DM) than growth (29.58 ml/g DM) and production diets (33.13 ml/g DM). In vitro methane production as a proportion of degraded DM (ml/g DDM and g/kg DDM) was similar for maintenance (14.21 and 29.53), growth (42.19 and 30.25) and production diets (41.26 and 29.58). Dietary chemical constituents such as EE, lignin, NDIN, ADIN and PB3 and Cc were (P < 0.05) negatively associated with methane production, while OM, NPN, SP, PA and PB1, TCHO and CB2 were positively (P < 0.05) correlated with methane production.