Carbon and nitrogen balance studies in Muzaffarnagari sheep fed diets varying in roughage and concentrate ratio.

摘要

Three groups (I, II and III) of 4 Muzaffarnagari [Muzaffarnagri] sheep were fed diets containing 92:8, 50:50 and 30:70 roughage (R) to concentrate (C) ratio. A conventional metabolism trial was followed by a gaseous exchange study in an open circuitrespiration chamber. The carbon content of feed, faeces and urine was estimated by adopting the soda lime method whereas carbon loss as carbon dioxide and methane was determined from gaseous exchange in a respiration chamber. Nutritive value in terms ofdigestible protein (%) and total digestible nutrients (%) was highest (P<0.05) for 30 R:70 C (7.11 and 68.70) followed by 50 R:50 C (6.83 and 66.0) and 92 R:8 C (5.50 and 55.8). Not total methane carbon, but methane carbon expressed as a percentage of intake was lowest in group III (1.84%) followed by group II (2.07%) and group I (2.44%). Energy balance (kcal/kg0.75) was highest in group III (43.5) whereas in group II (39.1) was not significantly different from group III or group I (23.5). Efficiency of utilization of ME for maintenance was 66.1, 62.8 and 69.2% in group I, II and III, respectively. Multiple regression of ME for production on energy retained as protein and fat gave cost of protein and fat synthesis as 14.38 and 11.71 kcal/g. The results indicate that 30 R:70 C is beneficial in the ration of Muzaffarnagri sheep for more protein and energy retention with less methane emission.