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

Three groups (III and III) of Muzaffarnagari sheep comprising each of four sheep were fed diets containing 92.8, 50:50 and 30:70 roughage (R) and concentrate (C) ratio. Conventional metabolic trial was followed by gaseous exchange study in open circuit respiration chamber. The carbon content of feed, feces and urine was estimated by adapting soda lime method whereas carbon loss as carbondioxide and methane was determined from gaseous exchange in respiration chamber Nutritive value in terms of DP (%) and TDN (%) was significantly (p<0.05) highest on 30 R:70 C (7.11 and 68.70) group followed by 50 R:50 C (6.83 and 66.0) and 92 R:8 C (5.50 and 55.8) group. Not total methane carbon, but methane carbon expressed as a percentage of intake was significantly lowest in group III (1.84%) followed by group II (2.07%) and group I (2.44%). Energy balance (kcal/kg W 0.75) was significantly highest in group III (43.5) whereas in group II (39.1) was not significantly different from either,group III or group I (23.5). Efficiency of utilisation of ME for maintenance was 66.1%, 62.8% and 69.2% in group I, II and III, respectively. Multiple regression of ME far production on energy retained as protein and fat gave cost of protein and fat synthesis as 14.38 and 11.71 kcal/g. The result of present study indicated that 30 R:70 C is beneficial in ration of Muzaffarnagari sheep for more protein and energy retention with less methane emission. (C) 1999 Elsevier Science B.V. All rights reserved.