A metabolism trial of 5-days adaptation period and 6-days collection period following 30 days of experimental feeding was conducted to determine the nutrient digestibility, plane of nutrition and nitrogen balance of the animals. The live weight of the sheep was recorded at the beginning and at the end of the metabolism trial prior to feeding. The allotted rations were fed to each sheep as explained earlier. Fresh drinking water was made available at all the times.
Daily feeds offered and orts left, total excretion of faeces and urine were recorded during the collection period. Representative sample of feeds offered and orts left were dried overnight at 60 °C in a hot air oven. The samples were pooled over the six days of collection and then ground to pass through 2 mm sieve and stored in airtight polyethylene containers for further analyses. The total amount of faeces voided by individual sheep during the preceding 24 h was collected and weighed. A suitable aliquot of the daily fecal excretion was then dried in a hot air oven at 60 °C, pooled animal-wise, ground and stored for further analyses. For nitrogen estimation, another appropriate aliquot of fresh faeces was weighed, mixed with 10 ml of 20% H2SO4 (w/v) and pooled into a previously weighed air tight container. At the end of collection period, the pooled aliquots of the wet faeces were mixed well, and sub-samples were taken for nitrogen estimation. The daily urinary outputs by individual sheep were recorded quantitatively and representative aliquots were collected in plastic bottles for further analysis.