Animal Nutrition and Feed Technology
Year : 2009, Volume : 9, Issue : 1
First page : ( 11) Last page : ( 20)
Print ISSN : 0972-2963.

Effect of Feeding Diets Differing in Partitioning Factor on Intake, Digestibility and Nitrogen Metabolism in Ram Lambs

Thirumalesh T., Krishnamoorthy U.*

Department of Livestock Production and Management, Karnataka Veterinary, Animal and Fisheries Sciences University, Bangalore-560 024, India.

*Reprint request: Dr. U. Krishnamoorthy, E-mail: ukmthy@yahoo.com

Received:  2  January,  2008.

Abstract

This study was conducted to determine effect of diets differing in partitioning factor (PF) on feed intake, N metabolism and urinary purine derivative excretion (PDe) in 12 bannur ram lambs (Body weight: 15.7±0.57 kg) in a 4 × 4 Latin Square Design (LSD) experiment. The diet consisted of Rhodes grass (Chloris gayana) hay as the sole forage and compound feed mixtures, with a concentrate to roughage ratio of 50:50, to provide metabolizable energy and other nutrients for maintenance, plus a weight gain of 50 g/d/ram. The concentrate supplements were formulated using tabulated PF data to differ in PF in order to create diets with PF values that increased linearly from 3.0 to 3.5. The feeding study lasted for16 weeks in 4 periods of 4 weeks with collection period of 7 days. Measured PF values ranged from 3.07 to 3.59, but k values were similar among the diets (i.e., 0.0496 to 0.0525/h). Intake of NDF and ADF was lowest (P = 0.05 or less) for the lowest PF diet, and digestibility of DM and OM decreased (P<0.01) as the diet PF increased. Digestion of NDF and ADF was lower (P=0.05 or less) as the PF of the diet increased. There were no differences among diets in purine derivative excretion in urine or estimated microbial N supply to the duodenum. Results appear to suggest that feeding of diets differing in PF to a much greater extent than k had no impact on measured microbial N flow to the duodenum.

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