Nitrogen partitioning differs in sheep offered a conventional diploid, a high sugar diploid or a tetraploid perennial ryegrass cultivar at two feed allowances
A Jonker, L Cheng, GR Edwards, G Molano, PS Taylor, E Sandoval, GP Cosgrove
ANIMAL FEED SCIENCE AND TECHNOLOGY | ELSEVIER SCIENCE BV | Published : 2018
Grazing sheep on ryegrass based pasture with elevated water soluble carbohydrate (WSC) concentration might improve N use efficiency and reduce N excretion into the environment. Diploid ryegrasses with elevated WSC have been bred and released as a high-sugar cultivars (HSG), and tetraploid ryegrass (TRG) generally has elevated WSC compared to conventional diploid ryegrass (CRG). The objective of the current study was to determine N partitioning in sheep fed HSG, TRG, and CRG offered at two feed allowances. Three N partitioning trial periods (Sep 2013, March 2014 and Nov 2014) were conducted with 30 Romney wethers (different sheep in each period) over 5 d of excreta collection measurements per..View full abstract
This project was funded by the Sustainable Land Management and Climate Change Fund administered by the Ministry for Primary Industries (Wellington, New Zealand). Dr. Long Cheng was funded by New Zealand AGMARDT Post-Doctoral Fellowship. The authors thank Grant Taylor, Fiona Smith, Phoebe Stewart-Sinclair and Sarah Lewis (AgResearch, New Zealand) for their help with animal handling and sampling. The authors also appreciate staff of Aorangi Research Farm (AgResearch, New Zealand) for pasture and sheep management. We thank Andrea Hogan (Lincoln University, New Zealand) for laboratory analysis.