Increasing ewe genetic fecundity improves whole-farm production and reduces greenhouse gas emissions intensities 1. Sheep production and emissions intensities

Abstract

Greenhouse gas (GHG) emissions from livestock constitute the largest proportion of Australian agricultural GHG emissions, necessitating development of strategies for mitigating GHG emissions from the livestock sector. Here we simulate a self-replacing prime lamb enterprise to examine the effect of increasing ewe genetic fecundity on whole farm GHG emissions, animal production and emissions per animal product (emissions intensity; EI).Breeding ewes were a cross-bred genotype containing the Booroola (FecB) gene with average lambing rates of 1.5-2.0 lambs per ewe. Lambs were born in winter on pastures of phalaris, cocksfoot and subterranean clover, and were sold at the beginning of summer. Floc..