Abstract

The number of ewe-lambs (8 to 9 months of age) mated in New Zealand has increased to approximately 33% over the last 15 years (Anon, 2009). There are many potential advantages to ewelamb breeding including higher net profits, more lambs produced per ewe productive lifetime, better use of spring herbage, increased efficiency, early recognition of fertility potential and increased rates of genetic gain (Hight, 1982). However, little is known about the long term impacts of selecting progeny born to these young ewes as replacement animals. There is some evidence from human studies to suggest that there may be negative impacts for both the offspring and to the first parity young mother (Lucas et al., 1999).

MFP, Loureiro, SJ Pain, PR Kenyon, and HT Blair

Proceedings of the New Zealand Society of Animal Production, Volume 70, Palmerston North, 118-120, 2010