There is debate about whether lambing as a yearling is in the long-term interest of the animal, with questions over wool quality and the size of subsequent litters, however new research suggests being a young mother is not so bad for a sheep.
“There is a feeling that if a ewe gives birth as a yearling it may take them too long to recover, which affects them in the future,” Dr Jolin Morel says. “So there would be a trade-off with getting that extra litter at the younger age. Currently only 30% of sheep farmers mate yearling ewes because of these concerns.”
The new research showed that two-year-old ewes that lambed as hoggets (yearlings) were less likely to have multiple births than those having their first lambs. Ewes reach sexual maturity at about six to eight months of age and give birth to between one and four lambs (usually twins) each year after a five-month gestation.
Dr Morel recorded the 250 litters born at his farm over the past decade. He found that while ewes that gave birth as hoggets (yearlings) did have smaller litters the next year, after four years they had produced more offspring overall.
The research was conducted for a paper called Effects of birth rank and yearling lambing on long-term ewe reproductive performance, conducted by Associate Professor Patrick Morel, his wife Jenny Wickham, Dr George Wickham and Jolin Morel, and was presented at the New Zealand Animal Production Conference.