Beef + Lamb New Zealand said a group of 15 top-performing North Island farmers, who supply lambs to Progressive Meats, analysed the records for 42,000 lambs across two seasons to look for impacts of feed, breed and gender on saleable meat yield.
The results emphasised the importance of treating the sexes of lambs differently. Group spokesperson Stuart Ellingham, general manager at Horizon Farming Limited, said: “The main message I took out of the trial was that farmers tend to treat lambs as lambs. They don’t separate out different sexes and recognise what the different sexes are doing at different times of the year.
“This method of management is particularly noticeable in terminal-sired lambs, where all sexes tend to be treated the same. An entire male lamb is different from a wether lamb, which is different from a cryptorchid, which is different from a ewe lamb.”
For example, he explained that times of slaughter need to be different: “When it comes to female lambs, you don’t want to be killing them in March or April. Their meat quality characteristics that you are paid for – depending on your processor – drop right off over that period. So process before or after that.”
The study also showed that at the same age, ewe lambs were fatter, on average, than male lambs, reinforcing the idea that “identifying different sexes and adjusting their feeding regime and timing of processing can improve the bottom line”.