Professor Paul Kenyon from Massey University says hogget mating should be a flexible policy as unless farmers can feed their in-lamb hoggets consistently well throughout winter, spring and into summer, their long-term reproductive performance could be affected.
“If you don’t do it well, they will fall out of the system later – you will ruin them for future years.”
This might mean only mating a proportion of the replacement ewe lambs- those individuals weighing over 40kg- or not mating any this year.
Paul says mated hoggets need to gain 20kg – or 135gms/day – throughout their pregnancy to meet their two-tooth target weights. Given the conceptus weighs 10kg, the hogget should weigh a minimum of 60kg the day before she lambs, and 50kg the day after.
The heavier the ewe lamb is at mating, the less pressure on winter feed resources to reach those post-lambing target weights.
Paul says that to meet the hogget’s energy requirements throughout pregnancy, she needs to be offered pre-grazing pasture covers greater than 1200kgDM/ha with minimum post-grazing covers of 1000kg DM/ha.
To achieve this within a farm system, farmers might have to reduce numbers of other stock classes – such as mixed-age ewes – or provide an alternative feed source, such as a forage crop.
“Regardless of what option you choose, monitor the hoggets to ensure targets are met,” says Paul.
“There are no magic bullets, but getting the feeding and liveweight correct are the major drivers of success.”
Done correctly, hogget mating can be an efficient use of feed resources. The extra herbage required to feed seven pregnant hoggets, compared to seven non-pregnant hoggets, is roughly the same total feed demand as one pregnant mature ewe in winter.
For more information, including podcasts, about hogget mating go to https://beeflambnz.com/search?term=hogget+mating