Mating underway for 2025 season

Fiona Mcgovern, Animal & Grassland Research and Innovation Centre, Teagasc Athenry, Co. Galway reports on mating on the INZAC and breeding flocks at Athenry.

Grass growing conditions have remained steady since my last update. Average growth over the past few weeks has been 55kg DM/day, with 26 days ahead. Having a surplus at this time of year is welcome as our grazing pressure increases with multiple mating groups. We are building grass supplies to carry us through to housing in December. Importantly, we will also concentrate on closing paddocks to ensure that there will be enough grass for ewes after lambing next year. Grassland will need a rest period of 120 days over the winter, which means we need to begin closing paddocks from October 15.

Breeding preparation

As we go to print, the INZAC Suffolk and Texel ewes are being sponged using Chronogest sponges and will receive an injection of 400iu PMSG prior to artificial insemination, which is due to take place on October 2 and 8. All ewes have been weighed, body condition scored and divided into mating groups. As we use approximately 30 rams across the flock for mating, it is important that all ewes are allocated correctly to their mating group. Each of our ewes is artificially inseminated using fresh semen and subsequently run with rams for up to two repeat cycles.

Inbreeding analysis is carried out across all of our flock to ensure there is no interrelationship between ewes and rams at mating. Prior to mating, rams receive 500g of concentrates per head per day to ensure they reach a body condition score (BCS) target of 3.5-4.0 at mating. Following CT scanning and measuring of methane output the majority of our cull lambs were slaughtered in September. Loin samples were collected from the carcasses and will be assessed for their sensory attributes; ultimately investigating if the genetic merit of the animal impacts the perceived taste of the meat produced. The remainder of the lambs continue to graze ahead of the ewes in a leader-follower system. Since mid September our lighter lambs are receiving concentrate supplementation at 350g/head/day.