Research update: Lamb performance in Athenry

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

Grass growing conditions are at an optimum for the time of year here in Athenry. All lambs in the INZAC flock were weaned on June 13, at approximately 100 days of age. As we go to print, lambs are currently averaging at 38kg liveweight, with a growth rate of 230g/day in the month post weaning. The first group of lambs have been drafted and sent for slaughter. All lambs receive a cobalt drench fortnightly at weighing.

This year, we are carrying out some additional work that focuses on lamb performance post weaning. A selection of 24 lambs have been individually housed and are being assessed for grass dry matter intake and digestibility.

At the beginning of September, we will measure 250 INZAC lambs through a mobile CT scanner to assess carcass conformation and rumen size prior to slaughter. The methane output of these lambs will also be monitored, which will enable us to investigate relationships between rumen size and methane output in addition to assessing the impact of genetic merit on carcass traits.

At this point, all ewes have been thoroughly examined and cross-checked against lambing records in order to make culling decisions and to avoid holding onto problem ewes within the flock. Any ewe with a lower body condition score (BCS) was drafted into a separate group and given priority access to grass in order to build condition prior to mating. Ewes will receive routine foot bathing and have their BCS assessed in mid-September prior to mating. Ideally, we would like our ewe BCS to be 3.5 on average at mating, which for us is at the beginning of October.

This article first appeared in the Teagasc Sheep Advisory newsletter for September. Click here to access the full publication.