Rams arrive at Lyons to start progeny test
Published 04/10/2011 | 05:00
As the year progresses, lamb growth rates will slow down. Over the past fortnight, growth rates have slipped to 160g/day at Lyons.
There are a number of reasons for this; the highest performing lambs have been drafted at this stage, many of the lambs remaining in the flock will be twins and triplets, which have inherently lower growth rates, and grass quality is beginning to slip.
Twenty-six lambs were drafted last week, averaging 44kg liveweight and killing out at 46pc. Grass growth is running at about 40kg DM/ha/day.
The rams for the central progeny test (CPT) scheme began arriving at Lyons last week and training these animals for semen collection is about to begin. These rams will then be used to provide semen for the four progeny test flocks.
These are part of the Sheep Ireland breeding programme, including Lyons, where all the ewes will be bred using laparoscopic AI. All our ewes and ewe lambs were sponged yesterday to synchronise ovulation and will be mated on October 17.
The sponges will be removed on October 15 when the ewes will receive PMSG to increase ovulation rate. The ewes will then be bred to Texel, Suffolk, Charollais, Belclare and Vendeen rams. The stock rams on the farm will be used to pick up the repeats.
All replacement ewe lambs were weighed last week and they averaged 50kg. Assuming a birth weight of 4.5kg on March 12, this gives an average growth rate since birth of 230g/day from grass only. Any lamb not reaching 45kg was removed from the replacement flock and will be slaughtered when finished. The exceptions to this are our mules, grey-face and half-bred ewe lambs, which we don't mate as lambs, and they will be carried over and bred as hoggets.