Sheep: Lamb growth hit by a triple whammy of negatives
Lambs were weaned at Lyons Research Farm three weeks ago and weaning weights were back 2.5kgs for the twin lambs from last year. There seems to be a number of reasons for this.
Initially the weather after turnout was very harsh and this impacted on lamb growth rate in the first four weeks of life, which is linked to reduced milk yield by the ewe. Secondly there appeared to be a secondary hatch of nematodirus when lambs were 10-11 weeks of age which again impacted on growth rate and required a second anthelmintic treatment.
Finally grass quality has proved to be a challenge in the run up to weaning when even low covers were heading out.
However, since weaning, growth rate has certainly stabilised and for the first two weeks post weaning growth averaged 240 grams per day which is running 50 grams per day ahead on the same period last year.
Grass growth is currently 40kg/DM/ha per day on the sheep grazing block, but this comes after a period of very high growth rate which saw around 40pc of the SmartGrass research platform cut for silage.
As weaning has taken place, we are now running eight separate flocks in this study, four groups of ewes and four groups of lambs. This is essentially operating as four separate farms with each farmer operating a leader follower system. The lambs graze paddocks down to between 5 and 5.5cm and then the ewes come in and take this down to 4cm.
This system will continue until eight weeks prior to mating at which time ewe body condition score will be assessed again and ewes will then be managed accordingly. Incidentally ewes had an average BCS of 2.8 at weaning.
Grass quality and supply will now be a key focus of our management for the foreseeable future.