Lambing Season
Lambing is always a highlight of the year and this year has been successful again. We have just about finished lambing the ewes, with a lamb rate of just under 140% (1.4 lambs per ewe) and survival rate of over 90%. The ewe lambs (from last year) are starting to lamb, we expect a lower lambing rate from them. By lambing them in their first year, theoretically the lifetime associated emissions per kg meat is reduced. We lamb the two groups separately so we can give the gimmers (ewe lamb) more attention. We have ended up with 5 lambs needing to be bottle fed which has highlighted the need to cull ewes whose udders aren’t working properly.
After our experiment last year, lambing both inside and outside, we are lambing everything outside this year. This approach reduces infection risk but asks more of the breed. Our Torddu badger face sheep are a hardy variety who are good mothers. So they have been able to get the lamb out, and up and suckling without much intervention. The field we used for lambing was kept free of stock for 4 months in order to build up grass residuals to feed the ewes. Plus we did not have any lambs in that field for the past 11 months in order to reduce parasite risk for the new lambs.
The lambs that did die did so either at birth, or shortly after it, as opposed to in the week that follows. Lambs are born without an immune system, they need their mothers colostrum (the first bit of their milk) in order to gain an immune system. That no lambs have died in the week after birth shows we were good at getting colostrum into the lambs, and that the approach of lambing outside has successfully reduced the risk associated with infection from the environment into which they are born. The deaths were largely associated with birthing difficulties, which is the major risk when lambing outside; you can’t check on them in the dark!
This year we are part of a colostrum experiment using a brix refractometer to measure quality. High quality colostrum will give a lamb a better immune system. Getting the condition of the ewe right, going all the way back to tupping time (when the rams went in), is important for colostrum quality, lambing rate and size of lamb. This year we have been really pleased with the condition of the ewes right the way from tupping time. The lambs we’re getting are a good size, which improves their survivability. Bigger lambs are harder for the ewe to birth, which has been our main cause of death but it hasn’t been a statistically big issue.
Another experiment this year is that we are crossbreeding a Kerry Hill ram with the badger face ewes. Mountain ewes make good mothers; badger face sheep are a mountain breed. Our farm is not that high up, so it’s suitable to put a hill breed to them; we range from 400-600ft altitude. Cross breeding gets hybrid vigour - taking on some of the characteristics of each parent. By using a Kerry Hill we can get a bigger carcass off a better mother. This would be considered a terminal sire, meaning it’s offspring is intended for slaughter. We could look to breed from the offspring; the danger of this would be that we could lose track of the genes and get Kerry Hill genes into the pedigree Torddu badger face group.
The main consideration for the future is how to overwinter the ewes. This year we kept them outside the whole winter. We are still in the process of working out the carrying capacity of our land. As the numbers increase we are at risk of overgrazing and not being able to rest pastures long enough to be ready for the spring growth. The two main options for overwintering are either to house, which requires more management to ensure correct feed and clean bedding, or to overwinter on fodder crops (turnips, kale, beet). Fodder crops have a lot of environmental drawbacks if managed poorly. Plus there are criticisms surrounding the nutrition and so flavour of the animal. We are looking to raise grass fed meat so this isn’t an option we are considering at the moment.
Shortening the period during which lambs are born is also an interest for us. It was our main mistake last year, there were lambs being born for months. The benefit is to save us management time over the lambing period and easier decision making with lambs who are all the same age and size. Some people use a hormone to synchronize the ewes cycle but our system doesn’t need us to be that involved. What we may try for next season is using a teaser ram. That is, a ram who has had a vasectomy, going in before the main rams go in. The idea is he goes and tries it on with the ewes and so stimulates them into cycling better ready for the main boys.
Photography by: Daisy Wingate Saul
コメント