Coming into the sheep breeding season, farmers around the country will be analysing their flock, to make sure they are in good condition. The target body condition score (BCS) of rams is 3.5-4.0; and ewes is 3.0.
Sheep are seasonal breeders – in ewes, oestrus begins as daylight hours start to decrease in autumn. Farmers will be aiming to condense the lambing season down to three weeks if possible.
One way to achieve this is by synchronising ewes. Oestrus can be induced by using progestagen impregnated sponges. For the vast majority of sheep breeds in Ireland, this is possible.
Even though typical breeds such as the Suffolk and Charollais are mid-season breeders, sponging is still a viable option if you plan on lambing down early.
The use of sponges allows for oestrus to be synchronised and thereby allows the use of pregnant mare serum gonadotropin (PMSG) to be used, to be able to increase ovulation rates and ultimately the litter size of ewes successfully mated.
Ewes should be weaned six to eight weeks before being sponged.
This would suit early lamb production systems, so that lambs are available for the Easter market.
It is recommended that the ewe to ram ratio does not exceed eight ewes to one ram.
It is important that ewes are flushed before breeding commences to onset oestrous. Flushing involves increasing the plane of nutrition to ensure weight and condition score gain prior to breeding.
This will give a better response rate, especially in mature ewes early on in the breeding season.
Important points to make note of are:
- Ewes should be in good condition, with no udder problems, missing teeth and no history of prolapse;
- Rams should not be lame and, if so, they should be treated or culled;
- Rams are at risk of burnout; it’s important to have more than the recommended number of rams to avoid this problem from occurring;
- If you plan to carry out sponging, the best practice is to carry out breeding indoors, so as you can keep an eye on animals that are not performing.
