Mating management and ram fertility

Breeding efficiency is a major component in the overall efficiency of sheep production. In this article, Teagasc Sheep Specialist, Damian Costello writes on practical management tips for a successful breeding season.

Ewe management before and during mating

Carry out any routine treatments before ram turnout to ensure minimal flock disturbance during mating e.g. fluke treatment, footbathing etc. Aim to have lameness under control and continue to monitor during mating so that individual cases can be treated.

After fertilisation, you are looking to give the embryo every chance of survival and successfully attaching to uterus. Post ram turnout, avoid things like excessive handling, dipping or sudden changes in diet. Also watch out for late blowfly strike and treat any incidences promptly.

The target is to have ewes in body condition score (BCS) 3 to 3.5 at mating. The good grass offered to achieve this in the lead up to mating should be maintained during the breeding season. Don’t force ewes too hard during mating in terms of grazing out paddocks and don’t let them run out of grass. The use of temporary fencing will help get paddocks grazed out without restricting ewes for too long a period.

Managing rams pre mating

Rams also need to be in good condition prior to mating (BCS 3.5 to 4.0) for two reasons:

• They eat very little during the mating season and can lose up to 20% of their bodyweight
• Thin rams tend to have lower libido and are less inclined to seek out ewes to mate

Concentrate supplementation is often needed along with good grass to build up their condition before breeding, ensuring the feedstuff is suitable for feeding to rams. It is also very important to monitor the health of rams in the run up to mating and buy in any replacement rams in good time.

Sperm production in the ram takes five to seven weeks. This means that a ram mating a ewe around mid-October will have started producing that sperm at the end of August / start of September. Anything that interferes with sperm production in the run up to mating can have disastrous effects on the ram’s ability to impregnate ewes. Any infection that increases the ram’s body temperature by as little as 0.5˚C for 24 hours can render a ram temporarily infertile. A spare ram is no harm as a replacement for any ram that may get lame or is unable to function for any other reason.

Ewe:Ram Ratio

As a guide to number of ewes per ram:

• 1 mature ram to 45 ewes (up to 70 ewes for more active ram breeds)
• 1 ram lamb to 25 ewes (up to 40 for more active ram breeds)

Ram group mating vs single sire mating

Letting out a number of rams to each group of ewes can help insure against the ram in the team that may be infertile or sub fertile. Ideally use 3 or more rams together per group of ewes. This eliminates the effect of the blocker ram - where two rams are ran together and the dominant one of them spends a lot of time and energy stopping his comrade from mating. Finally with groups of rams, don’t mix mature rams and ram lambs if possible.

With single sire mating or 1 ram per group, it’s all the more important to raddle your rams. With 1 ram per group, it’s a good idea, where possible, to rotate rams between groups after 14 days.

Raddling the ram

It is absolutely essential to raddle the rams so that you can keep an eye on how mating is proceeding. Do not to skip this very important task - even if running rams in groups as opposed to single sire mating.

Start with lighter colours which can be overmarked by a darker colour e.g. yellow to orange to green to red to blue to black, and change the colour at least every 14 days which will show repeats in the new colour. If a lot of ewes in a group start repeating, suspect that there is a problem with a ram. There is still time to do something about it, and it is much better than finding a lot of empty ewes at scanning.

Options for raddling

Many people mix raddle powder with oil to make a paste and apply liberally to the area of wool just above the brisket of the ram. It’s important to work the raddle paste well into wool and reapply every few days, especially during the first few weeks when rams are busy. Some rub on raddle crayon to this area and again it needs to be applied regularly.

The other option is fitting a harness to the ram to which the colour crayon can be attached – the crayon block can be replaced when changing colours. It is important to check that the harness stays in place as they tend to stretch and can bed into the wool – needs to be checked and adjusted as necessary. Avoid having it slipping back on ram as it can potentially impede him from mating ewes.

Also read: Autumn grassland management guidelines on sheep farms