Utility Nav

Ram fertility testing

Rose Young BVM BVS MRCVS, Molecare Veterinary Services

Rams must be in full health well in advance of the breeding season to ensure an efficient lambing block. Although few rams are thought to be completely infertile, as many as 30% are suspected to be sub-fertile, resulting in more empty ewes and drawn out lambing blocks. The four points detailed below will give a good idea of the breeding potential of most rams.

Whether purchased or home-bred, examine all rams at least 8 weeks before they go in with the ewes, this gives time to address any problems, or replace rams who are not up to the job. Health issues can affect sperm production for as long as six weeks, so getting in there early is really important. Bare these four points in mind when purchasing rams at sales too; you can check many things discreetly without too much bother and may give you a clue about a potential issue before purchase.

1. Teeth

Clearly tooth loss should not be an issue in young rams, although checking the mouth for signs of bad jaw conformation (undershot or overshot “parrot mouth” jaw) in unproven rams is a good idea; this type of deformity is often inherited and will cause problems in offspring.

Full mouthed rams need their teeth checked routinely; any found to be broken-mouthed will struggle to gain and sustain enough weight to work well over a season and should be culled.

2. Feet

Lameness will massively affect a ram’s ability to work; the most important step is diagnosing the problem. Turn the ram over, check all four feet and legs for evidence of pre-existing problems such as; bad conformation, hoof overgrowth or joint swellings. Decide whether the problem is treatable, such as foot rot or an abscess, or whether the ram should be removed from the breeding team due to an ongoing problem.

If you do find any signs of infection (foot rot, scald, abscess), the increase in body temperature can affect sperm production for six weeks; always include an anti-inflammatory in your treatment protocol and ensure testes have adequate recovery time before breeding

3. Testicles

Testicle circumference relates directly to fertility, so size really does matter! Actual size is breed and age dependent; testes will also be smaller outside the usual breeding season. A minimum of 35cm around the widest part of the scrotum is a good guide. If either or both testicles appear noticeably small or large, this could definitely be a cause for concern.

Both testes should be firm and smooth, with no hard lumps, ulcers, injuries, swelling or heat. You may be able to feel some of the structures inside the testicle at the top and bottom, which are normal. When you have the ram turned over, check his penis and sheath (prepuce) for any abnormalities including signs of infection or injury, and that the prepuce can move freely.

4. Condition

Rams work extremely hard during tupping, and therefore need body condition score to be 3.5 – 4 at the start of the season. While you condition score, check the brisket for any injury which may affect raddle placement or mounting behaviour. Rams can be supplementary fed in the lead-up to tupping to achieve good body condition and improve semen quality, however take care to ensure rams are not over-fat as this can reduce libido and serving ability.


If your general examination does not yield much information, you have suspicions about a particular ram’s working ability, or just want peace of mind that your ram team will be able to do the job, you can opt for a semen assessment by a vet using electro-ejaculation. This process will allow the vet to obtain a semen sample by passing a small electric current through a probe inserted into the rectum, which stimulates the reproductive structures and nerves inside the body. It can be a little uncomfortable for the ram, so if you can not obtain a suitable sample the first time,you will need to retest at a later date.

Alongside her/his in-depth clinical examination of the ram, the vet can assess the semen sample for quantity, quality, sperm count and sperm structure and activity. This will need to be done on-site using a mobile microscope and laboratory equipment, power and light will need to be made available in the vicinity. You obtain the most suitable samples during the natural breeding season, so timing of testing is key; check your rams now and book in Ramsure appointments  later in summer as days start to lengthen.

Remember: the fertility examination will test potential for breeding, we can only assess libido by direct observation. He may pass the exam with flying colours, but if he won’t mount, your ewes will most certainly not be getting in lamb!

For more information phone Molecare Vets on 01392 872934 or visit www.molecarevetservices.com

Comments are closed.