Diseases and conditions affecting ram fertility
Rams are prone to several infectious diseases that need to be kept under control, particularly ovine brucellosis and cheesy gland.
Ovine brucellosis and cheesy gland can have serious effects on ram fertility. Thankfully each of these conditions is relatively easy to control and, in some cases, can be eliminated altogether.
Ovine brucellosis can cause swelling in the ram's sperm duct, which subsequently blocks the transfer of sperm. This condition is known as epididymitis and may reduce fertility or, if both testicles are affected, cause total infertility.
Ovine brucellosis is spread when infected rams 'ride' other rams (more common in younger rams), and rams mate with ewes that have been previously served by infected rams.
To minimise the effects of ovine brucellosis you should:
- examine rams at least once a year
- cull any rams with clear abnormalities of the testes
- ensure joining percentages and joining length are adequate - if brucellosis is present you will need to increase the joining percentage
- separate and examine new rams on arrival. Keep new arrivals separate, if possible, for 8-12 weeks to allow any infected rams to show detectable lesions.
Learn more about managing replacement rams.
How to examine rams
To examine (palpate) your rams, start as high up in the cords above the testicles as possible, and gently squeeze the testes through your hands, feeling the top, body and tail for any lumps. Both testicles should be the same size, smooth and firm. All rams with testicular abnormalities should be culled.
Cheesy gland is a common bacterial disease of sheep. Cheesy gland abscesses often occur in the scrotum and can be found by palpation in the cords above the testicles. They can be easily detected as a hard lump up to about the size of an egg. If cut open, a large quantity of greenish-yellow pus will be obvious.
Cheesy gland is likely to interfere with temperature regulation of the testes as well as cause inflammation and some pain and discomfort, which are all capable of reducing fertility, ability and stamina.
There is no cure for cheesy gland but you can prevent it through a 6-in-1 vaccination program.