Good ram preparation leading up to joining is essential to ensure that ewes have the best chance to achieve optimum conception rates, and a tight joining and lambing period. To increase lambing percentages you first need to ensure you are providing the best opportunities to conceive. Rams need to be regularly checked for lameness, flystrike, fighting injuries and need to be in optimum body condition.Performing a simple ram check on the 5 T’s prior to joining can result in increased conception rates. The 5 T’s that need checking are torso, teeth, toes, testes and tossle.
The ram paddock should be easily accessible with adequate shade, cool water and access to good quality feed. Rams should be in a good condition Score 3.5 (torso) at 2 months prior to mating. Remember it takes 7 to 8 weeks to produce mature sperm and to reach maximum fertility, so any setbacks during this period can be disastrous.
It goes without saying that rams with poor teeth will have a reduced ability to intake feed, may suffer nutritional deficiencies and may be less fertile.
Poor hoof shape or abscess may also reduce the ability of the ram to serve a ewe.
The epididymis tail of the testes should be large and firm and of unirform size, not hard and diseased. A ram with abnormal lumps or non-uniform testes should be blood tested for ovine brucellosis.
A healthy well fed and sexually rested ram may hold up to 100,000 million sperm, of which 75% is stored in the tail of the epididymis. Palpation of the tail of the epididymis can indicate the level of sperm reserves in an individual ram. A small, soft tail indicates poor reserves of sperm.
There is a close relationship between testicular size and sperm production. Rams with small testes may not produce enough sperm throughout the joining period to maintain good fertility. Research has sown that improving the intake of protein and energy with supplementary feed such as lupins for 2 months prior to joining can increase testicle size and subsequently sperm production by up to 100 per cent. Ideally the scrotum should measure > 30cm in a 2 year or older ram.
Nutritional changes affect testicle size and sperm production much more rapidly than is reflected in live weight and body condition which highlights the importance of checking the ram’s reproductive soundness prior to joining.
Check the ram’s tossle for damage. Damage can easily occur during shearing and may result in a 10% reduction in productivity of the ram.
Environmental factors can also affect sperm production and lead to temporary infertility . Heat stress can affect sperm production and viability if the rams cannot keep the testes cool during the 8 weeks prior to joining. Hot weather with temperatures over 32 degrees Celsius for long periods or very high temperature over 38C for short bursts can affect sperm production. Mature sperm are less likely to be affected than sperm in the developing stages.
A ram who has suffered heat stress before joining could successfully serve ewes with the stored mature sperm (eg 2 to 3 weeks) then there will be a 7 week delay before new viable sperm is produced.
Shearing rams just before mating is not desirable as some fleece protects the ram from heat stress. Plan shearing so that rams have 3 to 4 months wool length at joining.
Temporary infertility from overheating can also be caused by the lack of paddock shade, mustering, transporting, fever resulting from flystrike and infections from cuts and injuries from fighting.
All efforts should be made to protect rams from these conditions prior to and during joining to ensure the best lambing percentage. Of course ewe management is also extremely important.
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