Ram preparation
The period leading up to joining is important to ensure that rams are healthy and in the best condition possible. Lambing potential is maximised when rams are able to work, and have viable sperm, throughout the joining period.
Preparation should commence at least eight weeks prior to joining because it takes about seven weeks for sperm to develop from initiation to ejaculation. Therefore, treatments to the rams between seven weeks and joining can only influence the proportion of developing sperm which would be delivered after joining has started.
Two actions should be taken prior to mating to ensure success:
- carry out the 'four Ts' health check (teeth, testes, toes and tossle)
- feed high protein and energy grain or pastures for maximum sperm production at least eight weeks before joining.
The four Ts health check
- Teeth — check that the ram has a sound mouth, with teeth and gums in good condition. Check for over bite (parrot mouth) or under bite. These defects are highly heritable and any rams with these defects should be culled.
- Testes and tossle — rams need maximum testes size to work effectively. Testes and epididymides (the long tubes which run up the sides of the testicles) should be firm and have no lumps. Spongy testes can be a sign of disease, poor nutriton or injury.
- Test all rams with unexplained lumps or swellings in the epididymides for Brucella ovis, a bacterium that can drastically reduce ram fertility. Don't crutch or shear rams during this time as infections from cuts, especially to the scrotum, can stop sperm production. Check the penis and the prepuce for any abnormalities or swelling.
- Toes — check and trim any feet as required. Remove, or treat and monitor, any rams with a sign of lameness. Lameness will affect the rams ability to work as well as his output.
Feeding rates for rams pre-joining
To ensure firm, large testes, feed lupins at up to 750 grams per head per day for the eight weeks leading up to joining (feeding rates may be lower if paddock nutrition is very good). Rams should be in at least condition score 3 but no more than condition score 4.
Joining percentage
Ensure you have adequate numbers of rams for joining. Fit, healthy rams should be used at a minimum of 1% (with a minimum four rams per mob). Join mature rams to maiden ewes.
Immature rams tend to have smaller testes size and therefore lower sperm production so a minimum of 2% should be used. With a synchronised joining, or out of breeding season joining, it is safer to use 3%.
Joining out of season and use of teasers
To join ewes outside the spontaneous breeding season, the ‘ram effect’ can be used. For the ram effect to be effective, all ewes must be kept at least one kilometre (km) from any ram (including neighbouring property’s rams) for four weeks before the introduction of teasers or rams. The introduction of teasers/rams to the isolated ewes will induce them to start cycling.
The major benefit of successfully using the ram effect induced by teasers is to get a high proportion of ewes in lamb over a short period of time which results in a more compact lambing. Teasers also stimulate more ewes to come into oestrus.
Teasing for 14 days followed by a 35 day joining is recommended.
Teasers can be testosterone treated wethers (or ewes) or vasectomised rams. If using vasectomised rams, they must be removed at the start of joining; wethers can be left in the mob until the rams are removed, unless they are large and aggressive and likely to compete with rams for ewes. Inject teasers with testosterone seven days prior to being used. Testosterone is available from your veterinarian. Teasers should be used at 1% for 14 days before the entire rams go in. Teasers must be introduced directly to the mob to ensure that all ewes make contact as soon as possible.
If teasers aren’t available, flock rams can be used but a longer joining is recommended (45 days).