Reproductive success of rams is the ability to sire a large number of offspring each mating season.
Rams should be selected and prepared at least two months prior to joining. This will ensure they are not stressed and are settled when joined.
The following considerations should be taken into account:
- Ram soundness.
- Shearing or crutching.
- Joining rate and time.
- Ram condition, health and nutrition.
- Australian Sheep Breeding Values (ASBVs) for birth weight and lambing ease and match this to ewe type.
- Avoiding stress by allow new rams to settle for at least two months prior to joining
- Rams should not be lame.
- Testicles should be firm and springy on palpitation with no lumps. Scrotal circumference should be greater than 28cm. If abnormal lumps appear on the testicles a blood test should be undertaken to check for ovine brucellosis.
- Prepuce and penis should be examined for evidence of inflammation and damage.
Shearing or crutching
- Shear or crutch rams at least eight weeks prior to joining. Shearing cuts and resulting fever or change in body temperature may affect semen quality.
Joining rate and time
- Rams should be joined at 1.5% plus one extra ram for mature ewes eg six rams for a mob of 400 ewes.
- Join at minimum 2% for maiden ewes and ewe lambs, plus the extra one ram per mob.
- Higher ram rates will be needed in large paddocks with multiple watering points or when rams are joined outside the main breeding season.
- Ewes cycle every 17 days and rams should generally be joined for at least two of these cycles (five weeks). If the ewes are joined outside the peak breeding season (before February) or joining paddocks are large, join for five weeks if teasers are used or six weeks if teasers are not.
- Maidens and ewe lambs should be joined for approximately six weeks.
- Avoid using inexperienced rams with maidens or ewe lambs.
Ram condition, health and nutrition
- Allow eight weeks for newly introduced rams to acclimatise if they have been brought in from outside the district. Housed rams may need more time to become accustomed to paddock feed prior to joining commencing.
- Body condition score should be around 3.5 at joining.
- Ideally feed a high protein ration, such as lupins or faba beans, for 50 days prior to joining to ensure maximum testes size and sperm output. Feed at a rate of 750g/ram/day.
- Rams should be vaccinated with 6-in1 and jetted on the poll and body to avoid flystrike.
- Any ram that has been sick with a fever in the last eight weeks should not be used for mating as high temperature disrupts semen production.
- If ewes are being supplementary fed during joining, rams should be introduced to the same feed prior to joining to avoid rumen acidosis.
Australian Sheep Breeding Values
- Producers should consider using ASBVs to select rams for low birth weight and higher lambing ease. This will help to minimise the risk of lambing difficulties.