Ram infertility, or sub-fertility problems, can have disastrous consequences for a flock during the mating season.
This is especially the case if issues go unnoticed with a serious risk of high barren rates.
Sub-fertility issues are relatively frequent where rams experience a health ailment or significant increases in body temperature.
With sperm used during mating produced six to eight weeks earlier, it is important that management practices and nutrition focus on having rams in top shape well in advance of the breeding season.
Identifying fertility issues
Despite your best intentions, there may still be times when fertility issues arise. In cases like this, having a plan in place to limit its impact or readily identify problems will greatly help.
The most common practices used are raddling rams, running rams in groups or switching rams between groups.
Raddling rams is the best way of identifying breeding issues with rams or ewes. Changing the raddle colour at least every two weeks will identify high repeat rates in ewes or animals not coming in heat.
Group mating or running rams in groups reduces the chance of a sub-fertile or infertile ram causing problems, but it should be noted that it does not dispel them outright.
Although minor in frequency, there have been cases of high barren rates where two unraddled rams were run with a group of ewes despite one ram subsequently being found to have no fertility problems.
What was actually found in these cases was that the infertile ram was dominant and was preventing the other ram in the group from mating with a high percentage of the ewes. Raddling the rams will help identify this problem.
Switching rams between groups will lower the impact of an infertile ram being continually run with a group of ewes. Rams should still be raddled and switched in a time frame that means they will not be back mating with the same ewes at the same time in their next breeding cycle.
The conventional method of raddling rams is to mix a powder solution with grease and oil and apply liberally to the ram’s brisket. The grease and oil mix will make the raddle waterproof and increase persistency on the ram.
In peak mating, raddle will need to be re-applied every two to three days. Some farmers change the raddle colour every week so that the lambing date can be predicted weekly rather than fortnightly.
You should start with lighter colours such as yellow or blue and work your way up to green and then red or black.
An alternative to applying raddle is to use a harness and crayon. Be careful when applying the harness not to apply too tight or in a manner that may impede the ram’s ability to serve ewes.
When using a new harness, check the harness after a couple of days, as there may be some give or stretch until the harness is broken in. Harnesses may be a better option in hill mating or where ewes are not flocked regularly.
Tip for catching the ram
Some flockowners feed rams a very small amount of meal daily or every few days in the run-up to mating. This gets the ram accustomed to coming to meal feeding and makes it easier to catch the ram during mating while also reducing the level of stress put on ewes.
The best situation is if the ram is fed in a small pen, made by temporary gates; he will be accustomed to walking into the pen and will be easier to handle.
The earlier rams are bought before the breeding season the better. This is especially true for ram lambs as in many cases these lambs will have been on a high plane of nutrition pre-sale and will need acclimatising to a different diet.
In some cases, rams may need to have their body condition trimmed back. This should be carried out on a gradual basis with the aim of having rams fit and not fat.
Try to find out as much background information on the ram as possible so that a feeding and health planning profile can be established. A quarantine procedure should also be carried out on rams entering the farm.