Flock Management at Mating
Breeding efficiency is a major component in the overall efficiency of sheep production. Damian Costello, Sheep Specialist, Teagasc takes a look at practical management tips for successful breeding, including body condition score, pre-mating tasks, raddle use, ram group mating and breeding ewe lambs
Target Body Condition Score (BCS) at mating
Aim to have ewes BCS 3 to 3.5 at mating, on a rising plain of nutrition in lead up to mating and maintain this during the breeding season. Don’t force ewes too hard during mating in terms of grazing out paddocks and don’t let them run out of grass. The use of temporary fencing will help get paddocks grazed out without restricting ewes for too long a period.
Rams also need to be in good condition prior to mating (BCS 3.5 to 4.0) for two reasons:
1) They eat very little during the mating season and can lose up to 20% of their bodyweight
2) Thin rams tend to have lower libido and are less inclined to seek out ewes to mate
Routine tasks pre mating
Carry out any routine treatments before ram turnout to ensure minimal flock disturbance during mating e.g. fluke treatment, footbathing etc. Try to have lameness under control prior to mating and continue to monitor during mating so that individual cases can be treated. After fertilisation you are looking to give the embryo every chance of survival and successfully attaching to uterus. After ram turnout, avoid things like excessive handling, dipping or sudden changes in diet. Also watch out for late blowfly strike and treat any incidences promptly. A spare ram is no harm as a replacement for any ram that may get lame or is unable to function for any other reason.
Observe rams pre mating
It is important to monitor the health of rams in the run up to mating and have sourced any replacement rams in good time. Sperm production in the ram takes five to seven weeks. This means that a ram mating a ewe around now mid-October will have started producing that sperm at the end of August/or start of September. Anything that interferes with sperm production in the run up to mating can have disastrous effects on the ram’s ability to impregnate ewes. Any infection that increases the ram’s body temperature by as little as 0.5˚C for 24 hours can render a ram temporarily infertile.
Raddling the ram
It is absolutely essential to raddle the rams so that you can keep an eye on how mating is proceeding. Do not to skip this very important task even if running rams in groups as opposed to single sire mating. Start with lighter colours which can be overmarked by a darker colour e.g. (yellow → orange →green → red → blue → black) and change the colour at least every 14 days which will show repeats. If a lot of ewes start repeating, suspect that there is a problem with a ram. There is still time to do something about it, much better than finding a lot of empty ewes at scanning.
Other benefits of raddling the ram
Many flocks change raddle colour more frequently (e.g., every 7 to 10 days). This enables ewes to be grouped together at housing by expected lambing date. Grouping ewes by expected lambing date and scanned litter size allows more accurate concentrate feeding prior to lambing. There is potential to reduce the amount of concentrate feeding thus reducing costs. Equally important is achieving the optimum lamb birth weight and thus reducing the incidence of oversized lambs and potential lambing difficulty.
Options for raddling
Many people mix raddle powder with oil to make a paste and apply liberally to the area of wool just above the brisket of the ram. It’s important to work the raddle paste well into wool and reapply every few days especially during the first few weeks when rams are busy. Some rub on raddle crayon to this area and again it needs to be applied regularly.
The other option is fitting a harness to the ram to which the colour crayon can be attached – the crayon block can be replaced when changing colours. It is important to check that the harness stays in place as they tend to stretch and can bed into the wool – needs to be checked and adjusted as necessary. Avoid having it slipping back on ram as it can potentially impede him from mating ewes.
Ewe:Ram Ratio
As a guide to number of ewes per ram:
- 1 mature ram to 45 ewes (up to 70 ewes more active ram breeds)
- 1 ram lamb 1 to 25 (up to 40 for more active ram breeds)
- Ram group mating vs single sire mating
Letting out a number of rams to each group of ewes can help insure against the ram in the team that may be infertile or sub fertile. Ideally use 3 or more rams together per group of ewes. This eliminates the effect of the blocker ram - where two rams are ran together and the dominant one of them spends a lot of time and energy stopping his comrade from mating. Finally with groups of rams don’t mix mature rams and ram lambs if possible. With single sire mating or 1 ram per group, it’s all the more important to raddle your rams. With 1 ram per group, it’s a good idea, where possible, to rotate rams between groups after 14 days.
Breeding ewe lambs
Ensure ewe lambs intended for breeding are at least 60% of expected mature weight e.g. mature weight 80kg, ewe lambs should be 48 to 50 kgs upwards at mating. Use a mature ram with ewe lambs as they will be better than a ram lamb at seeking out ewe lambs to mate. Very important when breeding ewe lambs to choose a ram known for ease of lambing.
Listen to this week's Ovicast where Ciarán Lynch catches up with sheep specialist Damian Costello to discuss mating management.