Mating management - the success or failure of next year's lamb crop

The annual mating cycle sows the lamb crop for the following year. The success or failure of next year’s lamb crop hinges on steps that have been taken over the past few weeks and steps that will be taken over the coming weeks, Michael Gottstein, Head of Sheep KT Programme, tells us more.

Timing

Many sheep farmers lamb their ewes too early and run out of grass three or four weeks after turnout each year. This means that ewes have to be supplemented with expensive concentrates and the milk yield of the ewe is compromised at a time when she is hitting peak milk yield. If this is happening on your farm in most of the last few years then you should strongly consider delaying lambing by two weeks. Delaying lambing has a number of advantages and, for a mid-season lambing flock, it has very few if any disadvantages. Remember that our summer lamb price is remarkably consistent throughout the main lamb drafting months of August to November.

Delaying mating will pay dividends in terms of:

• Allowing additional time for ewes to gain body condition pre mating;
• Increases the percentage of ewes cycling and being mated in the first 17 days;
• Compacts lambing, but concentrates labour over a shorter lambing season;
• Increases pregnancy rate and litter size.

Ram management

Aim to have all rams that you intend to use on your farm for six weeks prior to the mating season. This gives them time to acclimatise to a grass-based diet, allows time for health treatments and gives you confidence that the ram has not experienced a temperature rise that may make the ram temporarily infertile. Rams need to be in good body condition. Rams in poor body condition have lower libido and will spend more time eating and resting rather than seeking out ewes that are in heat.

Key points for successful mating are:

• Ideal ewe to ram ratios are 45:1 for mature rams and 25:1 for ram lambs;
• Three or more rams per mating group will help to guard against infertility and blocker rams;
• Raddle is cheap and the best insurance policy against empty ewes at scanning time. Change the colour every two weeks. Start with the lighter colours first (yellow>orange>green>red>blue>black).
• Avoid dipping rams six weeks prior to the breeding season or during the breeding season due to the risk of post dipping lameness. If absolutely necessary then make sure rams are dipped first in clean and freshly made up dip.

Lame sheep

Lame sheep are a big problem during the mating season. Lame rams will not be able to work properly and lame ewes will be losing body condition, as well as the potential impact that the lameness may have on their ability to mate.

Aim to have all lameness issues resolved in advance of the mating season. After ram turnout, keep an eye on any lameness issues that may be arising. Treat lame sheep promptly so as to minimise the severity of the infection and limit the impact it will have on the reproductive performance of the flock. There is no harm in bringing the sheep in for footbathing during the mating season provided it is done in a calm manner. 

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Also read: Store lamb markets and the challenges and potential of store lamb finishing