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Act now to beat infertility!
Now is the time to start planning to cope with autumn infertility. Why now? Because, if left until later, there is no time to get in extra replacement gilts to top up the inevitable drop in production caused by this condition.
Autumn infertility can cause severe economic loss, but is often disregarded because the impact is not felt until around a year later, when returns drop due to fewer pigs in the finishing pens.
Rapidly reducing day lengths at the end of June and in July and August are one of the triggers for increased returns over the autumn period — sows traditionally will not conceive to farrow in mid-winter, points out Malcolm Stead, production director of pig-breeding company, ACMC Ltd.
To reduce the problem, he says sows and gilts need to be subject to a 16-hour-light/eight-hour-dark cycle with a light source of at least 200 lux in the dry-sow/gilt house. It is important to check that all fluorescent tubes are working properly and to consider replacements with higher-intensity tubes. Light levels are difficult to judge by eye, but can be checked by using a light meter.
Following a spell of hot weather, sows may fail to conceive, reabsorb their embryos or abort and this can result in a 10-35 per cent drop in the breeding rate.
Hot weather also damages sperm production in the boar — it only takes a few days, but the effects can last up to six weeks. “That’s why it’s a good idea to use AI cover during summer and autumn, since semen will have been quality-checked before dispatch — something that can’t easily be done with natural service!” says Malcolm.
The best insurance against a dip in production is to serve extra gilts — around 15 per cent to be safe.
Gilts brought in now can be served after an acclimatisation/isolation period to cover for the inevitable shortfalls in the main herd. This means their pigs will be ready for slaughter, next spring just in time to catch the price recovery after the New Year dip!
4th May 2007
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