The infertility season is upon us 15 Mar 2007

It's spring again in the northern hemisphere! And for those pig producers keeping their sows outside the annual problem of summer infertility is here again. However, this problem can be solved relatively easily.

I live in a predominantly outdoor sow breeding area where the control of light is, of course, difficult. We therefore farm sows in a situation parallel to the nature of the seasons which are dominated by light - in our case natural daylight and daylength.

Because of this handicap we have had to learn management techniques which are essential if we are not to suffer the fall-aways in breeding performance in July and August (summer infertility) and in September to November (autumn infertility)

What's the difference?

Dull, rainy weather
In the northern hemisphere, we find the summer infertility problems are mainly caused - we think - around this time (March/April). After periods of dull, rainy weather, during which time the outdoor newly-weaned sows spend a lot of their days tucked up snug and warm in their huts, the bad-weather fronts pass and in early spring we get days of blue skies and brilliant, rain-washed sunshine.

Of course out come the breeding sows into the paddocks, happy to catch up on feeding, exploring and chatting up the boar/getting themselves ready for AI treatment.

Exposure
This sudden exposure to uninterrupted ultra-violet light at this critical time (of ovulation and implantation, we suspect) may disturb the balance of conception which shows itself in a poor farrowing rate in midsummer.

It is suggested that putting up summer heat shades early, i.e. in spring, encourages breeding sows to keep out of a full day's exposure to very bright light. It also prevents the sows getting a bit of sunburn from lying in the hut's dry-sow-shelter doorway. Also if a pile of bedding is placed in the heat shades with a handful of feed nuts scattered around this will encourage them to make use of these shaded areas.

Investing
Some people are now investing in relatively cheap ecoshelter breeding areas which do the same thing and are also useful during other seasons.

Autumn infertility is another thing altogether and there are a variety of management protocols which can be employed. I shall be covering them in my regular column in an imminent number of Pig Progress.