Summer's here in the Northern hemisphere, and with it those listless sows and languid gilts, reduced appetite, stuffy, overhot farrowing houses, sunburn for the outdoor pigs – and irritable stockpeople trying to keep pace with it all! Stimulated by some excellent and mainly new advice from PIC recently, I realised that the pig textbooks I have (and I have most of them) are not all that 'hot' on warm weather advice, so perhaps a few updating remarks may be useful.
Things the textbooks do mention
Obvious but vital are:
• Make sure there is plenty of water.
• Check up on ventilation – fans, fan belts, louvres and inlets.
• Don’t overcrowd.
• Clean all thermometers.
• Wrong- mucking? Look into the causes.
• Consider spray cooling growers – equipment is available now at a reasonable cost.
• Paint roofs white (this reduces internal radiation by up to one-third).
• Serve/ inseminate at the two cooler times of the day (repeats are 50% less and litter size can increase by one born-alive per farrowing). Boars need cooling as well as females – don’t forget them, as the damage to litter size due to poor sperm quality can occur when the hot spell is well over.
And so on – I won’t repeat the obvious; this column is about what the textbooks omit – not what they mention.
The PIC technical Services Team’s latest advice caught my eye. Some experienced producers are already doing some of the following, but many are not. Where appropriate I add some experiences of my own, having spent many tours in both ‘hot-wet’ and ‘hot-dry’ parts of the world. I have made minor adjustments to their wording which I trust improves clarity.
PIC advises, in hot weather…
• Any movement of pregnant females to farrowing, or weaned sows to the weaning area should be done as early in the day as possible so as to avoid stress.
• Increase gilt flow by 10 to 15% for eight to 12 weeks.
• House parity 1 and thin sows together at weaning.
Comment: Bullying from heavy- weight matrons is always a bad thing, but is especially damaging to implantation. Vital advice in hot weather.• Feed weaned sows twice a day.
• Heat checking: Heat check weaned sows, gilts and 21-day bred groups twice per day. Heat check open and new-intake females once a day.
• Start boar exposure to weaned sows on the day of weaning. Leave boars in front of the weaned sow after the heat check for one hour.
• When breeding, use two boars. The second boar should be 1.5 m behind the first boar for extra stimulation.
Comment: New to me – is this feasible?• PIC says that one boar should be able to stimulate four sows at a time, but do not inseminate more than four sows at once.
• Do not over-condition sows in pregnancy.
• Maximise lactation feed intake.
Comment: Notoriously difficult in hot weather. Feeding wet helps considerably, as my hot-weather clients have found. The nutritionist can reformulate lactation diets from the ingredient make-up, which lowers the heat increment from digesting food.• Full feed from days two to three after farrowing.
• Watch for off-feed sows and take
their temperatures the day after farrowing. Treat those with a temperature of 39˚C or above – and see your vet for the procedure.
• Be prepared to assist more sows at farrowing than in the cooler months. Comment: Assisted farrowing at any time, in my experience, is an underrated procedure which I should like to see become standard practice. Not always feasible, but breeders give up too easily on the understandable objections. Every farm I have visited since 2005 which has bitten this particular bullet has reported considerably more piglets reared/ litter.
• Early wean young sows that start to lose too much weight in farrowing.
• Consider culling older sows (Parity 5+) and sows in extremely poor body condition.
Last but not least: The table from my files adds some back-up information.