Pig Farming - Weaning to Service Interval Is Critical

By [http://ezinearticles.com/?expert=Andrew_Carter]Andrew Carter
A key performance indicator, critical to success or failure in a very low margin business such as producing pigs, is the weaning to service interval of the herd.  By this we mean the number of days between the day of weaning a sows' litter to the day that she is served again.
A herds' success can be best measured by the amount of pigmeat that each sow produces each year, which is in turn affected by the number of litters she has each year and the number of piglets produced from each littler.  There are obviously other factors involved, such as the age at weaning, and post weaning mortality, and of course, the rate of growth of the pigs and the weight at slaughter, but the key component is how many days she is 'empty' - that is not pregnant or suckling.  During these days she is eating your food, taking up your time, doing nothing productive - costing the farm money.  This isn't strictly true of course, she's getting her body back into reproductive mode after three or four weeks of lactation, and it's critical to manage these days carefully.
Once weaned, the physiological processes leading to ovulation kick in.  There's a change of hormones going on, a drying up of milk, and in short order big behavioural changes.  The sow comes out of confinement and the hassle of hungry dependents into a situation where she feels increasingly 'randy' as well as having to sort out where she stands with the adults that she finds herself mixed with again.  All very confusing, coupled with a change of environment (a different pen for example) and a smell of the boar that she hasn't sampled for a while.  It only takes three or four days, and the sow will start to get very interested in other sows in the group, even in the stockman when he's in the pen too.  She'll ride other sows, nuzzle flanks and get very agitated.  At the same time her vulva will start to redden and swell. All this time she needs to be able to touch a boar nose to nose through a gate or some other barrier, in order to be able to smell him and hear and talk to him.  On the third full day it's important to keep the ladies away from the boar, and from day four onwards introduce them to each other for a limited period of time once or twice a day.  When the sow is coming up to ovulation she will exhibit a 'standing-heat': she'll stand solid as rock for anything when pressure is applied to her back in the presence of a boar.  She should be served during this 24 (or thereabouts) 'window', during which the vulva swelling will subside, and after which she'll no longer stand and eggs will drop down the fallopian tubes into the semen which has been introduced into the uterus, either by the boar or via artificial insemination.
Top herds in the UK have twelve 'empty' days per sow per year, which is the equivalent of a five-day weaning to service interval.  The consequences for missing a heat are twenty-one more empty days before the animal stands again, all twenty-one of which she'll enjoy (literally) eating into your profit (if there is a profit to be made this year!).  To avoid these extra days, make sure that the sows are weaned in good condition - i.e. they have had plenty to eat during lactation - and that boar stimulation is good during the few days post weaning.  Then, just get the insemination right (needs very good levels of attention to detail/ stock management), and she'll be off again into money making mode, hopefully full off piglets to enter the world three months three weeks and three days later!
Andrew is a qualified teacher of English as a foreign language (TEFL), a farmer with twenty years agricultural experience, and worked for fifteen years in the global automotive industry.
Article Source: [http://EzineArticles.com/?Pig-Farming---Weaning-to-Service-Interval-Is-Critical&id=6636592] Pig Farming - Weaning to Service Interval Is Critical