Thursday, December 29, 2011

Pig Farming - Artificial Vs Natural Insemination

Now here's a question - should I use a boar or a 'straw' (that is a sachet or bottle of diluted pig semen) to get my sows pregnant? This is equally pertinent a question if you have 1200 sows or one, and the reasoning is pretty similar given either scenario - so lets start by comparing the two.

Boars need feeding and housing; semen packs simply need ordering, delivering and storing. I say simply: you have to remember to order the semen in time for it to be as fresh as possible when your sows are ready to be inseminated; you need to be able to get it from the postman or courier to storage as quickly as possible; and you need to be able to store it at (as near as is possible) a constant seventeen degrees Celsius for the duration of it's viability (which is about a week from collection given a long-life diluent and the right storage conditions).

So with the semen packs you're not having to pay for feed, you're not having to muck out pens, and you aren't running the risk of being bitten, chased, gored or eaten by them either. A semen pack will not need veterinary attention and won't smell either! It's easier to handle, and the insemination technique is easily learnt - a 'knack' rather than a great skill.

A boar, however, can tell when a sow is at her most receptive (and encourage her to that point), deliver semen in large doses (200 - 300ml at a time) into the right place inside the sow, and give you a consistent product during his useful lifetime on your unit.

But it'll always be his genes, and with pig genetics advancing year on year the semen pack from the AI (artificial insemination) stud will always be at the forefront of breeding, giving you more and better pigs per sow per year, year after year. The semen pack enables you to use more than one breed or bloodline, and gives you access to the best commercial sires available - they are a cost effective way of improving your output, which with the very tight financial margins involved in the pig industry is essential. Basically, by the time the young boar you've bought or bred (or kept back from your fattening pens) is ready to work, a genetically superior boar will be available to you from the AI stud.

Using 'teaser' boars it is possible to detect when a sow is ready to be served, and then use AI to get her pregnant, serving two or three times during her 24 - 36 hour standing oestrus (a boar will only be able to manage two or three times a week). It's an easily learnt technique, and results are excellent: most commercial farms now use AI, keeping only a few boars to encourage and detect standing heats (when a sow is at her most fertile she'll stand still given a pressure on the small of her back, whether that pressure is applied by a boar, a stockman or some mechanical device) - and then keeping the ladies chatting and interested whilst the stockman inseminates them (the teaser boars' main role is producing pheromones and grunting in just the right way).

But what if you've one got one or two sows to get pregnant? Is it worth keeping a large, potentially aggressive (and certainly strong and wilful) animal just to have it work a couple of times a year? Maybe you can hire one in for a few days (certainly the best option if you've got a rare breed) - but with this comes problems with disease transmission, problems with housing the visitor, as well as the technicalities of handling him and supervising service. One of the biggest problems with natural service (especially indoors with a single boar - less so in groups of pigs with multiple boars outdoors) is making sure that the boar has deposited his semen inside the right part of the pig, and so is best supervised in an appropriate facility.

In summary then, and in answer to our opening question: use a 'straw'! Today's technology enables pig keepers to use the best modern genetics, drawn from a variety of breeds and bloodlines without having to look after (and pay for) a boar for every ten females on the farm. The smallholder or pet-keeper can take advantage of AI too, reducing his costs and having a choice of sires.

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.

View the original article here

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