Today we are going to be discussing about the management practices of gilts and sows, including managing Insemination and managing Estrus.
A gilt is a young female pig and a sow is a reproductively active female pig.
We are going to talk about them in two categories:
1. Grandparent stock Sows (GP)
2. Parent stock Sows (PS)
Grandparent stock sows are purebreds used in crossbreeding programs while Parent stock sows produce pigs for growing for pork. Therefore, parent stock sows are usually got after crossbreeding GP sows.
The gilts and sows which are commonly used in commercial production of fattening pigs are First Generation gilts of Landrace and Yorkshire. These are highly prolific due to their high fertility levels and with enviable mothering ability.
Every breeder has his own choices depending on customer preferences but the globally known breeds that must constitute a potential hybrid for use as parent stock are Landrace and Yorkshire.
Commonly, purebreds are owned by breeders and their task is to crossbreed them and then select the most excellent individuals basing on standard criteria for sale to Pork producers.
Due to the need for study and selecting highly performing individuals, gilts are best bought at six months of age.
1. The gilt has a full record of its genetic performance and abilities regarding feed conversion, weight gain and disease resistance.
2. The gilt is at an age when fatteners are sold therefore must be of a minimum weight which is about 100 kilograms. Here you can confirm the possibility of your fatteners reaching minimum slaughter weight at six months.
3. The record on Production costs from birth to six months is available so easy computation and comparing profitability before choosing to purchase the pig.
4. The pig is grown therefore can’t be so much affected by stress during transportation, change of feed, management and climate.
This makes breeding pigs expensive and breeding a sophisticated job that should be performed by only those with adequate knowledge about the market, its genetic requirements and the art & science of breeding pigs.
In most parts of the country, breeding as an activity has many issues and actually some countries still lack typical breeders. This is why you see many importations of breeding pigs going on in the country.
Ways of Managing the Estrus
Well managed gilts are in puberty at 6 Months. This is when their first heat period is noticed. However, this can take beyond 6 months in poorly managed herds.
It takes you between 7.5 to 8 Months to achieve the above, therefore on average your gilts can only be inseminated at 8 months of age.
At six months, these gilts weigh about 100 kilograms or more. Depending on the source of your parent stock, the least recommended weight for inseminating a pig is 130 kilograms.
This can go to as high as 150 kilograms with some commercial breeds. Heavy gilts have higher chances of farrowing a larger and healthier litter.
Ways of Managing Insemination
Choosing a type of insemination is very important to farm profitability. The available options to a farmer don’t go beyond natural and artificial insemination.
Some experts advise a ratio of one boar to 10 sows, I personally don’t agree with this because if these gilts/sows are of the same age, there is a possibility of coming into heat at a relatively similar time.
Natural insemination requires keeping of Boar (s) on farm. Realistically, for any given sow, a boar is active only between 2 to 2.5 times annually. During this period, the boar will consume your food, occupy space, encroach on farm labor, security and health management for 366 days.
Also, Boars are limited in the number of inseminations that can be made in a week to about 3 times.
Therefore, in a situation where many gilts/sows come on heat, the farmer will have to lose the productive time and serve at such a time when the boar has not been at work. Or, the farmer will have to keep many Boars if keeping many gilts/sows.
Thou, Artificial Insemination is just improving in some part of the countries in the world but is at a stage where a serious commercial producer can make use of it efficiently. Artificial Insemination will enable you inseminate many sows at a go with no difficulty, reduce chances of disease transmission and give you liberty to choose favorite sire breed.
Also, even when gilts bought are of spaced age, they will at a given time be ready for insemination at almost the same time. In situations where the libido of the boar is low or having some health difficulties, the farmer will have to lose by again jumping the conceptive time.
And when a boar is overused, chances of a smaller litter are inevitable. Due to the higher costs of maintaining a boar, some producers choose to hire Boars from other farmers or use village Boars, “Seduume wekyalo”.
This has aided transmission of dangerous reproductive diseases such as Parvovirosis, also African Swine Fever which has ability to erode the whole farm in just days.
The best paternal breeds are Duroc, Hampshire and a cross of Duroc and Pietrain. These are selected due to their efficient muscling, carcass quality and early growing. Therefore, if Duroc (DD) is used your pigs for slaughter will be a mixture of Landrace, Yorkshire and Duroc (LYD).
Depending on the size of your farm, you may choose to keep a boar to help during heat detection and natural synchronization of gilts and sows.
Please don’t reproduce slaughter pigs because the offspring will be of reduced performance ability.