Some Thoughts on Lactation
Weaning day is a critical event on the pig farm. It is the culmination of four, five and sometimes more than six weeks, depending on the system, of managing the gilts and sows from the corresponding service group through their lactation.
On weaning day the focus for the stockperson is singular, it is the udder of each weaned sow. What you should be looking at is an udder that has reached full and maximum output relative to the number of pigs she has been suckling. What you should be looking at is 12 to 14 quarters reasonably plump and clearly working. This of course means that you should be looking at in excess of 11 pigs recorded against each sow. If, you are not, then there are a number of reasons why. The level of pigs born alive to the service group may not have enabled this. There are two possible primary actions to take to address this. In the short-term wean the oldest sows that are due for culling no earlier than 24 hours after the farrowing of the group has been completed and redistribute the foster pigs onto litters to raise the average litter size being suckled by the remaining animals. In the longer term address the management strategy for service and gestation management in order to optimize genetic potential which may include a review of the current genetics.
Weaning day is about the udder not the number of pigs because that udder is about to begin another production cycle. You cannot do anything more about the pigs.
Lactation is a critical period in the production cycle of the sow, properly managed it returns a parity one to four sow into a full potential, subsequent, production cycle with a high degree of uterine recovery essential to the first few weeks of that cycle. It also delivers strong weaners, from a 100kg total litter weight, into the first stage of the feeding herd already eating and no longer primarily dependent on mothers’ milk. This is a strong foundation, then, for feed efficiency and therefore cost benefit in the financially demanding area of the business.
In simple terms lactation is stimulated by the number and vigour of the piglets born. The demand for milk increases post farrowing in direct relation to the capacity and appetite of the suckling pig. Every producer needs to make a study of the feed scale for lactation in their herd(s). Logic must be considered, new born piglets requirements increase day on day as they develop and so the sows milk output must be carefully controlled certainly up to day 7 and then levels must be determined by the stockperson if daily rationing is the strategy or by the sow if ad-lib is introduced. The sow will hit maximum milk output around day 21 and probably also maximum body reserve depletion if she is doing a good job. This means that feeding her becomes aimed at her next production cycle in the third and fourth weeks of lactation to encourage uterine recovery and improving body condition.
Your pig veterinarian and nutritionist should be consulted on the details of the physiology of the breeding female in the period immediately preceding and following lactation as well as lactation itself. They have a lot of good information and experience to offer which covers a variety of possibilities.