When hyperprolific sows produce more pigs than teats, a recent study shows there may be better ways to manage those large litters. Abigail Jenkins, director of nutrition for Tosh Farms in Henry, Tenn., completed a study while she was at Kansas State University comparing the impact of sows nursing pigs above, at and below functional teat count.
She discovered the optimal litter size relative to functional teat count depends on the performance measure of greatest interest. Sows nursing a litter size below functional teat count have lower pre-weaning mortality and sow body weight loss and greater pig weaning weights. However, as litter size increases relative to functional teat count, overall farm throughput improves by increasing pigs weaned per litter, litter weaning weight and pigs weaned/sow/year.
The Need for Nurse Sows
Jenkins took her project one step further after compiling the data. Using the average pigs born alive and the average functional teat count at this sow farm at the time this trial was conducted, she determined how many nurse sows would be needed to handle the extra pigs because the live born was greater than the functional teat count. If the farm loaded 250 sows at each of the four treatments, this is what she found:
If the sows were loaded in groups of 250, at one less pig than functional teat count, 24 nurse sows would be needed for the extra pigs. If the sows were loaded at functional teat count, seven nurse sows would be needed. If the sows were loaded at greater than functional teat count (plus one or plus two), it actually resulted in negative nurse sows needed.
“Intuitively, this doesn’t make a lot of sense,” Jenkins said at the Allen D. Leman Swine Conference. “The explanation behind that is those sows are ones that we have cleared off her litter and put her pigs onto other sows to get them up to either plus one or plus two. Then, we have these sows that have just farrowed that now have an open crate that we can utilize as tools in our farrowing rooms. These sows can be used as what I refer to as opportunity sows.”
What is an Opportunity Sow?
Opportunity sows take pigs that are small, less than 2 lb. She says the key is the pigs are small, but they must be viable. The opportunity sows used for this should be younger parity, but not gilts. They should be sows that have proven production history. They also need smaller sized teats so the smaller piglets can nurse easily.
“The opportunity litters are going to be large — 15 or more pigs,” Jenkins says. “Essentially, this concentrates all your small pigs into a few litters, so you can have more in-depth care for these small pigs and less competition. We know that smaller pigs, especially those born less than 2 lb., if left in the crate, have a much higher chance of preweaning mortality. If we can focus them all into a few litters, give them less competition with those big pigs and give them more resources and more in-depth care, then hopefully we can raise more of those smaller pigs with less preweaning mortality, and get them up to a full-value pig at weaning.”
An Answer for Fall-Behind Litters
Another way to use these negative nurse sows, or opportunity sows, is in fall-behind litters – pigs that are removed from their initial litters because of failure to thrive or because they are not doing a good job nursing on their current sow.
“It’s important those pigs get removed early, whenever those signs are first being seen,” Jenkins says. “The earlier the intervention, the greater the chance that you can really make a difference, and the greater the chance that you wean a full-value pig.”
Although some people would use a traditional nurse sow for a fall-behind litter, she says the newly farrowed sows actually make an ideal sow for fall-behind litters for two reasons.
- These sows are still going to be producing a little colostrum or they’re going to be producing transition milk — both of which are higher in fat and protein content. It allows you to get more nutrients into those fall-behind pigs.
- Newly farrowed sows will allow the litters to nurse more frequently than a sow who has just weaned a litter of her own.
“When you combine having milk that is higher nutrient content and a sow that’s going to allow those pigs to nurse more frequently, your chances that those fall-behind pigs recoup faster is much better,” Jenkins says.
