Pipestone has continued to study the effects of lactation length and have completed two large scale trials through our research facilities.

The first trial was designed to understand lactation lengths impact on sow weight and growing pig performance.  We looked at five treatment groups from 21 days to 30 days wean age in 2-day increments.The second trial was designed to evaluate the impact of lactation length on sow performance and total born. Records of 99,653 sows farrowed between August 2016 and August 2017 were evaluated.  Genetic lines were PiC-L42, DNA, Topig-Norsvin and Fast.  Farms with health breaks were excluded and sows with total born less than 5 and greater than 25 were excluded.

Here are the top 5 things we learned from these trials.
#1 Elevated weaning age causes no change on sow weight loss or gain during lactation

The statistical model did show that a P1 sow lost significantly (-33 lbs) than P2+ sows (-2 lbs.)  And that a wean age of 29-30 days lost numerically the least (12 lbs.)  Sow weight loss in cohorts by 2-day increments of lactation length and by parity during lactation is described in the figure below.

#2 Elevated weaning age improves wean to finish ADG, but does not improve lifetime ADG.
The below chart shows that by weaning an older pig, you will have fewer days to market from placement, but will not move the physiologic lifetime growth rate of the pig.

#3 Elevated weaning age has minimal impact on wean to finish feed conversion

#4 Elevated weaning age reduces wean to finish mortality and culls and reduces removals

#5 Elevated lactation length elevates subsequent sow total born

Subsequent total born improves by 0.085 pigs for every day of lactation increase.

In summary, data overwhelmingly supports maximizing lactation length at sow farms.  There are benefits for the sow as well as the piglets.

For additional questions on the trial, contact Dr. Cameron Schmitt at cameron.schmitt@pipestone.com.