The paper “The effect of tissue mobilization and stage of lactation on energy partitioning in lactating sows: an analysis of commercial data“, published in The Journal of Agricultural Science, has been chosen as the latest Editorial Highlight and is freely available to download for one month. 

Lactation, a minority period (15-19%) of the sow’s productive cycle, is a period of maximum digestive and metabolic demand since in a few days (two weeks at most) the sow multiplies its production level by three. The first objective during the sow’s lactation is to optimize milk production, which requires cooperative work between the sow herself and the litter. For the sow to express the maximum potential for milk production, it is necessary for her to consume the maximum amount of feed and for the litter to adopt a proactive position by completely emptying the udder in each suckling sequence. When this occurs, in most cases, the sow’s energy and nutrient intake is insufficient to meet the nutritional needs of the litter, and the sow mobilizes her body reserves during a significant portion of lactation. The mobilized reserves will be recovered, totally or partially, throughout the following pregnancy.

The work reaches two important conclusions. It develops a factorial method that allows estimating the mobilization of energy reserves under commercial conditions from the non-linear adjustment of the sow’s feed intake and litter growth, and that, in controlled conditions, sows which mobilize more tissue and energy up to a certain level have a slightly lower feed intake, but wean more piglets and heavier litters than other sows.

Energy mobilization is greater at the beginning than at the end of lactation, and young sows make a greater mobilization effort than adults. However, it does not resolve what would be the safe threshold of energy mobilized by the lactating sow and the relative contribution of lean and fat tissue mobilized. It is necessary to better understand and predict changes in the lactating sow’s body composition with reference to lean and fatty tissues. Finally, note that the results cannot necessarily be extrapolated to current hyper-prolific sows, but neither can the main conclusions be ruled out.

The Journal of Agricultural Science Editorial Highlights are selected by the Editor-in-Chief and are freely available for one month. View the recent selections here.