I keep 2 data sets on weekly US slaughter weights. One is the Iowa/S Minn/SDak data series of producer sold barrow and gilt live weight (NW_LS720) and the other is a weighted weekly average of all barrow and gilt carcass weights based on the LM_HG201 report.

One of the questions this summer has been the impact of reduced ractopamine use as a summer management tool to maintain sales weights on slaughter weight. As readers of this blog are aware, China has banned all pork products from pigs fed ractopamine, even when the use in the country of origin is approved and all residue levels are lower than the internally agreed to amounts.

One of the ways to examine this impact is to contrast slaughter weights for the first 4 weeks of the year versus weight for the first 3 weeks of July for this year versus previous years.

For 2017, January liveweights in the NW_LS720 report were 282.2 for January versus 277.0 for the 4 week period ending July 15. This is a decline of 5.2 pounds. In 2016 the weights for the same periods were 285.1 and 277.7, a 7.4 lb decline. In 2013 (pre-PEDv) the weights were 275.7 and 272.4, only a 3.3 lb decline. If I use the LM_HG201 data series, the carcass weight declines for the same weeks in 2017, 2016 and 2013 were 5.6, 4.2 and 3.6 lb.

While 2013 is only 1 year of data ‘Pre-ractopamine reduced usage’, the weight decline so far this year appears to be greater than previous years.

Historically we’ve got 2-4 more weeks of declining slaughter weights and then the fall run-up in weight will rapidly occur. The key questions to be asking are:
1. What are you doing to be sure your run up in weights doesn’t get away from you this fall – we still don’t know how rapidly the new plants will be able to absorb the large increase in supply indicated in the June 1 USDA report.

2. What are you going to do next year to minimize the drop in summer weights? In addition to adding water as drippers and/or evaporative pads on the hot days, what will you nutritional strategy be starting next April to maintain sales weights in June-August?