With summer heat upon us, sale weights are dropping. The Iowa-Southern Minnesota average weight for the week ending July 17 was 267.3 pounds, down 0.9 pounds from the previous week. Last year at this time, weights were actually increasing due to the abnormally cool weather in July and August in the upper Midwest.

While every producer or production system has slightly different numbers, the decline is sale weight can be pretty dramatic. I’ve seen sale weights recently that are 15 pounds below the target sale weights for a production system. In one case, while feed intake had declined some, the decline was not enough to explain the sharp decline is sale weights.

Corn quality is an on-going concern. I expect quite a few comments and complaints regarding corn quality in the coming months. While much has been written about corn quality issues in the eastern cornbelt, I’m getting reports from clients in irrigated corn country where corn quality usually is very good.

In addition to low test weights, clients are becoming suspicious of vomitoxin and other mold caused contaminants in stored corn. With the Midwest having very good prospects of for a bin-busting corn crop, grain producers have begun to empty their on-farm storage in anticipation of harvest beginning in 2 months. The last corn from a grain producers bin is not what I look forward to feeding to growing pigs.

Traditional methods to overcome summer slumps in sale weight have been the addition of fat and Paylean to growing pig diets. Depending on marketing agreements with packers, Paylean may not be an option for some producers. This summer many are not using fat because of the relatively high cost of this ingredient relative to corn. Corn is currently costing about $0.06/lb, while fat is in the range of $0.25 to $0.30/lb. This means fat is costing 4 to 5 times the cost of corn.

Normally I would caution producers regarding the addition of fat to diets with this wide difference in price. However, the return for the addition of fat may be higher than normal this summer with the problems of poor corn quality combined with summer heat.

If you haven’t already done so, I encourage you to visit with your nutritionist about the relative economics of fat addition for the next 2-3 months. With the current slaughter market in the range of $55 to $58 per cwt liveweight, it may pay to add fat if it results in an increase in sales weight.