I’ve been tracking weekly weaned and feeder pigs prices from USDA for almost as long as the department has been reporting them here.
There has been a clear seasonal cycle to the pricing of these pigs. For example, since 2005, the yearly highest price paid in the spot market for weaned pigs has always occurred in January and February. This makes sense since the supply of weaned pigs is lowest at this time of year due to seasonal infertility problems the previous summer.
The expectation is also for sales of these pigs in relatively high summer markets. On the other hand, the lowest price typically occurs in July and August because of the abundance of weaned pigs and the expectation of sales during the yearly cycle low in prices.
Patterns for 40 lb feeder pigs have a similar cycle, but shifted about 1 month to reflect their one month advantage in days to slaughter.