I continue to get asked about expectations for slaughter weights this coming year. My standard reply – we’ll continue to add weight as long as feed grains remain relatively cheap and we continue to make progress in improving feed conversion. In reviewing data from private research trials where pigs have been taken to 330+ lb, it’s pretty rare to see feed conversions for terminal crossbred barrows and gilts get to 4:1 for any weigh period prior to 300 lb liveweight. Some genetic lines have conversions better than this to weights approaching 330 lb.

The challenge of heavier sale weights is facility space. A large portion of the US industry uses production contracts for access to facilities. These contracts most often spell out space by defining the capacity of the facility being contracted. For example, the contract will shttp://forum.mnpork.com/pecify a contracted facility will house up to 1250 pigs to slaughter weight. There is no language in the contract stating that if slaughter weights increase there will be fewer pigs housed in the facility.

This means a production system intends to always house 1250 pigs for each turn in the facility since the payment is a fixed fee per year, not a per pig fee. The data is very clear that because of growing the same number of pigs to heavier weights, daily gain declines (relative to pigs given more space per pig) because of a reduction in daily feed intake. However, the economics of this reduction in gain are not as severe as one might think because the impact of crowding on feed conversion is not as clear-cut. In many data sets in the literature, there is little if any correlation between space allocation and feed conversion, as long as feeder and drinker spaces remain adequate.

Because of the lack of correlation between feed conversion (the biggest expense in pig production) and space allocation, the economic models continue to support putting the same number of pigs in a production facility even as sale weights increase. The only time this doesn’t work so well is when the ventilation system becomes unable to manage the additional heat output of the faster growing pigs at heavier weights.

Further proof to support my conclusion that sale weights will continue to increase is the spread in carcass weight between producer sold and packer owned pigs in the National Daily Direct Prior Day Slaughtered Swine USDA mandatory price report (LM_HG201). For all of the slaughter days reported in 2015, packer owned pigs were always heavier than producer sold. The average for the year was 4.97 lb heavier carcasses for packer owned pigs.

Another interesting observation from the LM_HG201 report is the sale habits of producers. Over the 2014-2015 market years, carcass weights for all slaughtered pigs compared to Monday weights were 0.09, 0.88, 1.36 and 2.19 lb heavier on Tuesday, Wednesday, Thursday and Friday, respectively. Both packer owned and producer sold categories showed the same trend of heavier pigs later in the week.