Changes in feed prices have been causing a major strain on U.S. pork production since fall 2020. In fact, the cost of feeding a weaned pig to market weight fed a typical corn-soybean meal-dried distillers grains with solubles (DDGS) diet has increased by $27 to $30 per pig since July 2020. This magnitude is particularly challenging to find relief when all major ingredients and co-products have risen in cost, along with fat and synthetic amino acids. In the past, we were more accustomed to individual ingredient price increases, but not all of them for this prolonged period which looks to extend well into 2021.
We must focus on what we can control, and this should be the same whether we are in good or bad economic times in the pork industry. It can be easy to lose focus and begin to alter formulation and decrease nutrient levels which worsens feed efficiency or gain at a level that offsets any price savings, negatively impacting the bottom line. This is particularly important when developing a nutrition strategy for summer marketing periods (May to August). 
For pigs to be marketed starting in May, the time is now to get a nutrition program in place to maximize your return. The two main aspects to consider are dietary energy and amino acids.
Dietary Energy
Due to higher market prices in summer, improving growth rate by altering diet energy is a common method producers and nutritionists utilize. However, many producers experience a decrease in carcass weights when marketing in summer due to not implementing higher energy diets soon enough. When doing the backward calendar from marketing to the time of pig placement, summer program diets should be started in February for late nursery or beginning finishing pigs. At the same time, pigs marketed in February to April can remain on winter program diets to complete their feed budgets.
With continued high ingredient prices, determining the ideal economic value of dietary energy is even more important. In order to potentially increase diet energy, the main options are to 1) reduce the inclusion of lower energy, higher fiber ingredients such as DDGS or wheat midds, or 2) add fat. 
In most locations in the U.S., DDGS currently does price in, but not at high levels (greater than 15% to 20%) for medium fat (6% to 8% fat) but may not for lower-oil DDGS (<6% fat). Also due to a steady increase in liquid fat (animal or vegetable) price over the past six months, producers must carefully evaluate if adding fat is truly economical. When adding 2% to 2.5% of fat per ton of feed, it would be expected to increase carcass weight by 2.5 to 3.0 lbs. for the same feeding time period. Thus, the increased diet cost must be offset by this increase in revenue. 
This scenario is important in fixed time systems when there is not flexibility on longer feeding periods of individual groups of pigs. However, if an operation has some space flexibility, even allowing pigs an extra three to four days on non-added fat diets, they can achieve the same carcass weight of added-fat fed pigs. 
Amino Acids
When feed costs rise, there are always questions regarding reducing diet amino acid levels to lower feed cost. This is a two-part evaluation which includes diet lysine level by feeding phase and all other amino acid levels.
Routinely nutritionists evaluate the ideal dietary lysine level based on genetic requirements and optimum performance. It is not advisable to lower the diet lysine level below requirement as feed efficiency will worsen and most likely off-set any feed cost savings. However, data has shown that short-term reductions in early finishing are not detrimental when placed back on regular diets for the duration of finishing due to compensatory gain. Also, feeding above the lysine requirement may marginally improve feed efficiency but not increase daily gain, and thus is rarely economical.
For all other amino acids, their ideal economic level can change based on growth goals. One example is tryptophan which may have a slightly higher ideal level used for summer diets compared to winter marketing formulations. Currently with higher prices and potential shortages of methionine, evaluation of diet levels and potential of lowering without significantly altering growth is needed to ensure optimal economics.  
Finishing Diet Formulation Tips for Summer 2021