Maintain performance through summer heat – Part 2

Posted on July 15, 2015 in Swine Performance
By Leah Gesing

Heat stress can result in lost profits during the summer months and its after effects may be felt into the fall.  Proper diet formulation to compensate for decreased feed intake can moderate the customary summer dip in carcass weights.  Correctly utilizing supplemental fat, crystalline amino acids, chromium and ractopamine in diet formulation can translate into greater summertime profits.

Energy concentration
Increasing the energy concentration of diets in the summer is a simple strategy to maintain average daily gain and improve feed efficiency in the face of low feed intake.  Adding fat increases the energy concentration of the diet, meaning that the reduced calorie intake due to lower feed intake is somewhat recouped.  The economics of fat addition is not only based on feed cost, but also is dependent on performance improvements, the value of a pig space, and pork prices.

Crystalline amino acids
Maximizing the use of crystalline amino acids and, thereby, decreasing the level of crude protein in the diet during the summer months can also improve performance.  Digestion, metabolism and excretion all increase the animal’s heat production.  Heat production is greatest when intact proteins are metabolized.  Crystalline amino acids do not need to be digested before being absorbed, so they generate less heat in the pig.  Utilizing crystalline amino acids in swine diets improves the efficiency of metabolism and decreases heat increment, which is especially important when feed intake is limited.

Chromium is an essential mineral that has been shown to increase daily gains and feed intake.  Chromium improves tissue sensitivity to insulin and, therefore, improves glucose availability and utilization in the body.  This increased insulin sensitivity increases the deposition of dietary protein and carbohydrates in muscle cells and causes less energy deposition in liver or fat cells.

Additionally, due to the effects of chromium, the feedback mechanism that controls when pigs feel hungry kicks in sooner.  This effect tells pigs to eat the next meal sooner and increases feed intake.  Several studies have demonstrated that chromium inclusion in swine diets increases daily gain and feed intake across multiple stages of production, including both heat-stressed and thermal neutral conditions.

Lastly, the repartitioning agent ractopamine consistently increases rates of live weight and carcass gain, regardless of season.  Pigs consuming ractopamine have higher rates of protein deposition in the muscle and decreased energy deposition in fat stores.  This results in increased daily gains, improved feed efficiency and leaner carcasses.

These dietary strategies can help mitigate pig performance losses due to summer heat.  The Vita Plus swine nutrition team is available to help you determine which ingredients should be included in your swine diets during the summer (and during all seasons) to help you obtain maximum profitability.

Editor’s note:  This article is the second of three articles related to wean-to-finish summer performance and management challenges.  Click here for Part 1.

About the author:  Dr. Leah Gesing is a Vita Plus swine technical sales and support specialist.  She earned her bachelor’s degree in animal science from Iowa State University.  She continued there to earn her master’s degree in animal physiology, studying on-farm factors affecting market hog transport losses.  She then went on to the University of Illinois to earn her Ph.D. in animal sciences.  While in school, Gesing was involved with numerous research projects, teaching experiences, internships, and international travel.  Specifically, she conducted applied research in swine genetics, health, management and reproduction with Dr. Mike Ellis.  Her Ph.D. project evaluated the effect of timing of OvuGel® administration on reproductive performance in gilts synchronized for estrus.

Category: Feed ingredients
Feed quality and nutrition
Heat stress
Swine Performance