Summer is approaching fast in the Northern Hemisphere, and now is the best time to prepare those “summer” feed formulas to help animals, especially monogastrics, cope with heat stress. Apart from the many possible interventions in facilities and management, today we also employ successful nutritional methods to reduce internal heat production. This is done by four major ways, described below.
- Increased dietary energy density
This implies increased use of oils and fats. Ideally, the increase in dietary energy should be proportional to the expected drop in feed intake, but as feed intake can drop by 50 percent during a heat wave, such an increase in dietary energy is obviously unfeasible. It is suggested to increase dietary energy by 10 to 20 percent, with exact levels depending on feed manufacturing capabilities and current energy levels in feeds.
- Reduced dietary fiber
Fiber, among all nutrients, is the one generating the most heat while being digested and metabolized. Thus, reducing fiber specifications during summer remains a sound practice. But it is not that straightforward: not enough fiber, and constipation becomes a problem. Thus, it is a better balance of fiber sources is more appropriate than mere reduction of crude fiber content.
- Reduced crude protein
Excess protein requires expenditure of energy to remove it from the body. Thus, excess dietary protein during summer is contributing to discomfort and reduced feed intake. By carefully matching dietary amino acid specifications to actual animal requirements it is possible to reduce the need for excess protein. The use of crystalline amino acids is a great help in summer formulas. Reducing dietary crude protein by more than 2 percent points should only be done by highly qualified nutritionists as this might expose the formulas to severe imbalances in amino acids, which otherwise are routinely considered non-problematic.
There is a number of additives, or rather, compounds, that can enhance the resistance to heat stress. Depending on current feed technology employed in each farm, a qualified nutritionist or supplier should be able to identify these for each region of the world.
In conclusion, summer formulas should be implemented as soon as temperatures start rising to ensure animals receive adequate nutrition minimizing discomfort from feed-related issues.