The essential role of Amino Acids in heat stress mitigation

Published on 16-03-2023 - By Kemin

At Kemin, we have long been researching the effects of Amino Acid (AA) nutrition in heat-stressed ruminants. In fact, our research has shown an overall lessening of the negative effects of heat stress when animal diets are supplemented with rumen-protected Methionine (RP-Met) and Lysine (RP-Lys).

This comes as important news since heat stress has a significantly negative impact on ruminant performance. And if we don’t tackle this, it will sadly only worsen due to global warming and genetic selection.

The challenges of heat stress in ruminants

Firstly, it’s crucial to understand the key challenges regarding heat stress in ruminants. Heat stress is seen to affect cows in a myriad of ways:

  • Cows suffer a loss of milk production and changes in milk composition, such as a reduction in casein and milk fat production due to decreased rumination, resulting in reduced saliva in the gut.
  • The decrease in rumen pH affects the efficiency of fiber digestion, mainly the rumen fibrolytic bacteria, leading to other negative health aspects of heat stress, such as rumen acidosis, which impairs digestion and feed efficiency, affecting animal health and longevity.
  • Heat stress can also cause oxidative stress, making the animal more susceptible to inflammation, altering endocrine status and nutrient absorption, and decreasing nutrient availability.
  • Heat stress can negatively impact reproductive efficiency due to the negative protein balance and decreased protein efficiency, which increases plasma urea nitrogen, decreases heat duration, reduce blood flow to the uterus, and lower conception rates.

All of the above challenges greatly affect our animals and — added to that — have a huge impact on the running of the farm and its profitability.

Amino acids in ruminants

AAs are a trusted way to tackle heat stress. They are found in two main forms — essential and non-essential. Essential AAs cannot be synthesized by the animal and, therefore, must be added to the diet. And limiting AAs are those essential AAs contained in the diet at a lower level than the animals’ requirements.

Ruminants specifically have two major limiting AAs: Methionine and Lysine. We have seen that improving the provision of these AAs by using RP-Met and RP-Lys can enhance milk production, composition, feed efficiency, and animal health by improving liver function and reproduction and positively influencing gene expression.

Our approach to alleviating heat stress in ruminants

At Kemin, we believe the following are fundamental to lessening the adverse effects of heat stress in ruminants:

  • Proper temperature and humidity management.
  • Nutritional management and proper ration formulation.
  • Precision feeding, particularly regarding AA nutrition, is crucial in reducing heat stress effects on animals. AA nutrition can:
    • Improve glucose production and utilization, prevent negative energy and protein balance, and maintain milk production, or even increase energy-corrected milk output
    • Increase antioxidant capacity, and regulate immune and inflammatory responses and promote recovery of the intestinal barrier during periods of heat stress.
    • Alleviate the detrimental effects of heat stress on dairy cow health, dry matter intake, reproduction, and milk production and quality, as already mentioned.

Amino acid potential — Methionine and Lysine

AAs play a crucial role in boosting ruminant health. We can formulate low-rumen, degradable and undegradable protein diets to lessen the negative effects of heat stress.

We can do this by increasing the supply of high-quality protein, especially covering the first two limiting AAs, Methionine, and Lysine, with the use of RP-Met and RP-Lys and with an adequate energy level in the diet.

Methionine and lysine play a superb role in maintaining the normal biological functions of animals and are even more important during stressful situations such as heat stress.

The results speak for themselves — AAs improve glucose production and utilization and protein efficiency; they reduce negative energy balance and oxidative stress; maintain immune status, reduce intake loss, and ensure low heat increment diets; and they also restore the intestinal barrier.

Moreover, by improving the animal's metabolism and energy regulation, amino acids positively impact various physiological functions, such as health, immunity, milk composition, fertility, and nutrient efficiency.

Download our technical literature to learn more about our research into Amino Acids and their positive impact on heat-stressed ruminants. You can also learn more about all the other benefits of Amino Acid formulation.