Alleviating Heat Stress in Ruminants

• Our research has proved the following unfavorable effects associated with heat stress, namely:
• Negative impact on the normal physiological behavior of that animal.
• Decreased dry matter intake, directly impacting the output of dairy animals.
  1. 20 to 25% reduction in dry matter intake.
  2. 40 to 45% milk yield decline.
• Reduced fiber digestion efficiency impacting ruminal acidosis.
• Oxidative stress: This will alter the endocrine status and nutrient absorption.
• Loss of reproductive efficiency.

At Kemin, we believe it is essential to consider nutritional strategies that lower harmful protein and energy balance associated with heat stress, allowing cows to sustain milk production.

We have seen cows under heat stress reduce dry matter intake by 20-25%, accounting for 40-50% of the milk yield decline. As a result, cows enter negative energy and protein balance regardless of their stage of lactation, which can lead to losses in body weight (BW) and body condition score (BCS). 

We must take two crucial routes to mitigate the effects of heat stress. It’s important to ensure:

-    Overall health improvements

-    Proper nutritional strategy

Both these routes are not only crucial during heat stress but are, in fact, essential during all stages of the animal’s life. Here’s a breakdown of both routes with our recommended solutions:

1)     Overall health improvements

Improving dry matter intake to sustain and enhance productivity during heat stress can be done through two strategies: supplementing Choline and balancing dietary cation-anion (DCAB):

Choline. Choline nutrition has received much attention recently due to its role in improving liver function. Besides higher production levels, Choline’s role in improving dry matter intake, immunity, and health creates a strong argument for increased provision of bioavailable Choline. We have seen that holine alters the plasma NEFA concentration increasing the export of hepatic fat. This results in less hepatic fat concentration and, therefore, improved liver functioning, leading to optimal dry matter intake.

Balancing dietary cation-anion (DCAB). Dietary cation-anion balancing (DCAB) improves dry matter intake in animals. When plasma calcium levels fall during hypocalcemia, rumination activity suffers. Rumination is characterized by a complex series of muscle contractions that bring a bolus of ingesta to the mouth for further mastication before swallowing it again. DCAB can overcome reduced rumination caused by hypocalcemia in pre-calving cows subjected to heat stress.

Two recently published meta-analyses on the supplementation of rumen-protected Choline and one meta-analysis on DCAB show that Choline and DCAB significantly improve dry matter intake, which is critical in optimizing farm profitability. Alongwith, Choline nutrition with CholiGEM™ and DCAB with NutriCAB™ .

2)     Proper Nutritional Strategy — Diets with rumen-protected amino acids (AA), Methionine, and Lysine

Effective nutritional management and proper ration formulation are vital and positively impact health and production, therefore mitigating the negative effects of heat stress in dairy cows.

During heat stress, rumen and small intestine functionality are completely altered, affecting digestibility and feed efficiency, as well as metabolic adaptations to reduced intake and a reduction in endogenous heat produced to maintain gluconeogenesis.

That’s why precision feeding with Amino Acid nutrition, is crucial to reducing the effects of heat stress on animals. Formulating low-rumen degradable protein and also low-rumen undegradable protein diets along with meeting methionine (Met) and lysine (Lys) requirements reduces circulating insulin levels and improves both protein efficiency and the metabolic status of heat-stressed cows due to better AA utilization.

The only feasible way to achieve the above is by improving the protein quality supply, increasing, the level of the first two limiting AA, Met, and Lys with an adequate energy level in diets.

One fact is clear — no matter the production level, temperature-humidity (THI) index, or ingredients used in the diet, we cannot cover the Met and Lys needs without using both rumen-protected Met and Lys.

Coupled with that, formulating with AA is one of the most cost-effective ways to support health and performance during all periods, including during heat stress. 

We ensure a proper nutritional strategy through our range of products: for RP-Met, we use KESSENT®, and for RP-Lys, LysiGEM™. These solutions are proven to have the following benefits. They:

✓     Improve glucose production and utilization;

✓     Reduce the negative energy balance (besides the negative   protein balance) associated with heat stress;          

✓     Reduce the oxidative stress maintaining the immune status; 

✓     Improve antioxidant capacity, maintaining the immune status;

✓     Help us to create low heat increment diets;

✓     Enhance dry matter intake and energy-corrected milk under heat-stress  periods;               

 ✓    Restore the intestinal barrier after injury.

You can also read more about Rumen-Protected Amino Acids

Let’s work on a tailored solution together

At Kemin, our extensive research has proven that a balanced approach to the three key pillars of the animal production system — efficiency, health, and sustainability — can help us tackle any challenges, including heat stress.

More specifically, our solutions are even more critical during the two primary pillars affected during heat stress — feed efficiency and animal health.

Our Ruminant Essentialities portfolio comprises these solutions geared towards supporting your challenges and the key pillars. 

Moreover, we know every situation and farm is unique and are keen to work with you to ensure the best possible, tailored solution.