Betaine and zinc supplementation in Iberian pigs, studied by the Animal Nutrition Group at the Zaidin Experimental Station and reported in the Journal of Thermal Biology, does not eliminate the adverse effects of heat stress during the growth phase. This finding highlights that, despite prior ideas about their potential benefits, adding these nutrients may not protect pigs from the physiological strain caused by elevated environmental temperatures. The research contributes to the broader understanding of how nutrition interacts with heat exposure in this specific breed, emphasizing that protective strategies must go beyond simple nutrient fortification to maintain performance under heat stress.
Pigs exhibit high sensitivity to heat due to their elevated metabolic heat production, rapid tissue growth, and limited sweating capacity. The absence of sweat glands and the relatively thick subcutaneous fat layer further predispose these animals to heat stress, making temperature management crucial for sustaining welfare and productivity. In this context, researchers describe Iberian pigs as a breed with unique adaptations, yet with fat deposition that can exacerbate the impact of hot conditions. The study therefore situates betaine and zinc within a broader assessment of how such factors influence physiological responses and growth when animals are exposed to elevated ambient temperatures.
Pigs are extremely sensitive to high temperatures. due to its high metabolic heat production and rapid growth. Moreover, lack of sweat glands and insulation of the skin They make this mammal particularly susceptible to heat stress because of the thickness of the subcutaneous fat,” explains researcher Zaira Pardo of the EEZ.
This environmental variable threatens pig production worldwide and can lead to huge financial losses. The main areas of pig production in Spain endure the harshness of the Mediterranean climate in summer, when maximum ambient temperatures range from 31ºC to 36ºC on average. Despite being a global concern, little is known about the effects of this stress on native breeds. Although this animal is thought to be perfectly adapted to its environment, the thick layer of fat can make Iberian pigs more susceptible to high temperatures, adds Pardo. The results underscore that regional climate patterns demand tailored management approaches to safeguard performance and welfare during peak heat periods.
In the study, animals were randomly assigned to two environmental conditions and three dietary treatments: a control diet, a betaine-supplemented diet, and a zinc-supplemented diet. The experimental chamber was set at 30ºC to simulate heat-stress conditions similar to those encountered during the warmest months of the Mediterranean climate. Researchers note that the comfort range for pigs lies roughly between 18ºC and 25ºC, and temperatures above 25ºC trigger thermoregulatory responses and energy diversion toward cooling processes. The setup allowed a controlled comparison of how each feeding strategy modulates growth performance, feed efficiency, and physiological indicators under stress versus normal conditions.
In regions with hot climates, such nutrition-based programs can serve as practical tools to mitigate heat stress and its negative effects on growth, feed intake, and overall productivity. These strategies gain importance as climate change increases the frequency and intensity of heat waves. The next steps in this line of work will look at how heat stress impacts other stages of the production cycle in this breed and explore alternative or complementary approaches to alleviate adverse outcomes, including environmental modifications, genetic selection for heat tolerance, and management practices that reduce thermal load while supporting steady performance.