Date: 05/08/2019

Pig farming is one of the most profitable areas of animal husbandry. The low initial investment needed, the high meat performance and the pigs ability to adapt to different climatic conditions are the main factors that make this business able to guarantee the producer a relatively fast payback.

Smart practices in pig farming can ensure that the full potential of the activity is achieved. For this, it is necessary to know how some environmental factors can affect the breeding of pigs and reflect in its performance.

One of these factors is the temperature. Temperature variations cause the most varied effects on the metabolism of the animals and even affect the behavior of the pigs with the food.

Due to this, in this blog post we will go deeper into what these changes can cause in practice and how the pig organism responds to this type of variation.

How to protect pigs in cold weather

In countries with milder climates, low temperatures that extend over a long period and that may affect pig farming is not a major problem, different from countries in the Northern hemisphere.

But even in these regions, it is important to have the knowledge of how to act when temperatures fall during the winter.

One of the first measures is to keep the pigs in a closed environment. In this way, they will be more weather protected. However, it is necessary to maintain an access to the external area, so that the pigs can move and deposit their waste.

It is also important to always keep a reservoir of clean water, as well as constantly change the hay and blankets with which the swine warm up. By doing this, a comfortable and healthy environment is created for the animals.

If the choice is to keep the pigs in an open environment, precautions should be taken, such as the provision of burlap clothes to prevent heat loss, which could lead to pneumonia. It is also important to keep the blankets dry, with no water contact.

The relationship between high temperatures and feeding

In very hot weather, the pigs need to dissipate the heat to maintain their functions normal. One way to achieve this is by increasing heat loss (evaporation) and reducing heat production.

To reduce heat production, pigs reduce feed intake because the digestion process and nutrient metabolism contribute to the generation of heat. A study showed a 30% decrease in feed intake when a group of pigs was subjected to a temperature of 33 °C compared to a group that remained at a temperature of 23 °C.

The decrease in feed intake due to heat consequently causes decreased body weight as well. Considering this, i t is interesting, especially during this period, that the pig feed is rich in high quality nutrients and has high digestibility, so that the pigs can acquire the necessary nutrients even without ingesting the same amount of food as in other periods of the year.

Chicken Protein Hydrolysate is a good option for these cases, since it has a rich crude protein concentration, easily absorbed, from the hydrolysis of chicken slaughter by-products. Thus, pigs will be assured of a sufficient supply of all essential amino acids.

How reproductive rates are affected by heat

In addition to the influence on feeding, the high temperatures also have an effect on the fertility and fecundity of the pigs, which decrease during hot months.

One hypothesis that may explain this fact is that the reduction of reproduction rates in the summer occurs through reduction of GnRH hormone secretion and also through the impediment of development of the ovary follicle, which results in low concentrations of progesterone.

A change in temperature from 20 °C to 30 °C can decrease the reproductive performance of pigs by up to 10%. The mortality rate of sows is also affected by the increase in temperature.

A study showed that, regardless of the season, 68% of sow deaths occur 4 weeks before or 4 weeks after giving birth. It has been found that this risk increases even more in the summer months in the United States.

Decrease in growth rate

As a consequence of reduced feeding, pigs have their body weight negatively affected by thermal stress. A study compared the performance of a group of pigs in an environment at 34 °C with another group in an environment at 22 °C. The authors observed a 40.5% reduction in feed intake, which was reflected in a final weight 13.2% lower than that of the pigs kept at 22ºC.

It was concluded that thermal stress compromised the development of pigs by reducing feed intake and physiological changes. The extreme opposite of this scale is also a problem for pig growth.

When exposed to very cold weathers, animals consume an excessive amount of feed to maintain normal body temperature, producing an excess of fat.


Temperature can affect the pig farming in several ways. Cold climates can harm animal welfare, in addition to leading to an increase in fat content due to overeating.

On the other hand, high temperatures reduce the rate of pigs’ feed consumption, affecting their growth, which directly damages the profitability of the business. In addition, this factor also has a negative effect on the rate of reproduction of the animals.

Thus, in order not to have their business shaken, producers need to find ways to lessen the damage caused by sudden changes in temperatures. One way is by providing feeds containing high quality ingredients and digestibility, ensuring nutrition and growth of animals even in periods of reduced feed.