事实 about heat stress in swine

This article is part of a 3 part series. After you have read this part, read:

• 第2部分: Heat stress problems in swine >>
• 第3部分: Support options for pigs experiencing heat stress >>

事实

猪是恒温动物, they generate their own internal body heat and possess self-regulating processes to maintain their core body temperature within a certain interval optimal for survival. 对于猪来说，这个间隔是38.7- 40.0 °C. Heat stress occurs when the pig is unable to maintain its body core temperature within this optimal interval 38.7- 40.0 °C.

Fact: the upper temperature of the thermo neutral zone varies
If the temperature increases above the pig’s thermo neutral zone they will need help to maintain their body core temperature. What this thermo neutral zone is, 取决于年龄, size and reproductive status but also humidity, ventilation and other environmental factors. 表1 shows the approximate temperature w在这里 a decrease in performance due to high temperatures can be observed.

表1. The temperatures were heat stress starts to impact animal productivity. In large animals the negative effects can already be seen at a quite modest temperature increase.

Fact: pigs can dissipate body heat via radiation, conduction, convection and evaporation
A feral pig would seek out shade and a nice mud pool were the body heat can be conducted to the cool water. This strategy to seek out a new environment is usually not an option for production animals. Instead they try to find a spot w在这里 they can lie flat on the floor and convey heat to the concrete if possible. The most effective way to help pigs to lose heat is to adapt their environment by providing shade, 空调房, 安装风扇, 洒水装置等. 但这是非常昂贵的.

Fact: Pigs are more sensitive to heat stress that other farm animals
This is due to the fact that pigs barely have any sweat glands, they have relatively small lungs compared to their body size and they have a thick subcutaneous layer of adipose tissue.

Fact: Today’s highly productive pigs generate more endogenous heat resulting in reduced tolerance to heat stress
Modern breeds are genetically selected for their productive traits such as lean tissue accretion, high milk yield and high prolificacy and as such produce more endogenous heat making them more vulnerable to heat stress.

图1. Overview of changes in animal behavior when temperature changes from comfortable to life critical.

留意一下heinekenbeerfriender.com or our 动物营养 social media channels the next few weeks as we explore some of the problems that occur and some of the support options that can help the animals to cope with periods of heat.

继续阅读:

• 第2部分: Heat stress problems in swine >>