Farrowing pens
In the pig farming process, the period of parturition and lactation is the most vulnerable period for piglets to be lost. Generally speaking, the mortality rate of live piglets can reach up to 10-15% within three weeks after birth. The cause of death is mostly due to the squeezing of piglets by sows. The loss of piglets caused by squeezing by sows accounts for about 50% of the total loss.
In the past, when sows gave birth in the birthing pens with freedom of movement, the mortality rate of piglets crushed to death and crushed was higher. Now, in some European countries that pay attention to animal welfare, loose feeding systems are still adopted. At present, in most cases in China, the method of using sow farrowing pens is adopted to reduce the damage to piglets.
Although the various farrowing pens do not differ much in appearance design, their specific characteristics and overall dimensions are obviously different.
In general, the size of the farrowing pens is within the following range: 45-65 cm wide, 180-240 cm long, and 65-75 cm high. The specific size needs to be determined according to the size of the pig. In addition, there are many differences in the design of specific features of the farrowing pens, such as the distance between the horizontal bars and especially the shape of the low guardrails.
For the design of the farrowing pens, more attention should be paid. In particular, if the guardrails are too high, young sows and gilts can get under and get injured; if they are too low, it will affect the piglets’ feeding, affecting mortality and growth rate. In addition, restricting access to the udder generally encourages piglets to fight during nursing, increasing the incidence of injuries.
Some farrowing pens are now designed with curved low guardrails to increase the effective space for piglets to access the udder when nursing. The upper width of the farrowing pens is normal, which is used to restrict the movement of the sow. The lower horizontal guardrails are equipped with finger-like wooden bars pointing vertically to the floor, which allows piglets to access the udder more easily while preventing sows from getting under the farrowing pens. Different designs and layouts of farrowing pens allow piglets to access the udder more easily while preventing sows from getting under the farrowing pens. Different designs and layouts of farrowing pens are shown.
In addition, one of the latest innovations in farrowing crates is a hydraulic style with two movable sides controlled by hydraulic plungers. The sides close when the sow is standing and the sow must squeeze the plungers to open the sides in order to lie down. This slows the sow’s movement to the floor, giving the piglets enough time to escape from the danger zone next to the sow, thus reducing crush losses. However, this type of farrowing crate is much more expensive than other designs.
Other devices have been designed to be attached to farrowing crates to reduce crush losses. So-called “piglet-rescuer guardrails” can be hinged to the inside of any farrowing crate design. They can move up to allow the sow to stand up and return to their original position to prevent the sow from lying on her side. When the sow lies down, she needs to put her belly on the ground first and then roll to the ground. Studies have shown that this design reduces crush losses. Another design to reduce crush losses is called a “blow-away” device, which consists of a motor that blows cold air under the sow’s body. When the sow is nursing or lying down, the device is turned off. However, when the sow stands up, it blocks a beam of infrared light that passes through the middle point of the farrowing pen, which starts the motor, so that cold air blows out from under the sow, causing the piglets to run to a warmer area in the pen. When the sow lies down again, the piglets have left the dangerous area where they are easily squeezed.
For modern pig farms, the most common methods of raising pregnant sows are tethering and gestation cages. The use of gestation cages restricts pregnant sows to a very small range, limiting their range of activities to a very small area and making them unable to turn around. The use of tethering greatly restricts the range of activities of sows, and this feeding method is generally opposed by many animal welfare advocates.
Gestation cage
Now, the “turning gestation cage” developed by the University of Illinois in response to animal welfare considerations has replaced the original gestation cage. The design of the “turning gestation cage” is that the rear of the cage is hinged in the middle, and the sows turn around by moving the hinge part to increase their available space. Placing the water supply (usually a nipple drinker) at the rear of the crate also encourages the sow to turn around and make full use of the gestation crate. While this design allows for greater movement than traditional gestation crates, the confinement of the sow in a relatively small space is still a concern for animal welfare advocates. In addition, turning gestation crates are expensive and therefore have not been widely adopted by producers.