The two main causes of early piglet mortality are chilling and crushing, both of which can be reduced by providing appropriate piglet heating. For lactation crates there are several options available, including heat lamps, heat pads, under floor heating and piglet covers. These will be explored and the relative merits and downsides to each discussed. How effectively the products keep the piglet warm is not the only consideration; energy efficiency is a "hot" topic, one which will significantly affect producers' bottom line.
During the first weeks of life it is essential to keep piglets warm to maximize survival. Piglets are born wet, hairless and with limited energy reserves, therefore producers need to control heat loss to maintain body temperature. Providing a supplementary heat source is necessary to create a warm zone at piglet level. This will encourage the piglets to lie in certain areas, reducing the risk of over-laying. It should be a distinct area, kept at 27-32C for the first four to six weeks of life. Reducing drafts and maintaining a well-ventilated house is also essential to providing a healthy environment for the piglets.
Equally, the sow must not get too warm; she is already producing extra heat through the metabolic processes of lactation, and any time spent above 16C will decrease her appetite. If her voluntary feed intake (VFI) is reduced, then the overall cost of production will increase. However, it is recommended that the house be kept at 22-24C before farrowing and 18-20C afterwards. If uncomfortable, she may stand up and lie down more often, increasing the risk of over-laying. Therefore, two environments should be maintained; one for the sow and one for the piglets.
Heat lamps
Heat lamps are the traditional method of providing a supplementary heat source through radiant heat. The lamps available have a durable metal case with a protective wire cage around the infrared bulbs. They can be positioned in a particular area of the lactation crate, creating a warm lying area for the piglets. Lamps can be easily moved, and producers may choose to have the lamp at the rear of the sow during farrowing to prevent chilling as they are born. Heat lamps can then be put at the side of the sow or in a corner of the crate. However, the heat often also reaches the sow. They can also be placed under covers and in creep boxes, which conserves the heat produced.
A disadvantage of heat lamps is that the bulbs may only last two to four weeks and will need to be changed during the lactation period. As well as the cost implications of this, the bulb may blow overnight when the stockperson is not present. This means that the piglets could be without heat for several hours, often resulting in health problems or even mortality due to chilling. However, the initial outlay for heat lamps is the lowest of all the systems at approximately $337 (£200) per 10 sows and can easily be installed into existing housing.
Heat pads
Supplementary heat can be either provided "top-down," as in the case of heat lamps, or "bottom-up" by heat pads or mats. As heat rises, it makes a lot of sense to keep the piglets warm by placing a heat source underneath them. Economically, less heat is lost and the temperature of the sow is not affected. Pads can be positioned to allow the piglet to suckle but creating a gap to prevent them being crushed. The pads maintain a constant temperature, 16-20C above the ambient temperature.
Heat pads are either heated by electricity or by hot water. The electric pads can be used on both concrete and slatted floors, whilst the water-filled type is suitable for concrete floors where water lines can be installed. The designs of the products available are durable, safe, hygienic and easy to clean. They are made of fiberglass and/or reinforced plastic, making them water resistant and fire retardant. Manufacturers produce the pads in a variety of shapes and sizes depending on the shape of lactation crate and number of piglets in each litter. Two litters may be served by the same larger heat pad, saving space in the unit. Heat pads provide a larger area of evenly-distributed heat so that piglets don’t pile on top of each other. Many pads have optional thermostatic controls, allowing producers to gradually reduce the level of heat as the piglets grow.
Energy efficiency is a key selling point; heat pads have been shown to use at least 50 percent less power compared to lamps. So although they cost approximately three times the price of lamps to install, their running costs are significantly less. In addition to savings in energy usage, there are no replacement bulbs to buy and the units themselves can last 15 years. A disadvantage of heat pads is that they cannot be used in conjunction with bedding material of any kind.
Under-floor heating
Under-floor heating is another method of providing a "bottom-up" heat source. There are two main types of system, one of which where pipes are laid under the floor and heated water is pumped around them. Alternatively, under-floor electric heating mats can be used, if the floor is suitable. Either system can be used to heat the whole nursery, and the pipes can be laid in a pattern to create a warm area at the side of the sow.
Under-floor heating systems can be difficult to install retrospectively, so they are most suited to producers building new houses. The initial outlay is higher than for the other options, but they are efficient, reducing energy bills.
Covered creep areas
Covered creep areas provide a distinct area to keep piglets warm, encouraging the piglets to sleep away from the sow. Covering the piglets inherently limits observation, meaning that the stockperson may not notice problems as quickly. Any cover must be able to be lifted or moved so that the piglets can be checked regularly.
Plastic or metal covers are available to purchase, or boxes can be made out of wood or metal. The level of coverage is dependent on design, which varies from three sides, roof-only or a combination of both. The material used for construction should be carefully considered, as ideally it should reflect rather than absorb heat. In terms of efficiency, you are conserving heat produced by heat lamps or pads so that in theory less energy would be required. However, this does necessitate the use of thermostatic temperature controls, or regular temperature checks so that it doesn't get too hot.
By encouraging the piglets to lie under a cover there is extra protection against drafts. However, ventilation must be considered to prevent respiratory problems. Cleaning covered piglet areas can also be an issue, increasing the time spent on each pen. It is also another piece of equipment to purchase and maintain; any holes in the covers will create drafts and allow heat to escape.
Considerations
Ensuring an optimum environment for piglets in their first weeks of life is essential to the goal of producing healthy weaned piglets. Supplemental heating will be required for all systems, and choosing the most appropriate is key. Initial outlay is an important consideration, but depending on the size of the unit, it may be worth spending more to make savings later.
Whilst the primary goal is to keep the piglets warm, the efficiency of each system should be considered. Both heat pads and under-floor heating systems offer this advantage by reducing energy bills. However, heat lamps may still be useful, in addition to other heat sources, during farrowing or for the first couple of days. Farmers looking to update housing, improve performance or build new accommodations should carefully consider the heating options available. Any pig producer will benefit from assessing whether efficacy and efficiency could be improved by changing their piglet heating.
