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Cold weather preparation: Is your pig barn ready?

December 7, 2020

In-barn and in-feed strategies should be two main areas of focus for producers like you as you prepare pigs and your facilities for the winter.

'Tis the season to get pig barns ready for another cold winter. Another year is almost in the books, and there is no rest for pig farmers like you. Before more cold sets in and the snow piles up, there are many areas that need to be looked at to ensure that your pigs stay warm and your barn is ready for the winter.

In a recent webinar, swine experts Dr. Brett Ramirez, assistant professor at Iowa State University, and Dr. Leanne Brooks, swine nutritionist at Cape Fear Consulting, shared their tips and in-barn and in-feed strategies to help you prep your barn and pigs for the upcoming winter months.

How cold weather affects air quality and pig nutrition

The winter cold brings with it new sets of challenges both in your facilities and in the pigs themselves. One of the most common concerns as the weather gets colder is the potential spikes in diseases, such as PED and PRRS. Implementing sound biosecurity measures in your barn and adding feed intervention technologies are key to help reduce the risk of disease. However, barns closing for the winter also means that there needs to be a major emphasis on indoor air quality, as some of the main indoor pollutants, such as ammonia, can negatively impact your pigs and your barn employees. Cold stress in pigs increases the risk of reduced growth rates, health problems, poor reproductive performance and, overall, a diminished return for your animals. Making sure that these challenges don’t have the opportunity to peak during this season and ultimately affect your bottom line should be a major priority.

It is essential to look at different factors that affect air quality, including:

  • Housing systems (individual vs. group)
  • Ventilation and air exchange
  • Season
  • Stocking density
  • Nutrition

Focusing on air quality and nutrition is key for getting barns ready for the winter. Some of the main pollutants in the barn are ammonia, carbon dioxide, carbon monoxide, hydrogen sulfide, methane, total and respirable dust, and airborne microorganisms. Together, these pollutants can have a negative impact on your animals, and major health and performance issues can arise if they are not mitigated.

How cold stress affects feed intake

One of the nutritional challenges that pigs face when experiencing cold stress is an increase in metabolic heat production, meaning they need more nutrients for maintenance, leaving less available nutrients for growth. To compensate for this, pigs increase their voluntary feed intake, which leads to poor feed conversion, greater input costs, diminished carcass quality and an overall negative effect on your bottom line.

Why does this happen? The thermoneutral zone for growing pigs is the zone where pigs are at their most comfortable and their most productive, making it easy for them to maintain their body temperature and perform at their optimal level (Figure 1). When the temperature decreases so much that it passes the pigs’ lower critical limit, pigs will experience cold stress. At temperatures under the lower critical limit, feed intake increases and average daily gain decreases.

(Iowa State University, Miller 2012)

What does ammonia have to do with it?

Ammonia is a dangerous gas produced during the breakdown of urea and is a major source of air contamination on swine farms that can negatively impact pig performance. Its harmful effects on pigs include:

  • Reduced feed intake
  • Decreased growth performance
  • Increased risk of mortality
  • Reduced sow reproductive performance

Ammonia is formed as excess nitrogen is excreted in urine and feces in the form of uric acid and urea. This becomes a major issue because cold stress affects the pig’s gastrointestinal (GI) tract and leads to poor nutrient intake and feed conversion. When a pig’s GI tract experiences stress, it cannot absorb nutrients properly, leading to vital nutrients being excreted in the waste.

In the webinar, Dr. Ramirez focused on ways to make sure your barn’s ventilation system is prepared for the cold weather and Dr. Brooks shared her nutritional strategies to combat cold stress in pigs. Below are some of their tips to help you prep your barn and your pigs for the winter.

7 tips to prep your barn for the winter

1. Check your ventilation system:

Static pressure is the driver of ventilation. Check the pressure difference between the inside of the room versus the outside, and make sure that your primary ventilation route (typically, your sidewall and ceiling inlets) are unrestricted. Remember that your doors should not be the primary inlet. Also, check for condensation and leakage, especially in older facilities. A leaky barn can’t be well ventilated in the winter. Adjust your ventilation system based on your environment and the animal feedback.

2. Not all fans are created equal:

It’s important to recognize that each fan should be treated differently — and a 24-inch fan in one barn might not have the same effect as a 24-inch fan in another barn. Different factors affect ventilation rates, so adjustments should be made accordingly. It’s also important to know what the maximum static pressure is in your facility. Also, as you start running your minimum ventilation fans more in the coming months, remember to consider your fan’s energy efficiency and the fan air-flow ratio.

3. Keep equipment clean: 

Severely cold temperatures make it extremely difficult to wash, clean and sanitize your equipment and facilities. Dirty shutters and restricted inlets can negatively impact flow rate, ventilation and air quality in the barn, which, in turn, leads to poor animal performance. Make sure to keep shutters, light traps, intakes and other items clean.

4. Fresh air distribution is critical:

Avoid dead zones or cold spots throughout the barn by making sure fresh air is distributed properly. The proper placement and operation of barn air inlets and the use of static pressure are key. Make sure to drive air through your designated inlets and not through cracks in the barn.

5. Insulate cold surfaces:

When possible, put material like insulated bubble wrap in front of cold curtains, unused hot weather fans, tunnel doors and other cold areas. This not only helps create a better seal, but it also provides insulating properties to keep cold surfaces that are not as well-insulated as a normal wall warmer for your pigs.

6. Make sure your barn is tightly sealed:

The importance of a tightly sealed barn cannot be stressed enough. If the barn is not tight, it will be difficult to ventilate. For example, if the barn has any leakage and/or cracks, fresh air will take the path of least resistance and will go through any major inlet available — and it’s usually not the inlet you intend or expect. The key is to take total control of how and where air enters your barn.

7. Make sure your controller settings are correct:

Remember to clean your temperature probes and ensure that they are positioned at the right spot (ex: not too close to the heater or an inlet, etc.). Ensure that you are measuring the right temperature at the right spot of your barn to help better control propane costs.

4 nutritional tips to reduce cold stress in pigs

1. Understand how the environment affects voluntary feed intake:

It is extremely important to understand how colder weather will affect feed intake in pigs. Adjusting the nutrient density of your pigs’ diet accordingly is key to making sure that the pigs are getting the nutrients they need for optimal performance as it gets colder. Keep in mind that a lot of your pigs’ diet requirements could be on a grams-per-day basis rather than just a percentage of the diet, so it’s important to know what they’re eating and what nutrients they’ll need as we move into colder weather.

2. Feed pigs ingredients with high heat increments:

Provide feed ingredients that, upon being digested by the pig, will result in more heat from the digestive process. This can be achieved by adjusting the amount of fiber in the diet. Fiber has a high increment of digestion, so feeding your pigs more fiber leads to pigs naturally producing more heat as they digest that fiber. However, be mindful of how fiber can impact carcass quality, as feeding high levels of fiber in finishing pigs can decrease carcass yield.

3. Reduce crude protein:

Reducing crude protein affects gases and the overall atmosphere in the barn, as the nitrogen that eventually causes ammonia comes from crude protein.

4. Reduce ammonia in pig barns through in-feed additives:

Yucca schigidera, which is the base of De-Odorase®, is a widely accepted additive that is scientifically proven to reduce ammonia and its harmful effects.


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