7 Reasons Your Pigs Are Not Growing


One of the most frustrating things for small farmers and homesteaders when raising pigs is when they have a pig (or a group of them) that won’t put on weight like they’re supposed to. When you’re raising pigs for food, a pig that doesn’t put on weight means that you’re throwing feed at an animal that will not give you much return for your money. 

There are many reasons why pigs raised for food may not put on weight and size like some of their counterparts. Here are some of the causes of a pig not growing like it is supposed to, and what you can do to fix them. 

1.Sick Pigs Don’t Grow Well

The number one cause of a pig that isn’t putting on weight is a disease. (Source: National Hog Farmer) Many different common illnesses can strike pigs, and they usually have a serious dampening effect on a pig’s thirst and appetite. Without drinking and eating plenty of water and food, your growing pig will remain scrawny and have problems putting on muscle and weight. 

To know how to spot and control pig diseases, see Dr. Bryan Myers video above.

Different Type Of Pig Diseases

(Source: Queensland Department of Agriculture and Fisheries): 

  • Swine influenza
  • Porcine reproductive and respiratory syndrome
  • Mycoplasma hyopenumoniae (Mhp)
  • Exudative dermatitis
  • Coccidiosis
  • Swine dysentery
  • Mastitis
  • Intestinal torsion
  • Porcine parvovirus
  • Sarcoptic mange
  • Gastric ulceration

In many cases, the solutions for dealing with a sick pig are as varied as the sicknesses that can plague them. Some pigs are treated with antibiotics, while others are treated with a change in feed or lessening stress in their growing environment. Improving hygiene in the enclosure can also help prevent many types of diseases related to bacterial infection, such as exudative dermatitis (greasy pig) or coccidiosis. 

It is a longstanding (and misguided) stereotype that pigs are happy in filth, but in reality, pigs are very clean animals. Outside of wallowing in the mud to cool themselves, they’re no happier standing in their urine and feces than any other animal. So, it’s important not to keep too many pigs cramped in a small dirt enclosure, or you’ll end up with a stinking cesspool that will breed disease in your group of pigs. 

If you suspect that an underlying illness is why your pig isn’t growing, your best bet is to consult with a livestock veterinarian to diagnose and determine the cause of the pig’s illness.

Only after the illness is isolated and identified can a correct course of treatment be enacted. An untreated disease doesn’t just affect the growth rate of a pig; it can ultimately lead to the pig’s untimely death. 

Good hygiene and other proper animal husbandry practices can go a long way toward making sure that pigs don’t end up with medical problems that require veterinary intervention. Livestock vets are often expensive, and having to have a vet called out to your farm for sick pigs can put a serious pinch in your profit margin if you’re raising pigs for selling meat. 

Another way your pigs can get diseased is the type of bedding material they use, find out if straw or shavings is better for your pigs in my post.

2.Runt Pigs May Be Stunted in Growth

Another cause of a pig having a slow growth rate is when a pig is a runt pig, also known as a “poor doer” in pig-raising lingo. Often there is no underlying cause of slow growth in these pigs other than the fact that in many prey animals that produce large litters, there is often one or two animals in the litter who will be weaker, stunted, or more prone to illness than their larger, stronger siblings. (Source: Show Pig)

In many cases, the runt of the litter will not survive if early intervention isn’t done. In some cases, this means separating the runt from the rest of the litter entirely and raising it indoors for a time to ensure that it isn’t pushed off the teat and starved or stomped to death when larger, stronger piglets trample it. 

The runt of the litter in the above video was suffocated by its own mother! If you don’t separate the runt and give it time to get stronger it could easily die.

Making sure that runt piglets have supplements such as iron injections and antibiotics soon after birth can prevent them from becoming anemic and developing an infection through their navel because of lack of hygiene in their birthing pen, which can lead to loss of appetite and lack of growth. 

Many runt pigs never reach their full growth potential, and culling is usually performed in industrial or larger farm operations to prevent feed from being wasted on a runt. Instead, these animals are usually culled early to provide more milk and feed for the other piglets that are growing at a normal rate.

Do you raise your pigs on concrete? Learn why it’s bad for them in my post.

3.Pigs with Parasites Will Grow More Slowly

Along with disease, another factor that can significantly affect growth in young pigs is undiagnosed and untreated parasites. In many cases, treating pigs periodically with a dewormer can help prevent the build-up of worms and other parasites that leech nutrients from a growing pig, preventing them from growing to their optimal weight. 

The main parasites that affect pigs are roundworms, tapeworms, and a one-celled organism called Toxoplasma gondii. (Source: United States Department of Agriculture) Not only do these parasites negatively affect the growth of livestock pigs, but they also pose a threat to humans. For this reason, pigs that are raised for food should be regularly dewormed to prevent any build-up of parasites. 

Internal parasites aren’t the only parasites that can negatively affect a pig’s ability to grow. External parasites, such as mange or fleas, can cause a pig to spend a lot of their energy scratching and trying to get comfortable, wasting time that they could otherwise spend eating and putting on weight. 

4.Pigs May Have Congenital Flaws That Affect Their Growth

Aside from generally being “poor doers,” there are other congenital flaws that can affect the growth of livestock pigs. One such defect is poor kidney function, which can affect a pig’s ability to put on weight and eat and drink normally.

Many congenital problems affecting the internal organs of a pig may never be diagnosed without a formal autopsy through a veterinarian, leaving farmers only to speculate as to what may be causing a pig to fail on the scale. 

Here are a few other congenital flaws that may show up in livestock pigs and affect their growth rate: 

  • Heart defects
  • Cleft palate
  • Umbilical hernias
  • Splay leg
  • Congenital tremor Type B

Because leaving flawed livestock in the sounder is considered poor breeding practices when building up a strong pool of livestock, it’s a good idea to cull any pigs from the group that displays serious signs of genetic flaws as soon as possible to reduce the amount of feed that goes into them.

There’s no point in throwing feed at a weak or sickly pig that won’t put on weight and may die of congenital problems before it reaches the appropriate age for butchering. It’s sad but raising pigs is a business after all.

A major problem with congenital disabilities is that some of these defects—such as heart problems—can lead to sudden losses, and in many cases, the meat from these deaths can’t be salvaged. This can lead to hundreds of dollars in lost profit if several pigs are lost from a sounder at once, so maintaining strong breeding lines can help save money down the road.

 Do your pigs live outside? Learn how to keep them safe in the winter in my article.

5.Pigs Who Don’t Get Enough Protein Will Not Put on Weight

Malnutrition and improper feed are other major causes of poor pig growth. Many people end up “slopping” a pig with nutritionally poor food, such as day-old bread or other scraps with low nutritional value. 

A significant mistake that many new pig farmers and homesteaders make is not feeding their pig enough protein. Unlike cattle and goats, which are herbivorous, pigs are omnivores and require more variety in their diet. Without enough protein, pigs won’t have the nutrients to put on muscle and weight.

Issues Farmers Have With Feeding Pigs

  • The pig isn’t getting enough feed: It’s important to make sure that a pig is getting enough food for its age and size. These proportions are especially crucial if you’re raising several young pigs in the same enclosure, as stronger piglets can get aggressive around their food and easily push weaker pigs out of their way. Farmers can prevent this by ensuring that there are multiple feeders available to feed on so that all the pigs in an enclosure have equal access to food.
  • The pig is getting the wrong feed: Feeding pigs a diet that is too high in carbohydrates and not high enough in protein can lead to a pig that doesn’t put on weight properly. To combat this, a source of protein such as alfalfa hay or soybean meal should be added to feed to raise the ratio of protein to carbohydrates. Another good source of protein for pigs is whole fat milk, which can add protein, fat, and various essential minerals and vitamins.

While it’s tempting to cut corners when feeding pigs to increase your profit margin, this is a poor strategy because it often causes you to end up with a sounder of pigs that is significantly lower in weight than they would have been otherwise. 

There are ways to help reduce the cost of pig feed, such as supplementing with natural forest forage, that can provide pigs not only with a wide variety of nutrients but also the enrichment activity of rooting out and searching for their food. This can solve two problems at once—providing pigs with an omnivorous, varied diet and providing them with activities to help keep them from becoming bored and destructive. 

Do you know what foods are poisonous to Pigs? Learn the facts in my post.

6.Sunburned Pigs Will Not Eat as Much

One issue that affects pig growth that isn’t as obvious as some of the others is a lack of shade. It’s important to remember that pigs are primarily hairless animals.

Therefore, if they are left out in an unprotected feedlot with no access to shade or a wallow, it can result in a dangerous and painful sunburn. Not only does this sunburn pose a significant welfare problem for the pigs, but it can also put them off their feed because of discomfort. 

How To Prevent Sunburn In Pigs 

  • Provide shade: Pigs in an open lot will need a place to find shade to reduce their exposure to the sun, especially during the summer months when the sun is especially brutal. It’s better to keep pigs in a forested or shady lot so that they have natural access to shade. If you can’t provide a natural shade, a lean-to or barn can create a place for pigs to rest and get out of the sun.
  • Provide a wallow: Wallows are essential for pigs as an enrichment activity and a way for them to cool off by coating themselves with mud. This coating of mud can act as a natural sunblock for pigs and help prevent sunburn, overheating, and even many skin parasites. Providing a wallow can also help reduce the amount of damage that pigs do to their lots trying to make their own.
  • Provide plenty of cool water: Providing plenty of fresh, clean water daily is an essential part of preventing pigs from becoming sunburned and dehydrated. Do not allow water sources to stagnate, as this can both encourage the propagation of bacterial diseases and put pigs off their water.
  • Make sure water is located in the shade: Not only does keeping the water source for pigs in the shade help keep the water cooler (which encourages pigs to drink more and stay hydrated), it also encourages the pigs to hang out in the shady areas of the lot. (Source: Julesburg Advocate) This can prevent pigs from becoming sunburned accidentally by spending too much time playing out in direct sunlight. 

Keep in mind that there are certain types of pigs that are more susceptible to sunburn than others, such as pigs with a pale skin type or show pigs.

Show pigs can become especially vulnerable to sunburn if their hair is clipped to make them more presentable for the show ring. While these haircuts make show pigs look neater, they also remove much of the pig’s natural insulation against sunburn. 

You should also be aware that sunscreen is not approved as an effective treatment or preventative treatment for sunburn in pigs. So, don’t think you can slather your pigs down with sunblock and call it a day, because that’s not an effective or safe way to prevent sunburn in your sounder. Stick with animal-approved treatments, such as a proper environment, and you should be good to go. 

It’s beneficial for your entire sounder to make sure that your pigs are as comfortable as possible, not just for the welfare of the pigs but also to help them grow big and strong. In many cases, looking out for a pig’s welfare and enrichment also positively affects their growth as livestock and their final butchering weight when they go to market. 

Sometimes it’s difficult to know if your Pigs are happy, it’s important as a farmer to know the different ways pigs show happiness, learn in my post here.

7.Lonely Pigs Will Not Have Much of an Appetite

Another welfare issue that can cause poor pig growth is loneliness. While it might seem dramatic that a pig may pine and fast if it is bored and lonely, pigs are some of the most intelligent animals in the animal kingdom—as smart as a human toddler(see study). So, without other pigs to keep them company, pigs may eat a lot less than they would otherwise. 

The best solution for a lonely pig is to get more pigs, but this isn’t possible for some small farmers and homesteaders for a few reasons, such as budget limitations or space constraints.

However, even for a family raising a single pig for an annual fall butchering, it’s still important to make sure that the pig gets plenty of attention. This attention can be given by the members of the family or by providing the pig with another animal companion, such as a cow or a large goat. To see ways to entertain your lonely piggy, check my post out.

All pigs have different temperaments, and some pigs may not tolerate companionship from animals outside their species, especially animals that are smaller or weaker than themselves.

Don’t play pigs in a closed pen with a smaller animal unless you are sure of the pig’s temperament, as pigs have been known to maim and kill smaller livestock such as dwarf goats and chickens. Larger livestock, like small cows, is a better option, see if pigs get along with rabbits in my post.

For other ways of keeping a single pig happy, check out my article.

Pigs Stop Growing for Many Reasons That Can Be Prevented

There are many different reasons that pigs stop growing, but the good news is that many of these causes can be either prevented or easily treated by identifying and addressing them as soon as possible. Since the causes of slow growth in a pig can range from obvious causes like loneliness and sunburn to hidden issues like congenital disabilities and disease, there is no one-size-fits-all solution to make them grow.

As long as you’re proactive in managing your sounder of pigs, you can keep many of these problems from ever affecting the growth of your pigs. Even things as simple as keeping your pigs’ enclosure hygienic and their water clean and fresh can help them grow!

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