Regular

Changing behavior through genetics

By Jim Van Der Pol, Kerkhoven, Minnesota — As was noted in the last issue, changes we have made in our equipment, building layout, and feed production seem to have helped with our hog behavior and health problems. Feed production adds more work, while the equipment (pens) and building layout are small additional capital costs that allow us to work more effectively. Yet we have not entirely solved our problems, and we do not want to spend a lot more money and time adjusting our management and facilities to the hogs.

So we have a question: What could we change about hog behavior through genetics?

The problems with pig and sow savagery, flightiness, poor maternal behavior and poor fit with the environment I talked about last time were brought into a different kind of focus when I ran across an article by Dr. Temple Grandin, an animal behaviorist at Colorado State University. Grandin stated simply that modern, lean hybrid pigs are more excitable than their more old fashioned ancestors. She said that they chew and bite more on boots when someone stands in their pen, that they startle more easily, are more apt to pile up when surprised, and that they are more prone to tail biting behavior. Grandin said that many of the lean pigs will flinch and squeal when touched. We are seeing some of this behavior with feeding groups as well as our sows.

So perhaps “modern” genetics is partially at fault here. But genetics is a complex subject. It is unlikely that quick, easy improvements can be made by practicing intense selection for just one trait, such as a so-called “placid gene.” Indeed, it is just that kind of approach that has gotten us to where we are in the hog industry. The bad behavior that I am seeing in our herd may be the result of over selection for one trait — leanness — that has always benefited “the industry” more than the farmer.

Our business, and the business of most independent pork producers, is different from the industry model. It is driven by two needs: meat taste, and fitting the farm environment. Taste is critical because we create our own markets, and for us the customer is the person who actually eats the pork, rather than someone who just handles the live animal. If she likes the taste of our pork, that is good for our business. We sell our style of farming and our relationship to the customer, but taste is what will keep her coming back.

Fitting the farm’s environment is important because, while we cannot control some of our pork’s costs due to processing and transportation inefficiencies, we still need to not price ourselves out of the market. The place we can achieve good cost control is where the pig fits the farm. If the hog is well suited to our farming it will require less capital investment, less feed and less veterinary care.

So our breeding decisions must center on these two areas. Fortunately, there is linkage. The breeds that taste better, such as the Duroc and the Berkshire, carry more fat and exhibit less excitable behavior, as well as being generally more durable in an outdoor system. But what about individual selection within the breeds, where the best progress can be made?

Dr. Jerry Hawton, an animal scientist at the University of Minnesota, suggested to me that we might benefit by choosing boars that are slightly down the leanness scale. He said this should move us toward the better taste and calmer disposition end of the seesaw. We could also buy in semen rather than boars, using AI to breed our own herd sires from selected dams within our own herd. This idea would seemingly amplify our efforts to select for behavior, since we already have control of gilt selection. It should also go some ways toward solving the problem of boars that can’t thrive on our feed in our environment, as these boars would be homegrown.

This is complex. D. K. Belyaev, writing in the Journal of Heredity in 1979, points out that his efforts to select foxes for calm behavior resulted in some animals that showed abnormal maternal behavior. These foxes cannibalized their own young. This idea is backed by our own experience. The sows that eat their pigs or the pigs of others are nearly always tame and placid. This happens even though they tend to get treated pretty roughly when caught in the act. Behaviorists say that traits are linked in different species more often than not. While I do not know of any scientific work in this area, our observations suggest that Belyaev’s statements about foxes might also hold for hogs.

Yet there is also thinking in behavioral circles that high strung, excitable animals don’t do well maternally. Alain Boissy, in his essay “Fear and Fearfulness in Determining Behavior,” refers to studies on rats, mice, sheep, cattle and horses confirming that excessive fearfulness interferes with good mothering. He says, “increased knowledge of fear and defensive characteristics in animals could help predict an individual’s adaptive abilities.” This is good news, because if we do know more about animal fearfulness and can be sure that it is detrimental to an animal’s ability to adapt, we can go about breeding away from it.

So we have a complex problem. Some of our sows and hogs are too excitable. They easily startle, they pile up trying to escape, and flinch when touched. Meanwhile, some of our sows are pig eaters, which may be linked with overly placid behavior. And of course we have the general goal of making the hog better fit the farm’s environment, feedstuffs, feeding routines and housing to contain costs, including labor costs.

Fortunately, Temple Grandin notes that temperament is one of the most highly heritable traits. So are social and maternal behavior, so these are all things for which we can select. Our culling and gilt selection criteria, which I discussed in a previous article, are aimed at breeding a pasture and pen-farrowing sow that will fit our feeds and environment, is productive and does as much of the work as possible on her own. Those criteria about behavior in pasture, litter care, pig growth and thrift, as well as body type and size, are still valid as I stated them.

Yet we need to go a step further in this. We will take care from now on to select gilts and keep sows that are neither excessively fearful, nor too friendly. This should be a simple matter of acting on the basis of our daily observations.

Additionally, we will somewhat de-emphasize leanness in any purchased stock. Our specialty market and our own sales demand a certain level of carcass fat, and there seems to be a good chance that a little backfat makes for a good mother.

Jim Van Der Pol grazes and direct-markets pork, chickens, and beef from his farm near Kerkhoven, Minnesota.

June-July 2003

Changing behavior through genetics

By Jim Van Der Pol, Kerkhoven, Minnesota — As was noted in the last issue, changes we have made in our equipment, building layout, and feed production seem to have helped with our hog behavior and health problems. Feed production adds more work, while the equipment (pens) and building layout are small additional capital costs that allow us to work more effectively. Yet we have not entirely solved our problems, and we do not want to spend a lot more money and time adjusting our management and facilities to the hogs.

So we have a question: What could we change about hog behavior through genetics?

The problems with pig and sow savagery, flightiness, poor maternal behavior and poor fit with the environment I talked about last time were brought into a different kind of focus when I ran across an article by Dr. Temple Grandin, an animal behaviorist at Colorado State University. Grandin stated simply that modern, lean hybrid pigs are more excitable than their more old fashioned ancestors. She said that they chew and bite more on boots when someone stands in their pen, that they startle more easily, are more apt to pile up when surprised, and that they are more prone to tail biting behavior. Grandin said that many of the lean pigs will flinch and squeal when touched. We are seeing some of this behavior with feeding groups as well as our sows.

So perhaps “modern” genetics is partially at fault here. But genetics is a complex subject. It is unlikely that quick, easy improvements can be made by practicing intense selection for just one trait, such as a so-called “placid gene.” Indeed, it is just that kind of approach that has gotten us to where we are in the hog industry. The bad behavior that I am seeing in our herd may be the result of over selection for one trait — leanness — that has always benefited “the industry” more than the farmer.

Our business, and the business of most independent pork producers, is different from the industry model. It is driven by two needs: meat taste, and fitting the farm environment. Taste is critical because we create our own markets, and for us the customer is the person who actually eats the pork, rather than someone who just handles the live animal. If she likes the taste of our pork, that is good for our business. We sell our style of farming and our relationship to the customer, but taste is what will keep her coming back.

Fitting the farm’s environment is important because, while we cannot control some of our pork’s costs due to processing and transportation inefficiencies, we still need to not price ourselves out of the market. The place we can achieve good cost control is where the pig fits the farm. If the hog is well suited to our farming it will require less capital investment, less feed and less veterinary care.

So our breeding decisions must center on these two areas. Fortunately, there is linkage. The breeds that taste better, such as the Duroc and the Berkshire, carry more fat and exhibit less excitable behavior, as well as being generally more durable in an outdoor system. But what about individual selection within the breeds, where the best progress can be made?

Dr. Jerry Hawton, an animal scientist at the University of Minnesota, suggested to me that we might benefit by choosing boars that are slightly down the leanness scale. He said this should move us toward the better taste and calmer disposition end of the seesaw. We could also buy in semen rather than boars, using AI to breed our own herd sires from selected dams within our own herd. This idea would seemingly amplify our efforts to select for behavior, since we already have control of gilt selection. It should also go some ways toward solving the problem of boars that can’t thrive on our feed in our environment, as these boars would be homegrown.

This is complex. D. K. Belyaev, writing in the Journal of Heredity in 1979, points out that his efforts to select foxes for calm behavior resulted in some animals that showed abnormal maternal behavior. These foxes cannibalized their own young. This idea is backed by our own experience. The sows that eat their pigs or the pigs of others are nearly always tame and placid. This happens even though they tend to get treated pretty roughly when caught in the act. Behaviorists say that traits are linked in different species more often than not. While I do not know of any scientific work in this area, our observations suggest that Belyaev’s statements about foxes might also hold for hogs.

Yet there is also thinking in behavioral circles that high strung, excitable animals don’t do well maternally. Alain Boissy, in his essay “Fear and Fearfulness in Determining Behavior,” refers to studies on rats, mice, sheep, cattle and horses confirming that excessive fearfulness interferes with good mothering. He says, “increased knowledge of fear and defensive characteristics in animals could help predict an individual’s adaptive abilities.” This is good news, because if we do know more about animal fearfulness and can be sure that it is detrimental to an animal’s ability to adapt, we can go about breeding away from it.

So we have a complex problem. Some of our sows and hogs are too excitable. They easily startle, they pile up trying to escape, and flinch when touched. Meanwhile, some of our sows are pig eaters, which may be linked with overly placid behavior. And of course we have the general goal of making the hog better fit the farm’s environment, feedstuffs, feeding routines and housing to contain costs, including labor costs.

Fortunately, Temple Grandin notes that temperament is one of the most highly heritable traits. So are social and maternal behavior, so these are all things for which we can select. Our culling and gilt selection criteria, which I discussed in a previous article, are aimed at breeding a pasture and pen-farrowing sow that will fit our feeds and environment, is productive and does as much of the work as possible on her own. Those criteria about behavior in pasture, litter care, pig growth and thrift, as well as body type and size, are still valid as I stated them.

Yet we need to go a step further in this. We will take care from now on to select gilts and keep sows that are neither excessively fearful, nor too friendly. This should be a simple matter of acting on the basis of our daily observations.

Additionally, we will somewhat de-emphasize leanness in any purchased stock. Our specialty market and our own sales demand a certain level of carcass fat, and there seems to be a good chance that a little backfat makes for a good mother.

Jim Van Der Pol grazes and direct-markets pork, chickens, and beef from his farm near Kerkhoven, Minnesota.

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