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.

By Jim Van Der Pol Kerkhoven, Minnesota — For years we have fed a little hay in winter to gestating sows by throwing a small bale in their bedding every few days. This is no big deal, especially when compared to the summer pasturing we have been doing for decades. Grain has long remained the major part of the winter gestation ration.

But with major changes afoot with fuel and grain prices, we have decided to look closely and critically at forages with an eye to building a pig production practice that will be more durable going into the future. Sows are the place to start, as their systems seem to handle forage well, and we perceive that they benefit from it.

We will have to figure our own way into this, as universities seem incapable of something as simple as reading a forage sample and applying it to a simple-stomached animal. So we start with the practical questions and, when we have a few principles in place, we will push the envelope and observe the sow herd for effects.

How much hay can a sow eat? We know the daily digestive capacity of our sows tends to be around 13 lbs. of a mixed-grain ration. We know this because when we full-feed in lactation, this is about what they will clean up. But it is more the volume than the weight that fills an animal. The volume occupied by 13 lbs. of our sow feed is about three-tenths (0.3) of a cubic foot. When corrected to 18% moisture, one pound of our alfalfa/grass baleage fills six hundredths (0.06) of a cubic foot. Therefore we should be able to physically fill the sow with five pounds of hay every day if no grain is fed.

That won’t happen anytime soon, but we do want to explore how low we can push the grain part of the ration by giving the sow access to good hay. To do that, we will want to feed the hay continuously while reducing the grain ration regularly. Five pounds of a corn-soy diet is typical for a dirt-lotted sow in winter. This does not fill her up, and it is always too quickly available, meaning she has a lot of “search and find” instinct left over each day. This is where they start dismantling the barn! Hay is a wonderful addition for this reason alone.

So we have started with the five-pound ration while seeing how much hay the sows would eat from a cattle ring turned upside down. We found that 25 sows will get through a bale in about two weeks, wasting about 20% in the process. This comes to about 2.5-3.0 lbs. of hay/head consumed daily in addition to the 5 lbs. of grain, which is pretty close to the capacity figured above.

We know we have to do something in the way of hay-feeder design to cut down on the waste, and we are pretty confident we can design something. It also must be said that the hay feeding this year is mostly outdoors, so daily intake has had as much to do with temperature and wind as it has appetite. Still, we feel these are fairly solid starting benchmarks.

But what are the economics? If the farm’s hay is valued at $100/ton for 115 RFV, and corn is $6.00/bushel, the hay costs 5 cents/lb. and the hog feed about 14 cents. A sow eating 5 lbs. of a grain ration and 2.5 lbs. of hay will cost about 82.5 cents daily to feed. If we can cut her daily grain ration to 2 lbs., she should compensate by eating 4 lbs. of free-choice hay based on the above volume calculations. Daily feed cost would be 48 cents.

But will she thrive, growing a decent-size litter of strong pigs and coming back to breed again after lactation? This is what we must find out, because these numbers are significant for our farm. Saving 34.5 cents in daily feed costs for a gestating sow adds up to about $10,000 annually when figured over 100 sows. We may be able to reduce the grain ration even more. We won’t know until we try. This is where it would be nice to be able to get solid numbers on the amounts of energy and protein in hay actually available to a hog. We will have to make our moves by observation and long term study.

One problem we have involves how we feed the grain ration. We have several methods for feeding sows for different seasons of the year, and all of them are getting out of date in this time of high grain prices.

One method is to feed along an electric fence in the winter. The fast eaters get more this way, but it keeps them from savaging each other and completely starving the submissive sows. A better way, during those months when the pasture is usable, is to scatter the ration over a long distance in the pasture. This evens out the intake somewhat, but not completely. We can also just throw several pails to them in the building during bad weather, and hope for the best. This method doesn’t work very well at all.

The problem with all these cheap-grain solutions is that we end up feeding more than the group should have as a total in order to make sure we don’t have too many sows falling out the bottom. At 14 cents, even a single pound of extra daily grain per head costs about $40, or one pig/sow/year. About 30% of the herd consistently gets more than its share, becoming fat and lazy and failing to care for their pigs. Another 20% may have trouble breeding back after weaning because they aren’t getting adequate feed. And this problem will get worse if we back down the grain, as the fast eaters will have it all cleaned up while the meeker sows are still looking for a safe place to eat.

Come-and-go feeding stalls seem like a good option at this point. These allow the sows to be locked in during the time it takes them to eat their grain — generally less than a half-hour per day. This allows the meeker and thinner ones time to clean up in peace the bigger ration they are getting. This is pretty critical if we really mean to reduce the grain portion of the ration. And since the stalls open individually from the front, they serve as a kind of everyday sow sorter for individual breeding, AI, treatment of sickness, marketing open and cull sows, or whatever.

Already we have converted one of our feeding hoops for a breeding area, and we are thinking of converting the one next to it to house mid-gestation sows as well as a set of feeding stalls situated so they could be used for all breeding and gestating sows in turn. Both of these sow areas would be equipped with built-in silage bale feeders so that hay would be on offer continuously during the off-pasture season.

No hay will be fed during pasture season, as pasture is always cheaper. It is a nice coincidence that these hoops are situated at a pasture intersection, which allows us to send the sows out to pasture to graze along with the cattle anytime we choose, and allows them to come back for shade.

While feeding hay this way does take more time, it also allows closer individual observation and should therefore result in fewer empty sows at the end of the breeding cycle. This aside, the capital investment required for the set-up would be paid for in two years of operation just by the savings from reducing the sow herd’s grain ration by 1 lb./day through reduced waste in the feeding stalls. Any gains from better breeding, better culling, or replacement of grain with hay in the diet would be extra.

This should be a smart capital investment given the higher grain prices we seem to be facing. And it has good long term implications. If we can use this feeding stall set-up to help us reduce the gestation grain ration, we can begin to learn some things about how nearly a sow can support herself solely on pasture or good hay. We know that combination-grazing of hogs and cattle provides for better use of pasture. We know that sows reduce fly populations on pasture. We know that pastured sows have less difficulty at farrowing due to the forage-heavy diet and the extra exercise. These are reasons enough for pasturing, even though in our system it is difficult to figure just what the sows are eating in the pasture.

And the possibility exists that a farm set up to restrict grain to sows while offering free-choice forage year-round will tend to push the animal’s genetics in the direction of perennial feeds, and away from annuals. That is exciting to think about.

Jim Van Der Pol grazes and markets from his farm near Kerkhoven, Minnesota.

In our combination crop and livestock farm, the hogs are a better market than the elevator for the field crops. Hogs also provide a good balance in the cropping scheme through their ability to use anything from hay to grass to barley or rye, plus a healthy dose of crop residues. The cropping part of our farm, about 160 acres, is aimed at producing hog feed and bedding. The grass part of our farm, also about 160 acres, was until last year dedicated to sheep and hogs. This year the sheep (just a few, for our marketing business) will be bought in for the summer, and replacement dairy heifers have been added to the farm.

In both cases, there is a synergistic effect with multiple species. We do little species-specific grazing. The hogs were rotated with the sheep in the past, and will do so with cattle henceforth, on an annual basis to help nature clean up parasites. Our hope is that the cattle and hogs fit together ina way to maximize pasture production from year to year.

If a grazier is producing finished hogs, then annual pastures of high-carbohydrate forages are the ticket. Or perhaps working and composting of winter manure packs is better. We do some of each, and I will discuss finishing hogs in conjunction with alternative feedstuffs in a later article.

This article will deal with gestating sows. In the next, I’ll talk about pasture management of sows and piglets to weaning.

A hog-grazing operation can fit on annual pastures rotated with the cropping scheme, which has a nice parasite control aspect, or they can go on permanent pastures. For us, the sows fit on the permanent pastures because our land is heavy clay and poorly drained. The sows need that highly developed sod base to walk on. Our pastures are basically brome and quackgrass, with about 40-60% alfalfa and red clover. This is good hog pasture, and good footing.

Success with sows depends upon feeding the gestating sow right. Feeding only grass/legumes is just the ticket from a few weeks after breeding until six weeks before farrowing, provided she is in good condition and the pasture is prime.

For about half of her 114 days of gestation, plus a week of breeding, she needs a little grain in addition to the pasture. Our rule of thumb is about one and one-half lb./head/day, fed three times a week, which is about 20 or 25% of the conventional gestation grain/protein supplement diet. We feed just shelled corn. If she is to survive in our system, she must be able to gain her protein from pasture.

In our opinion, daily grain feeding for pastured sows is a waste of time. We generally feed the week’s ration in thirds on Mondays, Wednesdays and Fridays. The grazier has to determine how to feed grain. If your sow business will be year around, as ours is, and you have a feed center or “come and go” feeding stalls back at the barn, you will want to establish a return lane from whatever paddock layout you choose so that the sows can be fed a grain ration several times a week.

But if your barn feeding system is cheap or non-existent, you can just as easily establish a stocker-style layout where the sow herd lives in pasture at all time through the season. We use the stocker layout now, but as the wintertime production part of our business expands and we equip our sow barn for that work, we may want to establish walk-back lanes. (Wintertime production fits in with next month’s article on farrowing.)

Since we feed the grain on pasture, we use distance to get decent “boss sow” control. We take care to string a line of grain right in the grass for as much as five or six hundred feet. The dominant critter, if she is going to get more than her share, will have to run herself to death to do it.

We employ a stocker-style layout with division fences of polywire that we can drive over with our skid loader carrying the sow feeder. Our perimeter fences are all of four strands of high tensile wire, at one, two, three and four-and-a-half feet (bottom and top dead, middle two live). For subdivision, we have seven individual windup reels with two strands of polywire installed on each. We are able to get two runs of 600 feet on each reel. These two strands are strung out and hung upon fiberglass rod or plastic step-in posts.

This is something of a holdover from our former sheep grazing operation, but it works wonderfully for hogs — especially when there are piglets to train. For them we set one wire about six inches off the soil surface. The upper strand is generally set at about 18 inches for the sow, who will get a shock while slipping under it, and then another when running back through. Since hogs are very sensitive, a medium-size low impedance charger is plenty even for a large hog operation as long as you stay away from steel posts. The fence needs to carry just 3,000 volts to be really effective with hogs.

Stocking rate runs about nine to eleven sows per acre of good pasture for the growing season, though this gets a bit heavy for our western Minnesota land in September. This holds both for rotated gestating sows and set-stocked sows and litters, as the sows with litters are getting more grain. When we graze the hogs separately, we like to set up about four to six paddocks of one to 1.5 acres each. The entire herd of 50 to 70 sows is rotated about once a week as a group. The reason for this scheme is that we use the sows both to develop legumes in the sward for the current year and to prepare for overseeding legumes for the future. (More on overseeding in the farrowing article to come.) Since the sows eat the legumes by preference, we want to use them a little like a hay mower — not more often than once every month or six weeks. This is sometimes compromised to keep up with the grass, or we may need to clip the paddocks. This year, we will try to rotate the cattle right through hog paddocks in current use to deal with the grass.

Hogs are not like cattle, and they must be moved differently. We unhook the polywire reel at the high tensile division fence, walk it back to the first tread-in post, and wind the polywires around the post. The reel can then be laid on the ground, and the rest of the fence will look real. Give them a day to move themselves. Each one must decide for herself: Never rush a pig.

Since farrowing hogs must be set-stocked (more on that in a later article), you must have some sort of pasture water system unless you want to cart it to them regularly. We laid one-inch polypipe along two interior permanent fences. This year we will be burying 1.25-inch pipe for the first mile to make our pastures more user-friendly for the cattle in the winter, plus increase our water volume at the ends. We have a plastic-threaded tee every 75 feet or so with a brass hose bib screwed in. Our equipment is set up with garden hose fittings.

We water with a two-hole, float-style drinker bolted to a small wood platform or an old truck mud flap. It is wise to buy at least one drinker for each paddock in the grazing rotation, as they are harder to move than cattle watering equipment, and are cheap at $60 each. They will need to be staked down sometimes. Drinkers should always be installed close enough to the hot wire to encourage decent behavior. The hogs will let you know how close is necessary.

On warm days we use sprinklers for cooling and to increase grazing time during the daylight hours. We make them out of an 8002 crop sprayer nozzle drilled out round, and fastened to a post with duct tape (nothing too good for a hog, you know!). On a hot day this can be set next to the fence and connected to the pasture water line. It will spray a stream of water 20 feet into the paddock, diverting their attention from the drinker. On hot days it is also good to distance the drinker from the permanent fence. We tie polywire about 10 feet long to the hot wire and to a plastic post set off perpendicular to the fence. Lay the hose under the wire and set the drinker into the pasture at the end. It will make grade repair easier the next spring. Use a piece of soft (hot) wire to spiral down the plastic post to discourage them from playing with it.

Hogs also need shade, so we stake farrowing huts in the grazing paddocks. Two or three sows can get enough shade from every hut.

We ring the sows. We use a humane-style ring in the cartilage between the nostrils — similar to a brass bull ring. This is effective and does not create chronic soreness like the over-the-nose-lip style. We do not ring pigs, because they are off permanent pastures by the time they reach 50 pounds. Repairing hog bathtubs and drinker holes with the skid loader is a regular spring chore on our farm. It is not a big deal.

Try some good reading
The grazier who wants to add hogs needs to avoid much of the “pushing on the rope” knowledge that has powered the hog industry for the past 20 years. But there are two or three books worth reading. One is Swine Science, a text by M.E. Ensminger, distinguished professor at the University of Wisconsin in Madison. My edition is a 1970 republication of the 1952 original published by the Interstate Printers and Publishers, Inc., of Danville, Illinois. This book has been nearly as helpful to me as several older hog men in the area.

Also useful is an English book, Outdoor Pig Production, by Keith Thornton. It was published in 1988, by Farming Press Books, 4 Friars Courtyard, 30-32 Princes Street, Ipswich IP1 1RJ, United Kingdom. Thornton’s subject is the thriving British outdoor hog business, though he is not strong on the relationships between the animal and the grass.

And you might take a look at Dirk van Loon’s Small Scale Pig Raising, published in 1978 by Storey Books, Schoolhouse Road, Pownal, Vermont 05261. van Loon’s “homestead” approach results in much useful information about not only production, but also uses of the hog.

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