Feeding Iberico Pigs
When folks ask me, “What do you feed your Iberico pigs?” I understand the question, but I have come to believe there is a better one: “What does this pig need to do right now?”
A newly weaned pig trying to grow bone and muscle has one job. A gilt being developed for breeding has another. A pregnant sow, a lactating sow, a working boar, and a barrow headed toward the freezer are all doing different work. It makes about as much sense to feed them all exactly alike as it does to buy everybody in the family the same size pair of boots.
Good nutrition begins with the pig standing in front of you—its age, weight, condition, genetics, and purpose. Then we ask what a balanced ration should provide and what the pasture, forage, mast, and other resources of the farm can honestly contribute.
What the Feed Was Called, Not Just What Was Fed
Farmers like to talk feed. Somebody will tell you, “I put mine on such-and-such and they really took off.” That is useful information, but the name printed on the feed sack is only the beginning of the story.
What was actually in it? How much did they eat? How long were they on it? What did the pigs weigh when they started? Were they on pasture? What was the weather doing? How much feed wound up inside the pig and how much wound up underneath the feeder?
We keep feed labels and formulation information along with our animal records at Stillwater Farm because memory has a peculiar way of improving a feeding program the farther we get from when we actually fed it.
Research suggests that different pig populations may use nutrients differently. That matters when raising Iberico pigs, whose genetics, growth patterns, maturity, and fat deposition are not identical to conventional commercial hogs. But there is no single magical “Iberico ration” that fits every pig, every age, and every farm. If somebody tells you there is, I suspect there is a pretty good chance they are fixing to sell you a sack of it.
A Ration Is More Than Calories
Energy matters. Iberico pigs are famous for their ability to lay down the beautiful intramuscular fat that eventually becomes the marbling we prize in the pork. But energy alone does not make a balanced ration.
Pigs also need amino acids, minerals, vitamins, adequate water, and the right overall balance of nutrients. Adding a high-energy ingredient may increase calories while throwing something else out of balance. A full feeder does not necessarily mean a properly fed pig.
Crude protein can be misleading for the same reason. Pigs do not simply need a percentage printed on a feed tag; they need usable amino acids in appropriate amounts. Two feeds carrying the same crude-protein percentage can provide those nutrients differently.
And intake matters. If a pig eats less feed, it consumes fewer total nutrients even though nothing changed on the feed label. The feed tag tells us what is in the sack. The pig tells us what is happening on the farm. We need to listen to both.
Divide the Herd by the Job
Around Stillwater, I increasingly think of feeding in terms of jobs rather than pigs. Newly weaned and growing pigs need enough nutrition to develop well at the amount of feed they are capable of eating. Replacement gilts need steady development toward breeding maturity without simply getting fat. Gestating sows need their body condition watched through pregnancy. Lactating sows are doing some of the hardest work on the farm, producing milk for a litter while trying to maintain themselves, and their demand for both feed and water can be considerable.
Then there are the finishing pigs. With those animals, we are no longer simply asking how quickly we can put pounds on them. We are growing toward a particular kind of pork—flavor, fat, marbling, carcass size, and ultimately the eating experience at somebody's table. Same breed. Different jobs. That distinction may be one of the simplest ways to improve a feeding program.
Pasture Is a Contribution, Not a Guess
I believe strongly in pasture. I want our pigs outside rooting, grazing, walking, wallowing, and doing the things God apparently intended pigs to do before somebody decided they belonged all their lives on concrete. But green grass is not a feed analysis.
Pigs consume forage, roots, seeds, insects, legumes, and whatever else their remarkable noses uncover. The nutritional contribution changes with the plant, season, maturity of the forage, weather, pig, and amount actually consumed. So we should be careful about saying, “Pasture replaces 20 percent of our feed,” unless we have records that give us some reason to believe it.
If we want to know what the pasture is contributing, keep track of purchased feed, pig weights, growth, and body condition over time. Let the records teach us. The pasture is certainly giving us something. The question is what and how much. That is a better question than guessing.
Acorns Deserve More Than a Good Story
And then there are acorns. Few things are more closely tied to the great Iberico tradition than pigs beneath oak trees eating mast. It is one of the images that drew many of us to this breed in the first place. But the romance of the oak tree should not outrun the husbandry underneath it.
Acorns are not a complete ration for every pig on the farm, and having oak trees in a pasture does not by itself make an acorn-finishing program. If we are going to talk seriously about acorn finishing, then we ought to know the season, the oak resource, how long the pigs had access, what else they were eating, their beginning and ending weights and, as best we can determine, what those acorns actually contributed. There is a difference between pigs that ate some acorns and pigs intentionally finished on acorns. The Iberico tradition deserves enough respect for us to know the difference.
At Stillwater Farm we have been pecan farmers. Pecans are also very rich in oleic acid and finish our pigs on pecans as well as the hickory nuts and acorns that fall in October, November and December. Acorns, hickory nuts, and pecans seem to cycle from year to year, some being better nut producers as others. Therefore having a well-designed hi-oleic acid ration, using sunflower seed oil is a must to get the complete Spanish finish.
Watch the Feed Trough—and the Waterer
A nutritionist can formulate a beautiful ration on paper, but the pig still has to eat it. Waterers fail. Feeders bridge up. Rain blows into feeders. Feed spoils. Dominant pigs push smaller pigs away. And some pigs seem capable of throwing enough feed on the ground to make you wonder whether they have secretly invested in the feed mill.
Feed disappearance is not the same thing as feed intake. That is why delivery deserves almost as much attention as formulation. Check the water. Check the feeder. Watch the pigs eat. Look underneath the feeder. Pay attention to what is happening instead of assuming that because we filled it, they ate it.
Feed the Pig in Front of You
Good feeding records do not have to require a computer program, three graduate degrees, and a county agent living in the barn. For each group, record the kind of pigs, approximate weight, ration being fed, quantity supplied, dates, pasture conditions, and what you are trying to accomplish. Then weigh the pigs and watch their condition. Over time, those records begin telling the story of your farm.
And that brings me back to the question.Instead of asking only, “What do Iberico pigs eat?” Perhaps we ought to ask: “What does this pig, on this farm, at this season, need from us right now?” That sounds less like a formula and more like husbandry.
Good husbandry is mostly the discipline of paying attention—to the animal, the soil, the season, the weather, and the limits of the place entrusted to us. We provide what the farm cannot provide, make good use of what it can, keep records, and allow the pigs themselves to teach us something along the way. There probably isn't a magic feed sack waiting to solve all our problems. But there is a pig standing at the trough. Start there.
The most useful feeding question is not, “What do Iberico pigs eat?” It is, “What does this pig need to do right now?” A growing pig, a gestating sow, a lactating sow, a breeding boar, and a finishing animal are different feeding jobs. Good nutrition starts with the animal’s stage and a balanced ration, then considers what pasture, mast, and other farm resources can contribute.
Sources & Further Reading
• Brossard, L., et al. (2019). Modelling Nutritional Requirements of Growing Pigs from Local Breeds Using InraPorc. Animals 9(4), 169.
• Pork Information Gateway. Swine Nutrition Guide.
• Pork Information Gateway. Forages for Swine.
• Pork Information Gateway. Growing-Finishing Swine Nutrient Recommendations and Feeding Management.