Agroforesty/Includes pig production ideas

[Andy Carson]

Thanks a lot George, great to have a specific case to work with and some numbers. I’m going to try to figure out how many Calories the hogs are foraging in two ways, first by figuring out their total needs, and subtracting the whey. Secondly, I will calculate calories from the expected yield of acorns. If these two numbers match, then it gives me more confidence in the numbers. Actually, if the numbers don’t match, it’s even more interesting… Let’s see…

10,000 gallons of whey gives 160,000 cups whey, which is 59 Calories per cup, yielding 9,440,000 Calories or 9440 Mcal. I am going to figure an outdoor hog would take 1000 lb of corn to produce, I know this is a bit higher than the food requirements of indoor hogs, but I think it’s a good rough estimate given greater exercise of outdoor pigs and lower temps in winter. 1000 lbs corn x 1.6 Mcal/lb x 12 head = 19200 Mcal. 19200-9440=9760 calories from forage. So, with no supplemental feeding, your hogs would be getting 51% of their calories from forage. The supplemental feeding, or course, changes this. 500 lbs corn (800 Mcal) per year means the hogs are consuming 47% of their calories from forage (19200-9440-800=8960, 8960/19200 = 47%). Feeding 1000 lbs (1600 Mcal) means they are foraging for 43% of their calories (19200-9440-1600=8160, 8160/19200 = 43%). Feeding 2000 lbs (3200 Mcal) means they are foraging for 34% of their calories (19200-9440-3200=6560, 6560/19200 = 34%). Feeding 4000 lbs (6400 Mcal) means they are foraging for 18% of their calories (19200-9440-6400=3360, 3360/19200 = 18%). At 6100 lbs of corn, the hogs are essentially not obtaining calories from forage (9760/1.6=6100).

OK, lets see these calories are avaliable from the trees present. Forestry friends, please help me out here! A stand of oaks with a DBH of 18 inches might have a Basal area of 70 square feet per acre, which would yield about 40 trees per acre (here’s where I need the most help, I’m not sure I am even using these terms correctly!). With 10-25% oak in a stands, that would be an average of 7 oaks per acre (40×17.5%). Does this sound about right? Acorn yield is incredibly variable from year to year, but an average for northern red oak in forests around here is 75,000 acorns per acre (from http://www.fs.fed.us/ne/newtown_square/publications/research_papers/pdfs/scanned/ne_rp680p.pdf). 75,000 acornsx17.5%=13,125 acorns. At 85 acorns per pound this is only 154 lbs of acorns per acre, contributing only 1.4% of the total calories for 12 hogs (1.76 Mcal/lb= 271 Mcal, 271/19200=1.4%)… Perhaps it is possible to have the hogs collect acorns from several paddocks before deer and other wildlife get them, allowing consumption of three times this number, but that would still only contribute 4.2% of the total calories.

So, the hogs seem to be finding lots of food in the woods, but it’s not primarily acorns (unless you are feeding close to 3 tons of corn per year). Very interesting… I wonder what these “bonus” foods consist of and if they would also be available in groves or orchards of purely mast producing trees. It seems these are an important part of the diet of hogs at these lower and more sustainable stocking rates.

[CharlyBonifaz]

I wonder what these “bonus” foods consist of

as omnivores they will eat rodents, edible roots, bulbs and mushrooms, worms and grubs, snails and slugs, even aquatic plants, leaves and shoots and fruits/berries/nuts of various other woody plants and grasses/herbs, eggs and chicks of (ground-nesting) birds, they will even eat carrion and dig up young rabbits from their burrows
loooong list ….

[near horse]

@Countymouse 27714 wrote:

Thanks a lot George, great to have a specific case to work with and some numbers. I’m going to try to figure out how many Calories the hogs are foraging in two ways, first by figuring out their total needs, and subtracting the whey. Secondly, I will calculate calories from the expected yield of acorns. If these two numbers match, then it gives me more confidence in the numbers. Actually, if the numbers don’t match, it’s even more interesting… Let’s see…

10,000 gallons of whey gives 160,000 cups whey, which is 59 Calories per cup, yielding 9,440,000 Calories or 9440 Mcal. I am going to figure an outdoor hog would take 1000 lb of corn to produce, I know this is a bit higher than the food requirements of indoor hogs, but I think it’s a good rough estimate given greater exercise of outdoor pigs and lower temps in winter. 1000 lbs corn x 1.6 Mcal/lb x 12 head = 19200 Mcal. 19200-9440=9760 calories from forage. So, with no supplemental feeding, your hogs would be getting 51% of their calories from forage. The supplemental feeding, or course, changes this. 500 lbs corn (800 Mcal) per year means the hogs are consuming 47% of their calories from forage (19200-9440-800=8960, 8960/19200 = 47%). Feeding 1000 lbs (1600 Mcal) means they are foraging for 43% of their calories (19200-9440-1600=8160, 8160/19200 = 43%). Feeding 2000 lbs (3200 Mcal) means they are foraging for 34% of their calories (19200-9440-3200=6560, 6560/19200 = 34%). Feeding 4000 lbs (6400 Mcal) means they are foraging for 18% of their calories (19200-9440-6400=3360, 3360/19200 = 18%). At 6100 lbs of corn, the hogs are essentially not obtaining calories from forage (9760/1.6=6100).

OK, lets see these calories are avaliable from the trees present. Forestry friends, please help me out here! A stand of oaks with a DBH of 18 inches might have a Basal area of 70 square feet per acre, which would yield about 40 trees per acre (here’s where I need the most help, I’m not sure I am even using these terms correctly!). With 10-25% oak in a stands, that would be an average of 7 oaks per acre (40×17.5%). Does this sound about right? Acorn yield is incredibly variable from year to year, but an average for northern red oak in forests around here is 75,000 acorns per acre (from http://www.fs.fed.us/ne/newtown_square/publications/research_papers/pdfs/scanned/ne_rp680p.pdf). 75,000 acornsx17.5%=13,125 acorns. At 85 acorns per pound this is only 154 lbs of acorns per acre, contributing only 1.4% of the total calories for 12 hogs (1.76 Mcal/lb= 271 Mcal, 271/19200=1.4%)… Perhaps it is possible to have the hogs collect acorns from several paddocks before deer and other wildlife get them, allowing consumption of three times this number, but that would still only contribute 4.2% of the total calories.

So, the hogs seem to be finding lots of food in the woods, but it’s not primarily acorns (unless you are feeding close to 3 tons of corn per year). Very interesting… I wonder what these “bonus” foods consist of and if they would also be available in groves or orchards of purely mast producing trees. It seems these are an important part of the diet of hogs at these lower and more sustainable stocking rates.

I read some stuff on food habits of European wild boars/feral hogs and they made mention of a few interesting points:

1) hogs will raid the cached acorns of squirrels – sort of a eureka! moment. BTW – bears do this too. Life as squirrel is rough.
2) they also root and chew on the roots of growing trees for nutrients.
3) as CharlyBonifaz states below – they make use of just about anything they can get ahold of. Lots of earthworms …. As some who’ve tried doing integrated grazing/pasture mgmnt and had hogs w/ sheep – they’ll take newborn lambs too.

[Andy Carson]

George inspired me to ask my neighbor dairy farmer (and raw milk producer) what he does with his whey from cheese making. He dumps it into his septic and uses it to irrigate his fields. He said I could have all I want I just have to haul it, which seems like a damn good deal. He said they don’t make alot of cheese, but “alot” to someone with 50 head of dairy cows is very different from my view of “alot.” 300 gallons a pop, maybe twice a week, is alot in my mind, and likely morethan I can use. Kind of an unexpected bonanza…

[Andy Carson]

I had a very interesting conversation with Ken Asmus of Oikos Tree Crops about this project. This is a company also inspired by J Russell Smith’s book and they have done some selection and breeding to produce higher yielding, more disease tree crop varieties. Overall, Ken is a really nice guy and had alot of helpful thoughts and suggestions on this topic. I recommend you give him a call if you are interested in utilizing tree crops. His improved selections would probably help, but I also found the management techniques extremely interesting.

Ken said was familiar with people using acorns, chestnuts, and honeylocust as mast sources for pigs. Acorns are a common source of mast and are very hardy trees, but one drawback to acorns is that the yields vary greatly from year to year and from tree to tree. Ken suggested a couple of techniques that help with this natural limitation of oaks. One was to plant a variety of type of oak. As each oak variety would have a different “off year” and by planting a mixture, you have a greater chance of a reliable crop. The other suggestion was to graft extremely productive oaks onto less productive trees. It’s possible to do this with pre-existing trees, turning a “run-of-the-mill” oak into a very productive one in just one year (as opposed to a decade to grow one from a seedling). Simple technique, but the results can be very powerful.

Chestnuts are a little less hardy than oaks, but Ken was aware of people using these as mast sources for pigs (particularly the Chinese variety). As with the oaks, production will increase dramatically (very dramatically!) if you select and graft productive trees onto less productive roots. The grafting technique is especially important for trees grown from seed and wild trees.

Ken was also aware of research using honey locust as a fodder source for livestock (though usually not hogs). Yields here could rival field crops if the trees are well taken care of. Interestingly (this wasn’t Ken’s idea) productive honey locust could be grafted onto existing locust trees. I, for one, have a fair amount of black locust in my fence rows. Might be easy to “convert” them into a tree my pigs can eat… Again, this could save a decade.

Ken was less comfortable speculating on other tree types that he didn’t know of anyone using as sources of hog feed. He confirmed that Mulberrys, with thier extended harvest season, make sense but warned me that again, I would probably want to graft these. He wasn’t suprized that hazelnuts and walnuts produce the most calories per acre on paper, but these trees are often grafted and it’s not really fair to compare the productiving of grafted trees to that of wild ungrafted trees. If the wild trees were selected and grafted, who knows what the yields would be? It really gives me an appreciation for how powerful this selection technique is. Ken also suggested crabapples might be a good crop to incorporate, as some strains hold thier fruit well into winter, providing food (with a shake) during a difficult season.

[Andy Carson]

I talked to Doug Wallace, the Lead Agroforester for the USDA. Another informative and helpful call, and another great resource for anyone with similar ideas. He was not familiar with anyone specifically growing nuts or fruit for hogs to eat, but thought that it made sense. He was familiar with some people using hogs to “clean up” after fruit or nut harvest, but that is only roughly similar to what I am thinking of. Doug had some concerns about hogs damaging trees and recommended a system where tree crops with similar harvest/drops times are planted together in smaller pastures that hogs would “rotate through” at harvest time. I think this sounds like a good system as well. Again, Doug agreed that this would most likely be a system for spring born hogs that would be harvested in the fall. The seasonal fruit/nut harvest of trees is something that is difficult to get around, and other crops will be needed in the winter and early spring.

PS. The USDA agriforestry website is http://www.unl.edu/nac/index.htm , there is alot of info here on silvopasture systems for other animals, such as cattle sheep and goats. It seems hogs are missing from this group, but maybe I can change that a bit… I can’t resist an experiment.

[Andy Carson]

After much thought, I have decided to go with this concept. It’s going to be a process that takes many years to get going, but I’ll try to post periodic updates. I have devoted about 2.5 acres to this, so I think it’s enough to be a good sample and also be productive enough to be worthwhile. Here’s what I’m planting and why:

30 White Russian Mulberries: Productive trees with a somewhat extended and generally early fruiting season and good wintering ability

30 Sweet Crabapples: Productive and hold onto fruit into winter (which will provide forage in an otherwise difficult season -if the wild animals don’t eat them first)

30 Seguin Chestnuts: PRoductive and blight resistant. Provides a dense high carb diet in the fall for finishing hogs (too much fat in the finishing diet is supposed to lead to soft pork)

12 Wild Yellow Sweet Cherries: First tree to fruit, so that I can extend the “tree crop season” a bit -The timber value is also attractive (even though I might not live long enough to see it)

8 Honey Locust: Good productivity, I am using this in higher traffic areas where I hope the thorns will keep the pigs from “messing” with them too much

30 Black Walnut: I went with black walnut rather than english walnut because I was worried about the hardiness of the english tree. Maybe I didn’t need to (as peaches can grow here) but I figured that I should play it safe on such a long term project. The walnuts are high fat, so I am planning on using these to provide dense nutition to lactating sows and overwinter breeding stock. The timber value of the walnuts is attractive too (even though I might not live long enough to see it).

All these trees will be planting in different sections so that I can rotationally graze different crops when the fruit is in season (and thusly limit damage). Late winter and early spring is still a difficult time from a planning point of a view, so I am planning on 1) carrying only breeding stock during this time and 2) planting field crops which can be grazed during these lean times.

I ended up buying tree shelters for all these trees, as I am convinced the deer will eat them if I don’t. I may end up building cages around some of them too, if the rubbing is bad. I am still on the fence about investing in tree mats, and haven’t yet. I would be curious about other’s experience with them.

[dlskidmore]

Are you going to plant the field crops under the trees or in a different field? If seperate, is that part of the 2.5 acres? If the field crops are not going under the trees, what are you planning for understory plants? (Although you probably won’t get much understory in the Black Walnut area.)

How many hogs do you think you will be able to maintain this way? Or will you just do a slow buildup until you see fruit waste decline?

If you’re planting the trees at adult tree spacing, do you have plans for the space between while they are still young?

[Andy Carson]

I will be planting grass as an understory plant. I expect the pigs will obtain some nutrition from that as well as the dropped fruit. It will take a while to get up to speed, and there is alot that still isn’t know yet, but back of the hand calculations seem to indicate that these trees could provide enough nutrients to fatten about 10-20 hogs a year. Maybe this isn’t extremely impressive, but I think alot of it is scale-able, and I really believe it is sustainable too. If I add in the whey I can get for free and the field crops I can raise, and who knows how many pigs I can raise? Maybe twice that number, maybe more??? It’s pretty speculative right now. I am spacing the trees at near adult spacing and am trying to protect them well. I keep playing with the idea of planting something in the alleyways when the trees are young, but grass is useful anyway. I will probably plant a few rows of corn down one or two alleyways next year b/c I am curious.

[dlskidmore]

@Countymouse 28626 wrote:

If I add in the whey I can get for free and the field crops I can raise, and who knows how many pigs I can raise?

Depends on if you’re going to manage to get an artisian pork price out of mast finished pigs, or if this is just one sustainable part of your pig raising operation. Although the trees will ramp up production slowly and require supplementation the first years anyway, can’t try for artisian pork until the trees are mature. I’d be tempted to graze sheep or other more gentle grazers in there while the trees are growing. You can hay the lanes, but grazers will get closer to the trees than machines can.

[Andy Carson]

You make a good point about the sheep, especially when I’m establishing the grove/orchard. I will have to do some reading and thinking about this as my experience with sheep is almost zero. At first pass, they seem to make sense if I can move the meat. With pork, I am a pretty confident I can find people who want it. I really don’t know about selling lamb…

[Robert MoonShadow]

Perhaps pastured poultry or rabbits?

[Tim Harrigan]

@Countymouse 28623 wrote:

30 Black Walnut: I went with black walnut rather than english walnut because I was worried about the hardiness of the english tree. Maybe I didn’t need to (as peaches can grow here) but I figured that I should play it safe on such a long term project. The walnuts are high fat, so I am planning on using these to provide dense nutition to lactating sows and overwinter breeding stock. The timber value of the walnuts is attractive too (even though I might not live long enough to see it).

Black Walnut are nice trees but they can be hard to integrate with some other plants. Here is some information from Ohio. http://ohioline.osu.edu/hyg-fact/1000/1148.html

[Andy Carson]

Thanks Tim,
The juglone from the walnuts was an issue I had put some thought into as well, especially when I was thinking of mixing trees. In the end, I decided on keeping everything seperate and rotationally graze/forage. The cherries go on the “border” of the walnuts, which are on the far end of the field next to a somewhat wild fencerow. Actually, I was hoping the juglone would be useful in keeping some of this planting in the area at bay until until the walnuts can take over. The grass mix I am using does have bluegrass in it, which is resistant to juglone, so hopefuly will be able to subsist on the floor after the trees reach a reasonable size. For me personally, black walnut doesn’t do anything to me other than stain my hands (and stain them very badly). This isn’t an area where horses will graze either.

Overal, I think this toxicity is definately an issue that is important, and is probably the biggest downside to the black walnut. In the end though, the positive aspects (productivity, hardiness, future timber value, and ability to produce a nutritious nut that not all wildlife can readily eat) convinced me of it’s value in a diversified and roatationally grazed setup.

It has been very interesting, by the way, to learn about trees for this project. Trees seem to come with more “implementation complexities” than field crops do. Perhaps this is a result of thier often more “wild” background. Perhaps this is due to thier more permanant nature. Either way, with trees there seem to be less obvious choices from what species would be best for any particular application and many (if not most) have positive and negative aspects that one much make comprimises with in selection. Yes, field crops have these too, but the trees seem have exagerated positive and negative aspects. The juglone from black walnut is probably a perfect example of this, but is not the only example. Apples produce lots of fruit (although it in low in protein), but they attract wildlife, are prone to many diseases, and require more care than many trees. Cherry aren’t nearly as productive (calories per acre wise) as many fruit trees, the fruit attracts birds, and the trees are really quite large and slower to produce than might be ideal. The species of chestnut I am using is non-native (chestnut blight keeps me from using a native tree) and makes me worry there might be some disease or unforseen issue from using a non-native tree. The honeylocust’s thorns might be nice in keeping the hogs off the trees in higher traffic areas, but I worry the damn things will puncture the tires on my forecart or trailer, the pods aren’t really that competative with fruit and nuts (calories per acre) and the wood is of little value. Mulberries can have an extended fruiting season, but I don’t trust the hogs to leave the trees alone if they are in with the trees for entire season so it can’t really be utilized. Also, native mulberries haven’t been selected for fruit as strongly as more traditional fruit trees, and the non-native trees might bring inintended consequences. These are some of the issues I have struggled with in planning. I don’t mean this as a “bitch,” just an illustration of the complexity of the task. It is complex, but also fun. Now we’ll have to see if it actually works.

[near horse]

If you chose the right sheep breed, you could allow them to graze AND provide milk for growing your pigs until the orchard is up to speed. At least it’s an indirect way of raising your pigs on the bluegrass

[Author]

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