Now that this year's pigs have gone to the butcher, I've had a chance to compare the hanging weights of this year to last year. We raised the pigs for either 2 or 4 weeks longer than last year, but we kept the pig feed ration the same (5 pounds per pig a day (after a ramp up period during the first two months). The only other thing I changed was tilling up the pasture to plant more palatable clover. Here are the results:
I'm trying my best to make objective sense of these numbers. Since I fed basically the same ration both years, I have one important variable controlled. In 2013, I fed 4200 lbs of feed to produce 712 of pork, which gives a feed conversion ratio of 5.90 (most published ratios compare to live weight, but I don't really care about live weight and don't have a good way to measure it. We get paid based on hanging weight.) In 2014, I fed 8062 lbs of feed to produce 1416 lbs of pork, for a ratio of 5.69. While it's good to have a smaller ratio this year, the feed savings works out to about $6/pig. I spent $240 on seed last year to plant about 4 acres, plus fuel, depreciation, and my labor. I was hoping that 4 acres of clover would replace about 2000 lbs of pig feed per acre, but the math suggests that I only replaced about 290 lbs of feed for the 10 pigs (I had sows and weaner pigs on this pasture too, as well as two steers for the last month, so that complicates things a bit). So, what happened?
The first question might be to ask whether the pigs were eating the clover. They clearly were, and lots of it. The were mowing through a paddock in a few days in the last month. I opened up the gut of one of the pigs at slaughter and took the picture below. Full of clover.
The first question might be to ask whether the pigs were eating the clover. They clearly were, and lots of it. The were mowing through a paddock in a few days in the last month. I opened up the gut of one of the pigs at slaughter and took the picture below. Full of clover.
The second question might be to ask if they were converting much of the energy in the clover to muscle. This one is harder to tell. This type of clover is supposed to be the most palatable and digestible of all the potential forages. It's high in protein and reasonably low in indigestible fiber.
Another question is to wonder if I'm feeding too much or too little feed ration. My first year, I fed free choice and the pigs were too fatty for the average home cook's tastes. I chose 5 lbs as the ration last year and continued it this year essentially at random. The quality of the pigs and that fat/meat ratio was really good both this year and last year, so I'm hesitant to change it up.
There are lots of other questions, such as "is the benefit of the clover somewhat minimized by the increased exercise they get in foraging (I have a hard time believing that )", "Did improving the pasture not actually make that much of a significant improvement in the nutrition the pigs were getting from it (in other words, perhaps the pigs ate and converted just as much energy from last year's pasture), "Is there a specific age in which they start to convert pasture better because their gut has developed, and should I keep them longer to take advantage of this," "will continued selection for the best animals improve the feed conversion over time?" Some of these questions will be difficult to answer without rigorous controlled studies--studies I would like to do, but need to have sufficient herd numbers to be able to replicate my treatments (I am a scientist after all).
In the end, even though I didn't get the full benefit of the clover planting that I had hoped, I'm still pleased with how it turned out. My pasture is much improved from last year, and it should stay that way for several years with minimal management (white and ladino clovers tend to reseed and stick around, as compared to red clover). The pigs clearly ate a lot of clover, and I suspect the same nutritional benefits that come from eating grass fed beef are present in the meat of these pigs. I would really like to do a full nutritional comparison to supermarket pork--especially to look at things like omega3s.
One thing that I now have a much better handle on it the actual feed cost of raising pigs in my system. This year, it is about $170/pig. Hopefully, I'll find ways to nudge that down little by little over the upcoming years.
Another question is to wonder if I'm feeding too much or too little feed ration. My first year, I fed free choice and the pigs were too fatty for the average home cook's tastes. I chose 5 lbs as the ration last year and continued it this year essentially at random. The quality of the pigs and that fat/meat ratio was really good both this year and last year, so I'm hesitant to change it up.
There are lots of other questions, such as "is the benefit of the clover somewhat minimized by the increased exercise they get in foraging (I have a hard time believing that )", "Did improving the pasture not actually make that much of a significant improvement in the nutrition the pigs were getting from it (in other words, perhaps the pigs ate and converted just as much energy from last year's pasture), "Is there a specific age in which they start to convert pasture better because their gut has developed, and should I keep them longer to take advantage of this," "will continued selection for the best animals improve the feed conversion over time?" Some of these questions will be difficult to answer without rigorous controlled studies--studies I would like to do, but need to have sufficient herd numbers to be able to replicate my treatments (I am a scientist after all).
In the end, even though I didn't get the full benefit of the clover planting that I had hoped, I'm still pleased with how it turned out. My pasture is much improved from last year, and it should stay that way for several years with minimal management (white and ladino clovers tend to reseed and stick around, as compared to red clover). The pigs clearly ate a lot of clover, and I suspect the same nutritional benefits that come from eating grass fed beef are present in the meat of these pigs. I would really like to do a full nutritional comparison to supermarket pork--especially to look at things like omega3s.
One thing that I now have a much better handle on it the actual feed cost of raising pigs in my system. This year, it is about $170/pig. Hopefully, I'll find ways to nudge that down little by little over the upcoming years.
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