Telos said:
We often times forget how much energy it takes to get a calf ready for the Grocery Store case. Approx. 386 gallons of petroleum by the time you plant, fertilize, harvest, slaughter etc. for one single case ready carcass.
Telos, I thought this was an interesting statement. So I took some time to investigate it. I'm not coming up the same values and thought I would throw this out there for anyone to debunk my math or add to it. What am I missing?
Feed: Corn
Manufacturing 1 ton of anhydrous ammonia fertilizer requires 33,500 cubic feet of natural gas. ~ 16.75 cubic feet of gas per lb of anhydrous ammonia.
Average for years 2000-2006 was 150 bushels per acre of corn with an average N application rate of 148 pounds of N per acre.
So 148 lbs of N = 150 bushels and ~ 171 lbs of anhydrous ammonia or 19 cubic feet of gas per bushel to fertilize 148 lbs of N or 2864 cubic feet per acre. Then to account for DAP. Even doubling this which I would expect to be over kill, you have 38 cubic feet of gas per bushel.
Average 0.3 to 1.5 gallons of diesel per acre per pass for tillage and planting depending on implement. How many passes- 7 for prepping ground, planting, application of fertilizer/weed killer, cutting? Average is probably ~ 1 gal/acre with 7 passes- 7 gallons acre with per 150 bushels or 0.046 gallons per bushel. (
http://www.ext.colostate.edu/pubs/farmmgt/05006.html) (
http://www3.abe.iastate.edu/livestock/pm587.asp)
Hauling material is fairly limited to elevators and then on to feed yards per bushel due to them being close. Add even another 0.014 for processing hauling local. 0.06 gallons of diesel per bushel of corn for processing and planting.
Drying corn is ~ 1 gallon propane per 6 bushels.
Cattle:
Cow/Calf
Pasture for mama cows- let say average N application for grass is 100 lbs/acre and you run a cow calf pair per 2 acres. 200 lbs of N ~ 244 lbs of anhydrous ammonia = 4,087 cubic feet of natural gas fertilizer for cow calf unit. (so there is some positive left in the cow as well)
Hauling cattle average 8 miles/gallon with even pulling them out of Florida to Oklahoma for stockers- ~1,000 miles or 125 gallons per 100 head of 500 wts = 1.25 gallons shipping per calf
Application of fertilizer ~ 0.5 gallon per acre = 1 per head and general fuel usage ~ 5 gallon per head
Stocker
http://www.noble.org/ag/soils/winterpastures/ something worth noting is that "Research data show that if you do not fertilize winter pastures, you will produce about 2,000 pounds per acre of dry matter forage in a season. With good grazing management, cattle can consume all the forage except about 500 pounds per acre. Simple subtraction shows that the cattle will consume about 1,500 pounds of dry matter forage per acre from unfertilized winter pastures (2,000-500)."
However, using N average 100 lbs of N per acre of wheat again looking at 2044 cubic feet of natural gas per acre for gain of ~ 435 lbs but well just say 400. So 2044 cu ft per calf.
Fuel use is probably 5 passes so 5 gallons per acre or 5 gallons per calf.
http://www3.abe.iastate.edu/livestock/pm587.asp
Oklahoma city to Kanasas~250 miles to feed lot at 900 lbs =55 calves per pot load and 31 gallons per potload = 0.56 gallons of diesel per calf
General fuel usage ~ 2.5 gallons per head
Feedlot
Trucking corn to Feedlot, consider even 200 miles at 8 mile/gallon with 50,000 lb payload 25 gallons 893 bushels = 0.03 gallons of diesel per bushel fed for trucking.
Taking an all corn diet just to make it easier to calculate and assuming this would be the worst case scenario of using fossil fuels and resources, average calculation is 6lbs of feed per lb of gain. So for 900 lb calf to 1250 lb calf =350 lbs of weight gain therefor 350 x 6= 2,100 lbs of corn. So 56 lb to the bushel and you have 37.5 bushels per calf = 1425 cubic feet of natural gas and 2.25 gallons of diesel, plus shipping 1.12 gallons = 3.37 gallons of diesel used per calf per volume of corn consumed
Feed truck, loader, etc... ~ 0.75 gal per animal
Spreading manure 0.5 gal per animal
(
http://www3.abe.iastate.edu/livestock/pm587.asp)
Propane use is 6.25 gallons per calf
Feed lot to kill plant ~ 60 miles 1250 lb calves 40 head ~ 0.19 gallons per head
So roughly, from mama to packer, each calf uses: 4,087 + 2044 + 1425 = 7,556 cu feet of natural gas (over its life),
US produced 82 billion cubic feet per day.
So in 1 day, we produce enough gas for 10 million, 852 thousand animals from start to finish.
So roughly, from mama to packer, each calf uses: 1 + 5 + 2.5 + 1.25 + 5 + 0.56 + 3.37 + 0.75 + 0.5 + 0.19 gallons of diesel = 20.12 gallons of diesel per calf
So average to worst case scenerio 7,556 cu feet of natural gas, 20.12 gallons of diesel and 6.25 gallons of propane per calf to the packer.
Now, consider that I have documented estimated figures for usage of fertilizers and fuel use in intensive management. However, using the roughly estimated figures for general fuel use on the farm, the most usage of diesel or gas appears to me to be the day to day care of the animal (traveling to and from the pasture and looking through the spread out herd). If your going to fertilize grass, you are still going to consume fossil fuels and it appears possibly even more than by feeding cattle in an efficient concentrated system. Also, your still going to have some shipping of each animal to the slaughter plant and to the stores. If your running stockers, your going to have to ship them in and then on to kill plants as well.
If I had more time, I would analyze this further into looking at running those same cattle on grass for the amount of time it would take to gain the same wt for slaughter in a lot and see how much of a difference there really is in overall fuel usage. I don't think there is much and possibly even less.
With natural gas being used to produce N fertilizer, it is so cheap right now that many wells are shut in or just blowing it off as it cost's more to store it and ship it than it's worth. I don't see concentrated feeding as a waste but possibly a fuel saver along with making better use of one of the most scarce resources we have, land.
What am I missing?