The publication of this model in his book De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres) just before his death in 1543 was a major event in the history of science, triggering the Copernican Revolution and making an important contribution to the Scientific Revolution.
World market prices for dairy products The average world market price of butter in 1981-2006 was US$1 580/ton, fluctuating between US$1 000/ton and US$2 000/ton. It shot up to US$2 886/ton in 2007 and, in the first six months of 2008, increased further to US$4 021/ton.
Feed costs for heifers vary with age but we will use $2 per head per day to feed on the average for all the young stock. This gives us a total cost per day for feed for all of our animals of $800 per day. If the cows are milking an average of 80 pounds per day, they are producing 6400 pounds of milk per day or 64 cwt. This gives a feed cost of $12.50 per cwt of milk produced. If your margin is milk price minus feed cost, what does that leave you for a margin to pay your other expenses? Most producers are somewhat surprised at how high the feed cost is when dry cows and heifers are included.