Real, Live Milking Machines
On the edge of campus, past the colorful gardens of the Orfaleea College of Business, beyond the recreation fields covered with students playing Frisbee or catch, and off busy Highland Drive is the unpaved Mt. Bishop Road. Mt. Bishop Road is home to the crops unit, campus orchards, veterinary unit, and the Eugene and Rachel Boone Dairy Science Complex, more familiarly known as the Cal Poly Dairy. Walking through the dairy on a sunny Tuesday afternoon, I am greeted by fifteen or so calves chained to oversized dog houses called “hutches.” Petting them as they attempt to suck on my pants, I look up to see their mothers in the long cages just a few feet away. It is hard to leave the doe eyes of the Jersey calves, but I move on to the rows of enormous Holsteins. It is the late afternoon and their udders are filled to the brim with milk. The weight of ten bowling balls hangs from their bodies making their locomotion slow and awkward. The cow’s milking time is from four to six in the afternoon. Automatic milking systems milk the hundreds of cows quickly and efficiently.
I wonder if all that milk is due to the genetically engineered hormone, rBST, which increases the milk production in the cow. rBST is a man made reproduction of the cow’s natural growth hormone, Bovine Somatropin (BST). Economically the increase in milk supply caused by the hormone could lower prices on dairy foods, an appealing attribute to consumers, and feed more people with fewer cows than ever before. As I watch these dinosaur-like creatures stand motionless, I cannot help thinking my new friends on the other side of this gate do not benefit from this injected hormone in the least.
Bovine Somatropin is naturally activated when a cow is about to give birth. Experiments reproducing the lactation hormone in cows for economic purposes have been recorded as early as 1934. The genetically engineered hormone is named Recombinant Bovine Somatropin (rBST). It is made by extracting the BST gene from a cow’s DNA. The gene is “transferred to the genetic code of a common strain of bacteria which rapidly multiplies and produces large quantities of BST. The bacteria is then destroyed and the BST is isolated.” Injecting rBST into cows makes their lactation that of a reproducing cow even when barren. The agricultural genetic engineering company, Monsanto Co., began manufacturing rBST in 1989. Their product is called POSILAC and is sold to dairies throughout the world, including the dairy at Cal Poly.
At Cal Poly, rBST is used selectively on the dairy cows. Three factors are taken into account before a Cal Poly cow is put on rBST. The first is its flesh. If a cow is too thin, its body will automatically reject the hormone. The second is where a cow is in its lactation cycle. A cow is taken off of the hormone if it is expecting a calf because it will already have high lactation for feeding its baby. About 60 to 90 days...