Milk (10 page)

The picture really isn’t all that simple. Because many
breeds can have particular virtues, dairy herds with “grade” stock (purebred or close to it, but not officially registered), mixed stock, or deliberate crosses of several breeds are more common than ones made up of single-breed registered stock. Many a “grade” Holstein-Friesian herd owes its fine milkfat and SNF records to a strategic admixture of Jersey genes. But higher and higher volume per cow certainly is a universal (though not exclusive) goal.

Merely breeding dairy cows generation after generation for skinny contours and brimming milk pails would not have brought daily record yields from the neighborhood of 56 pounds (28 quarts) to 152.5 pounds (76 quarts, for Ellen) or roughly 186 pounds (93 quarts, for Lucinda) between the mid-nineteenth and late twentieth century. The early “scientific” breeders worked before it was possible to apply Mendelian genetics to the cows or chemical analysis to the milk. Not until these tools were mastered and coupled with artificial insemination (starting in 1938) and advanced record-keeping techniques did breeding for actual genotype heat up. There seemed almost no limit to yields once farmers could identify heritable milking qualities in the daughters of a particular sire who could then impregnate hundreds or thousands of other cows. But breeding by itself was only half the story behind today’s super-high-producing cows. The other half was
feeding, which has been revolutionized as drastically as applied cattle genetics by modern information technology.

The unimproved cows of yesteryear suckled their calves while eating what cows were made to digest:
grass. Like human mothers, some produced more milk and some less. The higher producers might eat more to compensate for the greater amounts of energy and nutrients being channeled into their milk, but the energy-balance system was largely stable and self-regulating. Genetic selection for abnormally high yields complicated the picture. It meant that the “best” cows were always in a sort of metabolic race to outrun “negative energy balance,” with capacity for intake being pitted against capacity for output.

Calves left to their own devices start experimentally nibbling grass within days of birth and are at least partly weaned in a few months. Suckling a calf places lesser demands on the mother’s body than being completely milked out in a milking parlor twice (or even three times) a day for a year or more at a time. A little arithmetic shows that the 1,750-pound Ellen was directing close to 8.75 percent of her own weight a day into that 152.5-pound milk output. Few cows can eat and drink fast enough to keep up with such losses.

Now, a ruminant’s stomach does not resemble a human stomach. It is a series of chambers that postpone the business of digesting food by gastric juices in the fourth stomach, or
abomasum,
until the cellulose of grasses has first been partly broken down by trillions of microbes in the gigantic fermenting-tank system formed by the
rumen
and
reticulum
(the first two stomachs) and ground fine by the many-leaved walls of the
omasum
(third stomach). Even the role of the mouth is different, for what the animal eats gets two chewings, one perfunctory, the other a more thorough “rumination” of a bolus of cud regurgitated from the rumen. Ruminants live in delicate symbiosis with their bacterial and protozoal guests, a multispecies population swimming in a reticulo-ruminal soup replenished by gallons of saliva per hour. As well as breaking down fiber, the microbes begin the work of elaborating the particular proteins and fatty acids that the host animal needs.

For millennia after cattle were domesticated, different sorts of grass (or hay) continued to be virtually their whole diet. The resident ruminal bacteria need it to maintain a stable balance of different microbial organisms. Altering the diet kills off some species while encouraging others, until the entire chemistry of the rumen may be thrown out of whack. This does the cow no good but, depending on what you’re feeding her, may make her give more milk. For generations it has been known that you can stimulate
dairy cows to higher yields by keeping them on low-fiber, “high-energy” rations with large amounts of “
concentrate” (mostly meaning grains, especially corn). Concentrate translates into more net caloric energy per pound than fiber, which siphons off more energy into the work of digestion. But at high levels it also changes the only slightly acid environment of a normal rumen to a lower pH. The unhappy animal often loses her appetite. She is constantly thirsty and tries to right matters by drinking more water, which means more (if thinner) milk and explains why one can speak of milk watered inside the cow. She may develop full-blown
ruminal acidosis.

Here we arrive at one of several déjà-vu-all-over-again moments in recent dairying history: Cows may no longer be munching distillery wastes in hideous city sheds, but it still is in at least some people’s interest to feed them substances injurious to their health. In acute and even subacute acidosis, the walls of the rumen become ulcerated, releasing infectious bacteria that often travel to the liver, where they cause abscesses, or generating by-products that
migrate to the interior of the hooves, where they cause a painful foot inflammation called
laminitis. (This condition probably was the reason that the “downer cows” surreptitiously filmed by the Humane Society at a California slaughtering plant early in 2008 had to be goaded onto their feet by electric shock.) In addition, lowered ruminal pH is ideal for encouraging the growth of
Escherichia coli
bacteria that can survive through the entire digestive tract (ending up in manure and fertilizer made from it) and often include the virulent 0157:H7 strain.

The elite, high-producing stars of dairy herds are the cows who suffer most drastically on large amounts of concentrate. Already pushed by genetic makeup to the threshold of negative energy balance, they are easily nudged over the edge by any loss of appetite. But the breeding-and-feeding stresses on high-producing cows don’t end there. Since the mid-1990s farmers have made them even higher-producing through injections of the
hormone bovine somatotropin (
BST), also called “bovine growth hormone” (BGH). Or more precisely, the
Monsanto Corporation’s laboratory-engineered “recombinant” version of the cow original, known as rBST or rBGH. Much controversy rages around rBST—and we now reach another
plus-ça-change
moment. Adulteration scandals, it seems, didn’t end with the practice of dyeing the milk. An angry faction has denounced rBST as a harmful foreign substance. Monsanto reasonably enough points out that it is indistinguishable from the BST made by cows and naturally found in milk. Its detractors, also reasonably, want to know whether consuming it can increase human blood levels of a potential carcinogen that occurs at higher concentrations in treated cows’ milk, “insulin-like growth factor-1” (IGF-1).

No clear medical consensus has emerged on these issues. On the other hand, it’s obvious that whatever increases milk production in already high-yielding cows also increases the physical stress on organisms that are stressed to begin with. Not only is rBST a serious additional risk factor for
mastitis (infection of the udder), to which today’s stressed-out cows are highly prone, but it tends to shorten the animals’ life expectancy—which in any case has been on a downward slope over the last half century. In 1950, farmers might have kept many or most cows milking for a dozen years after their first lactation at (usually) about age two. In 2007 a production span of three years before “culling” to be sold for cheap beef wasn’t uncommon. Forget the fact that in the Dark Ages of dairying a well-treated cow might often have lived out something close to the twenty-year potential of the species; enlightened modern management ensures that during their short term on this planet many of today’s cows will have to be repeatedly dosed with
antibiotics to pull them through their latest bout of mastitis or laminitis. Antibiotics are banned from milk sold for any food purpose whatever, and the milk from cows under antibiotic
treatment is supposed to be dumped. Nonetheless, contamination is regularly caught in inspections of farm-to-plant milk shipments, and whether it is sometimes
not
caught is anybody’s guess.

The pressures on cows mirror those on farmers—a word I use for want of a better one, though their job is really more like applied industrial engineering under the most unforgiving conditions. Farming to supply the fluid-milk market is an incredibly competitive business with painfully slender profit margins that make shaving a few cents from production costs for a thousand pounds of milk a matter of survival or collapse for large operations. And all operations are inexorably becoming larger. In the late 1940s sixty-cow farms looked as modestly middle-sized as three-hundred-cow farms do today. Only at the level of two thousand cows do dairyists start to talk about
big.
There are operations with eight or nine times more. The San Joaquin Valley in California has dairy farms so huge that the methane gas given off by ruminal bacteria and belched by the animals as they chew the cud is now regarded by air-quality experts as a major local pollutant.

Many small dairy farms stand, or stood before they disappeared, in the path of real-estate juggernauts in the ever-expanding orbit of cities. Those that survive often do so by leaving the fluid-milk market for arrangements with local makers of other dairy products;
ripened or aged cheeses are an increasingly lucrative destination for milk with good fat and protein content.

Meanwhile more and more of the fluid-milk supply comes from huge farm operations completely dependent on high-producing cows bred, fed, and injected to be still higher-producing. On many farms, the animals never see a blade of grass—not because farmers are unnatural villains but because pasture management for hundreds of ground-trampling twelve-hundred- to eighteen-hundred-pound Holstein-Friesians is a time-consuming luxury. Besides, grazing in an actual pasture distractingly complicates the job of evaluating any one cow’s performance in a several-thousand-cow herd.

The crucial task of tracking performance is now done by computer on most dairy farms. A cow may have a name, but she also has a number recorded on an ear tag, possibly one with a computer chip. She enters the herd along with crucial milking statistics from her dam’s and sire’s lineages. Everything she eats and drinks is measured against her milk-output data (weight as well as fat, SNF, and water content), which go into the computer from the milking machine. Her food ration is a customized recipe based on readouts of her milking record. It typically includes chopped hay, cornstalk or other silage, corn or cornmeal, ground soybeans or cottonseed, and beet pulp or molasses, not to mention chemical buffers like sodium bicarbonate, dicalcium phosphate, or powdered lime to lessen the risk of acidosis. The milking data dictate adjustments in the exact proportions of different nutrients.

This isn’t at all a matter of robotic programming replacing thoughtful human care, because every dairy farmer has his or her own priorities. Computer-monitored rations can be a tool for wringing the last drop of watery milk out of creatures on the edge of metabolic collapse, or a way of balancing quantity and quality while maintaining the animals in good
health. But it’s fair to say that any cow who performs poorly enough to bring down the herd average for desired characteristics will rapidly be culled.

If a cow proves really remarkable in an outstanding herd, she may well be chosen for supermotherhood via ET, meaning “embryo transfer” or “transplant” (hence the initials at the end of Muranda Oscar Lucinda’s name). She must first be induced to “superovulate”—release multiple ova instead of the normal single ovum—through a series of hormone injections, then inseminated with semen from a bull of proven excellence as a dairy sire. After some days her uterus is washed out with a saline solution that is microscopically scanned for fertilized eggs (too small to see with the naked eye). Meanwhile, several destined surrogate mothers have been brought synchronously into heat through rBST injections and are ready to be impregnated with the new embryos. The donor cow can thus become the mother of perhaps six or more calves almost simultaneously—all daughters, if the bull’s semen has been sexed to choose only sperm with X chromosomes. And the process can be repeated at intervals.

The steam that drives current
breeding-and-feeding technology along with the rest of the production engine is, of course, the bizarre exaltation of milk drinking over other forms of milk consumption since the nineteenth century. It can’t be too often repeated that pushing fluid milk into this extraordinary role has not made it more worth drinking (by those who can digest it) for the sake of flavor.

Dairy farmers are not to blame for the punishing realities of modern commercial milk production. Not only do they supply a food that everybody else takes for granted without understanding the first thing about it, but they were hit hard in the late twentieth century as the Nature’s Perfect Food myth began to be challenged by authorities on coronary artery disease and
heart attacks. When the diet-and-health battle heated up, the nation’s milk processors had some useful strings to their bow. Unfortunately these would provide no magic answers for farmers.

The cholesterol wars arrived several generations after three strategic developments that didn’t do much for the cause of good plain milk but would enable the industry to reinvent itself under fire. In the end, these bits of technical
progress would give
dairy processors the tools for taking Nature’s Perfect Food apart and—the really decisive factor—putting it back together with selling points that nature hadn’t thought of.

The first breakthrough, in the 1880s, was the mechanical separation of
cream by
centrifuge, far more thorough than any hand skimming. The next came in 1890, when a University of Wisconsin dairy chemist invented the eponymous
Babcock test for measuring the precise fat content of milk—at the time, the chief indicator of quality. These two advances led to intense growth in the
butter industry, which became the most lucrative destination for milk. Old-style farmstead buttermaking declined, while dairying regions became dotted with small factories called creameries that bought up shipments of high-Babcock-score milk and produced butter from cream so efficiently centrifuged that, like the cream my parents remembered buying in tiny Creamery, Pennsylvania, it had to be spooned rather than poured.