Modern dairy cows little resemble their wild ancestors and untamed relatives. However they share a common evolutionary history and developmental path. Searching for food, locating places to drink, finding shelter, and avoiding predators were matters of life or death. Those animals that survived represent the lineage of modern dairy cattle.

Although it has been suggested by some that modern dairy cows are “genetically predisposed to being jerks, in that they work to unbalance their own rations through sorting feeds and stealing food from their neighbors,” this is an inaccurate observation. There is little evidence to suggest that in the few short years dairy cows have been fed in confinement, they have entirely lost the ability to balance their own rations and learn from feedback. In fact, there is evidence to the contrary.

We conducted two experiments with lactating dairy cows. The first determined how varying the crude protein (CP) content of the concentrate fed in the barn would alter the amount of time cows spent foraging in grass (low protein), grass plus clover (intermediate protein), or clover strips (high protein). Pastures were seeded in alternate strips of 1) grass alone, 2) grass plus clover, and 3) clover alone. Twice a day, lactating dairy cows were fed a pelleted grain concentrate that contained .83 Mcal/lb net energy for lactation and either 11% or 21% CP. The cows then had free choice to forage in the grass, grass plus clover, or the clover strips.

When cows were fed 11% CP supplement in the barn, they spent a greater proportion of time foraging in the clover and grass plus clover strips than they did in the in the grass strip. However, when they were fed 21% CP supplement, they spent less time foraging in clover and grass plus clover strips and a greater proportion of time in the grass only strip.

The results of this study indicate that dairy cows have the ability to: 1) postingestively evaluate the quality of their diets relative to their nutritional needs, and 2) when provided with a diversity of foods actively seek to correct imbalances.

Studies have shown eating any food to satiety is likely to reduce an animal’s desire to eat more of the same food. However, in the dairy industry, it is common belief and practice that to maintain high food intake, cows must be “kept bored” by feeding them the same foods day after day after day. The objective of experiment 2 was to determine if cows will satiate on a single species of grass or if they prefer to eat the same species day after day.

In this study, we took cows that had been grazing pastures comprised of either orchardgrass plus clover or tall fescue plus clover for at least 12 consecutive days and offered them the opportunity to graze pastures with strips of orchardgrass plus clover and tall fescue plus clover in spring and aaing in summer. During the first two days cows were given a choice, the cows previously grazing orchardgrass plus clover preferred tall fescue plus clover and cows previously grazing tall fescue plus clover preferred orchardgrass plus clover. By the third day, cows grazed nearly equal amounts of time in the orchardgrass plus clover and tall fescue plus clover strips. Although milk production was not significantly different, production increased by about 3 pounds per cow per day when the cows had opportunity to select from alternative of foods during the spring grazing trial but not in the summer.

The result of this study suggests that dairy cows, like people, get tired of eating the same old thing. When provided with opportunity to eat something different, as long as the food is familiar and adequate in quality, they generally do.

Personnel:

Darrell Emmick
New York State Grazing Land Management Specialist
NRCS