12/7/2013 7:00 AM
By Deborah Jeanne Sergeant New York Correspondent
When it comes to dairy production, it all comes down to intake. Well-fed cows are healthy and produce better.
A Nov. 14 webinar, “Managing Pasture as a Crop: A Guide to Good Grazing,” hosted by eOrganic and presented by Darrell Emmick, focused on why grazing is important and how farmers can provide better forage through understanding behavior-based grazing management.
Emmick is the former state grazing land management specialist with the USDA Natural Resources Conservation Service, or NRCS, in New York. He earned his M.S. in resource management and ecology and his Ph.D. in range science from Utah State University.
For more than 30 years, Emmick has worked with farmers in the Northeast on grazing-based livestock production systems. He said while genetics influences how a cow grazes, early lessons learned from its mother can also factor in.
“Foraging behavior and diet selection are learned behaviors,” Emmick said. “If you’re a goat living in that part of the world, you become good at climbing trees,” he said, while showing a photo of a relatively bare savanna dotted with leafy trees. One tree held a munching goat in its branches. The other scenes showed grazing goats in a variety of scenarios, all finding forage in their own way.
Emmick cited E.L. Thorndike’s 1911 “Law of Effect” which states: “If an animal engages in a particular behavior and the outcome results in a satisfying state of affairs for the animal, the animal will likely repeat the behavior.
“If an animal engages in a particular behavior and the outcome results in an annoying state of affairs for the animal, the animal will not likely repeat the behavior.”
Using the animals’ own natural tendencies forms the premise of behavior-based grazing management, to “enhance animal well-being, ecosystem health and enterprise sustainability,” Emmick said. “Instead of fighting the nature of the beast at our cost in time, money, oil and effort, we transform behavioral principles and processes into low- or no-cost management practices that seek to accommodate what animals need rather than dictate what they are going to get and under what conditions.”
The notion diverges from the past 50-plus years of industrial-based animal management, where cows are “little more than machines and are forced to eat what they may not even like,” Emmick said.
He said cows are social creatures that prefer spending time with other cows, eating a variety of forage and eating when they want. What cows want to eat can vary. Their “favorites” change.
Just as animals influence plants with defoliation, trampling and altering nutrient dynamics, Emmick said plants influence animals through the nutrients they provide and defense mechanisms that allow the plants to avoid, tolerate, or resist defoliation, such as stickers, toxins, and thorns, and variations in forage quality, quantity, toxicity and availability.
Cows use all their senses for grazing, including the sense of touch.
“Whiskers have a one-to-one neurological connection to the brain,” Emmick said. “Those are so sensitive that they swing their faces back and forth through the forage and detect its value. This happens long before the animal reaches out and takes a bite of what they’re looking for.”
He compared the sensitivity of whiskers with human lips.
Cows remember what they like and what they don’t like, which is known as post-ingestive evaluation. Of course, taste matters to bovines as it does to humans. In a similar fashion, cows subconsciously recall what food benefits them and what doesn’t.
Internal chemical, osmotic and mechanical receptors make the connection between the animal’s brain and gut that links the taste of a particular food with its unique post-ingestive consequences. In other words, cows learn through experience to create preferences and aversions to their food.
If an animal tastes a food and it tastes good and feels good, that food is viewed as palatable and the animal acquires a preference. If it burns their lips and stomach and they don’t have any energy and they’re not able to outrun predators, they develop aversions to those types of foods.
“However, there is no such thing as a food always being palatable and always being preferred,” he said.
Taste develops with age. Personal taste varies widely among people, and cows are no different.
“When you give an animal the opportunity to select its own food, there not two that eat the same rate of barley to alfalfa,” he said.
The inter-relation between quality factors (nutrients, harsh texture, growth form and high leaf-to-stem ration) compared with anti-quality factors (toxins, pleasing textures, and low leaf-to-stem ratio) “make a difference on whether or not an animal will eat it,” Emmick said. “The true nutritive value of a plant is best described as the sum of its positive chemical and physical attributes — its quality — minus the sum of its negative chemical and physical attributes — anti-quality.”
Lab results from a chemical analysis do not account for the anti-quality factors. Emmick cited tall fescue as an example. Though high in protein and energy, animals must use some of that energy in eliminating the plant’s alkaloids.
The plant’s nutritive value changes as well. The growth stage, time of day and year, soil type and variety, and its landscape position and aspect all make a plant’s quality vary.
Cows often exhibit neophobia, or fear of something new.
“They don’t eat a whole lot of stuff they’ve never seen before,” Emmick said. If the new food can cause harm, they don’t want to eat a whole lot of it. Plus, they have not become accustomed to its taste.
Emmick experimented with sheep that had never seen rice before. The first day, he fed the sheep rice-based food, and the animals ate little. The second day, intake rose to about 50 grams. On day three, it rose to 100 grams, and on day four, the sheep ate around 250 grams.
On day five, Emmick added onion powder to the rice-based food. Intake plummeted to less than 100 grams, but quickly rose to day-four levels the following day, and continued to rise on day seven.
“They tasted it and remembered it from yesterday and it didn’t make them feel bad,” Emmick said.
Though familiarity can breed contempt.
“Eating the same food over and over again can cause an aversion,” he said. “Eating a food to satiety causes fairly strong aversions to form. These aversions cause animals to want to eat a whole lot of different types of foods.
“In dairy, we’re often telling them to feed the same thing day after day. They don’t like to eat the same thing over and over. Very few animals, like Koala bears, eat the same thing,” he added.
Emmick said the worst way to teach a calf to graze is to separate it from its mother and tie it to a calf hutch, “where all they learn is if they stand there and look cute or pathetic that a human will feed them. They learn nothing about grazing.”
He said cows like grazing during the dawn and twilight hours, when many dairymen schedule milking.
“Maybe you should change the time you milk by an hour,” Emmick said.
He also suggested that low-yielding pasture forces cows to walk more and waste energy. Conversely, pasture that’s too tall, 10 to 12 inches, “causes animals to decrease bit rate, take fewer bites, take longer to fill up and produce less ...”
“If we are looking to optimize the performance and health of our livestock and do so at reduced cost with the least amount of environmental damage, and with the least amount of stress on both human and animal alike, we must have a better understanding of their behavior and stop dictating to them what they are going to get and start accommodating what it is they really want and need to live contented healthy lives.”