Burritt: Fit eating habits to range conditionWritten by Gayle Smith
Burritt laid out plans for the study during the University of Wyoming SAREC Open House and Field Tour in Lingle on Aug. 23.
Research studies profitability
The two-year study will be held for 60 days each year and involves two groups of feeder cattle that will be fed two separate ways. The control group will receive a ration based on National Research Center (NRC) requirements, while the second group will be fed a ration based on choice – alfalfa hay, barley and corn. The animals will be fed as a group mimicking a feedlot situation. The first year, the cattle will be provided by UW, and the second year the cattle will be provided by four producers from Wyoming and one from Utah.
The object of the study is to evaluate the profitability of the two feeding systems to see what sources can be used and which are most economical.
“The idea is, if you are a producer and you have a choice between selling your grain or feeding it to your cattle, can you put out an appropriate free choice feed and let the cattle develop their own ration? If they don’t know what the best feed is, expose them to a variety to see what they like best,” Burritt said.
The rangeland specialist shared some information from other research indicating that when presented with a mixed ration versus choice, animals consumed the same protein to energy ratio and had the same average daily gain, but the choice group had slightly better feed efficiency.
The choice ration also cost 19 percent less to feed than a mixed ration, each animal could meet its individual needs, and they didn’t have to eat the same food day after day, she explained.
During her presentation, Burritt shared 30 years of research from Utah State University (USU) studies addressing why livestock eat what they do and live where they live. The program for this research is known as BEHAVE (Behavioral Education for Human, Animals, Vegetation and Ecosystem Management).
BEHAVE searches for new ways to manage livestock. The focus of this research is to understand the principles of behavior that may enable managers to develop livestock that fit rangelands, rather than changing the rangelands to fit livestock, Burritt shared.
Research conducted at USU has developed ways for ranchers to better utilize their rangelands by teaching livestock to eat weeds and sagebrush, turning them into valuable forage, she said.
Many of the early studies of livestock described their behavior as set-in-stone, Burritt said.
“Behavior is flexible and can be shaped throughout the animal’s life. Behavior relies on consequences. If an animal engages in a behavior, and the consequences are good, the chances that that animal will engage in that behavior again increase,” she explained. “On the other hand, if they engage in that behavior, and the consequences are bad, the changes they will engage in that behavior again decreases.”
Mother knows best
After 30 years of research, scientists have found the number one impact on diet selection is “mother knows best,” Burritt shared. “(The mother) is a role model for diet selection. Because of what she forages, she has been able to grow up and reproduce.”
To back up this research, Burritt shared a study from Australia where at six weeks of age, lambs were divided into three groups – those the had exposure to wheat, no exposure to wheat or exposure to wheat with their mothers. Three months later, the lambs were tested, and those with no exposure or were tested alone wouldn’t eat the wheat, while those that had first tested the wheat with their mothers would. At 34 months of age, the three groups were tested again.
“The ones that had been exposed with their mother remembered wheat was a good food and would eat it. The other two groups ate very little or none,” she said.
“Every animal is the sum of its genetics plus experiences in its social (mom and peers) and physical (where it was raised) environment,” she continued. “These experiences can cause changes in physiology, the nervous system and physical structures of the body. Animals change throughout their lives based on their experiences. However, experiences early in life often have the greatest effect on animals and can even affect gene expression.”
Teach them young
Burritt asked the group of nearly 100 producers, do animals need to learn how to eat? To demonstrate her point, she shared a video of a young goat raised on alfalfa pellets trying to figure out how to eat alfalfa off a plant.
“He knows it’s food, but he doesn’t know how to eat it off the plant,” she said.
In other studies, Burritt said researchers have found the younger animals are when they are exposed to foraging skills, the better foragers they will be. They learn from their mother, because she’s efficient, the rangeland extension specialist explained. She knows which plants are harmful and which are nutritious, and she passes this knowledge on to her offspring because it grazes close to her, eating the foods she eats and avoiding those she doesn’t, she added.
After weaning, animals sample novel foods carefully, and if they experience a positive consequence, they may increase consumption of that food. If the consequences are negative because the food is toxic or contains too many or not enough nutrients, they may avoid that food or reduce intake.
Burritt shared another study where animals sampled a new food, then were put under deep anesthesia and fed lithium chloride, which will make the animal nauseous. Despite being under anesthesia until the drug had passed, the animals still avoided the new food because of the negative feedback from the toxin – even though they were asleep, she said.
Burritt told producers they may be able to encourage livestock to eat certain plants by providing supplements. As an example, she said sheep, cattle and goats will eat more sagebrush, despite its terpene content, if they are supplemented with protein and energy. Similarly, researchers have developed a process to teach livestock how to eat some weeds in just five days.
“When weeds become a forage, we can manage grazing to reduce their abundance, use of herbicides and cost of weed control,” she said.
Some of the weeds cattle have been taught to consume successfully include Canadian, distaff and Italian thistle, leafy spurge, spotted and diffuse knapweed and black mustard.