sign in sign up
<<
Home , Grazing

Guides Knowledge of grazing behavior of can management.

by Heather Smith Thomas

nderstanding grazing Plant selection during grazing is distribution on . “If you let behavior can help partly instinctive and partly learned. them do all the selection on their Ustockmen optimize Social factors also affect where own, you may run into problems production when managing cattle and when cattle graze; they travel with some areas over-grazed and on pastures — so knowing cattle in groups and defer to the lead or others under-grazed,” he explains. can eat a lot of in a short dominant animal to make decisions If cattle have season-long use time, graze in the early mornings, about where and when they graze. in a mountain area, for instance, again in the late afternoon and Bart Lardner, research scientist they may go too high, too soon and into the evening, resting during the at the Western Development overuse immature higher grasses, middle of the day, graze at night in Center, University of Saskatchewan, leaving the lower elevation grasses hot weather and have preferences in says ranchers need to be aware of to become overly mature. It would forage plants can be beneficial. grazing behavior and to use this be advantageous to keep the cattle knowledge to help control animal in lower elevation pastures first — with fences or herding — to make

76 / May/June 2017 Hereford.org cattle use the lower elevations realize that the reason they graze while that grass is still green and more in the evening is because of palatable, allowing the higher the nutrition level of the plants at elevation grasses more time to grow. that time of day,” he says. “Cattle have patterns of grazing A series of United States behavior regarding time of day, Department of studies preferring to do most of their published in 1999, 2002 and 2005 grazing in the early morning or late looked at animals’ ability to choose in the day when it’s cool. During different . “The researchers the heat of the day they rest in a cut some in the morning and shady area to chew the cud and some in the evening and used this then head out to graze again in late in these choice tests,” Stookey says. afternoon,” he says. “They’ve done it now with cattle, Joseph Stookey, Western College , , and they all prefer and of Veterinary Medicine, Saskatoon, are able to select the hay that’s cut Saskatchewan, says cattle have in the late afternoon and evening. interesting aspects of grazing When you analyze that hay in the behavior. “Their natural diurnal lab, it shows it has a higher level grazing pattern, with the largest of carbohydrates because that grazing bout occurring before plant stored more nutrients during sunset, matches the photosynthesis through grazing habits may enable the plants’ highest nutrient the whole day.” producer to feed at the best time of content after a day “Their natural Carbohydrate level day to aid their total intake. of photosynthesis. diurnal grazing is much higher late in During summer in a rotational In a choice test, pattern, with the the day. By morning grazing or mob grazing program, ruminants prefer some of the nutrients knowing the natural grazing habits forage harvested in largest grazing have moved down of cattle may help producers decide the late afternoon and bout occurring into the roots during when the best time(s) of day might evening rather than before sunset, the night. be to move them to the new pasture. forage harvested in “We can’t see any the morning from the matches the difference with the Learned behavior same ,” he says. plants’ highest eye, but the grazing Young animals are highly influenced Since cattle tend nutrient content animals can detect by their mothers, plant to graze in the early the difference in these preferences and grazing habits from morning and again in after a day of forages,” Stookey says. their dams. If cows have been trained the evening, these are photosynthesis.” After thousands of to eat certain plants in certain the times of day they — Joseph Stookey years of evolution, the locations, they pass this behavior on may eat more feed. grazing animals are to their calves. “I don’t think people well tuned in to the Fred Provenza, professor pay much attention to feeding differences in the forage plants and emeritus at Wildland Resources, times in relationship to what have a keen sense of what is most Utah State University, has been the animals would do naturally,” palatable and nutritious. observing and researching grazing Stookey says. “There has been In cold weather, cattle tend to for many years. He has traveled some study looking at this in the graze after the sun comes up and to study animal behavior and to feedlot industry, regarding when is to stop grazing soon after sundown. consult with stockmen and land the most optimum time to feed,” “During sunlight hours they also managers around the world. When Stookey says. tend to avoid shade, even the he started graduate school at Utah Considering the amount of shadows of their herdmates, and State University, he and his wife intake when cattle are grazing, they prefer to stand perpendicular were on a study project in southern Stookey says they eat more in to the sun to soak in as much Utah near Gunlock. the evening than they do in the warmth as possible. They absorb “The goal was to use goats to morning. “Logically we’d say this a lot of heat from direct sunlight,” prune shrub blackbrush during is probably because it helps them he says. At sunup they generally get winter to stimulate new growth,” he get through the night, but you up from their beds and hike to the says. “This would be like pruning could also say that they’d need a spot in their pasture where the sun any shrub to encourage more new big meal after they get up again in will hit first. growth, which is much higher in the morning to graze, since they When feeding cows energy and protein, minerals, etc. are relatively empty,” he notes. “You supplementary forage or protein than the unbrowsed plants.” could justify either time, but we now during winter, knowing their continued on page 78...

Hereford.org May/June 2017 / 77 ...Grazing Guides continued from page 77

This was 45 years ago, looking at This is one reason that going the use of animals to target-graze. away from a natural grazing diet, “We did this with goats and were in which grazers sample a little bit able to show that it would stimulate of everything, can be unhealthy, new growth. But the goats wouldn’t such as forcing animals to graze a eat the new growth. This spurred my like a pasture planted interest in grazing habits. We weren’t to just one type of grass. “…it’s the body feedback sure why the goats refused to eat new “As we selected for quantity, growth even though it appeared to be from cells and organs that such as planting a pasture to a most nutritious,” he says. changes the animal’s desire single, high-producing species Provenza eventually found to eat foods.” high in energy and protein but low that ‘secondary compounds’ were in secondary compounds, rather present in high levels in the new — Fred Provenza than phytochemical richness, we growth compared to those in the shot ourselves in the foot. Now we old growth, and is the presence of and weeds, is that it’s the body have to add a lot of fossil fuel input these compounds was the reason feedback from cells and organs that in agriculture to try to replace why the goats were avoiding the new changes the animal’s desire to eat the roles that plant diversity and growth. “The compounds in the foods,” he says. secondary compounds used to play.” new growth bark were about 70% When animals eat a variety condensed tannins. It was a little , nutrition and health of different foods, those foods bitter, but we came to realize that Provenza and his team studied compliment one another. “There it wasn’t the taste that deterred the grazing behavior for many years, are thousands of compounds that goats. They avoided it because of looking at primary compounds work together and the body utilizes what happened once they digested it (energy, protein, minerals) and them,” Provenza says. “In agriculture and the tannins got in their bodies,” secondary compounds (phenolics, people went to and Provenza says. The tannins probably terpenes and alkaloids) with sacrificed quality for quantity, trying made them feel nauseated. relationships between the two. to maximize production to feed the “At first we thought they innately He says this work led to many world — not realizing the drawbacks. knew to avoid the new growth, but insights into the relationships among What they didn’t know is that when we found out later that they did the different compounds in foods. you have enough complexity and try it — and learned to avoid it It also led to a realization that quality you don’t need so much after the first bad experience. They biodiversity is important for health quantity,” he explains. were learning, and really quickly. through nutrition — for all animals, Provenza says they were thinking Unless you saw them the first day including humans. All plants have in terms of energy and protein, when they were sampling the new different kinds of phytochemicals, rather than phytochemical richness growth, you’d never see them the secondary compounds. and complexity, not realizing it’s all eating it,” he explains. “When we were starting to study tied together. “Many of the things Provenza had 20 goats in a trial this, the main researchers were those phytochemicals do are now and offered them pelleted chow at poisonous plant research labs,” missing in feeds, and we’ve ended with tannin on it. On the first day, Provenza says. “They were looking at up substituting fossil fuel inputs each ate all of the chow. “We things like pyrrolizidine alkaloids or — everything from pesticides, were stunned because we’d thought one of the 23 alkaloids in larkspur. dewormers, to ,” he says. for sure this was the ingredient they Alkaloids were viewed as toxins. But Some plants produce natural were avoiding. So we decided to try what we were not considering was pesticides and compounds that it again the next day. On the second that in small doses these things can hinder internal parasites, especially day, the goats wouldn’t touch it. We have health benefits.” if animals can move to new grazing realized they were learning to avoid When there is a diversity of plants areas in combination with eating it based on the consequences after on a landscape, animals learn to mix these plants. “There is research the food got into the body — giving their diet and to eat only a little bit of now on tannins, alkaloids and them indigestion.” each one. “These compounds have terpenes in certain plants that Provenza says this was a major an adverse effect on an animal if they reduce internal parasite loads. discovery because until that time eat too much, or cause them to reach When you have a variety of those he and his team had thought it was a point that they don’t want anymore, plants, animals can move around just taste and that animals innately ensure that only a little bit is eaten. the landscape and eat them, and know what’s not good for them. So the animals mix and match and parasites are not an issue,” he says. “What this study taught us, and eat many different things,” he says. Cattlemen who have decided led us to be able to train sheep to This selection ensures that they have to avoid the vicious cycle of using avoid the vines in vineyards while a varied and healthy diet, containing chemical fertilizers, dewormers, using them to keep down the grass all the different things they need. etc. are finding they don’t really

78 / May/June 2017 Hereford.org need them. They just need to figure to fully grow and to mature before It is healthy for them, and for the out how to manage pastures and the cattle come back to that area. land and plants, to move across animals to minimize the problems Favorite species are not repeatedly the landscape and utilize different and to add fertility naturally to grazed and weakened and killed foods. They rarely stay long in pastures. This helps producers stay out. Moving frequently as a large the same places. This helps them in business because it cuts costs. into new pasture also makes escape predators and also means cattle very competitive; they eat parasites can’t build up. The Species diversity aggressively and learn to mix their movement is important.” In nature, grazing animals move diets less selectively. Provenza says it’s healthiest for over the landscape in , eating “The frequent movement, and cattle when they can be encouraged a variety of plants and moving the challenge to eat a variety of to move to new pastures. There on. Mob grazing simulates this plants, helps them learn to mix are many benefits that come from and helps promote plant diversity their diet,” Provenza says. “In eating a variety of plants. HW because all of the plants are allowed nature, animals are always moving.

Learning from mom and nature The culture we grow up in, human or animal, shapes us. “In our they could change the culture of a cattle herd from bottom studies we’ve done a lot of work with wild and domestic animals, dwellers to ambitious animals that live in the uplands. Once you showing you can change the habits of animals,” says change their culture you don’t have to do as much, because the Fred Provenza, professor emeritus, Wildland Resources at Utah cows teach their offspring.” State University. Budd hired a rider full-time the first summer to continually Nature is the guide, and some ranchers are working with move cattle to uplands to show them there was good feed what’s natural for their . “We try to think about how there. They learned the advantages of being on the ridges where these natural systems work, and get back in sync with this,” there was a cool breeze and fewer flies—and more forage. “The he says. first year is the toughest, and by the third year you have the job Ranchers can utilize natural tendencies of grazing animals for done,” he says. If producers keep replacement heifers from those better management and can change some of these animals’ bad cows, those replacements already know good habits, learning habits — such as training lazy pasture cattle to climb up out of from their mothers. riparian areas and lowlands and use more of the upland areas for “For better land management, we can use cattle grazing and grazing. It’s all part of the culture they learn, regarding the foods stockmanship, as well as strategic supplements that help cattle they eat and places they go. Calves learn their habits from their use plants like sagebrush,” Provenza says. “In our work we’ve mothers, so if producers can train the cows to utilize a range done a lot of this to integrate cattle and sheep for sagebrush more efficiently and effectively, the calves will develop those control rather than using herbicides or mechanical treatments. If same good habits. we implement livestock into the system, they become a part of “This is where we can have a positive influence. We all get rejuvenating their own landscape.” into habits that are not the best for us, and sometimes need Provenza found the best time of year for grazing sagebrush to be re-trained.” Flatland-pasture cattle that haven’t had is late fall/winter. The deterrent compounds in sagebrush— to climb hills and work for their feed, or have depended on terpenes—are at low concentration then, and it’s easier for the someone bringing feed to them, are reluctant to change animals to utilize sage as part of their diet. unless someone shows them another way. Cattle take the “Producers with sagebrush land can strategically supplement easy way, welfare mentality, if producers pamper them too cattle out there, moving them across the landscape,” he explains. much and kill their creativity. “This creates mosaics and patches of changed . You “When we were working with Bob Budd at Red Canyon can’t change thousands of acres all at once, but you can work at , Bob was showing people that with good stockmanship it to rejuvenate the landscape.” HW

Hereford.org May/June 2017 / 79