How Pasture Structure effects Grazing Behavior

2366491541_cbacee5858Most grazing management is based on making sure there is enough feed for the amount animals in a certain period of time. Structure is not normally taken into account.

Brazilian researchers working in the temperate Pampa grassland system in southern Brazil, Uruguay, and Argentina evaluated the relationship between pasture structure and livestock grazing behavior. Pasture structure refers to forage height and type, such as bunchgrass or sodforming grass, and distribution of preferred plant species versus non-preferred.

These researchers found that regardless of the season or forage allowance,
cattle balanced their time eating against a relatively narrow window of structure conditions in this environment.

In extensive grazing management systems, the type of species in a pasture and how they’re arranged may be more important than how much forage is in your pasture in terms of grazing efficiency.

Future research will further illuminate this relationship and evaluate the
costs and benefits of modifying an easy to use and vetted forage allowance
management approach.

Da Trindade, J.K. et al. 2012. Forage allowance as a target of grazing management: Implications on forage time and forage searching. Rangeland Ecology & Management 65: 382-393. 

Photo: World Bank Photo Collection / Foter / CC BY-NC-ND

The Desert-Friendly Cow

By Cally Carswell
High Country News

Criollo cattleAlfredo Gonzalez manages a modest herd of 200 beef cows on the Jornada Experimental Range, a long-term ecological and agricultural research site near Las Cruces, New Mexico, where grass is scarce, and water scarcer. Occasionally, he says, fellow ranchers ask: “What the hell are you doing?”

Such skepticism is directed primarily at the animals he raises. They are speckled and streaked with brown, black and white, have horns that spiral as they age, bony frames, and a name that is endlessly fun to recite. These are criollo cows. (Try it: cree-oh-yo.). Criollo are unusually leggy. They are also unusually small, and top out near 1,000 pounds. Corporate meatpackers won’t buy them. Rick Estell, an animal scientist with whom Gonzalez collaborates, says raising criollo is “kind of like raising sheep if you’re a cow man.”

But in the criollo, Gonzalez sees only potential: an animal that could rescue ranching and rangelands in the Southwest from their failing marriage to Angus and Hereford. They require little water, live on available forage, and can withstand hot weather. Texas longhorns, Florida cracker cattle, and corriente sport ropers are among their descendants.

Around 2000, Ed Fredrickson, a former livestock researcher at the Jornada, became convinced that with the landscape beaten up, feed and fuel costs and global temperatures rising, Southwestern ranchers needed to change, raising smaller animals that could tolerate heat, eat less and more broadly, and move more to minimize overgrazing of native grasses.

Fredrickson’s early studies showed that criollo spend less time near water than British breeds, graze fewer hours and over more diverse terrain, and remain active during extreme heat. That might be because they store fat around their kidneys, rather than only under their hide, and thus retain less heat.

Dennis Moroney, of The 47 Ranch in southern Arizona, is converting his whole herd to criollo. Drought and the changing climate caused Moroney to cut his herd to half the size it was a decade ago to help maintain vegetation. Raising criollo, which he finishes and sells without a middleman, has kept him afloat despite the reduction. They range well over Moroney’s rugged terrain, browse shrubs, cactus, trees and grasses, calve easily, fall ill rarely and get little supplemental feed. “But the acid test for our business,” says Moroney, “is do our customers like the meat?”

It’s tender and beautifully marbled, Moroney reports, and farmers market and co-op customers accept smaller cuts-a 7 or 8 oz. ribeye. Moroney tells them about the animals’ historical relationship to the Southwest, “but the main pitch is that it tastes fabulously,” he says.

Find this article at The Desert-Friendly Cow

Photo: Ted of DGAR / Foter / CC BY-NC-SA

Where it Grows, Matters

IMG_7286Legumes are often grown with grasses in pastures to increase their protein content, and actually ruminants generally prefer forages high in protein. But how is forage preference affected when an increase in protein is accompanied by an increase in a toxic alkaloid? That’s exactly what happens when endophyte-infected tall fescue (TF-E+) is grown with alfalfa. Visiting scientist, Michael Friend, determined if sheep preferred TF-E+ grown near alfalfa (0.6 to 3 feet) (NEAR) or TF-E+ grown more than 15 feet away from alfalfa (FAR).

In his first experiment, lambs were offered a choice of freshly harvested TF-E+ NEAR and FAR for 12 days. Intake was measured each morning for one hour and at three more times during the day. As expected, NEAR contained more protein (8%) and the alkaloid ergovaline (360 ppm) than FAR (6% protein and 219 ppm ergovaline). Lambs preferred NEAR to FAR during the first hour of feeding, but not during feeding bouts later in the day.
In a second experiment, he examined the affect of odor on forage preferences by lambs. Lambs were offered TF-E+FAR in both feeders but one feeder contained the scent of freshly harvested alfalfa, the other the scent of freshly harvest TF-E+ FAR. Preference was greater for FAR with alfalfa scent than for FAR offered with FAR scent on two days of the eight-day experiment.

This research suggests that: 1) lambs initially preferred NEAR due to its higher protein content, but during the day the preference disappears due to the greater alkaloid content of NEAR compared to FAR, 2) olfactory cues influence preference, but to a lesser extent than the nutrients and alkaloids in TF-E+, 3) lambs adjusted their intake of forge and preference for forages during the day to balance their intake of nutrients and alkaloids.

Photo:  Thomas Hawk / Foter / CC BY-NC

Soil-Plant Relationships


Many livestock producers are using high-intensity livestock grazing to improve soils and plants in pasture. Andrea Clemensen has investigated how grazing and fertilization affects soil organic matter, nutrients, and microorganisms. Along with that, she also looked at amounts of nutrients and secondary compounds in alfalfa, birdsfoot trefoil, reed canarygrass, and endophyte-infected tall fescue.

Alfalfa contains saponins and birdsfoot trefoil contains tannins. Both plants fix nitrogen
improving pasture growth and the crude protein content of forage. Endophyte-infected tall fescue produces two types of alkaloids, those associated with the plant and those from a fungus that lives in the grass. Reed canarygrass contains eight alkaloids.These secondary compounds benefit the plant by reducing the need for pesticides and herbicides.

From 2009 to 2011, Andrea also examined how cattle grazing at high stock densities or hay production (no grazing) affects soils and plants growing in mixtures or monocultures. Trefoil samples were analyzed for condensed tannins, fescue samples anaylyzed for the alkaloid ergovaline, reed canarygrass samples for the alkaloid gramine, and alfalfa for saponins.

Finally, Andrea investigated how plants respond to nutrient inputs from animal impact by
applying commercial fertilizer, green manure and fecal manure to each of these forage species growing in monoculture.

Concentrations of secondary compounds varied during the growing season. Saponins in alfalfa ranged between 0.8% and 5%. Tannins in birdsfoot trefoil ranged between 0.8% and 8%. Saponins and tannins were lowest in May and highest in July. Alkaloids (ergovaline) in tall fescue ranged between 60 to 350 ppb with the lowest concentrations in May and the highest in August.

Concentrations of saponins or tannins in the legumes did not change when grown next to tall fescue. However, tall fescue growing near legumes had much higher concentrations of
ergovaline and crude protein than tall fescue growing in a monoculture.

Taking ‘Behave’ to the Classroom

By Jamie Keyes


Students listen as Beth talks about cattle learning to eat sagebrush.

Agricultural students gained more knowledge about rangeland nutrition this week after a two day presentation by Beth Burritt. The sustainable agricultural production systems’ class learned about the Behave principles and application techniques. Interested students asked multiple questions about winter feeding, biodiversity and the economics of it all.

“Beth is doing something very unique that a lot of ranchers don’t know about,” said Lyle McNeal, the USU class professor.

Calee Lott, a senior in the Plant, Soils and Climate Department, found the Behave doctrine very beneficial. She wished they had more time to learn about it.

“I want to be a range manager, so this is right up my alley,” Lott said.

McNeal invites Burritt to present every year.

“A lot of my students come from ranching families. This way they can get exposure, because it is a sustainable practice,” McNeal said.

To find out more information about the Behave principles, please visit our website!

Cattle soaking up the sun or finding the shade: The difference coat color makes

Cows in the shadeOn a warm sunny day, don’t you prefer to stand in the shade? Well, surprisingly some cattle don’t.

Apparently, whether or not a cow seeks out shade depends on its coat color. Four breeds of cattle, with four different coat colors were tested to see where they spent their time in the sun or the shade.

The percentage of time each breed spent in shade (standing and lying down) was: 89% for Angus (black), 81% for MARC III (dark-red), 57% for MARC I (tan), and 55% for Charolais (white). There was a direct correlation (R2 = 0.90) between absorption of solar load, by hair coat color and percent of time the heifers spent in shade. Providing shade alleviated heat stress by lowering body temperature, especially for black and dark-red colored cattle.

Reference: Gebremedhin, K.G. et al. 2011. Body temperature and behavioral activities of four breeds of heifers in shade and full sun. Applied Engineering in Agriculture 27: 999-1006.

Photo: Claudio.Ar / Foter / CC BY-NC-SA

Self-Medication on the Range

Self medication on the RangeAnimals adapt to changes in their environment and bodies not only through physiology changes that correct for deviation from homeostasis, but also by engaging in certain behaviors. Thus, a behavior like selecting a food containing a needed nutrient is no different than the secretion of insulin from the pancreas in response to rising blood sugar levels: both responses restore homeostasis. Behavioral homeostasis has been shown experimentally. Livestock modify their intake and diet selection to rectify nutritional imbalances. Besides balancing nutrient intake, herbivores are faced with other challenges such as disease. If behavioral homeostasis exists, then sick animals should self-medicate with substances that restore their health, even substances that contain no nutrients or could be potentially toxic at high levels like plant secondary compounds.

Parasitism is one of the greatest disease problems in grazing livestock. Controlling parasites with drugs is challenging, particularly in recent times due to the rise in drug-resistant internal parasites. Evidence suggests that parasitized apes use natural plant secondary compounds (PSC) as anti-parasitic agents. Can parasitized domestic sheep and goats also learn to use PSC? If the answer is yes, they could learn to self-medicate with PSCs and eat PSC-rich vegetation, either on rangeland or pasture, when needed, while having other nutritious and safe forages available to meet their nutritional requirements.

In a controlled experiment, lambs with parasites ate more of a supplement containing tannins than non-parasitized animals, even when the supplement was very low nutrients. In contrast, lambs without parasites ate more of the supplement without tannins than parasitized lambs.

In another study, lambs with and without parasites were given a choice of alfalfa and alfalfa mixed with 10% tannin. Lambs with parasites had a greater preference for alfalfa with tannins than lambs without parasites. These differences in preference did not exist before lambs with parasites experienced the positive effects of tannins or later after parasites were killed with drugs.

Collectively, the information above suggests herbivores are “aware” of the presence of parasites infecting their bodies. If herbivores are able to sense their parasitic burdens and if there are anti-parasitic substances in plants, which can potentially provide relief, then parasitized animals should increase their preference for such plants relative to healthy animals.

Besides being aware of their parasitic burdens, a second step of self-medication is that after eating or using a certain medicinal plant, herbivores should experience relief from the upset or discomfort caused by the parasites. Animals are more likely to learn about the benefits of a medicine when they experience illness or discomfort and then eat a medicine or plant that leads to recovery.

How is self-medication knowledge acquired? Individual foraging behaviors are mainly acquired by learning from social models, first from mother, then from peers, and from individual post-ingestive experiences. The spread of the self-medicative behavior within a group seems to be influenced by social models.

Juan J. Villalba and Serge Y. Landau. 2012. Host behavior, environment and ability to self-medicate. Small Ruminant Research 103:50-59
Photo: john shortland / Foter / CC BY

Eating to Protect the Rumen

Mixing quebracho tannins into feed rations has been proposed as a means to protect dietary protein from degradation in the rumen. Unfortunately, mixing tannins into a basal ration, even at low levels, may negatively affect some individuals. Supplementing tannins may be a better solution than mixing them in a basal ration. The objective of this study was to determine if voluntary intake of tannins by sheep would enhance nitrogen use.

Table 1
Experiment 1 is outlined in the table above. The high-protein (HP) basal diet was 22% crude protein (CP) with 17% rumen-degradable protein (RDP). The low-protein basal diet (LP) was 11% CP with 8% RDP.

Sheep fed the HP basal diet ate more than sheep fed LP basal diet in Period 1, but not Period 2. Sheep fed the HP basal diet and WB with tannin had lower amounts of blood urea nitrogen and rumen ammonia nitrogen than lambs fed the HP diet and plain WB.

A new group of sheep were used in Experiment 2. The design is outlined in table two. The HP basal diet was 19% CP and 16% RDP. The LP basal diet was 12% CP and 8% RDP. The supplement base in Exp. 2 was oat straw, which is much lower in CP and digestibility than the WB used in Exp. 1.Table 2a





Sheep fed HP and OS (oat straw) with tannin ate the greatest amount of the basal diet. They also had lower BUN concentrations than sheep eating HP basal diet and OS without tannin.

However, intake of OS with tannin was higher for sheep fed the LP than sheep fed HP basal diets. When given a choice, preference for the tannin-containing food tended to be greater for sheep fed HP than those fed LP.

Tannin supplements have the potential to reduce rumen ammonia nitrogen and blood urea nitrogen in sheep, even after eating high-N diets and offered low-quality supplements.

Fernández, H.T., F. Catanesea, G. Puthoda, R.A. Distel, and J.J. Villalba. 2012. Depression of rumen ammonia and blood urea by quebracho tannin-containing supplements fed after high-nitrogen diets with no evidence of self-regulation of tannin intake by sheep. Small Ruminant Research 105:126–134.

Barnyard animal furthers cure research for Huntington’s disease

By Jamie Keyes

Smart sheepSheep have a bad reputation for not being the smartest animals in the barnyard, but research has shown that reputation may be false.

In the past, monkeys and rodents have been the experimental animal of choice for cognitive function research, but why not sheep? In 2010, the Department of Pharmacology at the University of Cambridge, decided to experiment with sheep. According to their research article Executive Decision-Making in the Domestic Sheep, sheep have a good memory and, not surprisingly, have never been used to research the cognitive functioning system. Sheep are also less temperamental than monkeys. Trials using sheep can be conducted more quickly (three weeks versus several months) than those using monkeys.

In a 21 day study, sheep were placed in a pen with two passage ways. At the end of each passage was a correct or incorrect choice, a bucket full of pellets or an empty bucket. As the experiment went on, the choices become progressively more difficult. Changing color of the buckets, different shaped objects in the way and switching the correct passageways challenged sheep to make the right decision that led them to pellets.

Even with all the obstacles, the study discovered the sheep were able to learn the difference between correct and incorrect choices. They were able to discriminate between passages, and showed irritability if a wrong decision was made.

The study concluded that “sheep have great potential, not only for use as a large animal model of HD (Huntington’s disease), but also for studying cognitive function and the evolution of complex behaviors in normal animals.”

Alzheimer’s and Huntington’s disease are known for disrupting the cognitive functioning system. Now, through research, sheep can contribute a way to the cure.

Morton AJ, Avanzo L (2011) Executive Decision-Making in the Domestic Sheep. PLoS ONE 6(1): e15752. doi:10.1371/journal.pone.0015752

Photo: Bob Jagendorf / Foter / CC BY-NC

Digestion Trials with Fresh Forage

alfalfaBased on our previous experiments, Jake Owens designed a digestibility study to investigate how eating alfalfa or birdsfoot trefoil (BFT) before eating endophyte-infected tall fescue (TF) or reed canarygrass (RCG) might benefit livestock compared to livestock eating only tall fescue or RCG alone.

Trial 1: Lambs were offered alfalfa for 30 min then offered either TF or RCG for 3.5 h. In this study, fresh forage was cut and offered to each animal. Lambs ate more food, nitrogen, and energy when they ate alfalfa before eating TF or RCG compared to lambs fed only tall fescue or RCG. But eating alfalfa reduced the amount of TF and RCG compared to animals that did not receive any alfalfa.

Trial 2: Trial 2 used a new group of lambs and was similar to Trial 1 except lambs were fed BFT prior to receiving TF or RGC. Lambs fed BFT ate slightly less RCG, but much more TF than animals that did not receive BFT.

Overall, lambs ate less BFT than alfalfa, but lambs that ate BFT ate much more TF than lambs fed alfalfa. In both studies, feeding two forages had no affect on the digestibility of any of the forages.

The enhanced intake of TF by lambs fed BFT, as well as the greater nutrient intake by lambs fed a legume and a grass is likely due in part to complementary profiles of alkaloids, saponins, and tannins.

Owens, J., F.D. Provenza, R.D. Wiedmeier, and J.J. Villalba. 2012. Supplementing endophyte-infected tall fescue or reed canarygrass with alfalfa or birdsfoot trefoil increases forage intake and digestibility by sheep. J. Sci. Food Agric. 92:987-992.

Photo:  International Livestock Research Institute / Foter / CC BY-NC-SA