Synthesis Paper: Targeted Livestock Grazing: Prescription for Healthy Rangelands

Targeted livestock grazing is a proven tool for manipulating range land vegetation, and current knowledge about targeted livestock grazing is extensive and expanding rapidly. Targeted grazing prescriptions optimize the timing, frequency, intensity, and selectivity of grazing (or browsing) in combinations that purposely exert grazing/ browsing pressure on specific plant species or portions of the landscape. Targeted grazing differs from traditional grazing management in that the goal of targeted grazing is to apply defoliation or trampling to achieve specific vegetation management objectives,whereas the goal of traditional livestock grazing management is generally the production of livestock commodities. A shared aim of targeted livestock grazing and traditional grazing management is to sustain healthy soils, flora, fauna, and water resources that, in turn, can sustain natural ecological processes (e.g., nutrient cycle, water cycle, energy flow). Targeted grazing prescriptions integrate knowledge of plant ecology, livestock nutrition, and livestock foraging behavior. Livestock can be focused on target areas through fencing, herding, or supplement placement. Although practices can be developed to minimize the impact of toxins contained in target plants, the welfare of the animals used in targeted grazing must be a priority. Monitoring is needed to determine if targeted grazing is successful and to refine techniques to improve efficacy and efficiency. Examples of previous research studies and approaches are presented to highlight the ecological benefits that can be achieved when targeted grazing is applied properly. These cases include ways to suppress invasive plants and ways to enhance wildlife habitat and biodiversity. Future research should address the potential to select more adapted and effective livestock for targeted grazing and the associated animal welfare concerns with this practice. Targeted livestock grazing provides land managers a viable alternative to mechanical, chemical, and prescribed fire treatments to manipulate range land vegetation

Synthesis Paper: Targeted Livestock Grazing: Prescription for Healthy Rangelands

Targeted livestock grazing is a proven tool for manipulating rangeland vegetation, and current knowledge about targeted livestock grazing is extensive and expanding rapidly. Targeted grazing prescriptions optimize the timing, frequency, intensity, and selectivity of grazing (or browsing) in combinations that purposely exert grazing/browsing pressure on specific plant species or portions of the landscape. Targeted grazing differs from traditional grazing management in that the goal of targeted grazing is to apply defoliation or trampling to achieve specific vegetation management objectives, whereas the goal of traditional livestock grazing management is generally the production of livestock commodities. A shared aim of targeted livestock grazing and traditional grazing management is to sustain healthy soils, flora, fauna, and water resources that, in turn, can sustain natural ecological processes (e.g., nutrient cycle, water cycle, energy flow). Targeted grazing prescriptions integrate knowledge of plant ecology, livestock nutrition, and livestock foraging behavior. Livestock can be focused on target areas through fencing, herding, or supplement placement. Although practices can be developed to minimize the impact of toxins contained in target plants, the welfare of the animals used in targeted grazing must be a priority. Monitoring is needed to determine if targeted grazing is successful and to refine techniques to improve efficacy and efficiency. Examples of previous research studies and approaches are presented to highlight the ecological benefits that can be achieved when targeted grazing is applied properly. These cases include ways to suppress invasive plants and ways to enhance wildlife habitat and biodiversity. Future research should address the potential to select more adapted and effective livestock for targeted grazing and the associated animal welfare concerns with this practice. Targeted livestock grazing provides land managers a viable alternative to mechanical, chemical, and prescribed fire treatments to manipulate rangeland vegetation

Ecological Implications of Flavor Generalization by Sheep: Role of Flavor Intensity and Variation in Toxin Dose

Researchers studying diet selection of ungulate herbivores have generally considered plant palatability independent of animals\u27 dietary history. However, more recent studies demonstrate that experiences within the life of an animal strongly influence plant selection. We are beginning to understand how food preferences and aversions are formed through gastro-intestinal feedback. My research specifically examines factors that influence the formation of conditioned flavor aversions in the generalist herbivore, sheep. I first examined how variability of food toxicity affects the intake of those foods. I determined that sheep apparently have several mechanisms for regulating intake of toxic foods regardless of whether or not toxic variation can be detected through flavor changes. When changes in flavor correspond to changes in toxicity, animals adjusted intake based on an increase or decrease in toxin concentration. When toxic variation was not detectable through flavor, animals adopted a conservative strategy of eating an amount based on the maximum toxin dose they had experienced.\u27 I was also interested in how illness following the consumption of one food influences the selection of other foods. In diet selection, animals may generalize selection responses among foods with similar flavors. Generalization may be particularly important in the selection of novel foods, i.e., a new food may look, smell, or taste like a familiar food that is preferred or avoided. In several experiments on the generalization of flavor aversions I found that: 1) sheep generalize aversions from familiar to novel foods when both foods had a flavor in common; 2) the more sick an animal got after eating a food the greater the aversion formed to the food and the greater the generalization of that aversion to new foods; 3) the salience or intensity of flavor did not affect the strength of conditioned flavor aversions in sheep on the generalization of the aversion, but this may not always be the case; 4) flavor intensity strongly influenced the acceptance of a novel food. A novel food (wheat) with a strong flavor (3% added ground oregano) was more avoided than a novel food (wheat) with a mild flavor (1% oregano added)

The Effect of Flavor Concentration and Toxin Dose on the Formation and Generalization of Flavor Aversions in Lambs

If an animal experiences gastrointestinal malaise after eating a novel feed, it develops a dislike for the feed called a conditioned flavor aversion (CFA). Understanding flavor aversions is important for diet-training procedures, understanding animal responses to poisonous plants, and preparing animals for new foraging environments. Our research objectives were to determine how variation in 1) flavor concentration (oregano) and 2) dose of gastrointestinal toxin (lithium chloride; LiCl) affected the establishment of CFA in lambs. In a series of experiments feeding lambs ground grains mixed with oregano, we examined how the formation of a CFA to one ground grain, with or without oregano, influenced the consumption of another oregano-flavored grain. We determined that 1) the higher the toxin dose, the stronger the CFA, the greater the generalization of the CFA to a similar feed, and the greater the avoidance of a novel feed; 2) lambs generalized aversions from familiar to novel feeds when both feeds had a flavor in common; and 3) the concentration or intensity of feed flavor apparently did not affect the acquisition or generalization of a CFA, but it did influence the acceptance of a novel feed. Our findings suggest that flavor aversions may be important in the acceptance of harvested or processed feeds

Understanding Landscape Use Patterns of Livestock as a Consequence of Foraging Behavior

Many grazing-management challenges stem from poor livestock distribution resulting in overuse of some areas and low utilization of others. Managing livestock-distribution patterns requires knowledge of pasture characteristics and animal behavior patterns. Behavioral patterns result from recognizable processes that include inherited attributes, individual and social learning systems, cue-consequence specificity, predispositions toward novel stimuli, and spatial memory. Through these behavioral mechanisms, animals form and revise preferences and aversions for specific locations in their foraging landscape. To accomplish habitat selection, domestic herbivores use sight and sound cues to seek and return to high-quality foraging locations. Nested within habitat selection are learned diet preferences and aversions by which ungulate herbivores associate taste with positive or negative postingestive feedback. The deliberate and careful modification of animal attributes and habitat characteristics could yield options for adaptive rangeland management. In this article, we describe the basic principles that underlie how animals make decisions about where to forage and how long to stay in a particular habitat. We also suggest management practices designed to modify animal behavior and alter habitat-use patterns. The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 2020Legacy DOIs that must be preserved: 10.2458/azu_rangelands_v58i2_hower

The Evolving Role of Women as Rangeland Educators and Researchers in Colleges and Universities and in the Society for Range Management

On the Ground • In the last 30 years, women have increased in SRM membership percentage, which appears to have paralleled the number of women hired into academic positions and women entering the discipline. • Although the history of women as SRM members and rangeland educators is relatively short, the increase seems to reflect that of related disciplines. • Gender demographic changes have increased diversity within the SRM and many academic institutions, enhancing what each offers. • Disproportionately fewer women receiving recognition and advancing to leadership positions within SRM or higher ranks within academia may reflect opportunities for the range profession to address.The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202

Learning and Memory in Grazing Livestock Application to Diet Selection

When you think of intelligent animals, a cow or sheep is probably not the first creature that comes to mind. With respect to grazing, however, livestock are smart. Researchers consistently report that livestock select diets more nutritious than if they foraged at random (Arnold and Dudzinski 1978). However, scientists disagree on how livestock know which foods are nutritious or toxic. Some traditional theories suggest that animals are born knowing what to eat and do not need specific learning experience. These theories suggest that diet selection is inflexible and stereotypic. Range scientists have been reluctant to replace these traditional theories with concepts that depend upon animal learning and experience. However, many successful management practices which ranchers have been using for decades are based on the assumptions that livestock learn and remember the plants they eat. For example, many ranchers select replacement heifers from their own herd because they know the range better than heifers purchased from outside herds. Most managers realize that livestock deaths from poisonous plants generally increase when animals are not familiar with a particular plant, such as when livestock graze new pastures. A few savvy ranchers even wean animals on the same feed used for creep feeding because the calves seem to recognize the feed, eat more of it, and gain weight more quickly

Can Plants Practice Mimicry to Avoid Grazing by Mammalian Herbivores?

Mimicry has been suggested as a grazing avoidance mechanism for plants. This study examined the ability of a mammalian herbivore to generalize conditioned flavor aversions (CFAs) to determine if the conditions for plant mimicry exist. Nine sheep (treatment group) were averted to cinnamon on ground rice while an additional 9 sheep (control group) received cinnamon on rice with no negative post-ingestive consequences. When offered a choice between wheat and cinnamon-flavored wheat the control group ingested more (P \u3c 0.05) cinnamon-flavored wheat (45 ± 6%) than did the treatment group (3 ± 1%) in four test periods. This implies that herbivores generalize CFAs and thus non-poisonous plants could mimic the flavor of poisonous plants to avoid grazing. Next, the animals were given a choice between soybean meal (SBM) in a food box which smelled of cinnamon and SBM in a food box with no added odor. The treatment group ate less (P \u3c 0.05) SBM with cinnamon odor than did the control group in the first test period (13 ± 10% vs 58 ± 11%). However, the following three periods revealed no intake differences between control and treatment animals. This suggests that odor alone is not persistently effective in preventing herbivory by sheep, but that both taste and odor must be similar for one plant to successfully mimic another

Foraging on the Edge of Chaos

The foraging behavior of herbivores may appear to be little more than the idle wanderings of animals in search of food and a place to rest. A closer look reveals a sophisticated process by which herbivores survive in a tremendously complex, dynamic, and unpredictable habitat. How do creatures of habit, survive in a world where the only certainty is change? Most do fairly well despite the difficulties they encounter. These predica- ments arise because climate, soils, plants, herbivores, and people are interrelated facets of a dynamic system. Con- tinuous change demands that each component of the system continually react and adapt. This dynamic mi- lieu causes problems for individuals which are inflex- ible but, adaptive behavioral processes can turn nature from an adversary to an ally. Animals face several challenges in selecting foods and habitats in which to live. How animals cope with change, make foraging decisions, and overcome dilem- mas they encounter illustrate behavioral processes as old as life. Understanding that variety is the spice of life and that adaptive behaviors allow old dogs to learn new tricks, can give natural resource managers new tools to help animals deal with dynamic environments and cre- ate more desirable environments. In short, understand- ing the behavioral processes that allow animals to deal with their daily foraging crises, can help us to bett

Prescription Grazing for Rangeland Weed Management

The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform March 202