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Syndromic Surveillance Program

Syndromic Surveillance Program

We live in a global world where humans, animals, plants, insects, bacteria, viruses are free to move from one part of the world to another every day.  This movement can result in animal health syndromes to appear in a geographic area that has never experienced an outbreak before or release isolated cases to the rest of the world.  The Syndromic Surveillance Program was developed as an early detection system when a large-scale release of a biologic agent occurs.  Once an outbreak is detected by a medical professional or veterinarian, Syndromic Surveillance helps determine the size, spread, and tempo of an outbreak or provide reassurance that a large-scale outbreak is not occurring.

Learn more about Syndromic Surveillance:

Diseases & Emerging Diseases

Diseases & Emerging Diseases

Domestic livestock in open rangeland environments can be exposed to a number of diseases.  This section will focus on diseased found in range animals in extensive environments and highlights diseased that could be transferred between wildlife and livestock. 

Livestock Diseases:

Anaplasmosis 

Anaplasmosis (also called yellow bag or yellow fever) is an infectious disease in livestock caused by several species of the blood parasite Anaplasma.  Symptoms of Anaplasmosis include: anemia, fever, weight loss, breathlessness, jaundice, uncoordinated movements, abortion, and sometimes death (more prevalent in cattle 3 years of age or older).  Treatment is most effective if given in the early stages of the disease.

Bovine Babesiosis

Bovine Babesiosis (principle strains include Babesia bovis and Babesia bigemina) is a tick-borne disease that is transmitted from mother to calf. Symptoms of Babesia bovis: fever, anorexia, neurological signs (uncoordination, teeth grinding, and mania), dark colored urine.  Symptoms of Babesia bigemina: fever, anorexia, haemoglobinuria/anemia dark colored urine, lesions, and reluctance to move/separation from the herd.  Treatment is most effective if given in the early stages of the disease and cattle with mild cases of the disease may recover without treatment.

Brucellosis

Brucellosis (also called contagious abortion or Bangs disease) is an infectious reproductive disease caused by bacteria Brucella.  It is commonly transmitted by contact with infected birthing tissue/fluids or other bodily fluid.  There is no effective way to detect infected animals by their appearance, but symptoms of brucellosis include: reduced fertility, poor conception rates, abortion, weak and unhealthy calves (at time of birth or later in life), altered milk production, increased risk of uterine infection (due to retention in afterbirth), and enlarged and arthritic joints.  A vaccine is available and highly effective when administered to female calf when young.

Cancer eye

Cancer eye is skin cancer occurring on the eye or eyelid and is the most common form of cancer in cattle. Cancer eye mainly occurs in older cattle with unpigmented eyelids and eyeballs.  Cancer eye growths can occur on the eyeball, eyelid or third eyelid.  All eye cancers develop from precursor lesions including: plaque (a slightly elevated, flat, opaque area on the eyeball), papiloma (a wart-like growth protruding from the eyeball), keratoma (a horn-like projection attached to the eyelid), and a small ulcer on the eyelid.  Surgery to remove small lesions is needed in the early states to prevent and treat cancer eye.

Blackleg

Blackleg is one of several diseases caused by Clostridium bacteria and occurs when these bacteria enter the body through cuts, abrasions or ingestion. Blackleg tends to develop in young cattle most typically ranging in age from 6 months to 2 years. Prognosis in cattle diagnosed with blackleg is poor, often the first sign of the disease is death. Other symptoms of blackleg include: muscle trauma, rapid progression of gangrene, severe lameness, fever and eventual death. While the disease is infrequent in the United States, a vaccine does exist although treatment success is rare, therefore preventative measures are encouraged.

  • Blackleg - The Merck Veterinary Manual 

Foot and Mouth

Foot and mouth disease is a highly contagious and severe viral infection affecting ruminant animals around the globe. Foot and mouth causes hardship and production losses for farmers and ranchers and results in serious impacts to the livestock trade and economy due to the highly infectious nature of this disease. Foot and mouth is spread when animals come into physical contact with the virus.  All secretions and excretions from infected animals can contain the virus, as well as contaminated facilities, contact with contaminated people or equipment, drinking contaminated water, etc. Symptoms of foot and mouth include: fever and blisters of the mouth, feet, and udder. Discomfort from the blisters leads to a decline in milk production, anorexia and weight loss, excessive salivation, lameness, and reluctance to stand or move. Animals infected with foot and mouth will typically recover if given enough time, however the disease results in weak and unproductive animals, therefore infected animals are usually culled. 

Pink Eye

Pink eye is an inflammation and/or ulceration of the eye usually caused by the bacterium Moraxella bovis. The infection is spread through discharge from the infected eye by flies or discharge left behind by grazing animals. Signs of pink eye in cattle are: abundant watery eye discharge, sensitivity to sunlight, reddening or swelling of the eyelids, cloudy iris, and corneal ulceration. Typically, most cattle recover within 3-5 weeks after infection without treatment. If severe cases are left untreated, pink eye may lead to rupture of the cornea and permanent blindness.

Leptospirosis

Leptospirosis (commonly known as “Lepto”) is a contagious disease that affects both cattle and humans. While there are many different strains of Leptospirosis, the strains that primarily affect cattle are Leptospira hardjo-bovis, Leptospira pomona, and Leptospira grippotyphosa. Lepto is a common problem in the South particularly in herds that are not vaccinated or in cattle that are closely confined. The disease spreads when urine from infected cows comes into direct contact with eyes or mucous membranes in the nose and mouth. Symptoms of Lepto include fever, bloody urine, drop in milk production, low-grade uterine infections, repeat breeding, abortion, mastitis, and occasionally systematic infection can result. Vaccination of calves at weaning and annual boosters in adult cattle is effective in preventing Leptospirosis infection.

Animal Management

Animal Management

Animal management deals with a wide variety of issues related to caring for domestic livestock including: economic, environmental, community aspects, feed supplementation, large animal nutrition needs.

Learn more about Feed Supplementation and Animal Diet and Behavior:

Supplemental Feeding of Livestock on Rangelands

Written by Rachel Frost and Jeff Mosley, Montana State University

Under certain conditions, livestock grazing western rangelands are not able to consume enough nutrients from forage alone to meet their nutritional requirements. At these times, supplementary nutrients are often provided to maintain production levels. Supplementation is one of the biggest expenses of range livestock production, accounting for up to 70% of the operation's total variable expenses. Providing the proper supplements in the correct amount and at the appropriate time can save producers money and conserve forage resources.

Determining the proper supplementation program requires livestock managers to know the following:

  • nutritional requirements of the grazing animal
  • nutrient content of the forage
  • cost of supplementation and expected benefits

The decision to provide a supplement should be based on forage supply, protein content, and animal body condition.

Basic Ruminant Nutrition

Ruminants differ from pigs and humans in their ability to digest fibrous plants because they have a rumen that allows for fermentation before the food enters the abomasum (stomach) of the animal. The rumen houses microorganisms that are capable of breaking down cellulose through fermentation. These microorganisms break down consumed feedstuffs for their own nutritional requirements and in return release volatile fatty acids that are a major energy source for ruminants. The microorganisms eventually die, and their bodies pass into the small intestine, where they are digested and contribute to the protein supply of the animal. This symbiotic relationship, while essential, also adds to the complexity of predicting and effectively meeting the nutrient requirements of ruminant animals.

Relationship of Protein and Energy within the Ruminant

Ruminants need the microorganisms to "unlock" the energy in forage, allowing them to harvest and make use of cellulose that is unavailable to non-ruminants. The existence and growth of microorganisms depends on an adequate supply of nitrogen, primarily found in protein. Supplementing ruminants with protein increases the number and activity of microorganisms in the rumen, which improves forage digestion and increases passage rate and intake of forages. Increasing forage intake improves energy availability; therefore, correcting a protein deficiency is generally the first supplementation priority.

Types of Protein Supplements

Escape protein does just what its name implies and escapes digestion in the rumen. It travels to the small intestine where it is broken down and used directly by the animal. Escape protein can be important to the ruminant because any rumen degradable protein that is not consumed by the microbes can be lost through the urine. However, when animals are consuming low-protein forages, as is often the case on rangeland, then a supplemental protein source is required to stimulate rumen microbial activity and encourage forage intake. For cattle consuming low protein forage, 60 to 70% of the supplemental protein should be ruminally degradable.

Mineral Nutrition: Are Animals Nutritionally Wise? 

Early studies on nutritional wisdom focused on the innate ability of livestock to balance minerals in their diet. From these studies, nutritionists concluded that livestock are unable to consume minerals in correct quantities to prevent or correct mineral deficiencies and therefore are not nutritionally wise. However, many of the assumptions nutritionists held about diet selection are questionable if one considers that animals have to learn about foods before they can make correct choices. This fact sheet lists the assumptions implied by nutritional wisdom studies and alternative explanations about how animals learn about foods and nutrients, including minerals.  Read more here.

Experiences Early in Life Affect the Structure of the Body

Why do animals eat certain foods and live in certain locations? Every animal is born with a set of genes that determines how they look and what they need to survive, but genetics is only part of the story. As an individual grows, its body and physiology are shaped by experiences early in life. Changes within the body enable animals to adapt and thrive in a variety of environments. This fact sheet discusses how experiences early in life can shape an animal’s physiology, neurology, and morphology. Read more here.

Palatability More Than a Matter of Taste

Why do you like certain foods? Most people would say because they taste good, but research shows that palatability is much more than a matter of taste. Palatability is the interrelationship between a food’s flavor and its nutrient and toxin content. Palatability also depends on the nutritional needs of the animal and its past experience with the food. This fact sheet discusses in depth how animals learn which foods to eat and avoid, and what makes a plant palatable.  Read more here.

Preparing Animals for Moving Day 

We often buy and sell animals and move them to unfamiliar environments without considering where they were raised or their previous dietary experience — and then wonder why they don’t perform well. An animal’s performance depends on the amount and type of experience it has with the environment in which it is expected to forage. When bringing animals into a new area, managers can help ease the transition by: 1) selecting animals from areas similar to where they will be expected to graze, 2) introducing animals to foods they will encounter at new locations, 3) providing familiar foods at new locations, and 4) providing appropriate role models. This fact sheet discusses factors to consider when moving livestock to new environments.  Read more here.

Behavior Depends on Consequences

Understanding animal behavior is simple. All behavior is based on consequences. When an animal engages in a behavior, if the consequence of that behavior is positive, then the likelihood the animal will repeat that behavior increases. However, if the consequences are negative, then the likelihood the behavior will be repeated decreases. This fact sheet explains how behavior by consequences works to shape animal behavior and the pros and cons of shaping behavior with positive or negative consequences.  Read more here.

Mother Knows Best 

Young livestock and wildlife learn what to eat and where to live based on interactions with their mothers. Young animals learn about foods in the womb prior to birth, from mother’s milk, and through interactions with mom while grazing. This fact sheet discusses the importance of mother on the dietary and habitat preferences of grazing livestock and wildlife. Understanding that experiences early in life shape these preferences can enable managers to shape animals to be more productive on rangelands.  Read more here.

Role of Learning in Diet Preferences 

Herbivores forage in a complex environment. How do they learn which foods are nutritious and which foods are toxic or low in quality? Herbivores begin learning about what foods are safe before they are even born and continue the process throughout their life enabling them to survive in a world where toxin and nutrient levels of forages are constantly changing. These same processes allow them to make foraging decisions when they are moved to new pastures with unfamiliar foods.

Mom as a Role Model

A young animal first learns about which foods to eat and which to avoid by foraging with its mother. By the time the animal has to forage on its own, it is already familiar with a number of plants that are nutritious and safe to eat. Thus, an animal divides its foraging world into two food groups, familiar and novel. Animals learn through trial and error about novel foods based on the postingestive consequences of the novel foods they eat.

Novelty

Like most people, herbivores sample novel foods cautiously. If the consequences of eating the food are positive--feedback from needed nutrients---the animal will increase intake of the new food. If the consequences are negative --illness from toxins or lack of feedback because the food is low in nutrients--the animal will decrease intake of the food. When eating a meal of several foods, novelty is the key to figuring out which foods are harmful and which are nutritious. When animals eat a meal of several familiar foods and a novel food and then experience illness, they subsequently avoid the novel food. Conversely, when animals suffering from a nutritional deficiency recover after eating a meal of several familiar foods and a novel food, they learn to prefer the nutritious novel food. Herbivores also reduce intake of familiar foods when the flavor of the food changes. Changes in flavor may occur when forages grow on different sites or as plants mature. If the change in flavor results in illness, the animal avoids the food in the future. If, however, the change in flavor results in positive consequences then the animal will continue to eat the food.

Prior illness

Herbivores continuously sample foods, even foods that made them ill. If an animal gets sick after eating a meal of several familiar safe foods and food that caused illness in the past, subsequently it will avoid the food that caused illness. Animals are able to remember which foods previously made them sick for a long time.

Generalization

Animals use past experiences with familiar foods to make foraging decisions about new foods. If new foods have flavors simliar to foods that made the animal ill in the past, it is less likely to eat those foods. Conversely, if new foods have flavors similar to familiar nutritious foods, animals ingest those foods more readily.

Amount and timing

If the foods an animal eats during a meal are equally unfamiliar and the animal experiences illness, how does the body determine which food to avoid? Animals pair feedback--positive or negative--with the food they ate in the greatest amount, provided both foods are equally new. Animals also form aversions to or preferences for foods when food ingestion is quickly followed by either illness or positive postingestive signals, provided the foods are equally familiar to the animal.

Salience

At one time researchers thought animals formed aversions to certain strong flavors more readily than others. They referred to these flavors as salient. Bitter, for example, was thought to be a salient flavor because many toxic compounds are bitter. Further study indicated that the response the scientists observed was simply due to novelty. When animals are reared on bland foods and get sick after eating a meal of several foods, one of which has a strong novel flavor, they form an aversion to the food with the strongest flavor. If, however, they are reared on foods with strong flavors and get sick after eating a meal of foods with strong familiar flavors and a novel bland food, they form an aversion to the bland food. Thus animals associate illness with novelty not necessarily with strong flavors.

Animals depend on the availability of familiar foods to make correct foraging decisions. When animals are moved to new foraging locations that contain only novel foods, it is more difficult for them to select safe nutritious foods and to avoid toxic foods. Understanding how animals discern safe from harmful foods is important information managers can use to help animals make transitions to new locations or train animals to eat new foods.

Adapted from: BEHAVE

Learning About Foods and Locations

Animals learn which foods to eat by interacting with mother and herd mates, but in most cases they only continue to eat foods that provide nutritional or medicinal benefits. They can also learn about their physical environment and tend to live in areas that are safe. However, the body is designed to learn about foods and locations differently. This fact sheet discusses how animals learn about safe and harmful foods and locations. Understanding these differences is essential for managers who want to change animal behavior. Read more here.

Diet Mixing: Increasing Intake of Unpalatable Plants

Animals can learn to eat unpalatable plants and to mix palatable and unpalatable plants in their diets. The nutritional composition of an animal’s diet affects how much of these unpalatable plants animals can eat. Read more here.

Training livestock to avoid specific forage 

Livestock can be trained to avoid plants by creating a food aversion using the drug lithium chloride. They can be trained to avoid poisonous plants that are problematic on rangelands. They can also be trained to avoid agronomic plants such as grapevines and fruit trees to allow livestock to graze for weed control in vineyards and orchards. Read more here.

Can Cows Eat Snow to Meet Water Requirements?

Written by Jim Keyes - Utah State University Extension Area Animal Scientist

When winter hits and temperatures drop below freezing, it becomes harder to keep a fresh water supply for cattle grazing on range. It can be difficult to access areas to cut ice and open reservoirs or to haul tanks of water.

Many wonder if cows can eat snow in the winter to supply all their water needs. The answer is yes. There are many situations where cattle can survive on snow without having any other water supply. Many ranches throughout the West and Midwest with cattle on large pastures and few or no water resources depend entirely on snow for winter grazing. 

Just turning cattle loose on the snow sounds like a very simple management technique, but it requires that ranchers pay very close attention to the animal’s body condition and general health.

Several studies have shown there is no reason to expect cattle performance to deteriorate when animals use snow for water. Researchers found cows using snow for water did not differ in live weight amount of body fat compared to cows receiving water. 

Another study evaluated the effects of snow as a water source on milk yield and calf growth. A group of pregnant beef cows were provided only snow as a water source.

A similar group of cattle were given access to heated water.  Cows eating snow consumed between 30 and 40 pounds of snow per day to meet their water needs. Cows with access to water drank 2 to 3 gallons, but also ate 7 to 25 pounds of snow. In the end, there was no difference in average milk yield or body weight between the two groups of cattle or the calves they produced. 

Research in Montana showed when cattle have access to water and snow, 2% of cows never drank any water, and only 65% drank water every day. The other 33% drank every second or third day while eating snow the rest of the time. There was no visible difference in the appearance of any of the animals.

When using snow as the only water source, several points should be considered:

  • Thin cattle (Body Condition Score of 3 or less) should not be forced to depend only on snow.  Cattle should have at least a BCS of 4 and should be in good health.
  • An alternate water source must be available in case conditions change and there is not enough snow to meet the herd’s water needs.
  • Snow must be clean and accessible. Ice crusted, wind-blown or trampled snow is not adequate. It takes approximately 4 inches of snow to get a half-inch of water.
  • Make certain feed intake does not decline. A mature cow will eat 2.5 percent of her body weight on each day. Reduction in feed intake may mean insufficient water intake.
  • Eating snow is a learned behavior. It can take some cows 4 or 5 days to learn the technique. It’s always best to put inexperienced cows with herd mates that have experience using snow as a water source.

Cows can survive and do very well using snow as their only source for water. Ranchers can use pastures without water, increase the length of the grazing season, and save money by not having to provide water during times of snowfall. It is imperative, however, to continually monitor the feed intake and the body condition score of the cows. 

Prevention of Toxic Plant Ingestion

Prevention of Toxic Plant Ingestion

The best way to prevent livestock losses due to poisonous plants is to prevent animals from eating too much of a particular poisonous species.  This may be challenging because livestock often graze on large landscapes with a large variety of species and it is highly difficult to keep livestock away from a particular poisonous plant.  Rather than eliminate contact with all poisonous plants, a more realistic strategy is to minimize the possibility of a large-scale livestock losses due to poisonous plants.

Guidelines and strategies that help protect livestock:

  • Be able to identify poisonous species that grow in your area.  Plant identification is critical for planning and preparation.
  • Understand the conditions (i.e. temperatures, precipitation) that --Learn the conditions under which these plants can be dangerous to your livestock.
  • Create a grazing strategy that limits the time livestock spend in an area that has poisonous species.  Be aware that the timing of the grazing period may put livestock at risk.
  • Avoid moving overly hungry or stressed animals into an area where there is a large number of poisonous plants.
  • Ensure livestock have a sufficient quantity of water, salt and other supplements.
  • If poisonous plants are contained in a small area, treat undesirable species with herbicide or other eradication method.
  • Watch newly introduced animals carefully when poisonous species are present.
  • If livestock becomes sick, contact a veterinarian for diagnoses and to obtain treatment. 

Training Livestock to Avoid Specific Forage - Sometimes a single plant prevents managers from grazing livestock in an area with good forage production. Often the plant has high agronomic value, like fruit trees, Douglas fir trees or grapevines. Livestock could easily graze fruit orchards, forest plantations or vineyards, improving fruit harvest and tree growth, if only they could be persuaded not to eat the trees or vines. In such cases, the key is to train livestock to avoid the food.

There are very few treatments for livestock that ingest poisonous plants. Majority of poisonous plants have no known treatments for toxic exposure.  When a treatment is known, exposed livestock are regularly in isolated locations and are often not located in time to apply the proper treatment.  If an animal survives the initial exposure to a poisonous plant and begins to recover, treatment should aim to address symptoms (except in the case where a known treatment is available).

Poisonous Plants on Rangelands

Poisonous Plants on Rangelands

Poisonous plants are a major cause of economic loss to the livestock industry. Each year poisonous plants adversely affect 3-5% of the cattle, sheep, and horses that graze western rangelands.

There are many causes of livestock losses including if: 

  • Animals graze infested rangelands when plants are most toxic.
  • Animals are driven, trailed through, or unloaded from trucks onto rangeland or pasture areas infested with poisonous plants.
  • Animals are not watered regularly or are allowed to become hungry, making them more likely to eat lethal quantities of poisonous plants.
  • Animals are allowed to graze in heavy stands of plants that are highly poisonous.
  • Animals are grazed on rangelands early in the spring when there is no other vegetation except poisonous plants.

Explore more resources about Poisonous Plants on Rangelands:

Poisonous Plants – USDA ARS

Rangelands Plant Terminology & Basic Plant Identification

Rangelands Plant Terminology & Basic Plant Identification

Maintaining a healthy forage resource is vital to the ecological and economic sustainability of rangelands. The goal of forage management is to find an acceptable balance between forage yield and forage quality, while allowing the forage plants to stay healthy and vigorous following grazing or harvest. Yield and quality cannot be maximized simultaneously, and different management strategies are required to optimize these two factors separately. Forage yield (tons per acre, animal unit months) and plant persistence are usually maximized when plants are harvested at mature stages of growth. Forage quality, however, is usually highest when plants are harvested in a young, leafy stage of growth, at which point forage will be high in protein and digestibility and low in fiber. The challenge is to manage both forages and livestock to optimize forage yield, quality, and persistence as well as animal performance, health, and reproductive capabilities.

Learn about rangeland plant terminology: 

Learn more about Key Rangelands Plants:

Types of Plants

  • Grasses are plants with jointed stems. The stems are normally hollow between the joints (node). Leaves are in two rows on the stem. Veins in the leaves are parallel. Grasses are generally the most important and abundant kind of range plant for grazing animals.
  • Forbs are broad-leaved plants with aboveground growth that dies back each year. Most forbs have net veins in the leaves, but a few have parallel veins. Broadleaf weeds and wild flowers are examples of forbs.
  • Grass-like plants look like grasses but have solid, though not hollow, stems without joints. Stems may be triangular. Veins in the leaves are parallel. Sedges and rushes are in this group of plants.
  • Trees and shrubs are plants with persistent woody stems that live from one year to the next. Shrubs have stems that branch from near the base, while trees have a definite trunk and are usually bigger than shrubs. Some plants can take on a shrub or tree growth form, depending on environmental conditions.
  • Weed is a designation that can be given to any plant that grows where it is not wanted or interferes with the growth of desirable plants. The term "weed" is usually reserved for plants that have a persistent and aggressive growth habit.

Life Span of Range Plants

  • Annual species complete their lifecycle (emerge, produce seed and die) in one growing season that lasts 4-6 months. Depending on the season of growth, there are two types of annuals:
    • Winter annuals complete their lifecycle in the winter.  Germination occurs in fall and small basal leaves persist during winter. Early the next year, the plant will grow and produce flowers and seeds in summer.  Once the plant has produced seed it dies.
    • Summer annuals complete their lifecycles in summer.  Germination occurs in spring and grows throughout the summer.  In late summer or early fall the plant will produce flowers and seeds and die.
  • Biennial species live for two complete growing seasons. These species produce basal leaves (or a rosette) the first year.  During the second year, the plant will produce a seed stalk (or a bolt). Flowering and seed dispersal occurs during the second year and once the plant has reproduced it will die.
  • Perennial species live three or more years and each year the plant produces new plant parts (leaves, stems, etc.).  Majority of rangeland vegetation are perennial species.

Season of Growth

  • Cool-season species perform most of their growth while temperatures are relatively cool.  At higher elevations (generally above 44 degrees North) majority of vegetation is cool-season because temperatures are cool during all of the growing season.  These species are often less competitive when conditions are especially warm or dry.  Cool-season plants at lower elevations generally have growth in the spring, produce see in late spring/early summer, and new growth occurs in the fall with sufficient moisture.
  • Warm-season species perform most of their growth in late spring and summer and produce seeds in mid-summer and early fall.  These species are more competitive in warm and dry environments.

Origin of Range Plants

  • Native species are plants that originated, evolved, and are still present in a particular area.
  • Introduced species are plants that were brought to a particular area from another region.  Often times introduced species were intentionally introduced to a particular area to help meet rangeland needs (good forage value, erosion control, etc.).  In some cases, introduced species were accidentally introduced to an area through contaminated crops or animals (or humans) unknowing depositing seed.

 

Sheila Merrigan

Animal Health & Veterinarian Resources for Ranchers

Animal Health & Veterinarian Resources for Ranchers

By Doug Tolleson

Rangeland health contributes to animal health and well-being. Productive rangelands will provide nutrition and shelter for the animals residing there. Animals grazing well-managed rangelands should be less susceptible to the effects of ingesting toxic plants.   Additionally, well-fed and non-stressed animals should be able to meet the “costs of fitness” required to maintain a functional immune system. Animals experiencing sub-optimal nutrition during a prolonged drought, or cold stress during winter may, however, become immune-compromised and less able to ward off disease, parasites, or infections. Animal diseases do occur though and monitoring animal populations for early detection of disease or parasites is an important part of overall rangeland management.  In this section you will find information related to the symptoms, detection and etiology of diseases common to animals grazing rangelands.  

Poisonous Plants

Poisonous Plants

Written by Mindy Pratt, Utah State University Extension

Poisonous plants are a major cause of economic loss to the livestock industry. Each year poisonous plants adversely affect 3 to 5 percent of the cattle, sheep, and horses that graze western rangelands.

Livestock losses can be heavy if:

  • Animals graze infested rangelands when plants are most toxic.
  • Animals are driven, trailed through, or unloaded from trucks onto rangeland or pasture areas infested with poisonous plants.
  • Animals are not watered regularly or are allowed to become hungry, making them more likely to eat lethal quantities of poisonous plants.
  • Animals are allowed to graze in heavy stands of plants that are highly poisonous.
  • Animals are grazed on rangelands early in the spring when there is no other vegetation except poisonous plants.

Treatment. There are no known treatments for animals poisoned by most poisonous plants. Where treatment is available, affected animals are usually in remote places and cannot be reached until it is too late to apply the treatment. When they have recovered enough to be handled, treatment should consist primarily of symptomatic treatment except where a specific treatment is known.

Prevention. Preventing animals from consuming too much of a poisonous plant in the first place is the best way to avoid livestock losses to poisonous plants. However, livestock grazing on rangeland generally cover large areas with a diverse array of plants. It is difficult, if not impossible, to prevent livestock from coming into contact with poisonous plants; however, following a few guidelines can minimize the likelihood of a severe loss to poisonous plants.

To protect your animals from poisoning:

  • Learn to identify the poisonous plants that grow on your rangeland.
  • Learn the conditions under which these plants can be dangerous to your livestock.
  • Develop a grazing plan to improve your rangeland and prevent poisoning of your livestock by plants.
  • Graze your rangelands at the proper time, and do not overgraze them.
  • Do not allow animals that have been under stress or that are overly hungry to graze in areas infested with poisonous plants.
  • Provide adequate water for your livestock.
  • Be especially careful when grazing newly introduced livestock on your rangeland.
  • Provide adequate salt and other supplements as needed.
  • Control poisonous plants where feasible.

If your animals get sick, consult your veterinarian to ensure proper diagnosis and treatment. If a poisonous plant is involved, identification of the plant is essential for any corrective action.

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