- - AGRICULTURE CORE CURRICULUM - - (CLF3000) Advanced Core Cluster: ANIMAL SCIENCE (CLF3150) Unit Title: NUTRITION AND FEEDS ____________________________________________________________________________ (CLF3156) Topic: NUTRITIONAL Time: Year(s) DISEASES 2 hours 3 / 4 ____________________________________________________________________________ Topic Objectives: Upon completion of this lesson the student will be able to: Learning Outcome #: (B-6) - Describe the symptoms of five common nutritional diseases caused by vitamin or mineral deficiencies or toxicity and explain the treatment and prevention of these diseases. Special Materials and Equipment: Slides or photos of animals showing the physical signs of the diseases caused by a deficiency and/or a toxicity. Supplemental Worksheet #4. References: Ensminger, M. E. (1983). THE STOCKMAN'S HANDBOOK (6th ed.). Fridline, Clarance R. (1979). LIVESTOCK NUTRITION AND FEEDING. Ohio: Ag. Ed. Curriculum Materials Service. Evaluation: Quiz by instructor. Completion of Supplemental Worksheet #4. TOPIC PRESENTATION: NUTRITIONAL DISEASES A. Introduction: 1. It is important to note that a consistent feed regime is critical to prevent certain nutritionally-related diseases. a. If a livestock producer has any of the below mentioned diseases in his stock, the economic success of the enterprise is in serious danger. b. Subclinical deficiencies and toxicities can rob the producer of profits and cause economic failure long before they are detected. This is why one must prevent them by monitoring feeds and feed resources. B. Factors Causing Nutritional Diseases 1. There are many causes of nutritional diseases: a. Too little feed. b. Rations low in one or more nutrients. c. Forced production - for example, extremely high milk production. d. Feeding of forages or grains produced on leached or depleted soils. e. Increase in confinement of the animals. C. Vitamin Deficiency Diseases 1. Osteomalacia (Rickets) a. Caused by inadequate vitamin D or an incorrect ratio of calcium to phosphorus. b. Symptoms seen are lack of appetite, enlarged joints, stiffness of joints, weight loss, bowed legs. c. Treatment is limited once the animal shows signs of the disease however, vitamin/mineral supplements may help. d. Prevention consists of feeding balanced rations, proper fertilization of soils where feed crops are grown, and access to direct, unfiltered sunlight by the animals. e. This disease is rare in California. 2. Stiff - Lamb Disease (White Muscle Disease) a. Caused by a deficiency of vitamin E or selenium or an imbalance of Selenium and vitamin E. b. Symptoms seen are a humped or "roached" back and a stiff, stilted way of moving. Also inhalation pneumonia in lambs can occur because the pharyngeal muscles allow milk to be inhaled into the lungs where it promotes infection. Usually young, rapidly growing lambs are most affected. c. Selenium is now available in feeds and some trace mineral mixes. Make sure supplementary feed is actually low in selenium before adding it. Linseed meal is an example of a good source of selenium. d. Treatment can be very effective if started early and it consists of vitamin E/selenium injections. Prevention consists of giving vitamin E/selenium injections at docking time and at 2 to 4 weeks of age. e. Note that there are areas in California where there is so much selenium in the soil that it can be toxic to animals living on the grasses of the area. So before seriously considering selenium/vitamin E supplementation, consult your local veterinarian or extension specialist. 3. Night Blindness (Xeropthlamia) a. Caused by a vitamin A intake that is too low. b. Symptoms seen are faulty vision at night, rough hair coat, severe diarrhea in advanced cases, and failure to grow. c. Treatment consists of correcting dietary deficiencies by adding vitamin A to the ration or giving vitamin A injections. d. Prevention consists of providing good sources of vitamin A such as lush green pasture, yellow corn, or freshly cured alfalfa hay. Hay that is stored for 1 year loses 80 percent of it vitamin A. Mature animals can store vitamin A in the liver to satisfy their needs for up to 6 months. Young animals cannot do this. D. Mineral Deficiency Diseases 1. Milk Fever a. Caused by a low blood calcium concentration. Too much calcium in the diet during the cow's dry period can cause this disease. Often occurs soon after a cow has freshened. b. Symptoms commonly occur soon after calving in high producing dairy cows. This disease rarely occurs during the first calving. Loss of appetite, constipation, nervousness, and then a complete loss of consciousness occurs. The head is usually turned or twisted back toward the shoulders. c. Treatment consists of administering calcium salts intravenously. d. Prevention includes maintaining a diet with the proper calcium to phosphorus ratio (2:1), or lowering the dietary calcium 10-14 days before calving. This activates the cow's calcium mobilizing mechanism for drawing calcium from the bones. Feeding a high vitamin D ration five days before calving can help also. Be sure to restore calcium to the diet upon freshening. 2. Anemia a. Caused by an iron or copper deficiency. Internal parasites will cause anemia also. b. Symptoms include loss of appetite, emaciation, rough hair coat, pale membranes in the mouth and eyes, and swelling about the head and shoulders. Usually seen in suckling young, since milk is a very poor source of iron. c. Treatment consists of providing sources of iron such as access to sterile soil or iron injections. d. Prevention consists of providing balanced feeds to young early soon after birth. In swine, any of the following may be used: 1) Injections of Iron Dextran solution. 2) Clean soil placed daily in farrowing stalls (this is time consuming and not often recommended). 3) Iron tablets or paste given orally. 4) Swab the sow's udder with Iron Sulfate solution (this is not often recommended either). 5) Provide baby pigs access to creep feed which contains iron, before they are 10 days old. 6) If possible, the piglets should have access to soil in pen so they may root and acquire iron naturally. 3. Goiter a. Caused by a failure of the body to obtain enough iodine from the thyroid gland in the form of thyroxine. b. The most characteristic symptom is the swelling of the thyroid gland causing "big neck". Reproductive failures, hairless newborn piglets, and weak foals are also symptoms of this deficiency. c. Treatment is not always effective once the symptoms begin to appear. d. Prevention includes feeding iodized salt. e. It also can be caused by plant compounds which effect iodine absorption. f. It is a rare disease. E. Toxicity Diseases 1. These diseases are caused by too much of a certain vitamin or mineral or a combination of both. 2. Selenium poisoning, a. Caused by the consumption of plants grown on soils containing high selenium content. b. Symptoms include loss of hair from the tail in cattle, loss of body hair in swine, loss of the mane and tail in horses. In severe cases, the hooves may slough off causing lameness. c. Treatment is not practical in advanced cases. d. Prevention may include pasture rotation, and abandoning areas where soil is high in selenium. 3. Urinary Calculi a. Caused by a high intake of potassium, a high calcium-low phosphorus ratio, or a high silica content in the ration. Deficiency of vitamin A may be a contributing factor. b. Symptoms seen are frequent attempts to urinate, pain, and renal colic. Usually seen only in males. c. Treatments are advisable for valuable animals only, since success is limited. Ammonium chloride may be added to the ration, increase the salt content of the ration, remove alfalfa from the diet, and as a last resort, surgically remove calculi. Males may become nonbreeders after such as operation. d. Prevention includes increasing the salt content of the diet, delaying castration, and avoiding high phosphorus or high calcium diets. (Grains are often very high in phosphorus.) 4. Nitrate Poisoning a. Caused by consuming forages high in nitrates. This can be caused by crops such as Sudan grass, oat hay, corn stalks, and barley forage when the plant is stressed such as during droughts, high temperature, excessive cloudy days, excess nitrogen from fertilizers, low sugar content, or after spraying with a weed killer. It also can be caused by surface runoff from settling ponds or irrigation in well fertilized areas. b. Symptoms include accelerated pulse and respiration, diarrhea, frequent urination, and blue colored mucous membranes. An accurate diagnosis may be made by examining the blood. Normal blood is red and when exposed to air becomes brighter. Blood from affected animals appears brown because the hemoglobin molecule changed to methemoglobin which cannot carry oxygen. So, in effect, the animal is slowly suffocating. c. Treatment by a veterinarian with an intravenous solution of methylene blue or sodium sulfate is successful both in mild and in severe cases. d. Prevention includes feeding high levels of grains and molasses, ensiling forages high in nitrates (during the ensiling process the bacteria change the nitrates to gas), and analysis to pre- determine nitrate content. __________________________________________________________ ACTIVITY: 1. Complete Supplementary Worksheet #4, "Nutritional Diseases." 2. Observe slides or pictures of animals affected with the diseases discussed. __________________________________________________________ SUPPLEMENTAL WORKSHEET #4 NUTRITIONAL DISEASES NAME___________________________ DATE___________________________ PER.___________________________ Using your notes on Nutritional Diseases, answer the following questions: 1) What are 5 factors that may cause nutritional diseases? 2) What role could soil have in preventing nutritional diseases? 3) List 2 diseases caused by a vitamin deficiency, explain the treatment, and a source of prevention for each: ============================================================================ Disease | Treatment | Prevention ________________|_______________________|___________________________________ | | a. | | | | | | ________________|_______________________|___________________________________ b. | | | | | | | | ============================================================================ 4) List 2 diseases caused by a mineral deficiency, explain the treatment, and a source of prevention for each: ============================================================================ Disease | Treatment | Prevention ________________|_______________________|___________________________________ | | a. | | | | | | ________________|_______________________|___________________________________ b. | | | | | | | | ============================================================================ 5) List one (1) disease caused by the toxicity of a substance, explain the treatment, and a source of prevention: 6) List three nutritional diseases in which calcium plays a role: 7) List a disease that is caused by both a vitamin and mineral deficiency working together: 8) Complete the following chart: ============================================================================ Disease | 2 symptoms | treatment | prevention ============================================================================ Anemia | | | | | | | | | _____________|_________________________|___________________|________________ | "big neck" | | | hairless piglets | | | | | | | | _____________|_________________________|___________________|________________ | | vitamin E/ | | | selenium | | | | | | | _____________|_________________________|___________________|________________ | | | | | | soil testing | | | | | | | | | ============================================================================ 5/2/90sg #%&C