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Economically significant feedlot diseases

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Cattle in feedlots face disease challenges similar to other classes of livestock and production settings. The prevalence of disease in feedlots is influenced by many factors, including immune status, …

Cattle in feedlots face disease challenges similar to other classes of livestock and production settings. The prevalence of disease in feedlots is influenced by many factors, including immune status, level of stress, pathogen load, environment, nutritional background, and feeding management, as well as the level of execution of animal husbandry practices. Cattle in feedlots are primarily susceptible to infections and metabolic diseases, and are less threatened by neoplasia and poisoning due to their age and controlled environment, respectively.
The constant movement of cattle into and out of feedlots makes control of infectious diseases challenging, due to constant exposure to pathogens and the stress of commingling. In addition, cattle arrive in feedlots with a wide variation in their background; some have been managed so that they can withstand the rigors of adjustment to feedlot life, while others are very susceptible to most any disease exposure.
There are numerous health and disease issues commonly found within a feedlot system. Many are preventable, through vaccinations for common diseases (following veterinarian’s recommendations); vitamin shots when entering the feedlot, proper balanced feed rations, and good daily management

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  • 1. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 1 Jimma University College of agriculture and veterinary medicine Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed 2014 JIMMA oromiyaa ethiopia  Qaroo dhabeessi “maal barbaadda” jennaan “ifa” jedhe  “Nyaadhee sifixuu dadhabus, haadhee siballeessuu dadhabbaa” jette lukkuun  Kanaf namani oromo taatan komenti iti kanna itti fayyadama
  • 2. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 2 HEALTH PROBLEM OF BEEF CATTLE Introduction Cattle in feedlots face disease challenges similar to other classes of livestock and production settings. The prevalence of disease in feedlots is influenced by many factors, including immune status, level of stress, pathogen load, environment, nutritional background, and feeding management, as well as the level of execution of animal husbandry practices. Cattle in feedlots are primarily susceptible to infections and metabolic diseases, and are less threatened by neoplasia and poisoning due to their age and controlled environment, respectively. The constant movement of cattle into and out of feedlots makes control of infectious diseases challenging, due to constant exposure to pathogens and the stress of commingling. In addition, cattle arrive in feedlots with a wide variation in their background; some have been managed so that they can withstand the rigors of adjustment to feedlot life, while others are very susceptible to most any disease exposure. There are numerous health and disease issues commonly found within a feedlot system. Many are preventable, through vaccinations for common diseases (following veterinarian‘s recommendations); vitamin shots when entering the feedlot, proper balanced feed rations, and good daily management.. Many health problems in beef cattle can be managed successfully if they are detected early. Cattle owners can prevent or minimize losses by taking steps to keep the problems from recurring or spreading to the rest of the herd. 1 Economically significant feedlot diseases Many diseases are prevalent on feedlots and they include: Tick fever, Footrot,Enterotoxaemia (pulpy kidney), Bovine respiratory disease (BRD), Blight (Pink eye), feedlot bloat, acidoses, liver abscesses, botulism. 1.1 Respiratory diseases Respiratory diseases are common in cattle. A number of factors contribute to an outbreak: inadequate nutrition, stress, and viral or bacterial infection. Good management and vaccination of cows and calves is the best way to prevent outbreaks of respiratory disease. It is the most important cause of sickness (morbidity), death (mortality) and chronic, poor-doing animals in feedlots.
  • 3. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 3 1.1.1 Bovine respiratory diseases (BRD) complex/shipping fever BRD is the most significant cause of clinical death in feedlots and this disease is caused by stress from yarding, transportation over long distances, dehydration, feed deprivation and mixing with different groups of cattle. Once at the feedlot, the environment there provides further stress factors, which can cause BRD to occur. Most feedlot-associated deaths result from bovine respiratory disease (BRD), including bronchopneumonia and fibrinous bronchopneumonia, commonly referred to as ―shipping fever‖. pathogenic microorganisms associated with shipping fever Viruses Bacteria IBR – infectious bovine rhinotracheitis Mannheimia (Pasteurella) haemolytica PI-3 – parainfluenza virus-3 Pasteurella multocida RSV – respiratory syncytial virus Haemophilus somnus BVD – bovine virus diarrhea Arcanobacterium pyogenes Mycoplasma spp. (bovis) Pneumonia is a highly complex, contagious disease and may be caused by one of several viruses in concert with various bacteria. Pneumonia caused by bacteria is generally serious Fever, coughing and labored breathing are caused by inflammation and swelling of the lungs and the accumulation of mucus, blood and pus that interfere with airflow in the air passages. The animal tries to get more air by stretching out its head and neck and protruding its tongue. 1.1.2 A typical interstitial pneumonia/ acute bovine pulmonary edema & emphysema Acute bovine pulmonary edema is most common in feedlot cattle with more than 45 days on feed. Onset is acute, and signs include open-mouth breathing, extended head and neck, expiratory push, and frequently an elevated respiration rate. Cattle are generally in good to excellent body condition Commonly associated with  movement of cattle from dry pasture to lush pasture  ingestion of plants and mold contaminated plants
  • 4. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 4  ration containing high level of tryptophan Fever is not present; coughing is minimal; and the onset of symptoms is sudden. Breathing is obviously difficult, with the animal breathing through its mouth, extending its tongue and drooling saliva. 1.2 Digestive system disorder Digestive disorders, manifested primarily as rumen tympany or bloat, are the second leading cause of death in feedlots. It is important to note, however, that feeding of ionophores is a very useful tool to reduce the incidence of digestive disorders. Feed-grade tylosin is effective for reducing liver abscesses The most common digestive disorders are:- 1.2.1 Digestive disease due to infectious/septic/parasitic causes With exception of diseases associated with neonatal scour, it is little different from disease found in the husbandry situation. 1.2.2 Physical disorder disease: Organ misplacement, torsion, or volvulus of digestive tract is uncommon in feedlot cattle. The most common known is rumen tympanic (bloat) 1.2.2.1 Bloat Bloat is a common digestive disorder in beef cattle. It occurs most often in feedlot cattle but affects cattle in all production phases. It results when cattle can not belch (eructate) or release gases produced normally from microbial fermentation in the rumen. The animal may produce more gas than it can eliminate. Rumen expansion from gases puts pressure on the diaphragm and lungs. This compression reduces or cuts off the animal‘s oxygen supply and can suffocate cattle. Feedlot bloat is caused by finely ground grain which promotes frothiness of rumen contents. Frothiness of rumen contents during feedlot is due to a increasement of viscosity of ruminal fluid. Viscosity of ruminal fluid increase because of production of slime by encapsulated bacteria. As encapsulated bacteria increase their numbers on high carbohydrate diet.The slime may entrap the gas which is formed by fermentation so that the gas has no chance to coalesce and burst. As the result the gas may mix with moisture and form foam. The foam blocks the cardiac part of rumen so that eructation is impaired. So that insoluble extracellular polysaccharides in case of feedlot bloat are important for foam formation.
  • 5. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 5 Occurs when rapid fermentation in the rumen causes too much gas to be produced The rumen swells and the animal cannot get rid of the gas, The major cause of bloat is eating to much green legume too fast There are three types of bloat 1. Frothy bloat:-occurs when the gas produced by fermentation is trapped within the mass of ingesta . Frothy bloat (feedlot bloat) is the most common type of bloat. It results from foam in the rumen that stops the animal from expelling rumen gases. The foam can cover the cardia (esophageal entrance from the reticulorumen) and prevent the animal from belching. Frothy bloat occurs in cattle fed high-grain diets but is not a major concern for many Mississippi cattle producers. ―Feedlot‖ bloat is a concern, though, with cattle on high-grain diets, such as bulls on feed-based bull development programs. 2. Free-gas bloat: - occurs when animals consume higher levels of highly concentrated, readily fermentable carbohydrate rations. 3. Obstructive bloat, results from the inability to eructate ruminal gases due to obstruction of the esophagus. 1.2.2.2 Metabolic diseases The primary metabolic disease affecting digestive system is ruminal acidosis. Acidosis is often associated with a shift from a foragebased diet to a high concentrate-based diet or excessive consumption of fermentable carbohydrates. Acidosis may occur in cattle on high-grain diets common with bull development programs, and cattle finishing programs. It can also occur in stocker calves when self-feeders and high starch feeds such as corn are used. Acidosis is the most important nutritional disorder in feedlots today. Acidosis, which causes cattle to be stressed, is caused by a rapid production and absorption of acids from the rumen when cattle consume too much starch (primarily grain) or sugar in a short amount of time. This is due to eating highly fermentable carbohydrates, concentrates, where supply of food is interrupted and cattle over consume.
  • 6. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 6 Animals are usually affected to varying degrees, from mild indigestion to severe poisoning. Acute cases show staggering, appear blind and ‗drunk‘ and go down after 10 to 48 hours. Death can occur 12 to 72 hours after the onset of signs. Cause Too much grain eaten too quickly results in an excessive build-up of lactic acid in the rumen. Changing from one grain to another too quickly can cause similar problems, so a slow introduction to any grain diet is necessary. Grain or roughage too finely milled is a common factor in grain poisoning. The condition is accentuated when the animal is suffering from cold stress Its local effects includes:- Chemical rumenitis, rumen atony, death of normal micro flora and over growth of other microbes. Systemic effects includes:- Dehydration, death of normal microflora over growth of abnormal microflora and endotoxin 1.3 Diseases of Cardiovascular System in Feedlot Cattle 1.3.1 Myocarditis, Vaculities (inflammation of heart, blood vessels) Viral disease of cardiovascular system is not particularly important in feedlot cattle. Malignant catarrhal fever: - is viral disease of blood vessel, arteries, and smaller arterioles. Routes of transmission:-  Contact between cattle and sheep,  Sheep shed a causative agent from their nasal passages;  It is nothing to sheep but can causes severe systemic illness in cattle. NB. Black leg caused by clostridium chauvoei and causes pericarditis and pleuritis 1.3.2 Myocardial Degeneration, Cardiomyophat It has two causes:- 1. Nutritional causes: - includes vitamin A/selenium deficiency and copper deficiency
  • 7. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 7 2. Toxic causes:-includes faulty mixing of ionophores like, Gossypol (toxin present in the cottonseed). 1.4 Diseases Of nervous System in Feedlot cattle 1.4.1 Infectious/inflammatory disease of the nervous system: It includes:- Viral diseases:-herpes virus such as bovine herpesvirus Bacterial diseases:- includes thrombotic meningoencephalitis(TME or TEME) which is inflammation of brain and meninges ,is caused by Haemophilus somnus 1.4.2 Metabolic diseases of the nervous system Polioencephalomalacia (PEM): Is the single most important disease affecting the nervous system of feedlot cattle. Cattle with polio are thin and usually have been on a diet high in sulfate and low in protein and roughage. They probably have been confined and fed a grain diet without roughage. Affected cattle may die suddenly with no prior symptoms, or may die within 1–5 days of the onset of the following symptoms:  dull/dopey appearance  sudden blindness  muscle tremors  champing of jaw and frothing of mouth  convulsions  Collapse
  • 8. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 8 The major predisposing factors are: - ruminal acidosis and formulation of diet containing sulphur 1.5 Diseases of the urinary system in the feedlot cattle 1.5.1 Leptospirosis Caused by serovars of Leptospira interrogans At acute stage: - it has generalized bacteriemia, anemia, infertility, abortion hemoglobinuria At sub-acute and chronic stage: - it has  infection of kidney,  sudden leptospires in the urine, and  others abortion, and stillbirth,  Mastitis, and decreased milk production. 1.5.2 Pyelonephritis: - Is an ascending bacterial infection of the kidney. 1.5.3 Urolithiasis: - Is formation of calculi or stone in the urinary tract and it is a problem of male feedlot ruminant animals. 1.6 Miscellaneous Diseases Affecting Varied Organ System It includes: - lameness due to foot rot, abscess, and degeneration inflammation of joint and tendons. One syndrome of lameness and swelling of joint and periarticular tissue that affect multiple animals is attributed to Mycoplasma bovis 2 Control and Prevention of Disease in Feedlot Cattle Successful and economical control of diseases of feedlot cattle depends on many factors they are purchasing healthy animals; providing a transportation system that minimizes stress, a comfortable feedlot pen environment, and an adequate feeding system; establishing a good surveillance system; and judiciously using vaccines and, when necessary, antimicrobial agents 2.1 Feedlot Facilities One of the most important considerations in the construction of a feedlot is good drainage. The pens and alleyways should be well drained and easily accessible for scraping the ground surface as necessary. Good drainage requires a 6% slope. To avoid overstocking, each animal should be provided with 18 m2 of space in well-drained land and with 9 m2 in a paved lot. Trees should be planted to provide protection from wind, rain, snow, excessive heat, and sunshine. The shed should be open to the south or southeast
  • 9. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 9 and the front should be high enough so that sun strikes the ground at the back on the shortest day of winter. The back of the shed should be ≥2.5m high. 2.2 Cattle Purchase and Introduction in to a Feedlot The purchase of cattle and their introduction to a feedlot has been a controversial issue in beef production ever since the development of commercial feedlots. Commercial feedlots attempt to purchase the most inexpensive cattle that will perform the best and provide maximum economic returns. However, feedlot cattle are subjected to a variety of stressors when they are shipped to the feedlot and after they arrive in the feedlot. Several factors cause stress, which contributes to the occurrence of the acute respiratory disease complex in feedlot cattle. Any factor that causes stress at weaning time can result in an increased incidence of disease. Transportation over long distances without adequate rest and feeding periods may be followed by an epidemic or ‗wreck‘ associated with acute respiratory disease. Rapid changes in weather and unexpected snowstorms at the time of shipping may result in outbreaks of shipping fever. The placement of recently weaned beef calves, at six to eight months of age, into the feedlot is associated with much higher morbidity and mortality rates than older yearling cattle.Presumably, this is due to the higher level of acquired immunity in the older cattle. Mixing weaned beef calves from many different origins at the time of entry into the feedlot is considered to be a major factor in acute fibrinous pneumonia. Cattle are often vaccinated, dehorned, castrated, branded, implanted, and injected with vitamins and antibiotics within a few days after their arrival in the feedlot. The major objective is to get the cattle onto a high-energy diet which will result in rapid growth as soon as possible, usually within 21 days. At the same time the manager must minimize the morbidity and mortality associated with acute respiratory disease, some other common infections such as hemophilus septicemia, and digestive diseases associated with adjustments to high- energy diets. A major consideration is to achieve all of these objectives most economically. 2.3 Origin and Purchase of Cattle This is a very important phase of feedlot operations. The type of cattle fed will be influenced by the cost and availability of feeder cattle and feed, the expected performance of the animals and the net financial returns. The decision on what kind of cattle to buy and where to buy them is largely a matter of risk aversion. How much risk is the feedlot operator willing to take? It is possible to buy groups of uniform feeder calves or yearling cattle that come from one source and in which the disease incidence will be very low. However, these cattle cost more, and the gross margin is smaller than for cattle originating from several sources and accumulated and sold through public auction sales yards.
  • 10. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 10 The incidence of disease is much higher in weaned beef calves than in yearling cattle. Steer calves are preferred to heifer calves because of their availability, superior growth rate, higher selling price, and the absence of problems associated with estrus and pregnancy in heifers. Lighter weight calves (less than 500 lbs.) may be preferred to medium weight calves (500 to 750 lbs.) because they cost less per head and have a greater potential for low cost gains. Yearlings are preferred in some feedlots because more groups can be fed per year and the morbidity and mortality from respiratory disease is much lower than in calves. The disadvantages include higher purchase price, higher feed costs per unit of gain and uncertain availability. Yearling cattle may also originate from a backgrounding operation in which calves were placed on pasture or a growing ration for several months. They have adequate body size and gain well in the feedlot. The principles for consideration when purchasing cattle and introducing them to a highly intensive, heavy feeding environment are as follows:  Purchase healthy cattle;  Obtain cattle directly from the farm of origin if possible;  The disease incidence is lower in yearling cattle than in feeder calves;  Adopt the all-in-all-out principle.The cattle are purchased as a group, fed as the same group, and sold as a group. This would tend to break the chain of infection from one group to another. An important related principle is to avoid the mixing of recently arrived cattle with cattle already resident in the feedlot. Because of fluctuations in the supply of cattle that may occur, feedlots will often continue to assemble and make up groups of cattle over a period of several days or a few weeks. As recently arrived cattle are added to existing groups, new outbreaks of disease occur, which may be perpetuated for several weeks  Purchase preconditioned cattle if possible and if economical;  Transport the cattle to the feedlot in the shortest time that is economically feasible;  Develop a reporting system that regularly informs the cattle buyer of the condition of the cattle received and their subsequent performance. This will assist the buyer in the purchase of healthy cattle, avoiding unhealthy cattle and ensuring that they are transported by the most economical and least stressful method of transportation. If the cattle are not preconditioned, the feedlot should attempt to determine what vaccines the animals have received before they were shipped to the lot.  NB. If the cattle are kept in their original groups until market, the morbidity and mortality may be low. 2.4 Preimmunization and Preconditioning There are often large economic losses associated with the high morbidity and mortality due to acute respiratory disease in weaned beef calves. These calves may be shipped from the ranch, within a few days after weaning, to sales yards and finally to feedlots. The risk of these losses led to the development of the concept of preconditioning. Preconditioning is based in part on immunological and nutritional principles.
  • 11. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 11 The first principle is that effective immunity against infectious diseases of the respiratory tract can be achieved only if animals are vaccinated in sufficient time before natural exposure occurs after arrival in the feedlot. Preimmunization or vaccination of calves two to three weeks before shipment from the ranch to the feedlot, against the common infectious agents associated with acute respiratory disease was the beginning of the practice of preconditioning. In addition to vaccination, efforts were directed to feeding and management procedures on the ranch that would assist the calf in making an easier transition to the feedlot. Preconditioning of beef calves includes the following:  Be at least four months of age prior to being vaccinated;  Owned by the operator 45 days prior to sale or shipment;  Weaned for a minimum of 45 days;  Castrated and dehorned at least three weeks prior to sale or shipment;  Given IBR, PI-3, multi-clostridial (7 or 8-way), and Haemophilus somnus vaccines three weeks prior to sale or shipment;  Treated for warbles at least three weeks prior to sale or shipment;  Tagged with an official eartag applied under the supervision of a licensed veterinarian;  Accompanied by an official health certificate completed and signed by both the veterinarian and the producer. The proper preconditioning of calves involves cost to the primary producer. The rancher must gather and handle the calves early to vaccinate them, and after weaning he must provide an adequate diet until shipment. The loss of weight following weaning must be made up before the sale. If the producer is to engage in these practices, he must be adequately compensated. Reports indicate that preconditioned calves are healthier when they arrive in the feedlot and that the incidence of respiratory disease is lower than in non- preconditioned calves. However, other field studies indicate that, in general, because of the costs of preconditioning incurred by the cow-calf producer, the feedlot operator could not economically justify paying a premium for preconditioned calves. The primary producer has shown considerable interest in delivering a quality calf to the feedlot but is understandably reluctant to add extra expense unless the returns are greater than the costs. The future of preconditioning will depend in large part on whether the livestock industry becomes convinced of its value. 2.5 Backgrounding Backgrounding is a variation of preconditioning in which recently weaned calves are grown to yearling feeder cattle weight usually in a smaller feedlot. The principal objective is to prepare yearling cattle to adjust to a high-energy finishing ration in a feedlot with minimal problems. This is achieved by feeding the calves a growing diet that yields rapid, efficient body weight gains without fattening. Maximum use is made of roughage type rations.
  • 12. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 12 The spectrum of diseases that occur in backgrounding operations during the first 45 days after arrival of the calves will depend on whether the calves were preimmunized, preconditioned, or obtained from several different sources with no preconditioning.  Recently arrived cattle of unknown background (market) should be vaccinated and some need to be castrated, dehorned and treated for internal and external parasites.  None preconditioned, stressed, cattles of unknown back ground should be watched closely for sign of BRD for ≥3 weeks after arrival.  On their ration cattles are limited to feed good quality roughage along with a quantity of a highly palatable, dense concentrate ration.  The cattle also should be weighed as group, soon after arrival. 2.6 Processing Procedures 2.6.1 Identification Each animal must be identified immediately, preferably with a color-coded and numbered plastic ear tag that is easily visible from a distance. In many feedlots, each animal is not identified individually but instead receives a tag with a lot number (group) or pen number. Information that can be maintained on individual animals through this technology includes performance, vaccine, and treatment history. These tags remain on the animal until slaughter, at which time the identification from the ear tag can be transferred to the overhead trolley system. 2.6.2 Measurement of Body Temperature On arrival, some animals may be affected with acute disease but show no obvious clinical signs. Others may appear fatigued and gaunt but are not affected with clinical disease. Identifying animals with acute infectious disease that should be treated early to minimize mortality can be difficult. The body temperature of high-risk cattle (eg, unweaned calves, calves from auctions, or calves that have been transported long distances over several days) is often measured at processing. Animals with a body temperature >104°F (40°C) are treated with an antimicrobial. Treated animals may be tagged and noted in the individual animal database, or the total number of animals treated (total amount of drug administered) in a group or pen may be recorded. 2.6.3 Vaccination The value of vaccinating feedlot cattle for common infectious diseases, particularly those of the respiratory tract, has been controversial since the vaccines were introduced. Nevertheless, a wide variety of vaccines are used in feedlot health programs.Vaccines are available for the following diseases or infections of feedlot cattle: infectious bovine rhinotracheitis, pneumonic pasteurellosis, parainfluenza3 virus infection, bovine respiratory syncytial virus infection, Histophilus somni disease complex, bovine viral diarrhea, and clostridial disease. The vaccines available for clostridial diseases are highly effective.
  • 13. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 13 The number of clostridial antigens to be used depends on local prevalence of clostridial diseases, including blackleg (Clostridium chauvoei), malignant edema (C septicum), bacillary hemoglobinuria (C novyi, type D [haemolyticum]), infectious hepatitis (C novyi, type B), tetanus (C tetani), and enterotoxemia (C perfringens, types B, C, and D). Leptospirosis (Leptospira serovarshardjo, pomona, grippotyphosa, canicola, and icterohaemorrhagiae) bacterins are also used in some situations. Additional vaccines should be included only if 2 criteria can be met: the disease is enough of a risk that prevention is necessary (eg, leptospirosis in some areas), and data can be found to support the use of vaccines to prevent disease 2.6.4 Castration and Dehorning These surgical procedures are best performed well ahead of entry to the feedlot, but invariably there will be bulls and horned cattle offered for sale. When to castrate and dehorn these mismanaged cattle is quite controversial, with recent studies showing that performing surgery at initial processing 24 hr after arrival was superior to delaying these procedures. 2.6.5 Anthelmintics and Insecticides Anthelmintics and insecticides are administered according to local conditions. The feedlot operator and veterinarian should be informed about feeder calves or yearling cattle that have originated from farms or areas in which intestinal parasitism is likely. When compared with treatment with a topical organophosphate, treatment with ivermectin can cause improved average daily weight gain and feed conversion in feedlot calves under commercial conditions. Young cattle raised on small farms in which the stocking rate on pasture is high may harbor helminths. Young cattle may also be affected by chronic verminous pneumonia caused by Dictyocaulus viviparus. Most young cattle will be infected with coccidia, and having an appropriate anticoccidial agent in the feed is necessary. 2.6.6 Growth-promoting Agents Growth-promoting agents increase growth rate of animals without being used themselves to provide nutrients for growth. They are generally administered in small amounts—often via implants or in feed—to alter metabolism so that the animal increases body tissues and grows more rapidly. They include antibacterials, antimicrobials, steroids (eg, estrogens, androgens), and ionophores. They promote changes in composition, conformation, mature weight, or efficiency of growth, although these effects are frequently accompanied by changes in the rate of live weight gain
  • 14. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 14 3 Summary Prevention is the easiest and cheapest method of disease control. Clean sheds, lots, and feed and water troughs give disease less chance to get started. A sound vaccination program, parasite control, and frequent observation of the herd also help to reduce the occurrence of illness. Droopy ears, loss of appetite, head down, scouring (diarrhea), or inactivity may indicate illness. A high temperature usually indicates disease. The best course of action is to find a sick animal quickly, treat it, and then work to eliminate the cause of the sickness. If one or two animals come down with a disease, the rest of the herd has been or will be exposed to it. Health problems are more common during and after periods of stress, including calving, weaning, shipping, working or moving the cattle, and extreme weather conditions. Stress can reduce an animal‘s ability to resist infectious agents. After aperiod of stress, give extra attention to your animals‘ health. All animals must be checked daily when they are standing and moving around. The best way to do this is by walking or riding through the pen of cattle. Young cattle and recent additions to the feedlot should be checked twice a day. Any animals showing persisting signs of stress or illness should be separated. This will minimise the spread of infection and bullying by others. Acidosis or grain engorgement poisoning is possibly the most common condition affecting feedlot cattle. This can be avoided by introducing the cattle slowly to the grain diet and by incorporating buffers into the diet, at the rate of 1% of the total ration, to stabilise rumen pH. Bentonite or limestone can be used, but bicarbonate of soda is most effective. Other conditions such as bloat are associated with high grain diets. Urea poisoning also can occur if urea forms part of a poorly mixed ration. Diseases such as infectious bovine rhinotracheitis (IBR), laminitis, polioencephalomalacia, footrot, gastric ulcers, and liver ulcers/damage have also been recorded.
  • 15. Feedlot diseases of beef cattle and their control By Nejash Abdela Ahmed Page 15 Reference 2000. Evaluation of models of acute and subacute acidosis on dry matter intake, ruminal fermentation, blood chemistry, 58:1465–1483. Allen, M. S. 1997. Relationship between fermentation acid production in the rumen and the requirement for physically and endocrine profiles of beef steers. J. Anim. Sci. 78:3155-3168. and ruminal function: salivation, motility and microbes. J. Anim. Sci. 68:2811–2832. and ruminal pH of cattle. J. Dairy Sci.76:1589-1600. Bergen, W. G., and D. B. Bates. 1984. Ionophores: Their effect on production efficiency and mode of action. J. Anim. Sci. Bevans, D. W., K. A. Beauchemin, K. S. Schwartzkopf-Genswein, J. J. McKinnon, and T. A. McAllister. 2005. Effect of Blowey, R. W. 1993. Cattle lameness and hoofcare. An illustrated guide. Farming Press, Ipswich, UK pp 86. Brown, M. S., C. R. Krehbiel, M. L. Galyean, M. D. Remmenga, J. P. Peters, B. Hibbard, J. Robinson, and W. M. Moseley. Calsamiglia, S., A. Ferret, and M. Devant. 2002. Effects of pH and pH fluctuations on microbial fermentation and nutrient Carter, R. R., and W. L. Grovum. 1990. A review of the physiological significance of hypertonic body fluids on feed intake Cheng, K. –J., T. A. McAllister, J. D. Popp, A. N. Hristov, Z. Mir, and H. T. Shin. 1998. A review of bloat in feedlot cattle. Cook, N. B., K. V. Nordlund, and G. R. Oetzel. 2004. Environmental influences on claw horn lesions associated with Dado, R. G., and M. S. Allen. 1993. Continuous computer acquisition of feed and water intakes, chewing, reticular motility, Dirksen, G. U., H. G. Liebich, and E. Mayer. 1985. Adaptive changes of the ruminal mucosa and their functional and clinical Donovan, G. A., C. A. Risco, G. M. DeChant Temple, T. Q. Tran, and H. H. van Horn. 2004. Influence of transition diets on Dougherty, R. W. 1956. Physiology of the rumen as related to bloat. In: A review of bloat in ruminants. NAS-NRC Publ. effective fiber. J. Dairy Sci. 80:1447-1462. Feedlot Diseases of Cattle and Sheep DrDon Montgomery flow from a dual-flow continuous culture system. J. Dairy Sci. 85:574-579. J. Anim. Sci. 76:299-308. laminitis and subacute ruminal acidosis in dairy cows. J. Dairy Sci. 87(E. Suppl.):E36-E46. occurrence of subclinical laminitis in Holstein dairy cows. J. Dairy Sci. 87:73-84. rapid or gradual grain adaptation on subacute acidosis and feed intake by feedlot cattle. J. Anim. Sci. 83:1116-1132. significance. Bovine Pract. 20:116–120. http://www.merckmanuals.com/vet/index.html