DISEASE CARRIED IN CATTLE FEED by Mike Mehren Ph.D.

DISEASE CARRIED IN CATTLE FEED
BY MIKE MEHREN

Where do cattle diseases come from? There are many answers to this question. Some diseases are transmitted from animal to animal. Others come from organisms such as bacteria, protozoa, viruses, and worms living in the ground and the water. Others are airborne. Disease can be transmitted by dirty equipment. Mosquitoes serve as a host for several diseases; ticks also carry disease. One source of organisms that cause disease is the feed that cattle eat. We don’t think of animal feed as being a source of disease, however it shouldn’t be a surprise since humans can contract a disease from tainted food (the great spinach debacle of 06). We also know that E coli is a natural resident in the intestinal tract of cattle. Eating improperly handled beef may result in an E coli infection. I’ll bet the spinach farmers are a lot more sympathetic to cattle raisers than they used to be!

I’m not referring to nutritional diseases such as bloat, grass tetany, waterbelly, nitrate toxicity, or pulmonary emphysema or metabolic diseases such as milk fever, or poisons. Compounds in the plant cause these problems itself that are normal, healthy, parts of the plant. In this column we’ll look into the bacterial or parasitic diseases that may cause sickness in cattle when they eat the plants harboring those microbes.

The most famous of the diseases caused by feed is B.S.E. We believe that a prion present in animal protein products such as meat and bone meal causes cattle to lose normal brain function when they eat feed harboring this agent. B.S.E. may take a human form known as Variant CJD. Animal protein products from beef and sheep were banned as feed ingredients for cattle in 1997. In most instances feed manufacturers have removed all animal protein products from their mills to prevent any possibility of contaminating the feed that they produce. Most mills have also replaced animal fat with vegetable fat.

Salmonella is a bacteria that can gain entry into the animal’s body on feed or from dirty equipment or dirty water. The salmonella is in manure that comes in contact with the animals’ surroundings. There are several strains of these bacteria, but most seem to cause the same symptoms. They can cause severe diarrhea, which if not treated can lead to dehydration and death. Animals that survive may shed large numbers in their feces and milk. Humans can contract the disease by eating or drinking contaminated food or milk. Both animal and plant source feeds can be carriers of the bacteria. A study by Losinger et al. in 1997 found that feeding tallow, cottonseed or cottonseed hulls significantly increased the incidence of salmonella in pens of feedlot cattle.

Don’t take this to mean that only these feedstuffs can be bearers of salmonella. They were used as examples of animal feed and plant feed sources. Good management practices are the best way to prevent an outbreak. Water troughs should be cleaned routinely. In summer they require more effort than in winter, but wintertime cleaning shouldn’t be overlooked. A solution of bleach and water applied with a scrub brush does a good job of killing organisms in the tank. This can also be used on cattle handling equipment. Equipment used for feeding should never be used to haul manure unless it can be steam cleaned after manure hauling. Salmonella can grow rapidly when a feedstuff such as grain has too much moisture and is allowed to remain in a pile. We normally only worry about molds, but bacteria also grow in poorly managed feed piles.

Listeria is a bacteria that is quite prevalent in plants and soil. Where we encounter problems is mostly in poorly managed silage. Silage that isn’t packed well enough to exclude oxygen will not develop a pH that is low enough to kill bacteria such as listeria. Symptoms of listeriosis include ‘circling disease’, abortion, and mastitis. The ‘circling disease’ looks like a thiamine (B vitamin) deficiency where cattle are called ‘brainers’ or they become ‘starry-eyed’ because they lose their eyesight. Since listeria are everywhere, we can’t eliminate contact with them. However, good silage making and feeding practices dramatically reduce any chance of an outbreak.

Foot and Mouth Disease is caused by a virus. It only affects animals with cloven hooves such as cattle, sheep, deer, and swine. It is not transmitted to humans. Symptoms include a high fever for a short time followed by the appearance of blisters in the mouth and on the feet. The source seems to be contaminated feed, however it can be transmitted from one animal to another or when animals come in contact with dirty equipment or vehicles. Sources identified are meat, meat products, or garbage. There has not been a case in the U.S. since the early 1900’s; however outbreaks have occurred in the U.K. that means that it isn’t only a problem of underdeveloped nations.

Measles is a disease of cattle caused by a tapeworm. The animal eats this tapeworm on feed that has been contaminated with human feces. Humans don’t get measles if they happen to eat contaminated meat, however, they can get the tapeworm if they eat undercooked meat that is infected. When an animal goes to slaughter if there are many ‘measles’ on the carcass then it is condemned. If there are only one or two, it is frozen for a certain number of days, and then is used only in meat products that are thoroughly cooked before they are sold to the consumer. This problem has occurred in the Pacific Northwest as well as other parts of the country. Education and proper toilet facilities for all persons working around cattle can help to eliminate this problem.

A bacteria cause Johne’s Disease. Very young calves get exposed when drinking or eating milk or feed that is contaminated by feces. The symptoms are a severe diarrhea and rapid weight loss while the appetite remains good. The symptoms may not appear until years after the animal was infected. Animals showing symptoms will lose productivity and a high percentage die. At one time it was thought to be a disease only seen in dairies, however we now know that beef cattle herds are also infected. Treatment with antibiotics is not very successful. Whether Chron’s disease in humans is the same as Johne’s is quite controversial at this time. Most evidence indicates that drinking milk or eating meat from an infected animal will not cause the disease. Identifying and removing infected animals is the most effective means of control.

Diseases carried to the animal through the feed are a tough group to deal with. In most cases there is exposure through manure. We obviously can’t sterilize our animal’s environment, but we can minimize contamination by cleaning equipment, using feed equipment for feeding only, routine pen scraping, and feed bunk and water trough cleaning. We have also seen that good sanitation for humans that work with livestock is important. Feed Quality Assurance is a huge part of Beef Quality Assurance!

Michael J. Mehren, Ph.D. is a livestock nutritionist who checks his food very carefully when eating in Hermiston, Oregon. He may be contacted by Email @ mehrens@eotnet.net.



		DISEASE CARRIED IN CATTLE FEED BY MIKE MEHREN Where do cattle diseases come from? There are many answers to this question. Some diseases are transmitted from animal to animal. Others come from organisms such as bacteria, protozoa, viruses, and worms living in the ground and the water. Others are airborne. Disease can be transmitted by dirty equipment. Mosquitoes serve as a host for several diseases; ticks also carry disease. One source of organisms that cause disease is the feed that cattle eat. We don’t think of animal feed as being a source of disease, however it shouldn’t be a surprise since humans can contract a disease from tainted food (the great spinach debacle of 06). We also know that E coli is a natural resident in the intestinal tract of cattle. Eating improperly handled beef may result in an E coli infection. I’ll bet the spinach farmers are a lot more sympathetic to cattle raisers than they used to be! I’m not referring to nutritional diseases such as bloat, grass tetany, waterbelly, nitrate toxicity, or pulmonary emphysema or metabolic diseases such as milk fever, or poisons. Compounds in the plant cause these problems itself that are normal, healthy, parts of the plant. In this column we’ll look into the bacterial or parasitic diseases that may cause sickness in cattle when they eat the plants harboring those microbes. The most famous of the diseases caused by feed is B.S.E. We believe that a prion present in animal protein products such as meat and bone meal causes cattle to lose normal brain function when they eat feed harboring this agent. B.S.E. may take a human form known as Variant CJD. Animal protein products from beef and sheep were banned as feed ingredients for cattle in 1997. In most instances feed manufacturers have removed all animal protein products from their mills to prevent any possibility of contaminating the feed that they produce. Most mills have also replaced animal fat with vegetable fat. Salmonella is a bacteria that can gain entry into the animal’s body on feed or from dirty equipment or dirty water. The salmonella is in manure that comes in contact with the animals’ surroundings. There are several strains of these bacteria, but most seem to cause the same symptoms. They can cause severe diarrhea, which if not treated can lead to dehydration and death. Animals that survive may shed large numbers in their feces and milk. Humans can contract the disease by eating or drinking contaminated food or milk. Both animal and plant source feeds can be carriers of the bacteria. A study by Losinger et al. in 1997 found that feeding tallow, cottonseed or cottonseed hulls significantly increased the incidence of salmonella in pens of feedlot cattle. Don’t take this to mean that only these feedstuffs can be bearers of salmonella. They were used as examples of animal feed and plant feed sources. Good management practices are the best way to prevent an outbreak. Water troughs should be cleaned routinely. In summer they require more effort than in winter, but wintertime cleaning shouldn’t be overlooked. A solution of bleach and water applied with a scrub brush does a good job of killing organisms in the tank. This can also be used on cattle handling equipment. Equipment used for feeding should never be used to haul manure unless it can be steam cleaned after manure hauling. Salmonella can grow rapidly when a feedstuff such as grain has too much moisture and is allowed to remain in a pile. We normally only worry about molds, but bacteria also grow in poorly managed feed piles. Listeria is a bacteria that is quite prevalent in plants and soil. Where we encounter problems is mostly in poorly managed silage. Silage that isn’t packed well enough to exclude oxygen will not develop a pH that is low enough to kill bacteria such as listeria. Symptoms of listeriosis include ‘circling disease’, abortion, and mastitis. The ‘circling disease’ looks like a thiamine (B vitamin) deficiency where cattle are called ‘brainers’ or they become ‘starry-eyed’ because they lose their eyesight. Since listeria are everywhere, we can’t eliminate contact with them. However, good silage making and feeding practices dramatically reduce any chance of an outbreak. Foot and Mouth Disease is caused by a virus. It only affects animals with cloven hooves such as cattle, sheep, deer, and swine. It is not transmitted to humans. Symptoms include a high fever for a short time followed by the appearance of blisters in the mouth and on the feet. The source seems to be contaminated feed, however it can be transmitted from one animal to another or when animals come in contact with dirty equipment or vehicles. Sources identified are meat, meat products, or garbage. There has not been a case in the U.S. since the early 1900’s; however outbreaks have occurred in the U.K. that means that it isn’t only a problem of underdeveloped nations. Measles is a disease of cattle caused by a tapeworm. The animal eats this tapeworm on feed that has been contaminated with human feces. Humans don’t get measles if they happen to eat contaminated meat, however, they can get the tapeworm if they eat undercooked meat that is infected. When an animal goes to slaughter if there are many ‘measles’ on the carcass then it is condemned. If there are only one or two, it is frozen for a certain number of days, and then is used only in meat products that are thoroughly cooked before they are sold to the consumer. This problem has occurred in the Pacific Northwest as well as other parts of the country. Education and proper toilet facilities for all persons working around cattle can help to eliminate this problem. A bacteria cause Johne’s Disease. Very young calves get exposed when drinking or eating milk or feed that is contaminated by feces. The symptoms are a severe diarrhea and rapid weight loss while the appetite remains good. The symptoms may not appear until years after the animal was infected. Animals showing symptoms will lose productivity and a high percentage die. At one time it was thought to be a disease only seen in dairies, however we now know that beef cattle herds are also infected. Treatment with antibiotics is not very successful. Whether Chron’s disease in humans is the same as Johne’s is quite controversial at this time. Most evidence indicates that drinking milk or eating meat from an infected animal will not cause the disease. Identifying and removing infected animals is the most effective means of control. Diseases carried to the animal through the feed are a tough group to deal with. In most cases there is exposure through manure. We obviously can’t sterilize our animal’s environment, but we can minimize contamination by cleaning equipment, using feed equipment for feeding only, routine pen scraping, and feed bunk and water trough cleaning. We have also seen that good sanitation for humans that work with livestock is important. Feed Quality Assurance is a huge part of Beef Quality Assurance! Michael J. Mehren, Ph.D. is a livestock nutritionist who checks his food very carefully when eating in Hermiston, Oregon. He may be contacted by Email @ mehrens@eotnet.net.		About OFGA Services Join OFGA Meetings & Events OFGA Officers OFGA Bylaws Links Contact OFGA Articles Mike Mehren, Ph.D. Feed/Export Wheat Report