grazing Checklist by Mike Mehren Ph.D.

Spring and summer or whenever you have rich green feed is the time of year that cattle should perform well enough to sustain themselves and their owners during the year.
The following is a checklist of things that may need your attention.

Grass tetany. This is a problem that is normally seen in high producing cows. Too much protein and potassium in the diet interferes with normal calcium and magnesium use in their body. This is seen most often in the early spring when cows are grazing lush green pasture and milking heavy. It can also occur prior to calving, when calcium, magnesium, and potassium amounts and ratios are out of whack. In some areas grass hay is the culprit. It may also be seen when a lot of grass straw is being fed. Yearling cattle may also suffer grass tetany when grazing very lush pasture. However, this is quite rare relative to grass tetany occurrence in cows. Treatment may require the ‘jugging’ of a solution of calcium and magnesium to restore balance rapidly. Prevention is accomplished by feeding a mineral that is high in calcium and magnesium. Prevention can also be addressed by adding alfalfa hay to a diet of grass hay or grass straw.

Nitrate toxicity. Cattle may be grazing pastures that have weeds such as pigweed, some of the mustards, miner’s lettuce, thistles, and nightshade are just a few plants that have caused nitrate toxicity during the grazing season. If planning to graze immature grain such as barley, wheat, or triticale, test for nitrates before turning in. Nitrate levels can also be high in water. When using a new water source, a test will identify problems such as nitrates before they cause a wreck. Many labs have a ‘livestock water’ package that is a combination of tests that identify elements that have caused livestock health problems in the past. I’d like to tell you that a mineral supplement would prevent or treat nitrate toxicity, but none will. There are products on the market that claim to prevent toxicity, but none are backed up by research evidence. If in doubt, have the plants tested. Don’t force cattle to graze every plant in a field. If nitrates are found, wait a few days and test again. Nitrates not only kill the animal grazing those plants, but if a pregnant animal consumes those plants, may cause abortion in those cows not visibly affected.

Pine needle abortion. When cattle eat green or dry ponderosa pine needles, there is a potential for abortion. I have never seen research that explains why the cattle choose to eat the needles. They seem to do it whether there is lots of grass or very little grass available. Cases have been reported where cattle in a feedlot ate the dry needles from a tree near the edge of the pen. These cattle had access to hay, salt, and water at all
times. Cows eating pine needles during the last third of gestation put their calves at risk. Pine needle calves are born weak and smaller than normal. The toxic principle in pine needles interrupts blood flow to the unborn calf. The cow is also at risk because the birthing process is not normal. Cows may not clean and may get uterine infections. Cattle can be fenced away from trees during the critical time each year, but if a tree dies and a good storm comes along, pine needles can blow into a pasture that is several hundred yards from the trees. Once again, there is no mineral supplement that can prevent or treat pine needle toxicity.

Lupine. Lupine is a poisonous plant that grows throughout much of Eastern Oregon and Washington range. When cows graze this plant is causes their calves to be born with crooked legs and/or cleft palate. Research has found that cows in thin condition are more likely to graze these plants, and are less able to prevent problems. The most critical period appears to be between the 40th and 47th day of pregnancy. Weather also seems to be a factor as it relates to plant growth. There is no supplement that will prevent this problem. There is no treatment available for the deformed calves.

Simple nutrient deficiency. I finally found one that a mineral can solve. Most generally a green-growing pasture or range will have enough protein and energy to support some growth and maintain the health of grazing livestock. However, several minerals can be deficient in the forage. The minerals that are most often deficient are zinc, copper, and selenium. We used to believe that phosphorus was deficient in most forage during most of the year. This mineral is extremely important to normal performance; it is also the single most-expensive nutrient in your mineral supplement. The National Research Council has reduced their estimate of beef cattle requirement for phosphorus. They are the body of scientists that set guidelines for feeding cattle for nutritionists all over the U.S. The highest requirement is for a 500 lb calf being fed a very high energy ration. The amount is 0.34% of the diet. A 1400 lb superior milking cow requires 0.23% phosphorus. Most of the year a beef cow can get by with 0.17% phosphorus in the diet. It is definitely worth your while to find out if your grazing forage or hay has sufficient phosphorus. Minerals that are deficient can cause poor performance, reproduction, and health. If the animals can’t grow, milk, breed, and stay in good health why would they be left in that area? Those factors are basic to good livestock management. I won’t go into the functions of the minerals; because they are complex. Each mineral plays many roles in the body, and when it is deficient, the animal can’t perform that bodily function in a normal way. The only way you can determine forage mineral values is to take samples and have them tested. You might take several samples as the range changes while grazing. You don’t need to do it every year. One good test will provide you with an amazing amount of information. I know you won’t sample exactly what the cattle eat, but testing for minerals has shown to be a good indication of the minerals cattle were eating while on that range. In some parts of the Northwest, livestock and forage extension personnel have studied range forage and have values that you can use.

Worms. There is an excellent de-wormer that can be added to a free choice mineral supplement. The product name is Safeguard. It is fed for a period of 3-6 days. Cattle may not be slaughtered within 14 days of treatment. I think it will surprise you if you take manure samples to your vet after the cattle have been on grass 30 days or more, even if the cattle have been de-wormed in the fall or just prior to turn out. In many instances your vet may determine that there are enough worms to justify the expense of de-worming again. The biggest surprise comes to those who graze mountain meadows or desert range. We have always assumed that there are no worms in those areas, and de-worming wasn’t necessary. That isn’t always true.

Flies. There are two products available for controlling flies through a mineral. One is S-Methoprene. This is marketed as Altosid or RS-10. These products are labeled for control of horn flies. Preventing fly larvae development in the manure is the means of control. The KEY TO SUCCESS is to start using the product just before or as the flies appear. Using after the fly season has begun reduces the effectiveness.

Rabon is the other fly drug. It controls face flies, horn flies, stable flies, and house flies. It also controls flies by it’s’ action in the manure.

Foot Rot. There is no approved medicated feed additive for the control of foot rot. Foot rot occurs when the foot tissue is weakened or broken. Stepping on sharp rocks or ice may be at fault. Standing on ground that is continuously wet may also be a factor. The level of iodine in iodized salt is not sufficient to control this problem. Chelated zinc does help maintain hoof health, and as such offers protection to a degree. Treatment is by injectable antibiotic.

Bloat. If you graze legume pastures there is always a chance of bloat. Alfalfa and the clovers are more prone to cause bloat than other legumes. Bloat is prevented effectively by using Bloatguard. This product can be incorporated into a mineral. The mineral with this additive should be fed to the cattle 2 weeks prior to exposure to the legumes. Pasture management is especially important if you plan to graze legumes. Never
turn hungry animals into this type of pasture. It is also best if you wait until the dew is off the pasture before turning animals in. Treatment is by hosing (stick a piece of hose through the mouth into the paunch) to break up the foam and let the trapped gas escape. If that doesn’t work, mineral oil can be poured into the gut through the hose.

Pinkeye. This is a disease caused by a bacteria. It affects the tissue in and around the eye. Once the bacteria invades the tissue other bacteria may enter the body further compounding the problem. There are many factors that cause irritation that gives the bacteria a chance to take hold. Some of these factors are exposure to UV light (sunlight). Cattle with light colored skin seem to be more susceptible to sunlight than those having black or dark brown colored skin. Other factors include face flies, stable flies and house flies. Certain types of forage have long stems and awns that irritate the eye while cattle are grazing. Dust can also be an irritant that starts the problem. This disease can be prevented by vaccination. Pasture management to control old mature plants helps as does shade. Fly control is essential since flies spread pinkeye. Using an injectable antibiotic is usually effective in treating the disease.

There are many challenges that affect the performance and health of grazing livestock. In most instances there are means available to prevent and treat these problems through management or supplement before they cause harm to the animal and loss of income for the rancher

Michael J. Mehren Ph.D. is a livestock nutritionist who almost succumbed to bloat immediately following Easter dinner. He can be contacted by Email at mehrens@eotnet.net.



		Grazing Checklist BY MIKE MEHREN Spring and summer or whenever you have rich green feed is the time of year that cattle should perform well enough to sustain themselves and their owners during the year. The following is a checklist of things that may need your attention. Grass tetany. This is a problem that is normally seen in high producing cows. Too much protein and potassium in the diet interferes with normal calcium and magnesium use in their body. This is seen most often in the early spring when cows are grazing lush green pasture and milking heavy. It can also occur prior to calving, when calcium, magnesium, and potassium amounts and ratios are out of whack. In some areas grass hay is the culprit. It may also be seen when a lot of grass straw is being fed. Yearling cattle may also suffer grass tetany when grazing very lush pasture. However, this is quite rare relative to grass tetany occurrence in cows. Treatment may require the ‘jugging’ of a solution of calcium and magnesium to restore balance rapidly. Prevention is accomplished by feeding a mineral that is high in calcium and magnesium. Prevention can also be addressed by adding alfalfa hay to a diet of grass hay or grass straw. Nitrate toxicity. Cattle may be grazing pastures that have weeds such as pigweed, some of the mustards, miner’s lettuce, thistles, and nightshade are just a few plants that have caused nitrate toxicity during the grazing season. If planning to graze immature grain such as barley, wheat, or triticale, test for nitrates before turning in. Nitrate levels can also be high in water. When using a new water source, a test will identify problems such as nitrates before they cause a wreck. Many labs have a ‘livestock water’ package that is a combination of tests that identify elements that have caused livestock health problems in the past. I’d like to tell you that a mineral supplement would prevent or treat nitrate toxicity, but none will. There are products on the market that claim to prevent toxicity, but none are backed up by research evidence. If in doubt, have the plants tested. Don’t force cattle to graze every plant in a field. If nitrates are found, wait a few days and test again. Nitrates not only kill the animal grazing those plants, but if a pregnant animal consumes those plants, may cause abortion in those cows not visibly affected. Pine needle abortion. When cattle eat green or dry ponderosa pine needles, there is a potential for abortion. I have never seen research that explains why the cattle choose to eat the needles. They seem to do it whether there is lots of grass or very little grass available. Cases have been reported where cattle in a feedlot ate the dry needles from a tree near the edge of the pen. These cattle had access to hay, salt, and water at all times. Cows eating pine needles during the last third of gestation put their calves at risk. Pine needle calves are born weak and smaller than normal. The toxic principle in pine needles interrupts blood flow to the unborn calf. The cow is also at risk because the birthing process is not normal. Cows may not clean and may get uterine infections. Cattle can be fenced away from trees during the critical time each year, but if a tree dies and a good storm comes along, pine needles can blow into a pasture that is several hundred yards from the trees. Once again, there is no mineral supplement that can prevent or treat pine needle toxicity. Lupine. Lupine is a poisonous plant that grows throughout much of Eastern Oregon and Washington range. When cows graze this plant is causes their calves to be born with crooked legs and/or cleft palate. Research has found that cows in thin condition are more likely to graze these plants, and are less able to prevent problems. The most critical period appears to be between the 40th and 47th day of pregnancy. Weather also seems to be a factor as it relates to plant growth. There is no supplement that will prevent this problem. There is no treatment available for the deformed calves. Simple nutrient deficiency. I finally found one that a mineral can solve. Most generally a green-growing pasture or range will have enough protein and energy to support some growth and maintain the health of grazing livestock. However, several minerals can be deficient in the forage. The minerals that are most often deficient are zinc, copper, and selenium. We used to believe that phosphorus was deficient in most forage during most of the year. This mineral is extremely important to normal performance; it is also the single most-expensive nutrient in your mineral supplement. The National Research Council has reduced their estimate of beef cattle requirement for phosphorus. They are the body of scientists that set guidelines for feeding cattle for nutritionists all over the U.S. The highest requirement is for a 500 lb calf being fed a very high energy ration. The amount is 0.34% of the diet. A 1400 lb superior milking cow requires 0.23% phosphorus. Most of the year a beef cow can get by with 0.17% phosphorus in the diet. It is definitely worth your while to find out if your grazing forage or hay has sufficient phosphorus. Minerals that are deficient can cause poor performance, reproduction, and health. If the animals can’t grow, milk, breed, and stay in good health why would they be left in that area? Those factors are basic to good livestock management. I won’t go into the functions of the minerals; because they are complex. Each mineral plays many roles in the body, and when it is deficient, the animal can’t perform that bodily function in a normal way. The only way you can determine forage mineral values is to take samples and have them tested. You might take several samples as the range changes while grazing. You don’t need to do it every year. One good test will provide you with an amazing amount of information. I know you won’t sample exactly what the cattle eat, but testing for minerals has shown to be a good indication of the minerals cattle were eating while on that range. In some parts of the Northwest, livestock and forage extension personnel have studied range forage and have values that you can use. Worms. There is an excellent de-wormer that can be added to a free choice mineral supplement. The product name is Safeguard. It is fed for a period of 3-6 days. Cattle may not be slaughtered within 14 days of treatment. I think it will surprise you if you take manure samples to your vet after the cattle have been on grass 30 days or more, even if the cattle have been de-wormed in the fall or just prior to turn out. In many instances your vet may determine that there are enough worms to justify the expense of de-worming again. The biggest surprise comes to those who graze mountain meadows or desert range. We have always assumed that there are no worms in those areas, and de-worming wasn’t necessary. That isn’t always true. Flies. There are two products available for controlling flies through a mineral. One is S-Methoprene. This is marketed as Altosid or RS-10. These products are labeled for control of horn flies. Preventing fly larvae development in the manure is the means of control. The KEY TO SUCCESS is to start using the product just before or as the flies appear. Using after the fly season has begun reduces the effectiveness. Rabon is the other fly drug. It controls face flies, horn flies, stable flies, and house flies. It also controls flies by it’s’ action in the manure. Foot Rot. There is no approved medicated feed additive for the control of foot rot. Foot rot occurs when the foot tissue is weakened or broken. Stepping on sharp rocks or ice may be at fault. Standing on ground that is continuously wet may also be a factor. The level of iodine in iodized salt is not sufficient to control this problem. Chelated zinc does help maintain hoof health, and as such offers protection to a degree. Treatment is by injectable antibiotic. Bloat. If you graze legume pastures there is always a chance of bloat. Alfalfa and the clovers are more prone to cause bloat than other legumes. Bloat is prevented effectively by using Bloatguard. This product can be incorporated into a mineral. The mineral with this additive should be fed to the cattle 2 weeks prior to exposure to the legumes. Pasture management is especially important if you plan to graze legumes. Never turn hungry animals into this type of pasture. It is also best if you wait until the dew is off the pasture before turning animals in. Treatment is by hosing (stick a piece of hose through the mouth into the paunch) to break up the foam and let the trapped gas escape. If that doesn’t work, mineral oil can be poured into the gut through the hose. Pinkeye. This is a disease caused by a bacteria. It affects the tissue in and around the eye. Once the bacteria invades the tissue other bacteria may enter the body further compounding the problem. There are many factors that cause irritation that gives the bacteria a chance to take hold. Some of these factors are exposure to UV light (sunlight). Cattle with light colored skin seem to be more susceptible to sunlight than those having black or dark brown colored skin. Other factors include face flies, stable flies and house flies. Certain types of forage have long stems and awns that irritate the eye while cattle are grazing. Dust can also be an irritant that starts the problem. This disease can be prevented by vaccination. Pasture management to control old mature plants helps as does shade. Fly control is essential since flies spread pinkeye. Using an injectable antibiotic is usually effective in treating the disease. There are many challenges that affect the performance and health of grazing livestock. In most instances there are means available to prevent and treat these problems through management or supplement before they cause harm to the animal and loss of income for the rancher Michael J. Mehren Ph.D. is a livestock nutritionist who almost succumbed to bloat immediately following Easter dinner. He can be contacted by Email at 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