Post by Tammy on May 4, 2009 8:16:35 GMT -5
Reminder to everyone that this is the time of year when we have to be careful about providing high-mag supplements to our cattle!
Here is a good article:
Grass Tetany and Its Prevention
By Jackie Nix
As Old Man Winter finally loosens his grip, we need to think about protecting cattle
against grass tetany. Grass tetany (also called grass staggers, wheat pasture poisoning,
and hypomagnesia) is a metabolic disorder. Grass tetany happens most frequently when
cattle are grazing lush, immature grass and often strikes the best cows in the herd. This
disorder often results in death. Cattle producers collectively loose several million dollars
to grass tetany every year.
What are the Symptoms?
Symptoms of grass tetany include: grazing away from the herd, irritability, muscular
twitching in the flank, wide-eyed staring, uncoordinated gait, convulsions, coma, and
death. It is not uncommon for these symptoms to occur in a span of as little as 2 to 3
hours, making early detection extremely difficult. Often the first observed symptom is a
dead cow. If a cow has died of grass tetany evidence of thrashing is usually apparent in
the sod around the cow.
What Causes Grass Tetany?
Grass tetany is a metabolic disorder characterized by low blood magnesium levels. The
causes of low blood magnesium levels are varied and usually include one or more the
following factors: low dietary magnesium, nutrient imbalances that interfere with
magnesium metabolism and high milk production.
Environmental conditions and management factors combine to result in pasture forages
with low magnesium levels. Immature grasses and cereal grains have lower magnesium
levels than more mature forages. Additionally, cool, wet soil conditions reduce the
plant’s ability to utilize available magnesium, as do high nitrogen and potassium levels
from chemical fertilizers or manure. As a result, pastures receiving fertilization in early
spring tend to present a higher risk of grass tetany than pastures fertilized in the fall or
late spring. Conversely, inadequate phosphorus levels hinder the plant’s ability to absorb
magnesium, thus foregoing fertilization is not recommended.
Dietary imbalances also affect susceptibility to grass tetany. Studies have shown that
inadequate salt intake may increase susceptibility to grass tetany. Consumption of salt
and magnesium simultaneously may be critical to increasing magnesium absorption.
Also, feeding high levels of potassium result in reduced magnesium absorption.
Mature cows are more susceptible to grass tetany because the ability to mobilize
magnesium from body stores (to correct low magnesium blood levels) decreases with
age. Also, mature cows tend to produce more milk, thus increasing their magnesium
requirements. The animals hardest hit are mature cows nursing calves less than two
months old, particularly heavy milkers. Young cattle, steers and bulls rarely get grass
tetany.
When is the Risk of Grass Tetany the Greatest?
The exact time grass tetany strikes will vary from year to year depending upon available
moisture and temperature. Grass tetany occurs most frequently in the spring, often
following cool (temperatures between 45 and 60°F), rainy weather when grass is growing
rapidly, but also is seen in the fall with new growth of cool season grass or wheat
pastures. Symptoms are often seen 5 to 10 days after the onset of cold, wet weather.
Prevention of Grass Tetany
Because an outbreak of grass tetany can be so costly, prevention is the best course. Some
prevention tactics include: Graze steers, heifers, dry cows and cows with calves over 4
months old on higher risk pastures because these groups are less likely to develop grass
tetany. Another option is to feed hay to cattle prior to turning out onto lush pastures for
the first 10 to 14 days. In areas where the grass tetany risk is high, provide magnesium to
brood cattle in the form of free choice supplements to maintain adequate blood
magnesium levels.
When using free choice high magnesium supplements it is important to remember that
palatability is key. Adequate levels of magnesium must be consumed on a daily basis in
order to protect cattle. Magnesium is naturally unpalatable to cattle so it is important that
supplements contain highly palatable ingredients to stimulate consumption. Typically,
beef cows require 15 to 20 mg magnesium per head per day. Blood magnesium levels
may fall as quickly as 48 hours after supplementation is stopped so consistent
consumption of the supplement is critical. For this reason, it is vitally important that you
use a supplement with dependable consumption.
www.sweetlix.com/media/documents/articles/Cattle_GrassTetanyandPrevention.pdf
Here is a good article:
Grass Tetany and Its Prevention
By Jackie Nix
As Old Man Winter finally loosens his grip, we need to think about protecting cattle
against grass tetany. Grass tetany (also called grass staggers, wheat pasture poisoning,
and hypomagnesia) is a metabolic disorder. Grass tetany happens most frequently when
cattle are grazing lush, immature grass and often strikes the best cows in the herd. This
disorder often results in death. Cattle producers collectively loose several million dollars
to grass tetany every year.
What are the Symptoms?
Symptoms of grass tetany include: grazing away from the herd, irritability, muscular
twitching in the flank, wide-eyed staring, uncoordinated gait, convulsions, coma, and
death. It is not uncommon for these symptoms to occur in a span of as little as 2 to 3
hours, making early detection extremely difficult. Often the first observed symptom is a
dead cow. If a cow has died of grass tetany evidence of thrashing is usually apparent in
the sod around the cow.
What Causes Grass Tetany?
Grass tetany is a metabolic disorder characterized by low blood magnesium levels. The
causes of low blood magnesium levels are varied and usually include one or more the
following factors: low dietary magnesium, nutrient imbalances that interfere with
magnesium metabolism and high milk production.
Environmental conditions and management factors combine to result in pasture forages
with low magnesium levels. Immature grasses and cereal grains have lower magnesium
levels than more mature forages. Additionally, cool, wet soil conditions reduce the
plant’s ability to utilize available magnesium, as do high nitrogen and potassium levels
from chemical fertilizers or manure. As a result, pastures receiving fertilization in early
spring tend to present a higher risk of grass tetany than pastures fertilized in the fall or
late spring. Conversely, inadequate phosphorus levels hinder the plant’s ability to absorb
magnesium, thus foregoing fertilization is not recommended.
Dietary imbalances also affect susceptibility to grass tetany. Studies have shown that
inadequate salt intake may increase susceptibility to grass tetany. Consumption of salt
and magnesium simultaneously may be critical to increasing magnesium absorption.
Also, feeding high levels of potassium result in reduced magnesium absorption.
Mature cows are more susceptible to grass tetany because the ability to mobilize
magnesium from body stores (to correct low magnesium blood levels) decreases with
age. Also, mature cows tend to produce more milk, thus increasing their magnesium
requirements. The animals hardest hit are mature cows nursing calves less than two
months old, particularly heavy milkers. Young cattle, steers and bulls rarely get grass
tetany.
When is the Risk of Grass Tetany the Greatest?
The exact time grass tetany strikes will vary from year to year depending upon available
moisture and temperature. Grass tetany occurs most frequently in the spring, often
following cool (temperatures between 45 and 60°F), rainy weather when grass is growing
rapidly, but also is seen in the fall with new growth of cool season grass or wheat
pastures. Symptoms are often seen 5 to 10 days after the onset of cold, wet weather.
Prevention of Grass Tetany
Because an outbreak of grass tetany can be so costly, prevention is the best course. Some
prevention tactics include: Graze steers, heifers, dry cows and cows with calves over 4
months old on higher risk pastures because these groups are less likely to develop grass
tetany. Another option is to feed hay to cattle prior to turning out onto lush pastures for
the first 10 to 14 days. In areas where the grass tetany risk is high, provide magnesium to
brood cattle in the form of free choice supplements to maintain adequate blood
magnesium levels.
When using free choice high magnesium supplements it is important to remember that
palatability is key. Adequate levels of magnesium must be consumed on a daily basis in
order to protect cattle. Magnesium is naturally unpalatable to cattle so it is important that
supplements contain highly palatable ingredients to stimulate consumption. Typically,
beef cows require 15 to 20 mg magnesium per head per day. Blood magnesium levels
may fall as quickly as 48 hours after supplementation is stopped so consistent
consumption of the supplement is critical. For this reason, it is vitally important that you
use a supplement with dependable consumption.
www.sweetlix.com/media/documents/articles/Cattle_GrassTetanyandPrevention.pdf