|
February
|
| 19-24 |
Hardee County Fair, Cattlemen's Arena - Wauchula |
| 27 |
Johne's Disease Meeting - Hardee County Agri-Civic Center, 4:30 p.m. |
|
March
|
| 7 |
Beef Cattle Herd Health Seminar - Okeechobee |
|
April
|
| 3,5,10,12 |
Beef Cattle Management Short Course, Hardee County Extension Office |
| 21 |
Marketing Florida Cattle - Sebring |
| 24-26 |
Reproductive Management School - Wauchula |
Over the last few weeks I have heard of at least three cases
of nitrate poisoning in Hardee county cattle herds. What little grass may be available
quickly accumulates nitrates after even a small shower so this is something to be
keenly aware of during the drought. Be especially careful about reintroducing
cattle onto pastures recently fertilized with nitrogen. This short but timely article
by Dr. John Arthington at the Ona Range Cattle REC should be of interest to all cattle
producers.
- Nitrate Poisoning in Grazing Cattle -
Nitrate poisoning in grazing cattle occurs following the consumption of plants that contain
excessive amounts of nitrate. Nitrate is naturally converted to nitrite and then to ammonia by
microbes in the rumen. Acute or chronic nitrite poisoning occurs when the amount of nitrate
consumed exceeds the rumen's ability to convert into ammonia. This excess nitrite is then
absorbed into the bloodstream were it complexes with hemoglobin. Bound with nitrite,
hemoglobin is unable to bind and transport oxygen causing a buildup of methemoglobin in the
blood. Methemoglobin has a chocolate brown color, which is a telltale sign of acute nitrate
poisoning in cattle. By blocking the transport of oxygen to peripheral tissue, acute nitrate
poisoning results in suffocation.
Plants take up nitrate in normal growth and developmental processes. During
photosynthesis the plant converts nitrates into amino acids and proteins. Nitrate accumulation will
occur most readily in the structural components of the plant closest to the ground. Plant leaves are
usually low in nitrate. Nitrate problems are most common in young growing plants, which are
rapidly taking up nitrate to fuel growth.
Excessive plant nitrate accumulation may
occur in at least two ways:
-
Cultivated crop forages (typically annuals) which are grown on heavily fertilized and
cultivated soil tend to be the most common accumulators of nitrate. Problems with excess
nitrate accumulation may be most common in soils heavily fertilized with poultry or livestock
manure. Typically, commercial fertilizers applied at recommended rates are not contributors
to excessive nitrate accumulation.
- Plant stress and environmental factors which decrease the photosynthetic ability of the plant
will also contribute to nitrate accumulation:
(a) Hail or wind damage that may decrease plant leaf cover will decrease photosynthesis
and increase nitrate accumulation.
(b) Drought-stressed plants will rapidly accumulate nitrate after a rainfall. In these
situations, the harvesting of suspect pastures should be delayed by several days.
(c) Multiple cloudy days following a rain, especially in newly fertilized forages, will
contribute to nitrate accumulation.
Cattle consuming excessive amounts of nitrate will often exhibit difficulty in breathing, rapid
mouth breathing, bluish skin color around eyes and mouth, and muscle tremors. Although not
readily visible, blood with a chocolate-brown color is a classic symptom of acute nitrate poisoning.
Animals experiencing acute nitrate poisoning may die within 4 hours, therefore response time is
critical. Effective treatment is achieved by an intravenous injection of methylene blue (1 to 2 %
solution). It is important to note that methylene blue is not an approved drug for use in food
animals. Please consult your veterinarian for more information.
| Table 1. Ranges
in safety of nitrate in forages. |
| %NO3 |
%KNO3 |
%NO3-N |
Recommendations |
| 0 to .50 |
0 to 1.0 |
0 to .15 |
Generally considered safe |
| .50 to 1.5 |
1.0 to 1.5 |
.15 to .45 |
Caution - should dilute intake |
| >1.5 |
>1.5 |
>.45 |
Danger - Do not feed |
| *Values are reported on a dry matter basis.
|
If you suspect your forage may be high in nitrate it is a good idea to have it tested. Many
commercial laboratories offer nitrate testing in forage crops. It is important to note that
laboratories vary in their method of reporting nitrate concentrations. Results may be reported as
nitrate (NO3), potassium nitrate (KNO3), or nitrate nitrogen (NO3-N). The values provided are
commonly accepted ranges for determining the safety of forage nitrate concentrations (Table 1).
There is a great deal of variability in the range of susceptibility between cattle and these ranges are
provided only as general guidelines.
Dr. John Arthington, Range Cattle REC Newsletter, October 2000
- Beef Cattle Management Short Course -
By popular demand the Beef Cattle Management Short Course will be offered at the Hardee
County Extension Office again this year. This course is designed to cover a wide range
of topics of interest to beef cattle producers. It is offered on Tuesday and Thursday
evenings from 7-9 PM for two consecutive weeks. We have had about 55 ranchers take
the course. Some have a lifetime of experience and some are just getting started. We
have a good time and some lively discussion. Most of all we learn from each other.
One thing life is teaching me is that there is more than one way to accomplish the same
thing and what works for one person is not right for the next. Come join us. You'll
be glad you did!
- Beef Cattle Herd Health Seminar -
Plan on attending the next Beef Cattle Herd Health Seminar sponsored by the South
Florida Beef Forage Group. We put this program together with
the drought in the back of our minds and have asked the folks at the Ona Range Cattle REC
to speak to us about getting our cattle through a tough winter. There will
be several veterinarians from the Okeechobee area available to answer your
questions about herd health. We are expecting a good turn out.
- Marketing Florida Cattle -
The South Florida Beef-Forage Program group of agents are hosting a comprehensive
marketing seminar for Florida's cow-calf producers. The meeting will be on Saturday,
April 21st at the Highlands County Agri-Civic Center from 10:00 AM to 4:00 PM. Please
come and plan on learning more about increasing options which you have to sell
your products. Mr. Tony Yeomans, Livestock Market owner/manager, will be discussing
marketing your cattle through local auctions and spaciality sales. Dr. Jim Gibb, eMerge,
business director, will be discussing " A Better Way to Buy and Sell Your Cattle".
Dr. Mark Wade, UF Agribusiness Professor will have a representative present to discuss marketing cattle
through their program. A spokesperson from the satellite/internet auction company will discuss
how your cattle can be seen by thousands thanks to modern technology. Mr. John Rule, IBBA
Member Services, will be discussing "Value Based Marketing and the Gold Star Marketing
Options". We look forward to seeing everyone on April 21st. Should you have any additional
questions please feel free to contact James Stice at 352-521-4288.
STAFF CONTRIBUTORS
Lochrane A. Gary - County Extension Director
Mary Alderman - Administrative Secretary
For questions or comments regarding this
publication contact
Lochrane A. Gary
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