September 1999
Volume 2, Issue 6

INSIDE THIS ISSUE
Drought Concerns: Beware of Nitrates!, W. P. Shulaw, K. H. Hoblet, and D. F. Gerken
Calendar of Events
Cheese Inventories Dip – Cheese Prices Roar!, C. S. Thraen
Department of Animal Sciences Names New Chair, Associate Chair
Ohio State Fair Dairy Cattle Skillathon Results, J. E. Winkler

DROUGHT CONCERNS: BEWARE OF NITRATES!
William P.  Shulaw DVM, Extension Veterinarian; Kent H. Hoblet DVM, Extension Veterinarian;  Diane F.  Gerken DVM, Veterinary Toxicologist.
 

Drought Concerns

Reminiscent of 1988, we are facing possible problems with feeding drought-stressed plants and potential toxic plant consumption by animals that are short on feed because of the drought.  Recently, the Ohio Department of Agriculture’s Consumer Analytical Laboratory has announced free testing of corn/corn silage for nitrates because of the drought.  Although not all areas of Ohio are affected, most concerns center around animals being fed, or allowed to graze, stressed plants or plants not normally used for animals.  This article will focus on nitrate toxicity but cyanide (prussic acid toxicity) and the consumption of toxic plants by animals are also a concern during drought periods.
 

Nitrates

Nitrate, itself, is not highly toxic.  Problems develop when nitrate (NO3) is converted to nitrite (NO2) in the ruminant animal’s digestive system.  Plants normally convert soil nitrate to plant protein.  However, when stressed by dry weather, plants may be unable to totally effect this conversion and nitrates may accumulate.  In the live animal the nitrite which is formed binds to the hemoglobin molecules in red blood cells and  produces methemoglobin which prevents oxygen transmission to tissues and cells.
 

Diagnosis of Acute Nitrate Toxicity

1. In the live animal pale to brown mucous membranes, weakness, dyspnea, rapid breathing, rapid pulse, recumbency, and chocolate-brown blood are common signs of acute poisoning.

2. In the dead animal the chocolate brown blood with staining and congestion of the tissues are the predominant finding.   Methemoglobin is not stable in blood for more than an hour and nitrite may also rapidly disappear from the blood.   Attempts may be made to analyze urine, plasma, serum, aqueous humor and rumen contents for nitrate content if they can be collected immediately after death.  Results may vary depending on samples taken and freshness.  Samples that must be mailed or held overnight should be frozen.

3. Forage, hay, water or feed samples can be analyzed for nitrate content.  Producers should be advised that total nitrate from all sources must be considered.  In some cases water sources have been shown to be high in nitrate content.  Nitrate concentrations for feed samples are usually reported on a dry weight basis.
 

Plant and Soil Factors Important in Nitrate Toxicity

1. Species of plant.  Certain weeds and forage plants are known to concentrate nitrates.  These include: pig weed, lamb’s quarters, jimson weed, sweetclover, dock, nightshade plants, Johnson grass, sorghum, oat hay, barley, wheat, and corn.

2.Soil content of nitrates.  The form and timing of nitrogen application to plants, as well as the growth stage of the plant, influences the amount of nitrate accumulation.

3.Other soil factors.  For example, soils deficient in sulfur or phosphorous and high soil acidity favor plant nitrate accumulation.

4. Drought.

5.Herbicide use.  Some herbicides, such as 2, 4-D,  increase plant growth and nitrate uptake in the early period following application.
 

Other Determinants of Nitrate Toxicity

• Nitrates accumulate in vegetative tissue, not seeds, of plants.  Therefore, ruminants are more likely to be exposed than swine.  The highest levels occur just before flowering.  In corn, stalks are typically higher than leaves in nitrate levels.  Oat hay may be particularly high in nitrates.
• Proper ensiling causes a reduction of nitrates to ammonia so that a majority of nitrates are lost.  This process may take several weeks if corn is very high in nitrates when ensiled.
• Ruminants may adapt to relatively high nitrate levels when doses are spread throughout the feeding period or mixed into the total diet; i.e., diluted.  Tolerance also may be increased if ruminants are concurrently fed readily fermentable carbohydrates.
• Swine are relatively insensitive to nitrates in their diet because they can’t convert them to nitrites.  They are, however, very sensitive to feeds containing preformed nitrates.
• Nitrate toxicity is apparently neither reduced nor enhanced by simultaneously feeding urea.
• Feeding green feeds (e.g., “green chop”) or pasturing on forages high in nitrate presents the greatest risk of toxicity.
• Acute nitrate toxicity may be expected when forage concentrations alone exceed 1.0% nitrate (10,000 ppm) ON A DRY MATTER BASIS.  Acute toxicity from nitrate in water alone may be expected at 1,500 ppm (or 1500 mg/l.)
• The toxic level of nitrates to animals is ADDITIVE from all sources.  Because, in a drought year forages may be borderline toxic other possible nitrate sources must also be scrutinized.
• Chronic nitrate toxicity, although suspected, has not been documented in controlled studies.  In a Wisconsin, study dairy cows were exposed to 400 ppm of nitrate in their water for 35 months without significantly affecting either health or production.
• Laboratory Diagnosis - A number of public and private laboratories will analyze forages and water for nitrate levels.  If accurate interpretation of results are expected extra care should be taken in obtaining representative samples.  Most laboratories will report nitrate content as either ppm of nitrate (NO3) or nitrate nitrogen (NO3-N).  To convert NO3-N to NO3 multiply by 4.4.
• For livestock owners it is wise to sample to forages with a worst case scenario in mind.  This means to 1) always test before feeding if there is any question about the potential for nitrate levels in the feed, 2) sample areas of a field that may represent the most stressed plants if grazing them is anticipated, 3) sample corn to be ensiled in the most stressed areas, ensile under moisture and other conditions that promote ideal fermentation, allow 30 days of fermentation, and do not feed until the silage is tested for nitrates, and finally 4) be sure enough samples are taken to be representative of what is to be fed.
• Field test kits have been recommended for use in screening corn and other forages for nitrates.  Their accuracy is unknown.  The old field test based upon diphenylamine and sulfuric acid does not have a lower limit of detection capable of detecting nitrate at the lower levels that may still cause poisoning.  Color change indicates more than 2% nitrate.  One percent is lethal.  Some other kits have been developed to test water for nitrates and do not report results on a dry weight basis.  This may make interpretation of the result for forages difficult.  Be sure the sampling procedures and test method used to determine nitrate level are reliable.

Obviously we haven’t covered all the possibilities and potential problems that may be observed as a result of this year’s drought.  Furthermore, if alternative and damaged feeds will be used by producers, this will be a year to encourage forage testing for its nutritive value as a basis for ration formulation.
 

CHEESE INVENTORIES DIP - CHEESE PRICES ROAR!
Cameron S. Thraen
AED/ The Ohio State University/ OSUE
Dairy Economist / Extension Specialist

What is going on here?  What can I say!  The cheese market is incredible.  Repeat after me:  "It has been very, very good to me."  The 40-pound block cheese price has continued to sail to new heights this summer.  Back in late May it looked as if all was lost but then - walla - the price was off and running, increasing from a measly $1.21 per pound to a record $1.9725 on August 20th.  What the heck happened?

In the field of commodity economics there is an area of study aptly called "Impact of News Announcements".  In brief, the point of the research is to determine the extent to which "news announcements", e.g., market reports, crop reports, inventory reports, etc., move the market.  Well, the cheese market clearly got a boost upward from the USDA's June Cold Storage Report.  That report signaled lower than anticipated commercial stocks of cheese on hand and sent the cash and futures market prices seeking new highs.  Demand is strong, production off and inventories not as high as anticipated.  A recipe for high cheese prices.

Now along comes the July Cold Storage report and guess what?  The USDA has revised the June numbers UP a whopping 65.4 million pounds.  Add to this a reported increase in July commercial stocks of 15.4 million pounds and we have over 554 million pounds in commercial inventory.  This is whopping 20.3% larger than last year.  Total July 31 cheese inventory is put at 762.5 million pounds, 28% higher than last year at this time.

What about the effect of "news in announcements"?  From August 13th to August 20th, the November and December futures contracts on the Chicago Mercantile Exchange declined over $2.00 per hundredweight.  According the Dairy & Food Market Analyst Report, Inc. of August 20th, if you had been tracking the BFP futures contracts carefully you could have locked in the equivalent of $16.69 BFP for the 4th quarter of 1999!  To put this in perspective, this is over $4.00 higher than the average BFP for the typically experience in the last quarter of the year.

What about by the time you read this report?  You can still lock in some very good fall prices if you know your cost of production and have learned to follow the markets.  However, if you wait to see what the highest price will be you will miss the boat.  The $16.69 equivalent price vanished after August 12 as the market reacted to the "news" that there is a lot more cheese out there than formerly anticipated.  When the market breaks, and you can take it from me it will break, the price will come down faster than water off a tin roof and it will be too late to act.

What does mean for your operation?  If you are tapping into the wealth of information on the markets out there - good for you!  If not, now is the time to make this a priority.  As the new Federal Order provisions come into place, the tie between the dollars in your milk check and the behavior in the product markets will only become more pronounced.  These are the "new rules" of the game in the dairy business.

BFP for August and September

Given the impact of the cheese market on the BFP calculation and the well understood lag in NASS survey cheese prices behind the CME price, the expectation for the August announced BFP is $16.00 - $16.20.  Look for the September BFP to possibly surpass last years record of $17.34 and be in the $17.40 - $17.55 range!  What's the number of the tax accountant?
 

DEPARTMENT OF ANIMAL SCIENCES NAMES NEW CHAIR, ASSOCIATE CHAIR

The Department of Animal Sciences has two new leaders.  James E. Kinder, professor of animal science at the University of Nebraska and associate director of Nebraska’s Center for Biotechnology, has been named associate chair.

Kinder replaces Dave Zartman, who has returned to teaching after 15 years as chair.  Pate succeeds Forest Muir, who has moved to a position in the Director’s Office of the Ohio Agricultural Research and Development Center.  The appointments took effect June 15.

Kinder received his doctorate in animal science/reproductive endocrinology from Washington State University.  He received his master’s degree in animal science/reproductive physiology from the University of Nebraska and his bachelor’s degree in animal husbandry/production from the University of Missouri.  He has been associate director of Nebraska’s Center for Biotechology since 1990 and was promoted to professor in the university’s Department of Animal Science in 1986.  His research at Nebraska focused on neuroendocrine regulation of puberty, the estrous cycle, and ovarian follicular and corpora lutea development in female cattle.

Pate holds a doctorate in reproductive physiology from the University of New Hampshire.  She received her bachelor’s degree in animal science from the University of Delaware.  Her research focuses on corpus luteum function, including the regulation of luteolysis, prostaglandin production by the corpus luteum, interactions between the immune system and the reproductive system, and nutritional/metabolic effects on fertility.

enVision, August 1999
 

OHIO STATE FAIR DAIRY CATTLE SKILLATHON RESULTS
Jennifer Winkler
The Ohio State University
Extension Associate

Nearly 121 4-H and FFA youth participated in the 1999 Ohio State Junior Fair Dairy Cattle Skillathon, held August 6, 14, and 20 at the Ohio State Fairgrounds in Columbus, Ohio.  During the Skillathon, participants tested their dairy knowledge in the areas of quality assurance, feeds and feeding, external anatomy, udder anatomy, and milk products.  Awards were presented to the over-all high scorers in each age division and to the over-all winner.  Each age division winner received a monetary award in the amount of $75.20 from the Ohio State Fair Youth Reserve Fund and an inscribed wooden box sponsored by CT Farm and Country Stores.  Furthermore, the over-all winner received a banner and an embroidered jacket.

The winners for the 1999 Dairy Cattle Skillathon are as follows: 9 year-old - Megan Mowrer (Belmont County); 10 year-old - Curtis Bickel (Clinton County); 11 year-old - Wendy Sewell (Athens County); 12 year-old - Adam Specht (Tuscarawas County); 13 year-old - Amanda Scheibe (Wayne County); 14 year-old - Neil Moff (Mahoning County); 15 year-old - Jason Nuhfer (Huron County); 16 year-old - Mamie McGuire (Logan County); 17 year-old - Kristin Flowers (Wayne County); and 18 year-old - Brad Wilhelmy (Wayne County).  Brad Wilhelmy of Wayne County was also the over-all Skillathon winner.
 

CALENDAR OF EVENTS

Inaugural Tri-State Dairy Management Conference
November 10-11, 1999
Fort Wayne, Indiana
Contact: Jennifer Winkler or Normand St-Pierre
        Phone: 614/688-3143 or
        Email:  winkler.35@osu.edu
Registration deadline: October 15, 1999

All educational programs conducted by The Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Keith L. Smith, Director, The Ohio State University Extension.