Ag Connection
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This Month in Ag Connection
Prepare for Calving Season
Maintain Cow Body Condition for These Benefits
Stray Electrical Voltage Reduces Animal Performance
Flushing Takes the Work out of Cleaning the Dairy Barn
Callaway County Farmers Develop Environmental Protection Plan
January 1997
Volume 3, Number 1

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Publishing Information
Ag Connection is published monthly for Central Missouri Region producers and is supported by University Extension, the Commercial Agriculture program, the Missouri Agricultural Experiment Station and the College of Agriculture, Food and Natural Resources, UM-Columbia. Editorial board: Maryann Redelfs, Managing Editor; Parman Green, James Rogers, Mark Stewart, Melvin Brees, Don Day and Ron Alexander.

Comments or Suggestions?
Please send your comments and suggestions to Maryann Redelfs, Agronomy/Information Technology Specialist, University Outreach and Extension, 608 E. Spring Street, Boonville, MO 65233, call 660-882-5661, or send messages by e-mail to:

To send a message to an author, click on the author's name at the end of an article.

Prepare for Calving Season

Data collected over a 15-year period at the Livestock and Range Research Center in Miles City, Montana involving 13,000 calvings indicate that of all calves lost, 68% were lost within three days after birth. Of this percentage, 61% were lost as a result of dystocia (difficult birth). These data show that dystocia is the single largest cause of calf losses.

To decrease these losses, you need to understand the birth process and be able to recognize normal calving so that calving assistance can be given when needed. The birth process can be divided into three stages - preparation, fetal expulsion, and expulsion of the placenta (Table 1).

Table 1. Calving Stages

Stage Events Duration
1. Preparation
  1. Calf rotates to upright position.
  2. Uterine contractions begin.
  3. Cervix begins to dilate, allowing water sac to protrude.
2 to 6 hours
2. Fetal Expulsion
  1. Cow usually lies down and fetal contractions begin.
  2. Fetus enters birth canal.
  3. Front feet and head protrude first.
  4. Calf is delivered.
1 hour or less
3. Placental Expulsion
  1. Caruncle-cotyledon (button) attachments relax.
  2. Uterine contractions expel membranes.
2 to 12 hours

Cooperative Extension Service, Purdue University

At the beginning of stage 2, uterine contractions will occur every 2 to 3 minutes and last 1/2 to 1 1/2 seconds. Correct positioning of the calf as it enters the birth canal stimulates contractions of the diaphragm and straining of the abdominal muscles, which presses the head and feet of the calf against the cervix, causing it to relax and open.

If a cow shows signs of stage 1, but does not exhibit the straining associated with stage 2, check the position of the calf. As the calf continues through the birth canal and into the vagina, the water bag ruptures and the front feet appear first, hooves down, if positioned correctly. At this point contractions increase to every 15 seconds to 1 minutes. Following the appearance of the front feet will be the nose and head at which time maximum straining of the cow takes place to push the shoulders and chest through.

A cow's normal delivery time is 2 to 3 hours, however a calf can survive 6 to 12 hours in the uterus if progress is not made beyond the first stage of stage 1. To survive for this length of time, the umbilical cord must stay attached. Once the feet and head enter the birth canal, delivery should not be delayed or the flow of oxygen to the calf from the cow decreases which can cause stillborn births or brain damage to the calf.

When should you examine for abnormal presentation if no progress toward calving has been noted?

  1. If the cow has been in intense labor for 2 hours with no progress toward delivery.
  2. If the water sac or feet are observed, and delivery is not completed in 1 hour.

If, upon examination, you decide to assist the cow, make sure you are prepared. Table 2 offers a calving equipment checklist. What you do at this time impacts the fertility of the cow and the health of the calf.

Table 2. Calving Equipment Checklist

American Breeders Service. A.I. Management Manual

After calving is completed, a final crucial step must be completed --- expulsion of the placenta. If this does not occur within 12 hours after calving, treatment must be given to prevent infection (metritis).

Cows who have experienced calving difficulty are prone to retaining their placenta. A retained placenta is an ideal medium for bacteria and failure to treat can result in death of the cow or at the least, delayed rebreeding.

A final important tip --- cows are a lot tougher than we give them credit for. Winters are not so severe in Missouri to prevent calving out on the pasture. Calve those cows out on a clean pasture and not in a barn. It is the best scour preventer known.

Author: James Rogers, Livestock Specialist

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In return for maintaining cow body condition scores of 5 and 6 prior to calving, you can expect:

  1. Increased birth weights, resulting in healthy, vigorous calves.
  2. Increased calf disease resistance.
  3. Decreased calf death loss.
  4. Increased weaning weights.
  5. Increased colostrum quality and milk production.
  6. Reduced uterine infections.
  7. Quicker rebreeds. Research indicates that virtually all cows in good precalving condition start cycling within 90 days post calving. Only 66% of the cow herd starts cycling within the first 90 days if they were thin prior to calving.

Proper nutrition is especially critical for first calf heifers. Calves born to first calf heifers receiving proper diets prior to calving produced 11% more body heat and required less time to stand after calving compared to calves born to heifers receiving inadequate diets.

Author: Dale Watson, Livestock Specialist

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Stray Electrical Voltage Reduces Animal Performance

Stray voltage is a small voltage that exits between two surfaces (stanchion waterers, floor, ground, etc.). When an animal contacts both surfaces, current flows through its body. Voltages as low as 0.5V can affect some animals. Stray voltage can stress animals or cause them to avoid feeders and waterers, reducing production.

For example: In September, a dairy farmer called me stating that his cows were not drinking clean water from a tank and were drinking dirty ground water and urine. The cows were losing milk production and their somatic cell count was high. With a sensitive voltage meter we found 0.4V between the water and soil.

All electric power to the farm was disconnected and 0.4V was still present. Working with the electric company, the water tanks were grounded to a common electrical ground and soil around the tank, reducing the voltage to 0.05V. Cows are now drinking from the tank, and production is improving.

Author: Bill Buehler, Farm Management Specialist

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Flushing Takes the Work out of Cleaning the Dairy Barn

Remember the days when cleaning up after milking meant an hour or two of scraping, shoveling, and otherwise generally disagreeable work? A demonstration flushing system at the University of Missouri Foremost Dairy Farm shows that the manure from 200 cows can be collected and removed from the milking parlor and freestall barn with the turn of a valve, push of a button, or pull of a lever. The results are much better cleanliness and sanitation with less than 10 percent of the time and labor involved with the old scraping system.

When the University Dairy Farm received funding for a new freestall barn, Dr. Barry Steevens, and Dr. Charles Fulhage decided this would be a perfect opportunity to showcase and demonstrate the many advantages of flushing for collecting and removing manure. Five different flushing devices were designed and implemented in the new construction.

Rollover Tank ---

A 1,600 gallon cylindrical tank mounted to rotate on an axle through its center is used to flush the cow return alley at the dairy farm. Such a tank can be located as needed to flush areas which may not have been originally designed to be flushed. A design rule-of-thumb for such a tank is to provide 100 gallons of flush water volume per foot width of alley to be flushed. Rollover tanks are simple in design, easy to install, and can be discharged quickly for vigorous flushing action.

Gated Pipe ---

One of the four alleys in the freestall barn is flushed with a "gated" pipe. The 12" steel pipe recessed in the alley floor has 8 holes, each 3" x 6", in the exposed top. Water discharges at the rate of 7,000 gallons/minute through the holes when the 12" butterfly valve controlling the pipe is opened. The pipe is fed from a flush storage tower 9' in diameter and 24' tall (volume is about 12,000 gallons). Advantages of the gated pipe include even distribution of water over the width of the alley and adaptability of the design to virtually any alley width.

Pop-up Valve ---

Another of the four alleys is flushed with a pneumatically-controlled pop-up valve manufactured by the Ag-Pro Company. This valve is fed by 12" pipes from each of the two flush storage towers located at the front corners of the freestall barn. Use of compressed air enables the operator to simply open a small air valve which in turn releases pressure allowing the flush valve to open. Water pressure from the storage tanks causes the valve to "pop-up" as the water is released into the alley. Advantages of this valve include commercial availability and the recessed design with no protrusion above the alley floor.

Manual Valve ---

A manually-operated valve, also manufactured by the Ag-Pro Company is used to flush the third freestall barn alley. This valve is similar to the pop-up valve, except that it is opened manually by use of a lever. Simple design and no need for compressed air or electricity are advantages of this type valve.

Siphon Tank ---

A siphon tank is used to flush the fourth freestall alley. A 2,000 gallon tank discharges water through a 20" siphon tube to release water evenly over the alley width. Water pressure raises a flat, hinged lid as the tank empties in about 15 seconds. Advantages of the siphon tank include simple operation (no moving parts) and adaptability of the design to virtually any alley width.

"We have really improved our cleanliness and sanitation with a fraction of the labor since we began flushing," says John Denbigh, dairy farm manager. "All of the devices do an adequate job, but the gated pipe really stands out above the rest in terms of clean flushing, low maintenance, and ease of operation." During a typical winter, cold conditions will prevent flushing 14 to 15 days.

If you would like to see flushing in action, visit the Foremost Dairy Farm, 9617 W. Hwy. 40, Columbia, Missouri. A series of fact sheets on dairy flushing is available at your local extension center or on the Internet at For more information, contact your local University Extension Agricultural Engineering Specialist.

Author: Charles Fulhage Extension Agricultural Engineer

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Callaway County Farmers Develop Environmental Protection Plan

Farmers often refer to themselves as the first environmentalists. Unfortunately, the negligence of a handful of farmers has resulted in public scrutiny toward all livestock producers and how they manage the manure produced by their operations.

Realizing that public concern has increased toward their industry, a group of livestock producers in Callaway County came together this past summer to discuss how they can be better prepared to protect the environment.

This first meeting gave local producers the opportunity to share their ideas and have input into the proposed program. From this beginning effort, the Callaway Livestock Producers Environmental Protection Program was developed. More than thirty livestock producers attended the meeting in September when the final draft of the program was presented.

"Most livestock producers are good stewards of our natural resources and do a good job protecting our water, soil, and air," said Gary Ryan, Callaway County Farmer who initiated the Environmental Protection Program. "By getting local farmers together to talk about managing the manure nutrients produced on our farms, we want to reinforce our role as stewards of the land and let the public know we sincerely care about the environment."

The environmental protection program includes preventive planning and an emergency response plan. To participate, producers are asked to review their manure handling practices and to write a plan of action to follow in the unlikely event of a livestock manure spill.

During this process, producers will identify alternate contacts who can assist in the event of a problem, equipment needs, and where this equipment is located. A copy of the action plan will be placed on file with the Callaway county emergency operations center, along with contact names and phone numbers.

"The manure nutrients produced on Missouri farms are usually harmless to the environment. The problems occur when the livestock producer is careless. It is important that these Callaway County livestock farmers took the time to attend the meeting this summer to ensure they are doing the right things on their operations," said Leigh Burkhalter, Director of Producer Services of the Missouri Pork Producers Association.

Additional information is available by calling the Callaway County Extension Office (573-642-0755) or Leigh Burkhalter at the Missouri Pork Producers (573-445-8375). The text and decision making flow chart of the Callaway Livestock Producers Environmental Protection Plan is on the University Extension Central Missouri home page on the world wide web at

Author: Mark Stewart, Livestock Specialist

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University ExtensionAg Connection - January 1997 -- Revised: February 17, 1997