Ag Connection
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This Month in Ag Connection
Missouri Heifer Development Program off to Good Start
1996-97 Heifer Development Program Accepting Entries
Winter Nutrition
Additional References on Feeding Livestock Available from University Extension
Anhydrous Ammonia Treatment of Low Quality Forages
Six Steps for Successfully Using Ammoniated Forages
Found on the Internet
October 1996
Volume 2, Number 10

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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.

Missouri Heifer Development Program off to Good Start

Four consignors placed 10 heifer calves each in the 1995-96 Missouri Heifer Development Project. Both purebred and cross bred heifers were consigned. The average receiving weight for the heifers was 588 pounds, with a range in pen weight from 527 to 700 pounds. The frame score average was 5.2 with a pen range of 4.7 to 6.3.

These heifers were developed on a ration composed largely of a mixture of cotton seed hulls, soybean hulls and free choice hay. Rations were formulated for gains of 1.75 pounds per head per day. Due to favorable weather conditions, gains averaged slightly more than 2 pounds per head per day for the 153 days prior to breeding.

The heifers were delivered on November 21, 1995 and released on July 31, 1996. The cost of maintaining these heifers ranged from $304.65 to $377.13 with the pen average being $322.69 for the 254 day duration of the project. Feed costs were allocated within each consignment using the net energy system. This system considers the energy content of the ration, average weight, and average daily gain of the heifers.

A synchronized breeding program was used and pregnancy examinations were conducted on July 31, 1996. Thirty-five of the forty heifers were determined to be pregnant.

Animal Health Advisors for this program were Dr. Dave Hardin and Dr. Richard Randle. Cosponsors are the University Extension Commercial Ag Program, Pfizer Animal Health, Merck AgVet, Farmland Industries and Addison Biological Laboratories. (Dale Watson, Livestock Specialist)

1996-97 Heifer Development Program Accepting Entries

The 1996-97 development program will be conducted at the Rocking 8 Cattle Company, Fayette, MO. Heifers will be received at the Rocking 8 on Tuesday November, 19, 1996. Entries must meet the following requirements

  1. A consignment will consist of a minimum of 3 head.
  2. Heifers must be born after January 1, 1996;
  3. weigh in excess of 450 pounds; and
  4. have the following immunizations: Brucellosis, IBR, PI3, BVD, BRSV, Hemophilus Somnus, Pasteurella, ND 7- or 8-way Clostridial. The IBR, PI3, BVD, AND BRSV are to be modified live vaccines.

Entry deadline is Wednesday, November 1, 1996. For additional information and entry forms, contact Rocking 8 Cattle Company, (816) 248-1640 or (816) 248-1631, Chris or Jan Amos, (816) 248-3239, Dale Watson (816) 542-1792, Chris Zumbrunnen (816) 265-4541, Melvin Brees (816) 248-2272 or David Patterson (573) 882-7519.

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Winter Nutrition

For optimum reproductive efficiency, plan your winter feeding program now. Begin by using established nutrient requirements to determine the needs of your cattle during different production periods. The 60 days prior to calving and 60 days after calving are the most nutritionally critical periods of production for the beef cow.

Fall calving cows need more feed than spring calving cows since lactation and rebreeding occur during winter months when low temperatures increase dietary energy requirements. Adequate nutrient intake is critical for first calf heifers. They need the additional nutrients for growth, along with their needs for lactation and rebreeding.

Separate heifers and cows, based on their feeding requirements. Next, inventory the quality and quantity of your feed resources. Then, determine how you are going to supply the required nutrients to the animals. Providing a ruminant sufficient quality and quantity pasture to supply themselves with required nutrients will always be cheaper than feeding harvested forage or grain. In Table 1, (below) the cost of supplying a unit of digestible energy to a ruminant from different sources is compared with grazed pasture having an index value of 1.00. For example, using 1979 data, grains and concentrates cost 4.57 times more than pasture.

Table 1. Relative economic efficiency of supplying a unit of digestible energy to ruminant livestock.
  Comparative Cost Ratio
Grazed pasture 1.00
Alfalfa hay 1.52
All hay 1.60
Timothy hay 1.61
Silage 1.95
Dehydrated forages 3.20
Grains and concentrates 4.57
(Source: 1995 Missouri Grazing Manual from USDA and Agriculture Canada. 1979)

Stockpiled tall fescue can be used to extend the grazing season. Tall fescue has unique physiological characteristics that make it superior to other grasses for stockpiling. The growth season of tall fescue is longer, allowing for dry matter accumulation later in the season. Tall fescue accumulates high levels of soluble carbohydrates, making the nutritional quality high (12% crude protein, 0.58 net energy maintenance, 0.32 net energy gain), and a heavy waxy cuticle layer that acts to preserve the quality of the grass after growth stops.

Tall fescue is also very responsive to nitrogen fertilizer (N). August applications of 40 pounds of N per acre have produced 2,519 - 2,980 pounds of forage per acre at the Forage Systems Research Center (FSRC) near Linneus, MO.

Timing and method of grazing influence both the quality and utilization rate of the stockpiled forage. Utilization of stockpiled tall fescue should be planned to allow limited access. Research conducted at FSRC indicates that allocating a 3-day grazing strip increased grazing days/acre by 40% and decreased the feed cost per day by 30% in comparison to a 14-day grazing strip.

Forward grazing (leader-follower or graze ahead systems) can also be used for first calf heifers or background calves to allow access to the higher quality and quantity forage followed by mature cows or non-lactating ruminants. If continuous grazing is used, expect trampling, increased selectivity and decreased utilization.

If stockpiled pasture is not available, hay is normally a cheaper alternative to grains and concentrates (Table 1). It then becomes imperative to know the quality of the forage you are dealing with as this will directly influence dry matter intake and the amount of daily nutrients consumed by the animal (Table 2, below).

Table 2. Quality influence on dry matter intake of beef cows.
Ingredient Expected Intake
(dry matter basis, % body weight)
Pelleted hays 3.0 - 3.5
Grains 2.5 - 3.0
High quality forage (legume hay, silage, green pasture) 2.5
Average quality forage (non-legume hay) 2.0
Low quality hay (straw, dry grass, meadow hay) 1.5

By taking the information given in Table 2, we can illustrate the importance of quality and intake. Consider a 1000 pound cow that requires 1.6 pounds of protein to meet her daily dietary requirement. Using alfalfa hay with a protein content of 17.1%, only 9.4 lbs. of hay is required to meet this protein requirement.

If the forage is low quality tall fescue hay with a protein content of 5.5%, the cow will have to consume 29 pounds of dry matter to meet her requirement. This is 2.9% of her body weight. The stomach capacity of a 1000 pound cow is not large enough to consume and digest this much low quality forage.

This is an extreme example and is used to illustrate the importance of intake. Forages can supply most if not all of the protein required for many classes of grazing animals providing that intake is not a limiting factor (refer to UMC Guide 2067 for nutrient requirement information).

Protein is an expensive supplement and can affect profits if not properly fed. Compare cost of supplemental protein based on the amount of available protein supplied. Costs of protein supplements can differ by more than $1.00 per pound of useable protein supplied.

If using low quality fescue hay (for example, holiday hay baled after July 4), problems can arise with limited intake. Anhydrous ammonia treatment can be used to increase the digestibility, intake and protein content of these low quality forages.

Energy is often the most limiting factor to animal performance on forages. The most common source of supplemental energy is corn. Current corn prices have producers looking for other sources of energy such as the by-product feeds, including corn gluten, wheat midds, and soyhulls. Unfortunately, prices for these products have followed the increased corn prices and may not be the bargain they once were. Price and compare energy sources on the basis of cost per pound of total digestible nutrient (TDN).

Final thoughts:

  1. Segregate feeding groups on the basis of nutrient requirements (keep in mind those first calf heifers and old cows).
  2. Inventory quality and quantity of feed on hand and make comparisons to what will be needed. (hay test, grain test).
  3. If stockpiled forage is available, extend its use through limited access.
  4. Determine what nutrients need to be supplemented and feed accordingly. Don't feed a protein supplement if energy is what's needed!
  5. If nutrients need to be purchased, price them based on pounds of useable protein or energy.

(James Rogers, Livestock Specialist)

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Additional References on Feeding Livestock Available from University Extension:

MU Guide 2051 "Feed Composition Tables"

MU Guide 2052 "Formulating Rations for Beef Cattle"

MU Guide 2067 "Nutrient Requirements for Growing and Finishing Beef Cattle"

MU Guide 2070 "Salt to Limit Intake of Protein and Grain Supplements"

MU Guide 2071 "Urea Supplements for Beef Cattle"

MU Guide 2072 "Grain and Protein Supplements for Beef Cattle on Pasture"

Click here to E-mail a request to your local University Extension Center for a free copy of any of these guidesheets.

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Anhydrous Ammonia Treatment of Low Quality Forages

High quality cool season grass hay which was baled by mid-June is in short supply. Hay baled later than this date (such as holiday hay) will likely require supplementation. One option to consider is the ammoniation of low quality hay or wheat straw. The anhydrous ammonia provides a non-protein nitrogen source for mature ruminates while it improves the digestibility.

Anhydrous ammonia is very toxic and extreme care must be used when treating forages. The best results occur when forages contain about 15% moisture. While most producers ammoniate large round bales, ammoniation of square bales will work just as well.

Diagram of Ammoniating Hay

A heavy mil plastic sheet (6-8 mil) is used to cover the stack. To best utilize the plastic cover, large round bales are stacked two bales wide and two bales high (see diagram). To allow the plastic sheet to better cover the ends of the bales, the top row of bales contains one less bale than the ground row. The bales on the top row are then offset by of a bale. The edges of the plastic need to be sealed to the ground by placing soil on top of the plastic.

Anhydrous ammonia is injected under the plastic through a 1" plastic pipe. The pipe needs to be placed close to the center of the stack and attached to a fence post to prevent it from moving. Open the valve on the anhydrous tank carefully and apply the anhydrous slowly to keep from blowing the plastic off the stack. Anhydrous ammonia is applied at the rate of sixty pounds per ton.

A roll of 40' x 100' plastic will cover 38 bales. If the bales are 1500 pound bales, the stack will contain 28 tons of forage. In Central Missouri, anhydrous ammonia is available for about $.20/pound and a roll of 6 - 8 mil plastic can be purchased for $130.00. The cost of treating a ton of forage will be around $17.00. (Update for August 1997: anhydrous ammonia is available for about $.14/pound, making the cost of treating a ton of forage around $13.00.) Plastic meeting these size and weight specifications is available through many farm supply outlets but may be a special order item.

While ammonia treatment of forage has been used very successfully, there are some possible problems. Ammonia toxicity can occur. Toxicity has occurred when cattle were fed ammoniated forage sorghum, hybrid sudan, small grain hay (not straw) and high quality brome and fescue hay.

The symptoms include extreme excitability, circling, running, convulsions and death. For these reasons it is recommended to only treat low quality forages. If toxicity should occur, avoid working the livestock and remove the ammoniated forage for several days. A mixture of 50% ammoniated hay and 50% untreated hay should prevent future problems. (Mark Stewart, Livestock Specialist)

Six Steps for Successfully Using Ammoniated Forages

  1. Use proper safety precautions during application, storage and opening. Special care should be taken when handling small square bales. See MU publications G1920, MX0385, MX0386.
  2. Place stack on well drained ground. Warning - this area will probably not grow a crop the next year.
  3. Cover with 6 - 8 mil plastic. Place soil, gravel or crushed limestone on edges of plastic to form a gas tight seal.
  4. Add 60 lb/ton of anhydrous ammonia through a 1" plastic pipe. Fasten the pipe to a fence post and be sure the pipe does not point directly toward the plastic.
  5. Allow 2 weeks for the reaction during the summer months, 4 to 5 weeks during cold weather.
  6. Carefully open the stack a few days prior to use so excess ammonia can dissipate. Do not completely uncover a stack that is stored outside. The treated forage will absorb moisture from rain or snow very quickly and begin to spoil. Livestock consume the treated forage more quickly if individual bales are removed from the stack 24 hours before feeding. This allows the ammonia smell to dissipate.

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Found on the Internet

Missouri Beef Page

National Pork Producers Home Page

Cowtown America - Information from the National Cattlemen's Association

WWW Virtual Library - livestock section

(Don Day, Agricultural Engineering/Information Technology Specialist)

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University Extension Ag Connection - October 1996 -- Revised: August 21, 1997