Published: May 03, 2008 10:48 pm            

OSU Extension Notes 05-04-08

Ag News

Poultry litter program scheduled for May 12

Payne County Extension will be holding a poultry litter program May 12 at 7 p.m. in the Community Building of the Payne County Expo Center. This workshop is open to the public and free of charge. For additional information regarding this program, please contact the Extension office at 747-8320.

Attention cattle producers

The Payne County Extension Center is interested in being notified if circumstances arise that would result in any orphan calves for use in the bucket calf program. Please contact our office at 747-8320. We appreciate your help as we assist the youth involved in the 2008 Bucket Calf Show.

Choosing summer annual forage crops to reduce risk of nitrate toxicity

Annual forage crops like forage sorghums make valuable contributions to the hay supplies in Oklahoma. They are well adapted, very productive and provide high quality forage. However, some of these plants accumulate toxins that can result in costly livestock losses.

Nitrate is the primary nutrient form of nitrogen in most soils and is a normal constituent of plants. Normally, nitrate is assimilated into plant protein so rapidly following uptake from soil that its concentration in plant tissues is low. Occasionally, excessive levels occur in plants. The most notorious accumulators of nitrate in Oklahoma are the plants in the sorghum family including johnsongrass. Certain weeds (pigweed, mustard, nightshade and lamb’s quarters) also can contain dangerous levels. Some perennial grasses (bermudagrass, fescue) very rarely have been reported to accumulate high levels of nitrate.

Accumulation is usually triggered by some environmental stress, where plant growth is restricted but absorption of nitrate from soil continues. The most common stress of summer annuals is drought. Lack of moisture, together with excessive soil nitrogen for existing growing conditions, is a frequent cause of toxic levels of nitrate in sorghums.

The level of nitrate that causes toxicity in ruminants varies depending on rate of intake, diet, acclimation to nitrate and nutritional and reproductive status. As a rule, forage containing less than 5,000 ppm nitrate on a dry matter basis is safe for non-breeding cattle. Forage containing 5,000 to 10,000 ppm nitrate is considered a potential source of production loss when provided as the only feed. Production losses are usually manifest as reduced milk production and lowered reproductive performance. Forage containing over 10,000 ppm nitrate is considered dangerous and potentially lethal.

These high concentrate forages often can be fed safely after proper dilution with other feeds. Questions among cattle producers and hay growers about the potential nitrate accumulation in various forages caused the following experiment to be conducted and reported.

During the first summer, 17 varieties of Sorghum x Sudan, 12 varieties of Sorgo x Sudan, five varieties of Sudan x Sudan hybrids and six varieties of Pearl Millets were being grown at three Oklahoma State University Agronomy Experiment Stations for yield evaluations. The second year of the study was conducted with 18 varieties of Sorghum x Sudan, nine varieties of Sorgo x Sudan, two varieties of Sudan x Sudan hybrids and five Pearl Millets. Field locations were: Eastern Oklahoma Agronomy Experiment Station at Haskell in Muskogee County, South-central Oklahoma Agronomy Experiment Station in Grady County near Chickasha and the Southwestern Oklahoma Station near Tipton in Tillman County.

Millets have been shown in other research to be unlikely to accumulate a different toxin called prussic acid. Prussic acid will tend to dissipate when the crop is cut for hay and, if allowed to cure thoroughly, will be reduced extensively. Therefore, if the summer annual, that producers plan to plant this spring, is targeted to be a hay crop, it makes sense to plant one of the other forage sorghums, not the pearl millets. Planting one of the other forage sorghums does not eliminate the risk of nitrate toxicity (but does reduce it), and if grazed after stress such as frost or drought may accumulate prussic acid. Therefore, if the plan for the crop is to graze it in the early fall (when frost and prussic acid is probable) then the millets may still warrant consideration.

Producers are strongly encouraged to plan the use of the crop before they select and plant the seed.

4-H News

Cookie baking for troops

May 17, from 2 through 5 p.m. in the Payne County Expo Center in Heritage Hall, the Payne County 4-H members are invited to come and help make and bake cookies for our troops in Iraq. The event will be a come and go atmosphere and members are encouraged to bring cookie making supplies such as ingredients and utensils. Any individual that may have a heavy-duty mixer available for use is encouraged to bring it as we could use extras. Also, if you can not participate on the 17th, you are able to drop off any baked, labeled cookies to the Payne County Extension office by May 16 by 5 p.m. or can be delivered to the Expo Center during the event. For a list of other items that can be donated to the troops please contact our office at 747-8320.

2008 4-H Camp

Any 4-H member from Payne County, age 9-13 years old by June 3, is encouraged to attend this fun and educational summer event that will be held at Saint’s Grove Camp from June 3-5. Please see (oces.okstate.edu/payne) for additional information and to download a copy of the registration form.

Payne County 4-H Food Show

The Payne County 4-H Food Show will be held June 21 in Skyline Elementary School starting at 9:30 a.m. Additional information can be obtained by visiting our web site or contacting the Extension office at 747-8320.

4-H archery shooting practice is available every Tuesday at the Payne County Fairgrounds between 6:30 and 8:30 p.m. For more information call Chris Harris at 612-5718.

        

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