by Dr. Don Ball
As summer turns to autumn, livestock producers usually see a need to put more focus on forage management than was required during summer. However, the severe drought during summer 2006 has limited forage growth and further amplified the need to think about autumn management. Here are some thoughts about several issues or opportunities that may have relevance on many livestock farms this autumn.
Fertilizing Perennial Grasses
- When pastures are short and hay production has been poor, livestock producers want to get as much production as possible from summer grasses before they go dormant. Auburn University recommendations are to apply nitrogen to summer pastures or hayfields no later than September 1, and experience has shown this is probably the right place to "draw the line." On the other hand, application of 60 pounds of nitrogen per acre in September to cool season perennial grasses such as fescue or orchardgrass is a recommended practice to stimulate forage growth for autumn grazing.
- The term "stockpiling" refers to allowing pasture to accumulate, then grazing it at a later time. Stockpiling can be done with any type of forage, but it works especially well with tall fescue. To stockpile fescue, a pasture should be clipped, followed by application of 40 to 80 pounds of nitrogen per acre in September. Animals should be excluded from the pasture until hay would otherwise need to be fed. Strip grazing results in the most economical use of the accumulated forage.
- Each year several hundred thousand acres of winter annual pastures are planted in Alabama. Because of the severe drought this year, it is likely that the acreage of winter annuals planted this fall, both on a prepared seedbed and overseeded on summer perennial grasses, will be sharply higher than usual. Planting winter annuals can be a great strategy because this helps reduce stored feed requirements while providing excellent nutrition for grazing livestock. The cost per pound of dry matter produced by a good stand of winter annuals will likely be lower than the cost per pound of dry matter for purchased hay.
- Grazing management offers numerous potential advantages, one of the most important being reduction of forage waste. Research has shown that in many poorly-managed continuous grazing situations, less than half of the forage produced in pastures ends up being consumed by grazing animals. Rotational grazing (moving animals periodically from one pasture to another) and limit grazing (allowing animals to graze for only a few hours each day) may reduce forage waste by 20 to 30 percent.
Test For Nitrates
- Because of the drought this summer, there is no doubt that some hay has been baled that contains high levels of nitrates. Hay of many forage crops and weeds can potentially contain toxic levels of nitrates, but pearl millet, sorghum-sudangrass hybrids, corn, and pigweed are perhaps most commonly involved in livestock poisonings. If you have hay that you think might contain dangerous levels of nitrates, you should have it tested.
- Given the expense of hay, it makes sense in any year to protect any that has been purchased or produced so as to minimize the total amount needed. However, it especially makes sense to protect hay in a year like this with hay being in short supply, causing its value to be even higher than usual. In our region, hay that is stored outside unprotected for several months often loses 30 percent or more of its dry matter during storage. Hay feeding losses of weathered hay are also much higher due to lower palatability.
- Another potential autumn toxicity is prussic acid poisoning. The pasture plants most likely to result in grazing animals consuming toxic levels of prussic (or hydrocyanic) acid are johnsongrass, sorghum, sudangrass, and sorghum/sudan hybrids. Although drought and other stresses sometimes result in high prussic levels, the most dangerous time is immediately after a killing frost, so animals should not be pastured on these species when frosts are likely. Fortunately, prussic acid is unstable, and after a week or so after being frosted, the plants are no longer toxic. There is no danger of prussic acid in dry hay.
Forage Crop Website
- For more information on stockpiling fescue, testing for nitrates in hay, minimizing losses during hay storage and feeding, and other forage topics, see the website www.alabamaforages.com
Dr. Don Ball is an Extension Forage Crop Agronomist with Auburn University.