Grazing Bites

October 2009
Victor Shelton, NRCS Grazing Specialist

There was crispness in the air this morning and so I reluctantly grabbed a light jacket as I went out the door.  I guess I hate to give in to the thought that summer really is over and fall is here.  Autumn’s destiny is to quickly turn to winter, or at least that is the way it appears to me.  This makes me consider sprouting some snowbird wings until I once again get used to cold weather. 

This colder weather also starts affecting forages that the livestock are grazing or we are considering to harvest.  With shorter days and cooler weather, cool-season grasses start slowing down growth and increase storage of carbohydrates in the stem bases, rhizomes and/or roots.  Until these plants go dormant, they will continue to build carbohydrate reserves, slowly grow leaves and develop next year’s first tillers.  If the forage stand is particularly weak or has been extra weedy this year, then it would be to the plants advantage, and thus ours too, to make sure the stand is not grazed heavily, or maybe at all, until it has gone completely dormant.  Grazing much now on this weak stand would force the plant to utilize some or all of those carbohydrates for new growth instead of storage.  It is actually also to this stand’s advantage, especially the weedy stand, to delay grazing in the spring as long as possible so weed seedlings are crowded, shaded or smothered out by the desired forage plants.

Most of these cool-season grasses are “dormant” after receiving a good freeze…but not always.  If they are still growing, they are not dormant.  In Southern Indiana, this can often be November.  If you are shy on pasture, then you might want to consider feeding some hay for a while to allow the forages to actually grow rather than continuing to graze them.  This is one reason many producers that have access to corn residue utilize them in the early fall; this allows time for new pasture growth.  The first 30-60 days after harvest is the best time period for corn residue grazing when soil conditions are favorable.  Spring calving cows are the best choice for grazing the residue.  If time allows, it would be advisable to plant a cover-crop after grazing, especially on any rolling ground.  This cover-crop might contribute to some early spring grazing if soil conditions allow it.  Cereal rye can usually be planted up to November 1st in southern Indiana.

Once you do start grazing “dormant” cool-season grasses, it would be to your advantage to strip graze them allocating only small increments at a time just like feeding hay.  Tall fescue, like mentioned in previous articles, holds its nutritional value the best for long term winter grazing.  Not overgrazing at this point will also help jump-start the forages in the spring and also help with weed suppression next year.  Ideally, three to four inches of residue should always be left. 

How about warm-season grasses?  Most of the native warm-season grasses such as switchgrass, big bluestem or indiangrass are ideally harvested by grazing or haying during the summer.  Livestock will eat them along with green forages late in the year, but typically most of the nutritional value is gone or is very low.  Summer annual warm-season grasses such as sudangrass or sorghum-sudangrass hybrids often have some late season value, but caution needs to be taken utilizing these forages this time of year. 

Once frosted, these forages produce a cyanide containing compound commonly called prussic acid.  It is the same compound that is produced by these same plants under stressed conditions, (such as drought) and is found in stressed Johnsongrass and cherry leaves too.  Once frosted, this plant quickly starts shutting down and prussic acid is produced.  Livestock should be removed from these forages for 10-14 days to allow for the forages to “dry down” and the prussic acid to dissipate before grazing again.  Frosted sudangrass or sorghum-sudangrass hybrids can be harvested for balage right after being frosted and later fed as long as they are allowed their normal fermentation process time period of three or four weeks.  The fermentation process breaks down and dissipates the prussic acid according to Purdue Extension Forage Specialist Keith Johnson.  Keith also notes that it would really be advisable these forages would be better off “bellied or baled” prior to October!  Frosted areas could be only “pockets” in a field to start with.  Any regrowth from the base of the plant after a frost can also be very high in prussic acid.

Before I sign off today, I have to put in a quick pitch for lime.  Like I’ve said many times over, a dollar spent on lime is one of the first and best dollars spent.  It is an ideal time to be getting that lime applied so it can help those forages the next growing season.  Lime does not break down and become available over night, especially regular ag-lime, so “now” is the time to get some on.  Utilizing results from a recent soil test would be a good place to start.

Keep on grazing!

4th NATIONAL CONFERENCE ON GRAZING LANDS

December 13-16, 2009.   John Ascuaga’s Nugget Hotel & Casino, Sparks, NV

http://www.glci.org/4NCGLindex.htm

Heart of America Grazing Conference, Roberts Conference Centre, Wilmington, OH - January 20-21, 2010.  Details coming soon!

Northern Indiana Grazing Conference, Antique Auction Barn, Shipshewana, IN, February 5^th, 2010 - Details coming soon!

Southern Indiana Grazing Conference, Simon Graber Community Building, Odon, IN, February 11, 2010 - Details coming soon!