Caswell County Center

126 Court Square

Post Office Box 220

Yanceyville, NC 27379-0220

(PHONE) 336-694-4158

(FAX) 336-694-5930

Caswell AMAZING GRAZING Extension Notes

FALL 2007

It finally rained the week before last! In three days, up to seven inches of rain fell to help restore the dry ponds, creeks and burned up pastures. This drought year will definitely be recorded in the history books along with 1953 and 1983 years. The 2007 year went by fast and we are already getting into the holidays. It has been another busy week with many questions coming in on drought and hay availability. Obviously, with all of the calls this summer, you all are scrambling and thinking about how you can feed your livestock without selling out and paying a fortune for hay. It is really now a matter of survival for many of our livestock producers and we need to be putting as much effort into this as we can. Here’s some information that may help some of the livestock farmers survive the upcoming winter with limited feed supplies. Grazing small grains or annual ryegrass are the only two seeds left that you can plant this year in order to get some late winter and early spring grazing. No-tilling the ryegrass in existing pastures works well.

If there is anything we can do to help you in your farming enterprises, family and consumer sciences, or 4-H youth development, don’t hesitate to call us at 336-694-4158.

North Carolina Cattle Industry Assessment Referendum

The North Carolina Cattlemen’s Association (NCCA) has announced that the NC Cattle Industry Assessment Referendum vote will take place on November 14, 2007. At the NC Cattlemen’s Association’s joint Board of Directors and annual Business Meeting in February, during the 56th annual NC Cattlemen’s Conference, the Board of Directors voted to pursue the referendum. The County Extension Office will serve as the poling place in Caswell County.

The referendum language will be to assess all cattle one dollar per head for the purpose of promoting the cattle industry in North Carolina. The funds will be used for producer education regarding beef production topics, beef production research, youth education and leadership development events, NCCA administration, beef industry leadership development, promotion and marketing of NC cattle, and promoting the interests of the cattle industry. Current beef check-off funds cannot be used for any of these purposes. The NC Dairy Industry should benefit from this program, as dairy cattle will also be assessed at the same level.

The beef check-off does a fine job of increasing consumer demand for beef; however, there are many cattle production issues within the state we need to address. By federal law, beef check-off dollars cannot be used for any purpose other than the promotion of beef or research to improve beef quality. For this reason, after a lot of discussion within the industry, we are convinced of the need to reinstate the original state assessment program.

All NC cattle owners over the age of 18, as of November 14, 2007, are eligible to vote during the regular business hours (8 a.m. to 5 p.m.) at the Caswell County Extension Office.

Potential for Prussic Acid Poisoning

Every year at first frost we get a lot of questions about grazing frost bitten sorghum-sudan. Anytime you have frost on a sorghum or sorghum x sudan crop there is potential for prussic acid poisoning. Prussic acid, also known as hydrocyanic acid, is a problem in wilted wild cherry leaves and occasionally wilted leaves from other fruit species. The other major plants with potential for this problem are members of the sorghum family including Johnsongrass, shatter cane, grain or forage sorghum, and sorghum x sudan hybrids (aka sudex or sudax). There are several other grasses that may be a problem including sudangrass, but most don't grow in our area. Any of the sorghum species can be toxic very early in their growth (maybe up to knee high), and then when there are new sprouts that grow following a drought or frost. Johnsongrass is the most problematic plant, and to be totally safe you should wait until it is waist high and starting to head to graze the early growth, or when it is frosted on you need to wait two weeks after the killing freeze. When Johnsongrass is in pastures as a spotty weed, it does not pose as great a risk as long as there is little enough to where cattle can't eat it as a high proportion of their diet. Right now, the best advice we can give is that there will be a risk in grazing it from now until about two weeks after the killing freeze. If a producer chooses to harvest forages that have been frosted on it is best to make dry hay from it. The prussic acid will dissipate from the hay. In silage, some of the prussic acid will be retained, but some of it will dissipate during removal and handling of the silage, although it probably will be retained in the balage to a higher extent than chopped silage. If a producer really wants to graze the crop and it has had just a touch of frost (or for future reference when summer growth resumes after drought) it is advisable to turn in a few low value animals (i.e. open cull cows) and see how they do. If they stay out for several days without any symptoms it is likely safe, but keep in mind that the problem can develop when there is a series of light frosts followed by regrowth. The symptoms of prussic acid poisoning are gasping, staggering, trembling muscles, convulsions, and death from respiratory failure. The mucus membranes will be blue in color. There is a treatment for the condition, Sodium Thiosulfate, but that can only be administered by a veterinarian and generally will not be in time to save the animals. Hungry cattle are more at risk. Never turn hungry cattle into a stand of forage with prussic acid potential. Interestingly we get a lot of calls this time of year, but the greatest problem is with wild cherry trees during the summer thunderstorm season, and very few producers seem concerned that those trees are in their pastures.

Ruminal Impaction Problems

Ruminal impaction is a situation where the rumen becomes packed, usually with low quality forage, to the point that the opening into the lower gut is obstructed and animals go off feed and eventually die. We have seen this in two situations. One is when cattle are fed very low protein forage and ruminal digestion can't work fast enough to clear the forage from their system. They get backed up, the rumen gets impacted and they bloat and die. This is usually associated with a ruminally degradable nitrogen deficiency. In this case a protein block or lick tank probably would be a lifesaver, although there are more economical protein supplements that will help. It appears that letting cattle get hungry so that they eat a lot of low quality hay in a short time probably is also involved with impaction cases caused by mature bermudagrass, which can have very tough stems. The other situation is where hungry cattle very rapidly eat higher quality forage. They essentially gorge on it, and don't chew it as much as they normally would. This results in a larger particle size in the rumen than they would have when eating slower and chewing better. It makes sense that forages with very long stems would be worse on this, but it is not always clear exactly why it happens because sometimes it is caused by feeding a large amount of very fine textured forage as well. What happens in this situation is that the long particles get knotted up in a ball in the reticulum (also known as the honeycomb where the esophagus comes in and below it where the exit to the rumen is) obstructing the opening and preventing digestion from flowing on down the track. Eventually both the entry and exit will be blocked and they will then bloat and die. Usually death from impaction occurs over a longer time and the animal loses weight rapidly and goes down, but in the situation where something that is pretty fermentable is fed to cattle and impaction occurs, death could happen quickly. There are related problems including abomasal impaction that have similar results. Sometimes it is caused by nothing more than a problem in an individual animal that has reduced ruminal motility. This is a complex problem with many factors influencing it including lack of water, so the water source should always be checked when investigating any problem like this.

Water Availability

Don't take water availability for granted. Much of the state was blessed the week before last with enough rain to at least recharge some of the ponds and streams. However, groundwater levels are still depleted and wells in some areas will continue to go dry. If the water source is a shallow pond, old and weak cattle and calves may have a hard time reaching it and get stuck in the mud. We need to stress that the water source should be checked every day in these situations where sources are drying up.

Nitrate Poisoning

Go to for detailed information on nitrate poisoning. This is one of the times of the year we see a lot of problems with nitrate poisoning. Basically in the fall of the year producers keep cattle on pasture as long as they can, and then pull them in and feed hay. In this situation cattle are often hungry when first offered hay. Cattle have been on hay in the Piedmont for sometime now, but in the mountains many producers are getting ready to feed hay, and some of that from unusual sources. Make sure you know the nitrate level in your hay, and stress that hungry cattle should never be fed hay of unknown nitrate status, or hay known to contain over 0.25% nitrate. Rolling out some hay when grass is starting to play out is an advisable management practice, as opposed to abruptly starting full hay feeding. I have had questions from agents about how to manage hay with greater than 1.5% nitrate several times this week. Diluting it with other feeds (i.e. unroll some of the high nitrate hay to provide 1/4 of the cows daily need) with other hay free-choice, or grinding it with other feeds is ideal. Another option is to use the bacterial inoculant called “BovaPro” that is a bolus that can be given to cattle two weeks before they need to be fed high nitrate hay. That product is backed by a lot of research and experience, and might be indicated in some situations. Cost is somewhere around $8/cow and it can be obtained on-line (search for Feed Safe, BovaPro) or from major animal health distributors.

Acorn Poisoning

There is always a risk of acorn poisoning in the fall of the year where oak trees are in pastures. This condition is somewhat of a paradox because we know acorns are an important source of feed for wildlife, and cattle will readily eat them. They generally cause few problems, and cattle will always eat most of the acorns available in pastures. If they consume too many, too fast, the tannins they contain can be metabolized in the rumen into a substance that is a kidney toxin. The toxin is thought to be gallotannin or a metabolite of that compound. The condition is not totally understood, but in affected animals kidney function is compromised (because of tubular necrosis) and cattle go off feed and rapidly lose weight. Sometimes they will recover, but often the condition is fatal. Most poisoning cases here appear to be due to white oak and chestnut oak acorns. The only treatment is to remove them from the source of acorns and feed a very low protein diet. Acorn poisoning seems to be more of a problem with larger calves that have been on limited grass and are then moved into a pasture with many acorns on the ground resulting in a rapid intake. Nursing calves can also be affected because the toxic principles can be transferred to the milk. Acorns can also cause agalactia (no or little milk) in fall calving cows. Affected cattle will first show signs of constipation, followed by an abnormal (dark or yellowish) colored thick diarrhea, sometimes with blood. A common practice to prevent the condition is feeding a 10% calcium hydroxide (slaked lime or hydrated lime), 90% grain supplement at 4 lbs./day for mature cows and 2 lbs./day for weaned calves. This preventative was developed to prevent oak sprout poisoning, but appears to also help in preventing acorn poisoning.

December Beef Management Tips

Spring Calving Herds

Market backgrounded calves
Feed replacement heifers to gain 1.5 to 1.75 lbs. per day
Monitor body condition of cows
Attend bull and replacement heifer sales
Market cull cows this month or in January; hopefully you have already done this with the summer drought
Send in soil samples if not done earlier this year

Fall Calving Herds

Begin breeding season on cows; complete AI on heifers
Monitor body condition on cows and especially first calf heifers
Feed cows extra energy after calving
Keep cows on stockpiled grass as long as available
Check heaters in waterers regularly
Send in soil samples if not done earlier this year

January Beef Management Tips

Spring Calving Herds

Begin to gather calving supplies
Keep late pregnant cows gaining 1.0 lb. per day
Pregnant heifers and 3 yr. olds should gain 2.0-2.5 lbs. per day
Keep high quality minerals available
Review calving assistance procedures
Stockpile a few gallons of colostrums
Attend performance tested bull sales and/or order semen for AI
Soil test pastures not tested in last 3 years
Order clover seed for frost seeding later this winter

Fall Calving Herds

Begin/continue breeding
Check cow and bull condition
Supplement energy to young bulls during breeding season
Send in forage test if not done earlier this year
Continue to check calves closely for health problems
Re-implant September and early October born calves that were implanted at birth
Soil test pastures not tested in last 3 years
Order clover seed for frost seeding later this winter

Sincerely,

Joey E. Knight, III

County Extension Director

JEK/psm