Fall 2002 Issue    Volume 2, Issue 2                                                                                                                                                                    Oct 21, 2002

DELAWARE

DAIRY REPORT

Newsletter From the University of Delaware

Animal and Food Science Department

and Cooperative Extension

 

 

 

Mastitis Meeting, November 5, 2002  Hartly, DE

 

All dairy farmers interested in learning more about mastitis are invited to a meeting on that topic co-sponsored by Maryland Cooperative Extension, DE Cooperative Extension, Pharmacia Animal Health, and local veterinary clinics.

 

On Delmarva, the meeting will be held on November 5 at Hartley Fire Hall, Delaware from 10:30 a.m. - 2:30 pm.  Register by October 31 by calling the Kent County Extension Office (302) 730-4000. 

 

The invited speaker for these series is a well known dairy veterinarian, Dr. Andy Johnson, from Clintonville, WI.  Dr. Johnson is known as the “Udder Doctor” and travels throughout the world speaking on Milk Quality Management.  The topics he will discuss include milk quality, cow comfort, milking equipment analysis, and mastitis control and prevention. 

 

Dr. Andrew Johnson presently owns Total Herd Management Services, Inc. He is a production medicine consultant to the dairy industry in 47 states and 26 countries. He consults on herds ranging from 2 cows to 22,000 cows. Dr. Johnson is a graduate of the University of Minnesota. He is known for his expertise in milk quality and cow comfort.

 

He consults for every major milking machine manufacturer in the field of milk equipment analysis and milk quality. Dr. Johnson has recently chaired the National Mastitis Subcommittee on Milking Machine Analysis guidelines. Their new testing procedure has been accepted as the US standard for testing milking equipment. He currently is on the Executive Board of the NMC.

 

Dr. Johnson has been a speaker on the programs of every major veterinary meeting such as the AVMA AABP, NMC, Western and Eastern States and many state veterinary meetings. He also authors several books and writes several columns for different national dairy magazines and cooperative newsletters.

 

Dr. Johnson received the National Award for Excellence in Preventative Medicine from the American Association of Bovine Practitioners in 1995 and was named AABPIS Practitioner of The Year in 1998. In 1994, He was awarded Wisconsin Veterinarian of the Year.

 

Dairy Quality Assurance Program Continues

 

The Dairy Quality Assurance Pilot program is continuing in Delaware with 3 herds completing the initial assessment and 4 more scheduled for this Fall. 

 

Dairy Quality Management is a total farm, dairy, and herd assessment program.  It encompasses overall herd health, vaccination programs, biosecurity, manure management, feed management, water management, facilities, and record keeping. 

Another key component is assuring safe, quality meat and milk.  This would include drug use, antibiotic withdrawal, and disease management.

 

In this program a team with expertise in animal health and dairy management does a comprehensive on-farm assessment.  After the assessment, a plan is then drawn up to address identified management or health issues. The farmer implements the plan with their veterinarian and other advisors. 

 

Delaware dairy farmers, veterinarians, and dairy consultants interested in participating in this program should contact Gordon Johnson at (302) 730-4000, email gcjohn@udel.edu.

 

 

UD Extension Dairy Group

 

In an effort to bring more and better extension programming to the dairy industry in DE, a working group has been formed of faculty and extension agents with dairy interests.  We have recently met to start planning for extension dairy programs for the next 2 years.

 

The working group includes Dr. Limin Kung, Dr. Bob Dyer, Dr. Jim Maas, Susan Garey, and Gordon Johnson.  This group brings to the table expertise in dairy production, herd health, nutrition, milk quality, youth programming, forages, and many other areas relevant to the dairy industry.

 

We welcome input from producers and others in the dairy industry in planning educational programs and on-farm extension projects.  Feel free to contact any one of the UD Dairy group with your ideas.

 

Gordon Johnson, Extension Ag. Agent, Kent County

         

Dr. Bob Dyer                                                   Dr. Jim Maas                            Susan Garey                  Gordon Johnson                                                                     

 

 

 

 

 

Dr Limin Kung

 

 

 

Dairy Advisory Committee

The UD Extension Dairy Working Group is seeking to form a Delaware Dairy Advisory  Committee.  The committe e would consist of producers from each county and representatives from dairy service industries. 

 

The role of this committee would be to advise on needed education opportunities for dairy producers in the state, help in planning programs and projects, assist in finding resources for programs (such as farmer cooperators), and provide general support for dairy extension programs. 

 

We will calling on a number of you in the near future to volunteer your time to this effort.  For more information contact Gordon Johnson at (302) 730-4000. 

 

 

Dairy Programs and Projects for 2003

 

We are currently in the planning process for dairy programs and projects in 2003.  Included are:

 

A series of workshops on Biosecurity and Addressing Johne’s Disease on dairy farms,

 

On farm workshops on Identifying Problem Signs in the herd,

 

Classroom workshops on Getting the Most from Dairy Herd Records and DHIA,

 

Ongoing Dairy Quality Assurance assessments and follow-ups,

 

The annual Delmarva Dairy Day at Hartly, DE in February,

 

Continuation of the pilot Dairy Fly Management Program on participating farms,

 

Nutrient Management Certification classes for those who have not already attended the 3 certification sessions,

 

A workshop on Hand-held Computers for Dairy Record Management,

 

On-going offer of doing Dairy Financial and Business Analysis using FINPACK or dairy benchmarks on interested farms,

 

And an on-farm Forage and Feed Quality Initiative helping dairy farmers evaluate their forage and feeding program including forage production practices, harvest management, and silo, feedout, TMR, and bunk management practices.

 

 

 

 

 

Dairy Youth News

 

2002 Cow Camp a Huge Success

 

On the morning of Saturday July 6^th, 41 eager campers arrived at the Delaware State Fairgrounds with 41 not so eager bovine partners for a fun filled weekend of Cow Camp! 

 

After getting their belongings and animals organized, campers rotated in smaller groups through mini workshops on topics such as knot tying, the proper way of bedding a stall, packing your show box for the fair, and washing your animal.  Campers had a break for lunch and then half of the group worked on clipping their calves with some assistance when needed, from adult and teen dairy leaders.  The other half of the group was busy learning and practicing proper showmanship techniques. 

 

Dinner was a hot dog and hamburger cookout with recreation time and music afterwards.  Later that evening a delicious dairy dessert; ice cream sundaes was enjoyed by all.   Then it was lights out in the barn as cows, campers and chaperone snuggled in for the night. 

 

Sunday morning began bright and early with a pancake breakfast cooked by Chef Richard Morris and then youth began to prepare their animals and themselves to test their newly acquired knowledge in a mini show.  Lee Tolson came to judge the show and spent a great deal of time explaining to participants about their fitting and showmanship and how she determined the class placing.  Congratulations to Jenna Morris for being named the 2002 Cow Camp Champ!   Jenna took home a new show box just in time to pack it for the 2002 Delaware State Fair.

 

Family members that attended the show were invited to enjoy a Jimmy’s Grille picnic lunch with their campers.  Fun awards were given to camper’s after dinner.  All participants received a red, white and blue rope halter that they could use at the upcoming patriotic themed 2002 Delaware State Fair and then the clean up began!  The Schabinger Pavillion was dismantled and cleaned in record time thanks to many willing hands.

 

A big thank you to all of the many enthusiastic people who volunteered to plan, organize, and run this event!  The campers had a great time and the adults did too.  Funding for this event was provided by Delaware DHIA and the Delaware Holstein Association.  Photos from the 2002 Cow Camp can be viewed on the State 4-H website at: http://ag.udel.edu/4h/cow_camp.htm

 

A grant has been received from the Mid Del Foundation to help provide funding for this event in 2003.  If you are interested in participating on the 2003 planning committee, please contact Susan Garey at the Extension Office, 730-4000 or truehart@udel.edu.

 

 

Delaware Dairy Leasing Program:  Leasing to Learn Lifelong Skills

 

In the early 1990’s the number of Delaware youth carrying 4-H and FFA Dairy projects were decreasing as family farms were going out of business or being sold for development.  Several dairymen felt the need to educate the general public about dairy farms as well as develop the public’s appreciation of agriculture.  These people began to search for a way to increase the number of Delaware youth participating in the dairy industry and in doing so, helped to lay the foundation of what would later become the Delaware Dairy Leasing Program.

 

In the beginning animals were transferred into student’s names through the breed association.  This became very expensive, time consuming and in some cases prevented breeders from being able to use their prefix to name offspring.  After a couple of years Mr. Stephen Cook looked to other states for leadership in developing a program to overcome the challenge of a decreasing number of dairy projects.

 

Through several conversations with Dr. Lee Majeski of the University of Maryland, who helped establish a leasing program at the Naval Academy in Anne Arundel County, MD the Delaware Dairy Leasing Program began to evolve.

 

The first step to launch this program was to gain the support of local organizations.  The program received the backing of both the State 4-H Program Leader Mrs. Joy Sparks, of the University of Delaware Cooperative Extension and the State FFA Program Leader Mrs. Karen Hutchison, of the Delaware Department of Education.  The program was then brought to the General Manager of the Delaware State Fair, Mr. Dennis Hazzard.  Once it received the fair’s approval, the Delaware Dairy Leasing program was set in motion.

 

Since the mid 1990’s, the number of students working with dairy animals and the number of farms leasing animals to students has greatly increased.  Along the way, over 150 non- farm youth have been given the opportunity to work with and show dairy projects.  This past year (2002), the number of dairy leases on file with the 4-H office quadrupled from 2001.  Youth leasing dairy projects now have the opportunity to participate in additional events besides the state fair such as the Spring Dairy Show and Cow Camp which makes their learning curve and their experience that much greater.  They are also required to complete a 4-H Record Book as part of the program.  FFA members use the leasing program as part of their Supervised Agriscience Experience (SAE) which leads to degree awards and proficiencies.  The records students are required to keep for these awards cover more than one year.

 

The benefits to this type of education, combining consumers with producers, go well beyond the supermarket.  Youth leave the program with a sense of accomplishment and take with them lifelong skills such as responsibility, accountability, record keeping, and patience that make them more attractive to potential employers in the future.   In addition, as the youth who have been a part of this program go on with their lives, some related to agriculture, some not, they will all have a stronger understanding of the time and commitment the American Dairy Farmer puts forth to provide a safe and inexpensive food source. 

 

If you would be interested in learning more about participating in the Delaware Dairy Leasing Program either as a producer or a youth participant, please contact Stephen Cook at Caesar Rodney High School at stephen.cook@cr.k12.de.us or Susan Garey at the Kent County Extension Office 730-4000 or truehart@udel.edu

 

-Submitted by Stephen and Kristin Cook and Susan Garey

 

 

 

Nitrate Poisoning from Drought Stressed Plants

 

I talked to Ralph Ward from Cumberland Analytical Services a few weeks ago and he told me that this has been the worse year for forages with extremely high nitrate concentrations that he has ever seen.  With this in mind, lets go over a quick review of the situation.

 

Many plants can accumulate nitrate under stressful conditions (excessive

fertilization or water stress from rain after a drought).  Sunflowers, corn, wheat, barley, rape, bromegrass, and sweet clover are some of the more common

Total NO3-N intake		Total NO3 intake
ppm	%	ppm	%	Comments
up to 400	up to 0.04	up to 1700	up to 0.17	Safe to feed under most conditions.
>400 to 1300	>0.04 to 0.13	>170 to 5700	>0.17 to 0.57	May see reduced fertility (increase services, repeat breeding).
>1300 to 1700	>0.13 to 0.17	>570 to 7500	>0.57 to 0.75	May see reduced gains and increased abortions.
> 1700	> 0.17	> 7500	> 0.75	Clinical symptoms (respiratory distress).

plants that can accumulate high levels of nitrates.  Nitrates are converted to nitrite and ammonia in the rumen.  However, when there are excessive nitrates, nitrite accumulates and is absorbed into the blood stream.  

 

There, nitrite binds to hemoglobin and reduces the oxygen carrying capacity of

the blood.  Acute poisoning can be observed within 6 hours of forage consumption and is characterized by dark-brown blood, labored breathing,

 

 

 

tremors, and weakness.  The ensiling process can decrease nitrate levels in plants by about 50% but in some instances, the remaining nitrate is still too high to be safely fed to ruminants.  Thus, suspect samples should be tested before being fed to animals. 

 

Problems with nitrates are dictated by two factors, 1) total nitrate consumed and 2) the amount of nitrate consumed in a single meal.  Reviewing the published information on nitrate toxicity from various universities can often leave one very confused because 1) nitrate can be presented as nitrate-nitrogen (nitrate-N) or nitrate ion  (nitrate), 2) safe levels of nitrate to feed are sometimes on a “forage basis” and other times are on a total DM intake basis, and 3) nitrates concentrations are listed as ppm (on a DM basis) or directly on a % DM basis.

 

I suggest you look at total nitrate intake (based on nitrate consumption from forages and in some instances concentrates and water) to calculate what levels are safe to feed (see table below).

 

Don’t forget that sometimes, water can contain high levels of nitrates that may

 

 

 

add to a problem.  Get your suspect forage and water tested if need be. Although it is a bit complicated, the Pennsylvania State University fact sheet on nitrate toxicity is a good source of information (http://www.das.psu.edu/dcn/catforg/DAS/pdf/nitrate.pdf).

 

For safety reasons, calculate the entire potential intake of nitrate.

 

Dr. Limin Kung, Jr.  UD

 

 

 

 

 

 

 

Milk Component Notes

 

It is particularly nice to see some positive information in the news and in particular the scientific press relating to consumption of dairy products.  A recent article published in the Journal of the American Medical Association (M. A. Pereira, and others, 2002) describes the analysis of 10 year long study of consumption of dairy products and incidence of Insulin Resistance Syndrome (IRS).  IRS is somewhat analogous to type II adult onset diabetes.  It is characterized by obesity, glucose intolerance, and hypertension.  People with these conditions also have a much higher risk of heart disease.

 

What the researchers found was that obese young people between the ages of 18 and 30 years of age had a much lower incidence of IRS if their daily consumption of dairy products was increased.  The same correlation was evident between calcium intake and reduced incidence of IRS.  This would appear to be logical because a high proportion of the total calcium consumed was in the dairy products consumed.

 

This provides some very interesting opportunities for the dairy industry.  About 60-70% of all the calcium contained in most dairy products is contained within the milk proteins.  Most of you will be familiar with the milk protein % on your milk payment or individual cow DHI records.  You now see these reported in terms of “true protein”.  About 85% of the true protein in cows milk is in the form of a specific protein called casein, the primary protein used for cheese production.  Total casein is actually comprised of a group of proteins that are slightly different in their conformation.  The names include rather archaic Greek letters, and are called αS₁-casein, αS₂-casein, β-casein, and K-casein.  These individual caseins vary in their ability to bind calcium in the same order as listed above, αS₁-casein can bind more calcium than αS₂-casein and so on.

 

Thus in the future, if we choose to select specific cows that produce milk with increased content of αS₁-casein, and αS₂-casein composition, it may have significant health benefits for the consumer.  I would expect that there will be substantial future research to determine what the mechanism is that facilitated this apparent reduction in IRS, and the industry would do well to monitor this carefully.

This is just one of the many exciting possibilities for the future of the dairy industry.

 

Dr. Jim Maas, UD

 

 

 

Fly Management on Dairy Farms – What We Have Learned

 

Results of our pilot IPM program for Fly Management on Dairy Farms indicates that two key elements are critical to manage flies: identifying key fly breeding area areas on your farm and sanitation to reduce breeding areas.

 

 In order to identify possible breeding areas in and around the farm, both pre-season (March - April) and in-season evaluations are needed.  Observations of maggot populations in various areas around the farm indicated that the highest levels can be found in areas with moist (around an 18% moisture level), undisturbed organic material.

 

Over the past 3 seasons, calf pens/hutches, spilled feed, edges of silage piles, and manure deposits near posts and walls were manure was not removed were all identified as key breeding areas on most farms.

 

Although sanitation is the key to fly management, we have also looked at the following strategies to help reduce adult and larval (maggot) populations: 

 

Adult Management Strategies:

 

-Monitoring  populations using spot cards placed on key fly resting surfaces

 

-A combination of fly tapes and baits

The use of residual and space insecticide sprays timed when levels increased about the threshold of 50 fly spots per card

 

Larval (Maggot) Management Strategies:

 

-The releases of  parasites in calf barns/hutches

 

-The use of Fly Cracker along the edges of calf hutches

 

-The use of alternative bedding including sand in larger calf areas and peanut hulls in calf pens to reduce moisture levels resulting in reduced maggot development.

 

Our results indicate that successful fly management on dairy farms is dependent on the use of a combination of management strategies. The following strategies, when used in combination with a good sanitation program, have shown promise: 

 

-A combination of White fly tapes and baits has significantly reduce adult fly populations. 

 

 

-Residual sprays of Demand, Tempo and dimethoate provided the best reduction of fly populations in season. You must remove cows from the barns before treating and they should not return for 4 hours after treatment. Unfortunately, the dimethoate label for dairy barns will be cancelled after this season. 

 

-A combination of peanut hulls mixed with straw and the use of fly cracker along edges of calf pens reduced seepage and resulted in lower maggot populations in calf pens.

 

We have had mixed results with the use of parasites. Although they do reduce fly populations, it is essential that they be used in combination with a good sanitation program.

 

Alternative bedding appears to be a key component of fly management resulting in reduced seepage and a poor environment for fly egg laying and breeding.  Further evaluation of costs and labor requirements is needed.

 

Joanne Whalen, Extension Integrated Pest Management Specialist, UD

 

 

 

Use of Alternative Bedding Material to Manage Flies in Calf Pens

 

One of the key findings over several years of work on fly control in dairies has been that calf pens are a major breeding area for flies.

 

This summer we did a small trial comparing several bedding materials for use in calf pens.  These materials were evaluated for bedding characteristics and attractiveness to flies as a breeding area.

Four bedding materials were used:

- Straw,

- Peanut Hulls,

- Coconut Fiber (Coir), and

- Composted Pine Bark Fines. 

 

Straw is most commonly used for bedding calves and served as the control.  Peanut hulls have shown some ability to limit fly development in past work.  Coconut fiber is a by-product of the coconut industry overseas and is being imported in quantities to use in the greenhouse, nursery and bioremediation industries.  It is very absorbent and has the positive characteristic of drying rapidly on the surface.  Composted pine bark fines are a by-product of the forestry industry and are readily available.  It is used extensively in the nursery industry and has been shown to have some pesticidal properties.

 

Each treatment was applied to a separate pen and this was repeated three times (a total of 12 pens).

 

Bedding was maintained from the time calves were placed in the pens until the time they were removed (60 days).  Pens were bedded initially and additional bedding was added as needed.  Some manure and bedding material was removed in several treatments during this period when excess built up in the pens.

 

During the period the calves were housed, the pens were evaluated for the following:

- Calf comfort

- Calf cleanliness

- Seepage from pens

- Fly levels

 

After calves were removed, pens were cleaned in layers, the manure/bedding material was sorted through, and levels and locations of fly maggots and pupae were recorded.

 

Results from this small trial were very interesting.  For the first month of the study, seepage from pens was highest in the straw treatment followed by peanut hulls and pine bark.  During the second month of the study, seepage was similar these 3 treatments.  In contrast, the coconut fiber treatment had little or no seepage during most of the test. 

 

Calf comfort and cleanliness were acceptable in all treatments, although calves on the pine bark tended to be less clean.

 

Adult fly levels were variable and no conclusions can be made from the numbers recorded in the different pens.  However, there were dramatic differences in maggot and pupae levels with treatments.

 

The highest levels of maggots were found in the straw treatment.  Maggots were found at all levels in the straw bedded pens.  Maggot levels in the peanut hull treatments were also high but located more at the top of the manure pack.  In the coconut fiber treatments, there were much lower maggot levels in the pens and they were located in a small hot spot in the middle of the pen.  The pine bark treatments had virtually no maggots, suggesting the pine bark indeed has pesticidal properties.  Overall, pupae levels were low in all treatments except the straw.

 

Although this is one small test, it does strongly suggest that flies in calf pens can be managed through bedding choices.  Because pupae levels are directly related to potential adult fly populations, all 3 alternative treatments show promise as alternative bedding materials. Of particular interest is the possibility of layering pine bark fines with other bedding.  The coconut fiber also looked promising as a bedding alternative.

 

Written by Gordon Johnson, Extension Ag. Agent, Kent Co..  Research conducted by Joanne Whalen, Extension IPM Specialist, Marty Spellman, Extension IPM Associate,

and Gordon Johnson

 

 

What Evaluating Your Manure Can Tell You

 

Screening manure

 

Evaluation of manure can provide information on rumen function and digestion of the ration. By understanding the factors that cause changes in appearance, consistency and particle size, we can interpret what is happening in the gut. In context with other "cow observations", manure evaluation can help to diagnose areas for improvement in both ration formulation and management.  

 

Some diseases can cause changes in how manure looks. In addition, where, what, how, and to what extent feed is digested affects manure consistency and appearance. To begin with, different nutrients are digested or fermented in different portions of the gut. 

 

 Rumen digestion is a fermentative process involving rumen microbes.  Crude protein, fiber, sugars, starches and soluble fiber are acted upon here.  The next site of digestion is the small intestine where enzymes work to break down true protein, sugars, starches, and fats.  The final site of digestion is the hindgut where again through fermentation, crude protein,  fiber, sugars, starch and soluble fiber are also digested.

 

Microbial fermentations in the rumen or hindgut produce the same products. These products influence how manure looks. If a great deal of fermentable material, usually mostly carbohydrate, reaches the hindgut, then diarrhea may occur due to an extensive hindgut fermentation (acid production).  Manure may be very bubbly or foamy indicating gas production.

 

Diarrhea

 

Mucin casts may be found in the manure. These represent damage to the walls of the hindgut, possibly caused by low pH from an extensive hindgut fermentation. If the gut is damaged, the cow secretes mucin or fibrin to cover the area. Intact casts resemble tubes. These casts may be found in manure of any consistency.  

Mucin casts

 

If you think about it, the three descriptions of extensive hindgut fermentation look like the symptoms we tend to associate with ruminal acidosis. What does rumen function have to do with the appearance of manure? If insufficient physically effective fiber is fed, if too much starch is fed, if rumen pH declines, digestion of feeds in the rumen may decrease, passage out of the rumen may increase, with undigested feed passing down the tract. When the feed reaches the hindgut, we see the changes in manure appearance described above. 

 

The rumen will also be the main site that determines the size of particles that reach the manure. Most fiber digestion and particle reduction occurs in the rumen, if enough physically effective fiber (peNDF) has been fed. peNDF is the chewable fiber that enhances rumination and good rumen function, and helps to build the rumen mat. The rumen mat is the raft of coarser, floating feed that can help retain particles in the rumen for chewing and digestion. 

 

To evaluate fecal particle size and undigested feed, use a screen or kitchen strainer (do not return it to the kitchen) with 1/16 inch (1.6 mm) openings. This is a qualitative, on farm evaluation, so getting very specific about mesh size is not crucial. A strainer that is 7 inches (17.8 cm) in diameter and 4 inches (10.2 cm) deep works well. Disposable coffee cups, or 8 oz (237 ml) sample cups with snap on lids work well for sample collection.  In a pen of cows, collect a number of samples from individual cow pies to give a fair representation of the variety in the group -- make sure that they are not contaminated with uneaten feed. This may be 3 - 6 samples per pen of 100 cows. Identify the samples by the group they came from.  

 

With water flowing gently but in a steady stream from a hose, rinse a single sample into/onto the screen, and rinse gently but thoroughly until the water flows clear. The remaining material gives a clear view of large particles and undigested feed in the manure. 

 

When not enough physically effective fiber is eaten by cows, particle size in the feces increases. Without the fiber to make a good mat in the rumen, larger particles pass out. You may see pieces of hay, pieces of corn stalk, etc. in the feces. As effective NDF in the diet decreases, fecal particles become coarser.

 

Generally, you do not want to see many fiber particles greater than 1/2 inch (1.3 mm) in the feces. The small size of the particles on a 40% sorghum silage ration  (% of dry matter) – see picture on the following page - and the lack of apparent grain suggest that the ration was retained in the rumen long enough to be chewed and fermented. 

Manure screening that  indicates proper rumen function

 

Whereas, very long pieces of coarse fiber in manure suggest that rumen retention time was far too short. The sample below came from a herd in which cows were extensively sorting their feed to eat the grain and refuse the forage. Many of the cows were suffering digestive upset. Note the one long piece of hay (~6 inches/ 15 cm) that passed thorough. 

 

A lot of long fiber in screened manure indicates digestive upset

 

Cows can sort out fiber that is more than 2 inches (5 cm) long from a moist total mixed ration. If sorting is a problem, all hay or forage should be chopped to 1 - 2 inch lengths, and mixed into a moist total mixed ration that does not separate. 

Problems also occur when rations are only partially mixed.  This will create situations where sorting is likely and where cows are receiving inconsistent levels of effective fiber.  Trying to mix forage of too long of length often leads to a PMR (Partially Mixed Ration), instead of a well mixed TMR (Total Mixed Ration).  

 

If feed such as cottonseed with the lint still on or pasture grass that is still green is found in the manure screenings, this indicates that the feed passed through the rumen and the whole gut too quickly, usually because not enough physically effective fiber was eaten by the cows. 

 

Whole kernels of corn in the manure often mean that the grain in the corn silage was not properly processed, or there is a problem with the ground corn. A quick inspection of the concentrate and silage can decide which is the culprit. Corn in silage must at least be nicked to allow access to microbes and enzymes. 

 

Whole kernels in manure is also a sign of poor digestion or improper processing

 

Finding ground grain in the manure can indicate corn that is ground too coarsely, or insufficient consumption of physically effective fiber. More peNDF can hold the grain in the rumen for more extensive digestion. Grinding the corn more finely can also increase its digestibility. Make sure that enough fiber is fed so that the finer grind does not lead to ruminal acidosis. 

 

Manure consistency, good or bad, should be consistent within a group of cows that are receiving the same ration. If it is not, it suggests that the cows are sorting their feed, either aided by poor mixing, or by deliberate efforts on the cows' parts. Watch them eat. If you see them push the feed from side to side, and then dive to the bottom of the bunk for a mouthful, they are usually pushing the forage out of the way, and eating grain that falls to the bottom. If bunk space is limited, and the group is sorting, the timid cows may eat the most forage, but may not get enough energy or protein. The boss cows may get acidosis. 

Manure consistency differences

 

Heat stress can also change manure consistency. Cows drink more water, and their rumen pH decreases (due to less cud chewing, more slug feeding, changes in their acid-base balance, etc.). Their manure will be loose.

 

Sometimes, a large amount of sand/soil may be found in manure. When cows consume a great deal of soil, it may be a non-specific indication of digestive upset, ruminal acidosis, etc.  

 

Many of the undesirable changes in manure are related to underfeeding physically effective fiber, or overfeeding the non-NDF carbohydrates, notably starch. What matters is what the cows actually eat, not what we think we are feeding. Unlike the hay in this rack, sources of effective NDF must be available and the cow must actually eat it.

 

Manure can tell us a variety of things about how and where feeds are being digested in the gut. It is important to put that information in context with how well the cows are ruminating, incidence of digestive upset or laminitis in the herd, information on milk yield and composition, and other observations to decide 1) Is there a ration problem? 2) Have we diagnosed it correctly? Used with the other tools at our disposal, manure evaluation can help to interpret how cows are eating and digesting their rations. 

 

To see color pictures of manure analysis, visit Dr. Mary Beth Hall’s web page at : http://www.dps.ufl.edu/hall/MBManure.htm

 

From the web publication: Manure Evaluation Guide, Dr. Mary Beth Hall, Assistant Professor, Dairy Cattle Nutrition

Department of Animal Sciences
University of Florida, Gainesville

 

Comparing Corn Grain and Silage Yield

 

In a drought year, where corn silage yields are down, you also get a reduction of the amount of corn grain in a ton of silage.  The following table can be used to estimate the reduction to expect.

 

Table 1.  Approximate bushels of grain contained in a ton of corn silage at 65% moisture at different yields.

 

Grain             Silage          Grain

Yield              Yield       Equivalent

(bu/a 15.5%)   (Ton/a)      (Bu/T silage)

 

  25                   7.1           3.5

  50                   9.0           5.5

  75                   11.1          6.8

 100                  13.4          7.5 

 125                  15.9          7.9

 150                  18.7          8.0

 175                  22.2          7.9

 

Adapted form Field Crops 28.5-27.  The relationship between corn grain and silage yield, Dept. of Agronomy, Univ. of Wisconsin-Madison          

 

 

 

 

 

MANURE EVALUATION FIELD STUDY By Mike Hutjens, Extension Dairy Specialist, University of Illinois, Urbana   In the September 19th issue of Agri-View, Mary Beth Hall, University of Florida, reported on an interesting article on manure evaluation   “Reading” manure continues to be an active area of interest on dairy farms.   Dairy managers, feed consultants, veterinarians, and feed company specialist see manure changes and attempt to interpret these changes.   Personnel from Dairyland Labs report manure samples are sent in for evaluation, but guidelines are needed to interpret and apply in the field.  Can manure samples be analyzed in a lab and “tells” us anything about the herd or cows?   To answer this question, Becky Meier, a senior in Animal Sciences from Riodott, Illinois, conducted an honors project collecting information on manure variation.   The study had the following format: manure samples were collected from research cows on a current University of Illinois study.   One cow was sampled three times during the collection period (#6921) to see if changes occurred in early lactation.   Cows in the manure study had been on a transition cow study by Heather Dann.   Manure sample were collected within 60 days after calving (all cows were on the same diet after calving).   Information on dry matter intake, days in milk, and milk yield was collected on day of sampling.   Five hundred grams of fresh manure were washed through screen number 8 (2200 micron), number 16 (1120 micron), and number 30 screens (500 micron); dried at 55 degrees until a stable weight was achieved, and weighed to measure amount of particles on each screen.   A second set of fresh manure sample was collected and sent to Dairyland Labs for dry matter, pH, and starch content.    Preliminary results are reported in Table 1.  A complete summary will appear in the 2003 Illinois Dairy Report.    The following points can be observed:   -A wide range in fecal starch was observed varying from 2.3 to 22.4 percent.   -Fecal pH varied from 5.4 to 6.5 units. Fecal dry matter ranged from 9.2 to 11.6 percent.   -A wide range in milk yield (75 to 119 pounds), dry matter intake (44.3 to 60.7 pounds), and days in milk were in the data set.   -Manure from the one fresh cow monitored did not vary greatly during three weeks in early lactation.   We will be statistically analyzing the data to see if relationships exist, but the information so far does not show strong relationships.   Field Applications of Manure Evaluation Two ways to evaluate manure on farms can be used even if manure analysis is not conclusive and needs more study.   Method 1.  Monitor manure scores (1 as very watery to 3 as ideal to 5 as stiff and stacking) as rations change and cows increase in days in milk.    a.  Fresh cows could range from    2 to 2.5    b.  Early lactation cows can range from 2.5 to 3.0    c.  Mid to late lactation cows may range from 3.0 to 3.5    d.  Dry cows can range from 3.5 to 4.0   Manure scores below 3 may be due to lack of rumen transition when shifting cows from the dry to early lactation ration, too much protein is fed, excessive starch intake occurs, high mineral intake is happening, and/or a lack of functional fiber exists.   Method 2.  Wash a cup of manure (about 8 ounces of wet manure) using a number 8 screen (eight squares to the inch or 1/8 inch openings) to monitor the following:     a.  If more than 8 to 10 intact cottonseeds (fuzzy removed) remain, nutrients inside the seeds are lost (due poor rumination or lack of functional fiber).     b.  If whole or split roasted soybeans exist, additional processing is needed.     c.  If partial or whole corn kernels remain from corn silage, the corn silage was not processed, was processed incorrectly, and/or was too mature at harvest.     d.  If small pieces of corn grain remain on the screen from corn grain, the grain was not processed adequately.     e.  If forage particles over 0.5 inch remain on the screen, forage digestibility and quality can be a limitation.   Manure evaluation can be a useful field tool and diagnostic benchmark.  Unfortunately, lab  analysis has limited application at this point.

 

Animal	DIM	Milk	DMI	%BW	Fecal	Fecal	Fecal
(cow #)	(days)	(lb)	(lb)	(%)	DM	pH	Starch
					(%)	(units)	(%)
6484	29	76	50.7	3.1	18.11	6.35	17.06
6606	28	119	60.7	4.5	16.90	6.35	2.31
6696	62	89	na	na	15.80	6.55	17.28
6877	25	104	54.6	3.7	17.98	6.33	14.29
6881	48	113	57.7	4.1	16.14	6.04	21.25
6921	46	103	53.1	3.7	19.20	5.93	9.48
6921	53	98	54.1	3.8	16.16	5.99	9.65
6921	63	93	na	na	17.90	6.34	8.64
7009	35	116	54.4	4.1	11.59	6.15	22.43
7063	34	77	56.1	4.4	15.10	6.04	6.56
7084	19	99	59.0	4.9	18.06	6.18	13.23
7097	25	92	44.3	3.9	16.39	6.63	2.81
7144	54	81	47.6	3.4	17.35	5.89	11.70
7146	58	78	na	na	18.87	5.44	10.44
7158	24	80	47.3	3.9	14.82	6.54	10.80

 

 

 

 

Aflatoxins: Some Answers

 

Although aflatoxin production occurs somewhere in the country every year, the recent media releases fueled by drought have made this problem a harvest season highlight. Following are some answers to frequently asked questions:

 

Aflatoxins are a group of agents produced by Aspergillus flavus (thus

the name A. flavis > Afla). This toxin group includes several similar

 

compounds; regulations and most test formats are specifically for aflatoxin B1.

 

This mold species is common, especially in corn, peanuts, and cottonseed. Even when mold growth is apparent, toxins will not necessarily be produced.

 

The visual appearance of mold and mold spore counts are not useful in determining aflatoxin presence.

 

 

 

 

 

Preharvest (field) aflatoxin formation is favored by high temperatures, prolonged drought conditions, and high insect activity. Postharvest (storage) aflatoxin production is favored by warm temperatures and high humidity (or insufficient grain drying).

 

Black light fluorescence from a corn sample results from a metabolite created by the mold, but the agent is not aflatoxin. There is some correlation between a black light positive test and the occurrence of aflatoxin in the grain. However, another test is necessary to confirm presence and determine the concentration of aflatoxin.

Proper sampling is the key to accurate aflatoxin analysis. Because the presence of the toxin is spotty, multiple random samples are essential.

 

The FDA established guidelines for acceptable maximum levels of aflatoxin in corn are: 300 ppb for finishing beef cattle, 200 ppb for finishing (>100 lbs.) swine, 100 ppb for breeding beef cattle, breeding swine, and mature poultry, and 20 ppb for other animal feeds including dairy.

 

Dairy cattle diets should not contain more than 20 ppb. This is not because of a health threat, rather it is related to milk residues.  Aflatoxin B1 is metabolized by the cow and some is excreted in the milk as aflatoxin M1. When the total diet contains over this amount of aflatoxin, milk residues are possible. The maximum allowable level of aflatoxin M1 in milk is 0.5 ppb.

 

Na Ca aluminosilicate (e.g., Novasil™) has been shown to bind aflatoxin to varying degrees and reduce the disease potential. Other binding agents such as clays or bentonites have produced mixed, often disappointing results.

 

Once formed, aflatoxin is virtually indestructible (without altering the integrity of the grain). Ammoniation of grain is effective in aflatoxin reduction and is used in certain applications. The aflatoxin present at harvest is not reduced by grain drying or ensiling.

 

By Gavin Meerdink, DVM, Beef and Feed Safety Extension Veterinarian, University of Illinois at Urbana-Champaign

 

 

The Confusing World of Mycotoxins

 

Although between 300 and 400 mycotoxins are known, those mycotoxins of most concern, based on their toxicity and occurrence, are aflatoxin, deoxynivalenol (DON or vomitoxin), zearalenone, fumonisin, T-2 toxin, and T-2-like toxins (trichothecenes).

 

 In a recent survey of suspect feed samples, some amount of aflatoxin, deoxynivalenol, or fumonisin was found in over 70 percent of the samples tested. Over a 10-year period, data collected from suspect samples analyzed at the North Carolina State University (NCSU) Mycotoxin Laboratory show: that 20 parts per billion (ppb) or more aflatoxin occurred in 34 percent of corn samples tested; deoxynivalenol was detected in over 60 percent of poultry and dairy feeds tested; zearalenone was present in 15 to 20 percent of feedstuffs tested; and T-2 toxin was present in about 5 percent of the feeds tested. Fumonisin, a mycotoxin often associated with horse deaths, is thought to occur very frequently; however, its discovery is so recent that data on occurrence has not been established.

While the concentration of aflatoxin in suspect samples in North Carolina has remained fairly constant, the incidence of aflatoxin contamination has decreased. Nonetheless, both the incidence and concentration of aflatoxin can change as suddenly and dramatically as the weather. Thus aflatoxin monitoring should not be neglected. Furthermore, the effects of high levels of aflatoxin on animals are well documented, but exposure of animals to low levels of aflatoxin, especially when combined with other conditions or mycotoxins, can produce confusing symptoms, particularly in field situations.

 

Deoxynivalenol (DON), zearalenone, T-2 toxin, and fumonisin are all produced by molds of the genus Fusarium. Molds in this genus are found in virtually every lot of corn and collectively are capable of producing 70 different mycotoxins. Some strains of Fusarium may produce as many as 17 mycotoxins simultaneously. Thus Fusarium mycotoxins are the most frequently identified group of mycotoxins in grains and feeds.

 

Effects of Mycotoxins on Dairy Cattle

 

Aflatoxin-contaminated feed not only reduces animal performance and overall health, but it also creates risks of residues in milk. Aflatoxin is secreted into milk in the form of aflatoxin M1 with residues approximately equal to 1 to 2 percent (1.7 percent average) of the dietary level. This ratio is not influenced greatly by milk production level since higher producing cows consume more feed and have a slightly higher transmission rate. Due to risks of milk residues, dietary aflatoxin should be kept below 25 ppb. This level is conservative due to: (1) nonuniform distribution of aflatoxin in grain and feed, (2) uncertainties in sampling and analysis, and (3) the potential for having more than one source of aflatoxin in the diet. Replacement animals may tolerate 50 to 100 ppb aflatoxin.

 

In dairy cattle DON is associated with reduced feed intake, lower milk production, elevated milk somatic cell counts, and reduced reproductive efficiency. Milk production loss appears to occur when diets contain more than 300 ppb DON. Although controlled research has shown no cause and effect relationship between DON levels and reduced milk production, field observations have shown that reductions in milk output of 25 pounds per cow were seen when DON was 500 ppb or more.

 

This suggests that DON may serve as a marker for feed that was exposed to a situation conducive to mold growth and mycotoxin formation. The possible presence of other mycotoxins, or factors more toxic than DON, seems likely. Dietary levels of 300 to 500 ppb DON in dairy feeds indicate mycotoxin problems and warrant attention.

 

Zearalenone causes estrogenic responses in dairy cattle, and large doses of this toxin are associated with abortions. Other responses of dairy animals to zearalenone may include reduced feed intake, decreased milk production, vaginitis, vaginal secretions, poor reproductive performance, and mammary gland enlargement in virgin heifers. Establishment of a tolerable level of zearalenone for dairy cattle is difficult, and is at best only a guess based on a meager amount of data and field observations. As with DON, zearalenone may serve as a marker for toxic feed. It is suggested that zearalenone not exceed 250 ppb in the total diet.

 

In dairy cattle T-2 toxin has been associated with feed refusal, production losses, gastroenteritis, intestinal hemorrhages, and death. T-2 has also been associated with reduced immune response in calves. Data with dairy cattle are not sufficient to establish a tolerable level of T-2 in the diet. Therefore, a practical recommendation may be to avoid T-2 in excess of 100 ppb in the total diet for growing or lactating dairy animals.

 

Fumonisin is another commonly isolated mycotoxin. However, fumonisin has only recently been isolated and only enough data exist to know that levels in excess of 20,000 ppb are potentially toxic to ruminants.

 

From the North Carolina Cooperative Extension Service publication number AG-523. Prepared by Frank T. Jones, Editor, Extension Poultry Science Specialist, Mary Beth Genter, Extension Toxicology Specialist, Winston M. Hagler, Director of NCSU Mycotoxin Laboratory, Jeff A. Hansen, Extension Animal Science Specialist, Bob A. Mowrey, Extension Animal Science Specialist, Matt H. Poore, Extension Animal Science Specialist, and Lon W. Whitlow, Extension Animal Science Specialist

 

NRC Dairy Nutritional Requirements On-line

 

Many of you are aware that the dairy nutritional requirements were revised and published in early 2001.  However, did you know that you can look at these recommendations on-line. 

 

The National Academies Press has made the Nutrient Requirements of Dairy Cattle: Seventh Revised Edition, 2001 available for reading on-line at

http://www.nap.edu/books/0309069971/html/

 

In addition, you can download a simulation that allows you to vary different animal and feed inputs to see how they meet these requirements.  It also includes spreadsheets for determining nutritional programs for calves and heifers. This free program can be downloaded at:

http://bob.nap.edu/html/dairymodel/

 

 

 

 

 

 

 

 

Dr. Limin Kung

Ruminant Nutrition and Microbiology

Research and Extension

Department of Animal & Food Science

(302) 831-2522 Email lkung@udel.edu

 

Gordon Johnson

Extension Agriculture Agent, Kent Co.

(302) 730-4000 Email gcjohn@udel.edu