North Dakota State University
NDSU Extension Service
Vol. 9, No. 4, December 1999
Editors Note
J.W. Schroeder Completes Ph.D. Degree
Milk Quality
Herd Health
Calves/Young Stock
Dairy Cow College 2000
Nutrition
Business
Friendly fall and winter weather to the middle of December has been a blessing for everyone. With this copy of my quarterly Dairy Connection, another holiday season has arrived and the winter meeting schedule begins.
Happy New Year
J.W. Schroeder, Ph.D.
Livestock Specialist-Dairy
Announcement from Dr. Chung Park
J.W. (Jerome) Schroeder has recently completed the requirements and been approved for Doctor of Philosophy from North Dakota State University, Fargo. This degree encompassed advanced course work in biological sciences and nutritional physiology, preliminary examinations (both written and oral), and successfully defending his doctoral dissertation research
Dr. Schroeder conducted in vitro research studying the effect of phased-nutrition on mammary development in the Laboratory of Growth and Lactation. His dissertation entitled, "Compensatory Nutrition Regulation of ß-(beta) casein Gene Expression in HC11 Mammary Epithelial Cells," was a cell culture investigation to study the molecular aspects of our stair-step energy regime for growing and developing dairy heifers. In experimental procedures, he employed the HC11 mammary epithelial cell line which has the unique ability to produce ß-casein. This cell culture model allowed him to mimic live animal research in the laboratory by altering glucose levels to the cell to examine their response to compensatory nutrition. The practice of restricting energy intake during key periods of development, followed by brief refeeding periods where extra energy is supplied at specific intervals to induce compensatory or catch-up cell development.
Our novel "stair-step" program has been well established in dairy and beef heifers, swine, and laboratory rats, but J. W.'s work is the first data we know of that actually looks at what is happening at the cellular level. This work is instrumental to our lab's long-range goals to extend mammary cell proliferation (growth) and delay apoptosis (natural cell death) to improve lactation persistency and longevity.
Through his Ph.D. study, J.W. has gained considerable experience in basic cell and molecular biology, including the measurement of cell proliferation, determination of the milk producing cells' ability to secrete protein, the isolation of gene signals to look at the genetic expression for casein production and the search for other gene markers for mammary and lactation functions.
The implications of this research will eventually help scientists discover the key to raising milk production, lengthening lactation persistency, and improving protein content of milk to increase its value to the producer and the processor in North Dakota and other regions.
In addition to his Extension responsibilities, J.W. will continue to teach Dairy Production/Products, a capstone course in the Department of Animal and Range Sciences. He is actively seeking continued support for the new North Dakota Dairy Diagnostic program. He is expected to lead dairy production/nutrition research in the department. Currently, he is conducting research on tempered barley and hull-less oats for lactating dairy cattle. Previously he has completed several other projects, including waxy corn and corn gluten feed experiments. He will also be involved in recruiting and training graduate students in dairy science.
(Kudos Dr. Schroeder)
There can be single or multiple sources of high standard plate counts (SPC) in bulk tank milk. After determining which area is the source of the problem, a corrective plan can be put in action.
Consider the following sources when troubleshooting high SPC:
- between the cow and pipeline.
- between the pipeline inlet and the receiver.
- between the receiver and plate cooler.
- in the plate cooler.
- between the plate cooler and tank including the drop pipe.
Source: NMC 1997 Annual Meeting Proceedings, pg.80
A common observation on individual farms is that SCC increases with advancing age and stage of lactation. However, research has shown that if cows were separated into groups by infection status, it becomes obvious that there is little change in SCC in uninfected cows, either as a cow ages or in late lactation.
Additional work has confirmed the finding that milk from uninfected quarters displayed little change in SCC with increasing number of lactations or with advancing stage of lactation. Inspection of stage of lactation data showed that the SCC of milk from uninfected quarters rose from 83,000 at 35 days postpartum to 160,000 by 285 days. However, Staphylococcus aureus infected quarters rose form 234,000 to 1,000,000 over the same period. All quarters, regardless of infection status had elevated SCC immediate postpartum, but those quarters with no infections or with minor pathogen infections showed a rapid decline in SCC to 35 days postpartum. Further, a 1997 study found no significant effect of parity or stage of lactation on SCC in bacteriologically negative (uninfected) cows. One study showed a rise in SCC at the end of lactation only after production had dropped below 4 kg (8.8 lb) per day, but the infection status in these animals was not determined. Feed or water deprivation results in decreased milk yield and increased SCC which can be interpreted as a dilution phenomenon. It has been suggested that a modest rise in SCC in uninfected quarters at the end of lactation could be a dilution effect. Thus, the major influence of parity and stage of lactation on SCC is related to intramammary infection status.
Source: NMC 1998 Regional Meeting Proceedings, pg. 40
There are at least three approaches to treatment of footwarts: topical treatment applied under a bandage, topical spray application, and possibly footbaths. Each has advantages and disadvantages.
Treatments applied under a bandage include various antibiotics (tetracycline, oxytetracycline, lincomycin, and the combination product lincomycin/spectinomycin). Clinical and anecdotal information suggests that most anitbiotics are effective in the "under a bandage" application. However, only lincomycin has data to support an efficacy claim. The advantage of treatment under a bandage is that lesions extending into the interdigital space can be effectively treated. The disadvantage of antibiotic treatment is that it represents extra-label drug use, and as such can only be used under the order and guidance of a veterinarian. For this reason, the availability of non-antibiotic disinfectant-type compounds is desired, but to date there are none which have established efficacy as bandage treatment alternatives.
With regard to topical spray treatment, antibiotics as well as a few disinfectants appear to be effective based on studies here and elsewhere. Florida researchers recently reported on studies using "Victory" (a product marketed by Westfalia-Surge) in topical spray treatment of naturally occurring footwarts. "Victory" performed as well as oxytetracycline in the treatment of footwarts in our study. They concluded Victory to be a viable topical spray treatment option that poses no antibiotic residue risk. Other non-antibiotic alternatives with evidence of effectiveness in topical spray application include formalin (formaldehyde), "Hoof Pro Plus" (SSI, INC.), and "Restore" (WestAgro, Inc.).
The advantage of a footbath is that it provides for treatment of the interdigital space where the lesions of footrot, interdigital dermatitis, and footwarts often occur. But, there are no products with established efficacy in footbath application. Anecdotal and published information suggest that most antibiotics as well as non-antibiotic compounds are rapidly neutralized by the contaminated conditions that exist in footbath solutions. There is some suggestion in the literature that formalin may be less susceptible to neutralization in footbaths, but data establishing its effectiveness in footbath application is lacking. Furthermore, the use of formalin carries with it significant human health concerns. Therefore, its use must be considered very carefully.
Thus, treatment under a bandage coupled with topical spray application of effective antibiotic and non-antibiotic preparations will help to provide manageable control of footwarts. Use of a walk-through footbath may provide some additional assistance but only if solutions are changed frequently enough that they are able to maintain some level of antimicrobial activity.
Source: J.K. Shearer, DVM, Extension Dairy Veterinarian, University of Florida
One of the most common problems seen in newborn calves are extra or supernumerary teats. Extra teats should be removed for cosmetic reasons and to help prevent mastitis when cows go into the milking herd. Removing these teats will improve udder appearance. This can be an important factor to producers who show or sell dairy cattle for dairy purposes. Extra teats can interfere with proper placement of the milking unit preventing good milk out and provide another portal for mastitis-causing pathogens to enter the udder.
While a relatively simple procedure, removing extra teats needs to be done properly to prevent complications. For several reasons, removing extra teats should be done to calves as young as possible (under six months old). Smaller calves are easier to restrain and will undergo a minimal amount of stress. Since the extra teats are still small, the wound is smaller, calves will experience a minimal amount of bleeding and the wound will heal easily without complications.
Checking for extra teats can be done at the same time as dehorning or vaccinating. The first step is to identify the normal teats from the extra teats. Normal teats are generally properly placed and are larger than extra teats. When removing, the extra teat should be gently pulled away from the udder and cut with a pair of scissors. The scissors should be cleaned and disinfected after use on each calf to minimize the risk of infection or BLV. The angle of the cut should run head to tail, so the scar will blend with the normal folds of the udder. Spray the wound with iodine or other antiseptic.
Place calf in a clean well bedded pen to prevent infection. During warm weather, use fly spray after teat removal to reduce risk of fly-transmitted infection. If there is any doubt as which teats are supernumerary or if they are located close to a normal teat, have your veterinarian remove these teats.
Source: C.M. Burns, Extension Assistant, Veterinary Science, Penn State University
By now you should have received a bright yellow and red flier announcing this year's schedule. We have another full agenda and will be combining meetings with Gary Hoffman and your ADA district at the following locations:
January 31 Linton
Emmons County Courthouse Auditorium11:00 a.m. CT
February 1 Dickinson
Knights of Columbus, 1531 Villard10:00 a.m. MT
February 2 New Salem
Morton County Fairgrounds 4-H Building10:00 a.m. MT
February 3 Minot
North Central Research Extension Center10:00 a.m. CT
February 4 Jamestown Eagles Club 10:30 a.m. CT
Many DHI laboratories now have the capacity to measure milk urea nitrogen (MUN) concentrations. Milk urea nitrogen (MUN) concentrations are directly related to rumen ammonia nitrogen and blood urea nitrogen concentrations and provide an indirect measure of how dietary nitrogen is used by the animal. In general, high MUN concentrations and provide an indirect measure of how dietary nitrogen is used by the animal. In general, high MUN concentrations indicate that there is an excess of nitrogen whereas low MUN concentrations indicate that the diet may be limiting in degradable nitrogen. Results of MUN analysis may be used to fine tune rations and identify mixing or feeding errors that reduce feed cost and/or improve milk production. Research has shown that high MUN's (> 19 mg/dl) may contribute to reduced conception rates. Some consultants and veterinarians are recommending producers test for MUN to provide more information to make decisions, but many producers still have questions about the reliability of this information, what constitutes a "desirable" MUN, and how to use the information.
There was considerable variation in results among laboratories with some of the initial equipment and methods used to measure MUN. Improvements have been made in the equipment and methodology has become more standard among laboratories, so the lab to lab variation has decreased. It is still a good practice to send all samples to the same lab so the values from each test can be compared without worrying about any potential difference among labs. The key is the relative change from month to month.
The cow to cow variation in MUN concentrations is similar to that of milk fat and protein. This may be due to genetic differences, but could also be due to selectivity of the cow when she eats. The Pennsylvania DHIA reported the following averages for MUN concentrations by breed: 12:85 mg/dl for Ayrshire; 16.05 mg/dl for Brown Swiss; 13.75 mg/dl for Guernsey; 13.56 mg/dl for Holstein; and 15.72 mg/dl for Jersey. From these averages, MUN values for Brown Swiss and Jersey will be higher than that for Holstein. Producers should keep this in mind as they interpret MUN results.
Individual cow results are misleading due to the large variation from cow to cow. Research at Iowa State University suggest that producers should test at least 50% of the cows in the herd (or group) to be confident of the results. Testing a smaller percent of the herd will give a less reliable picture of what the MUN actually is. There is some evidence to suggest that bulk tank samples can be used for Mun testing. Again due to the variation, at least five samples should be taken for analysis. One MUN analysis is not considered adequate to determine what is going on in a herd. Producers who plan to use MUN should have samples analyzed for several months to establish a base line.
The table below provides some guidelines for inter-preting MUN concentrations. Many experts differ on what values should be considered desirable, but most agree that a desirable value falls into the range from 10 to 14 or 16 mg/dl. It would not be uncommon to see MUN concentrations vary by 1 to 2 mg/dl from one month to the next due to changes in forages and feeding management. For MUN analysis to be meaningful, producers must be able to relate the results back to their feeding program. When more than one ration is fed to groups of cows, MUN results must be summarized by group. Changes made in the feeding program can be detected in MUN analysis as soon as the next day.
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Milk % LOW MUN DESIRED MUN HIGH MUN
Crude Protein < 10 mg/dl 10 - 14 mg/dl >14 mg/dl
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< 3.0 Low CHO +/or NEL SIP, DIP, AAA in Excess SIP +/or DIP
Low SIP +/or UIP balance. Low CHO relative to CHO/NEI.
+/or NEI Excess UIP or
imbalance in AAA.
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3.0 - 3.2 Low SIP +/or DIP Balanced SIP, DIP, Excess SIP +/or DIP
+/or UIP. And UIP, AAA, NEI relative to CHO.
CHO/NEI. balanced.
----------------------------------------------------------------------------
> 3.2 Low SIP +/or Balanced SIP, DIP, Excess SIP +/or DIP
DIP, AAA UIP, AAA. relative to CHO
balanced.
Excess CHO/NEI. Excess of UIP vs NEI
Excess CHO/NEI or AAA imbalance.
----------------------------------------------------------------------------
This table should be used on average MUN for the whole herd or groups of Holstein cows (Standard deviation of individual cows MUNs = 3 - 4 mg/dl). MUN = Milk urea nitrogen (mg/dl)
SIP = Soluble intake protein
DIP = Degradable intake protein
UIP = UndegradableAAA = Amino acids that are actually absorbed
CHO = Rumen fermentable carbohydrate
NEI = Net energy for lactation
Producers who are considering testing for MUN should understand the usefulness and
limitations of MUN. If MUN testing is used, samples should be sent to the same lab each
test and greater than 50% of the cows in the groups or herd should be tested. If MUN
results are outside the normal range, producers should work with their nutritionist to
reformulate the rations and then retest to confirm the changes.
Source: C. Sniffen and A. Nelson
Is your banker not too excited to loan you money for that project you have planned because of doubt that it is feasible? Are you frustrated by getting professional advice from so many experts who can't seem to agree on anything?
Well, maybe having a `dairy advisory team' is something you should consider. A dairy advisory team is a group of farm advisors that meets on a regular basis (monthly or quarterly, for example) to discuss farm issues and to make suggestions that can help the producer achieve his or her goals, whether those be personal/family, profitability or productivity goals. These teams are usually relatively small (four to six people), and can be made up of various advisors or specialists such as a veterinarian, a crop specialist, a nutritionist, a financial advisor/lender, extension personnel, or others, depending on the producers goals and concerns. Other specialists may be consulted from time to time if the team does not have the expertise to address a particular issue or concern within the group. The herd owner(s) remains, of course, ultimately responsible for choosing to implement, modify or ignore the recommendations of the advisory team.
Even though farm advisory teams may not fit everyone's situation, they can be an excellent way to have important farm advisors discuss issues face-to-face and to reach consensus on the best way to reach farm goals and address areas of concern. If you would like to know more about how these teams can function or how to go about setting up an advisory team, please contact John Johnson, Statewide Project Coordinator, North Dakota Dairy Diagnostic Advisory Team 701-231-7993 (NDSU), 701-361-2987 (cell).
We will be giving a presentation at 12:30 p.m., on January 6 at Marketplace 2000, in the Spruce Room of the Civic Center, Bismarck. It will include members of various teams now working in the state. So if you need a day out and want to hear more about an advisory team first hand, come and see us January 6.
Dairy Connection, Vol. 9, No. 4, December 1999
NDSU Extension Service, North Dakota State University of Agriculture and Applied Science, and U.S. Department of Agriculture cooperating. Sharon D. Anderson, Director, Fargo, North Dakota. Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. We offer our programs and facilities to all persons regardless of race, color, national origin, religion, sex, disability, age, Vietnam era veterans status, or sexual orientation; and are an equal opportunity employer. This publication will be made available in alternative formats for people with disabilities upon request, 701/231-7881.
North Dakota State University
NDSU Extension Service