Vol. 12, No. 3, September 2002
EDITORIAL
NUTRITION
REPRODUCTION
HERD HEALTH
MANAGEMENT
MILK QUALITY
From drought to flood, the weather conditions in North Dakota this summer have made it one for the books in terms of extremes. We've had one foot in the fire and the other in water (figuratively speaking), but when we read the weather statistics for North Dakota, years from now they will suggest that, on the average, precipitation was normal. But life on the farm has been anything but normal! With feed shortages, low milk prices, the investment community in a tizzy and the first anniversary of 9-11, many people are very concerned about the future of their families, their community and their business.
It's become apparent that our future will be quite different from our past. However, we are hopeful that today's challenges will provide tomorrow's opportunities. For dairy producers, one of these opportunities may be the development of heifers for other dairies. At the 2002 Dairy Convention, the planning committee has chosen to address change, both in business and family. This year's theme, "Preparing for the Next Generation," has dual meaning. That is, it refers to the next generation of dairy producers and the next generation of dairy animals. See the insert for this year's program and watch for more publicity to come.
In the meantime, mark your calendars for Oct. 24-25 at the Seven Seas in Mandan and join us for a day and a half of education and fellowship.
Regards,
J.W. Schroeder
Extension Dairy Specialist
One objective of the feeding program should be to efficiently utilize dietary protein. Too little protein does not support desired levels of milk production and too much protein is not cost effective and may have a negative effect on reproduction. One way producers can monitor protein use is to have milk samples tested for the concentration of urea nitrogen. Milk urea nitrogen (MUN) provides a measure of how dietary nitrogen (protein) is used by the cow. Some producers have this test run each month as part of their DHI program whereas other producers prefer to have bulk tank samples analyzed periodically. If different rations are fed, bulk tank analyses will not provide the correct information and individual cow samples should be collected for analysis.
The recommended MUN concentration for Holsteins is in the range of 8.5 to 11.5 mg/dl. Typically MUN values will be 2 to 3 mg/dl higher for colored breeds and will be higher for herds fed haylage based diets or are grazing. High MUN concentrations have been associated with decreased reproductive performance. This is related to the accumulation of ammonia in the reproductive tract which alters the pH and resulting environment for an embryo. However, several reports point out that MUN value can be extremely variable among cows. More than one MUN test is advised to monitor the nitrogen status of the herd.
If MUN concentrations are not within the desired range, several areas should be examined.
Using MUN information can be a tool to help improve milk production and/or reduce feed cost. In some areas of the United States, producers are using MUN to fine tune their feeding programs to reduce the amount of nitrogen they must dispose of. Many North Dakota producers are working on their required nutrient management plan to comply with the new environmental regulations. As these plans are being developed, it may be useful to consider using MUN to fine tune diets to reduce the amount of nitrogen produced.
Source: J.K. Bernard, Dairy Research & Extension, University of Georgia
The most recent state averages for Virginia DHI members revealed the average calving interval is now 14.5 months, the longest since Virginia DHI started reporting summaries. It is not efficient or profitable for the majority of farms to have a 14.5 month calving interval. The major inputs that determine the costs of extended calving intervals are the level of milk production, milk price, culling rate, and cost of replacements. We are presently experiencing record highs for milk production, milk price, culling rate, and cost of replacements. Therefore, the cost of extended calving intervals is more expensive now than ever before. Detection of cows in heat is half the pregnancy rate equation. Realize it is difficult to observe cows in heat because cows come into heat equally during all hours of the day, are not very active, and do not stay in heat very long. The equal distribution of the onset of estrus during the day combined with an average duration of estrus of eight hours dictate heat detection observations should occur three to four times daily, approximately six to eight hours apart. To achieve accurate and efficient heat detection requires extra effort and organization. Most farm's detection of cows in heat has failed because only 40 percent of all cows that should be detected are actually observed and inseminated. Cycling cows require good nutrition, excellent cow comfort, the best hoof health possible, and attention to details.
Methods of synchronizing estrus were originally devised to decrease the time spent detecting estrus; however, systematic breeding programs especially Ovsynch and Pre-synch are now being used for convenience while increasing pregnancy rates and decreasing days to first service.
Systematic breeding programs provide an organized approach for administering AI at first service and achieve higher pregnancy rates because more cows have a chance to become pregnant. Ovsynch consists of a GnRH injection at a random stage of the estrous cycle, followed by PFG2a seven days later, a second GnRH injection 36 to 48 hours after PGF2a, and timed AI 12 to 16 hours after the last GnRH injection. Routinely, pregnancy rates of 25 to 35 percent are achieved in dairy cows inseminated at first service using the Ovsynch protocol. However, it is possible to manipulate the estrous cycle of cows such that they are in the ideal stage of the estrous cycle when the Ovsynch program is initiated. Thus, the name Pre-synch which applies two injections of PGF2a 14 days apart with the second PGF2a injection 12 to 14 days before the initiation of Ovsynch. The Pre-synch protocol groups a higher percentage of the cows into days 5 to 12 of their estrous cycles when the first GnRH injection of Ovsynch is given. Modification of the Ovsynch protocol to Pre-synch is shown below with suggested days in milk (DIM) at each hormone injection.
Source: R.L. Nebel, Ext. Dairy Scientist,
Reproductive Management. Virginia Tech, Blacksburg
Johne's disease is one of the most prevalent in U.S. cattle and sheep herds. It is estimated that this disease has caused more than $1.5 billion in losses to U.S. agriculture — costing farmers between $40 and $227 per cow. About 40 percent of dairy herds have at least one cow infected with the disease, according to the USDA National Animal Disease Center.
Attempts to develop early diagnosis tests and a vaccination for Johne's have been unsuccessful because animals carry the infection but show no signs of disease for a long time. Charles Thoen, Iowa State University professor of veterinary microbiology and preventive medicine, has developed a delayed hypersensitivity test — a derivative of purified protein that increases sensitivity to detecting Johne's. Veterinary pathologists, J. Hostetter and E. Steadham are conducting research to determine how the mycobacterium survives. When researchers understand how the infection grows, a screening process for the disease will be possible. The researchers also are working to produce a vaccine that will be effective for fighting Johne's.
So while this is good news, they have a way to go before it is available to producers.
Is your cow bedding clean and comfortable? Frequently, the "knee test" can be used to test if the resting surface is comfortable, and, to a degree, clean enough for the cow to lie. To perform the test, kneel in the stall or dry lot area, then rock back and forth on one knee. How does this feel on your knee?
If it feels comfortable, it is probably okay for the cow to use as she shifts in the stall. However, it is recommended that you try the second test. In the stall or dry lot, drop quickly to your knees from a standing position. Does this impact feel comfortable? If the answer is yes, the cows will not be reluctant to lie down. If it hurts, most cows will be reluctant to use this area.
Next, stand up and look at your knees. Are they wet or covered with manure? If they are, your stalls need some serious attention as well as fresh bedding. The last, and perhaps most telling question is: would you lie in the bedding? If not, change it immediately. After the knee test, be sure to make a visual assessment of your cows' and heifers' cleanliness.
Source: NMC 41st Annual Meeting proceedings, pg. 45. 2002.
Excel Dairy prefers the versatility, safety, and
economic advantage of using a small tractor rather
than a skid steer to scrape free-stall barn alleys for
our 1,100-cow dairy. Employees also prefer the
tractor because getting on and off and visibility is much
better. Each machine performs other operations at the
dairy, with the tractor mowing lawns during the
summer using a 48-inch, three-point PTO mower. Following
are the pros and cons for each machine.
---------------------------------------------------------------
Tractor Skid Steer
---------------------------------------------------------------
$14,000 Cost $22,000
6,000=10,000? hours Useful Life 4,000 hours
---------------------------------------------------------------
Rating: 1 is good; 5 is poor
1 Operator accessibility 3
1 Visibility backing up 4
1 Damage control 5
2 Maneuverability 1
---------------------------------------------------------------
$240 Tire wear, operator cost $1,152
---------------------------------------------------------------
---------------------------------------------------------------
COST: There is a substantial difference in
up-front investment and possibly trade-in value.
USEFUL LIFE: Our oldest tractor has almost 7,000 hours. At 6,000 hours we did some major work and now expect to get another 2,000 to 3,000 hours.
OPERATOR ACCESSIBILITY: The tractor is easier to get on and off than the skid steer. We have had three workers compensation claims from slips and falls getting on/off the skid steer and none for the tractor.
VISIBILITY: The tractor is very easy to turn and look behind while backing up. Our model of skid steer limits visibility when looking behind, and the safety belts prevent a lot of body movement.
DAMAGE CONTROL: Our main reason for switching to a tractor was the amount of damage that was done to gates, doors, walls, and mounted fans by the skid steer. The damage from tractor operation has been almost nothing.
MANEUVERABILITY: Our center alley in the lactating barn is 15 feet wide and we have no trouble turning into each alley to scrape out manure. In our prefresh barn the alley is only 12 feet wide and our tractor still turns fine. The skid steer can turn around in the alley but we see this as a negative because manure gets dripped onto the stall beds, free stalls get bent, and fans have been knocked off their posts.
TIRE WEAR: The tractor with 6,000 hours has had six front tires replaced at a cost of $40 each for a total of $240. We use regular car tires on the front. The skid steer with 4,000 hours has used 12 tires at $96 each for a total of $1,152.
One final note on the tractor is the modifications that we made. The Ford Boomer that we use needs two modifications to the three-point hitch arms to avoid bending and breaking the lower pin. This can be done for about $100.
Source: L. Amundson, Excel Dairy, Thief River Falls, MN.
Dairy Initiatives Newsletter, Vol. 11, Summer 2002.
Information in the most recent National Milk Drug Residue Database Report (Fiscal Year 2001 Annual Report) showed that less than one-tenth of 1 percent of milk samples tested positive for drug residues last year.
The report contains data on samples and tests conducted during fiscal year 2001 (Oct. 1, 2000 - Sept. 30, 2001). During this period, 4,203,616 samples were analyzed for drug residues. Samples included bulk milk pickup tankers (78 percent), producer milk (18 percent), pasteurized products (2 percent), and other (2 percent). Of the total samples, 3,401 were positive for a residue.
A total of 4,314,181 tests were reported on the samples for 14 different groups of families or individual drugs. Forty-seven methods were used to analyze the samples for residues.
The National Milk Drug Residue Database is a voluntary industry reporting program. The database includes results of the National Drug Residue Milk Monitoring Program, which is administered by the Food and Drug Administration with full cooperation by the states.
Vol. 12, No. 3, September 2002
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.