Vol. 11, No. 2, May 2001
Editorial
Forages
Herd Health
Nutrition
Business
Miscellaneous
Herd Management
With this issue, we look forward optimistically to another growing season. Herein I've addressed some of the typical topics for the season, with hopes of providing assistance in your upcoming decisions. June is also Dairy Month. Coming up are 4-H and FFA events, expositions, lots of fieldwork and hopefully a little time to enjoy the summer. Have a good season, and I hope to see you at some of the upcoming events.
Regards,
J.W. Schroeder
Extension Dairy Specialist
Forages have a variety of moisture levels and determining dry matter yield can be difficult. So how do you measure the amount of forage dry matter in a wagonload of silage?
Measurements taken at the University of Wisconsin's experiment station in Marshfield give producers a starting point in estimating their forage dry matter yield. For three years, a total of 486 wagonloads of haylage, corn silage, grass, clover and oatlage were measured and tested for moisture at the station. The table shows these forages had a typical density of around 5 pounds per cubic foot.
This estimate can help you calculate the amount of dry matter in a wagon. For example, if you have a wagon of silage that measures 16 feet long by 7 feet wide, and it is filled to a depth of 6 feet, you would have 672 cubic feet of silage or approximately 3,360 pounds of dry matter [(16x7x6)(5)=3,360].
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Forage Cutting
Type Number Avg. Density Std. Deviation
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- lbs. dry matter per cubic ft. -
Haylage first 5.67 1.13
Haylage second 5.00 0.97
Haylage third 5.10 0.77
Haylage fourth 4.95 0.65
Corn silage — 5.05 0.87
Grass all 4.55 0.61
Clover all 5.48 0.95
Oatlage — 4.99 0.65
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------------------------------------------------------- Source: Dairy Herd Management
Forage quality allows medium-producing herds to attain cost-effective milk production with lower levels of supplementation and higher producing herds to achieve cost-effective production by optimizing income over feed costs on a per cow basis.
Gauging alfalfa quality in the first crop depends on determining if the alfalfa is in the pre-bud, bud and flower stage. A simple measurement of height of tallest plant in a 2-foot square in five to six random locations of a field will determine approximate Relative Feed Value (RFV). Higher mixtures of grasses, due to their earlier maturity, will reduce the approximate RFV. This method has been research verified over a multitude of locations and years across the U.S. This table depicts the RFV's based on growth stage listed at the top of the column and heights in the first column.
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Height Pre-Bud RFV Bud-RFV Flower RFV
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23 195 185 174
24 190 181 170
25 185 176 166
26 180 172 162
27 175 168 158
28 171 164 154
29 167 160 151
30 163 156 147
31 159 152 144
32 155 149 140
33 152 145 137
34 148 142 136
35 145 139 131
36 142 136 128
37 138 133 126
38 135 130 123
39 132 127 121
40 129 124 118
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-------------------------------------------- Source: D. Thoreson, Iowa State University
There continues to be much debate about the value of using anthelmintics (dewormers) to treat internal parasites in adult dairy cattle. Over the years numerous studies have attempted to settle this debate once and for all. However, many of the studies conflict in the method and timing of the treatment and, most importantly, in their conclusions about the benefit of deworming mature cattle.
While more than half of the studies indicate an improvement in performance (milk yield) in treated cattle, the range of responses is quite large. This means that even if treatment improves performance it may not be economically justifiable to use anthelmintics in this group of cattle.
The use of strategic spring and summer deworming programs (rather than treating at dry-off or freshening, for example) may result in a more predictable response to treatment. Given the unpredictable response to anthelmintic treatment (some studies actually showed a drop in milk production after treatment!), one recommendation would be to work with your veterinarian to assess the level of internal parasitism in your mature herd, especially if they are on pasture during the spring and summer. If fecal egg counts indicate the presence of a large number of `worms' in animals, a deworming program could be put in place. Although this approach could not guarantee that treatment would be economically justifiable, it would increase the chances of observing a positive and worthwhile response in milk production.
Source: E. Hovingh, DVM, Virginia Tech
The dietary cation-anion difference (DCAD) is a useful way to evaluate forages for prefresh dry cows. The equation, however, often either scares farmers or puts them to sleep. It's not really that difficult; if it was, I wouldn't understand it. First, multiply the percent concentration for each of the nutrients by the appropriate factor. Then add up the values for the cations, add up the values for the anions, then subtract the anions from the cations. The goal for dry cow forages is +350 or less. The DCAD equation includes estimates of relative availability of each nutrient to the cow, but we've accounted for this in the multiplication factors. Here's an example using a grass silage sample from our farm:
Cations Anions
Miner Institute Miner Institute
Nutrient Sample % x Factor Nutrient Sample % x Factor
Sodium 0.005 x 435 = 2 Chloride 0.63 x 282 = 178
Potassium 2.15 x 256 = 550 Sulfur 0.18 x 322 = 58
Calcium 0.67 x 75 = 50 Phosphorus 0.24 x 156 = 37
Magnesium 0.18 = 22
----- -----
624 273
624 minus 273 = +351
A few comments: Note that sodium concentration doesn't amount to much. For most
grasses we've tested, the cations sodium, calcium, and magnesium just about
offset the anions sulfur and phosphorus. Potassium and chloride are the two
nutrients driving the DCAD equation. Chloride concentration in grasses differs
considerably. While the chloride concentration in this grass was worth 178 megacalories/Kg,
the DCAD value of the chloride in grass silage we've fed our cows in the past
year has ranged from 70 to 347.
Good news. The North Dakota Dairy Diagnostic Program (ND3P) received its third (albeit final) round of funding from APUC this spring. This means we can begin to expand the program.
There are changes in program personnel as well. Tom Risdal has joined us as the statewide coordinator. He is off to a fast start and many of you have already met him. Currently Tom and Merna Bredwick are working diligently to take us to the next level. In addition, Cass Clay has made a three-year commitment for 10 of their producers. So if you're looking for an opportunity to get started, now's the time.
The ultimate question for considering ND3P is, "does it help you reach your goals?" For many, the goal is increased profit. Here are a couple of examples of actual results currently being summarized. The names have been withheld to maintain confidentiality. If you wish to learn more, we will ask the dairy farm family for permission to make contact.
Farm No. 1—
Expanded from 87 to 130 cows while maintaining milk production at 57 lbs. per cow per day. Gross Economic Impact _ $85,969 (based on $11.50/cwt. milk price and a 305 day period; typically return to labor and management is 30% of gross).
Farm No. 8—
In one year, expanded herd from 110 to 208 cows. Feed costs decreased from $5.21 to $4.41 per cwt. of milk. Milk production increased from 21,069 lbs. to 22,528 lbs. Net return increased after all direct and overhead costs from $73,773 to $93,059. Net Return $19,286 (actual net return increase after all expenses including depreciation and inventory changes).
There are now more full-time prisoners in the U.S. than there are full-time farmers. If Holland implements European environmental rules as written, it will have to reduce dairy cow numbers by 50 percent in the next few years (by 2004). U.S. farmers over the age of 65 outnumber those under 35 by three to one.
Aventis CropScience has canceled the registration of StarLink corn and has offered to purchase the total production from the 300,000 acres of corn grown with the StarLink trait. This corn would be fed to livestock or processed into ethanol. Dennis Avery, director of global food issues at the Hudson Institute, is concerned that agriculture will lose on biotechnology issues. The reason, he says, is that the opposition is well funded and "because we're cheap, defensive and feel inferior."
Somebody left a glass of milk next to the keyboard. Reaction:
OPTIMIST: The glass if half full.
PESSIMIST: The glass is half empty.
FUTURIST: The milk's in the wrong half of the glass.
PASCAL PROGRAMMER: Well, what type of milk is it?
C PROGRAMMER: No thanks, I drink straight from the jug.
ASSEMBLY PROGRAMMER: No thanks, I drink straight from the cow.
BASIC PROGRAMMER: No thanks, I'm still breast feeding.
FUZZY LOGIC GUY: I may or may not have drunk some part of that milk.
PENTIUM USER: I drank Glass #.49999999 . . . but don't hold me to that.
WINDOWS USER: Where's my straw?
MAC USER: Where's my pump?
UNIX USER: Nahh . . . too easy.
SHAREWARE GAME AUTHOR: That glass is free, the next one you have to pay for.
CIA: What makes you think that's milk?
COPY PROTECTION CRAZY: Somebody drank half my milk and didn't pay for it!
BILL GATES: Not enough market share to be Microsoft Milk.
APPLE COMPUTER: You guys really oughta be drinking Perrier.
NATIONAL NEWS MEDIA: Hey, we wanted OJ!!!
Reprinted by permission — Washington Apple Pi, http://www.wap.org/
In a recent study, scientists at University of Georgia looked at several factors affecting the reasons cows leave the herd, including the effect of region. Herd summary information for over 11,000 Holstein herds obtained from the Dairy Records Management Systems (DRMS), Raleigh, N.C., was analyzed for the three regions and is shown in Figure 1.
Figure 1. Assignment of states to north, mid-south and south regions.
The overall culling or left herd rate and the specific reasons cows left the
herd expressed on a percentage basis are shown in Table 1. Herd Summary Report
values for your herd can be compared to this summary. Convert the number of
cows for each reason as shown on the Herd Summary report to a percentage as
follows:
Number cows leaving
for a specific reason
% Left for a specific reason = ----------------------- x 100
Total cows left
Table 1. Effect of region on reasons cows left the herd.
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Left Low
Region (all reasons) Reproduction Mastitis Udder Died Production
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- - - - - - - - - - - - - - - - % - - - - - - - - - - - - - - - -
North 35.1 17.1 11.9 0.2 14.8 11.6
Midsouth 36.3 16.8 11.9 0.3 17.5 13.3
South 34.5 20.8 10.1 0.2 20.1 15.8
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Continued...
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Injury/ Feet & Not
Region Other Dairy Legs Disease Reported
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North 25.8 2.9 5.6 3.5 6.6
Midsouth 16.5 5.3 6.1 4.6 7.8
South 14.8 4.4 5.9 3.8 4.2
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Herds in the Midsouth reported a slightly higher percentage of cows leaving
(36.3%) than herds in the South region (34.5%). A culling rate of about 25 percent
is considered optimal. Culling in all regions was well above the optimum rate.
Reproduction is frequently reported as a primary reason for culling. In this study, reproduction was significantly higher in the South (20.8%) compared to the other two regions. This difference may be due to the negative effect of heat and humidity in the South.
The percentage of cows reported as leaving for mastitis was lower in the South. Higher somatic cell count (SCC) levels in the South are usually attributed to the warm, humid environmental conditions. The lower culling rate for mastitis may also contribute to the higher average SCC levels in this region. The general lack of an economic incentive to lower SCC levels may be an additional factor.
Reported death losses were highest in the South and lowest in the North. The injury/other category followed an opposite trend. This difference among regions represents a significant economic loss for herds in the South region. Little or no salvage value is received for cows that die and additional costs are incurred for disposal.
Culling a particular cow from the herd requires either a voluntary (choice) or involuntary (forced) decision. Involuntary culling occurs when a cow leaves because of an accident, disease, injury or death. Voluntary culling occurs when a cow is sold because she does not meet certain herd standards such as a minimum level of milk production. Cows sold to other producers for dairy purposes are also voluntary culls.
In order to improve a herd's production efficiency and profitability, the number of cows culled involuntarily must be reduced. A starting point is to begin accurately recording the reasons cows are leaving your herd. Then determine which of the involuntary culling categories is high.
Certainly the highpercentage of cows leaving for reproduction and death in the south region is a cause for concern. Much progress has been made in reducing heat stress on many farms. The prime motivation has been to improve milk production. This study would indirectly suggest that controlling heat stress may also have additional economic benefits by reducing the number of cows leaving the herd for reproduction and death.
For example, herds of 200 cows in both the North and South regions would each cull 70 cows annually (200 x .35). However, death losses average 14 cows in the South (70 x .20) and 10 cows in the North (70 a .148). If replacement heifers are valued at $1400 each, the additional cost in the South because of higher death losses would be $5600. Lowering death losses by reducing heat stress or instituting other management practices could have a significant impact on profitability.
Source: W. Smith and O. Ely, Georgia DairyFax
The bottom line: Cows come into heat equally during all hours of the day,
are not very active, and do not stay in heat very long, making it difficult
to observe them in heat. The equal distribution of the onset of estrus during
the day combined with the average estrus duration of seven hours dictate that
heat detection observations should occur three to four times daily, approximately
six to eight hours apart. Providing an environment that encourages cows to express
heat and conducting frequent heat detection are essential to improve reproductive
efficiency. Allow cows to interact in a small, uncrowded area with secure footing
and make use of heat detection aids to catch as many cows as possible. Eight
times out of 10, the area of reproductive management that needs improvement
is heat detection. There are very few dairy farms that could not reduce the
average calving interval and culling rate by spending a little more time and
effort on heat detection. Achieving accurate and efficient heat detection requires
extra effort and doesn't just happen. Cycling cows require good nutrition, excellent
cow comfort, the best hoof health possible and attention to details.
Source: R,L, Nebel, Virginia Cooperative Extension
Dairy Connection -- Vol. 11, No. 2, May 2001
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.
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