Archive for August, 2008

New publication teaches livestock operators how to mitigate high-phosphorus soils

Managers of Idaho’s confined animal feeding operations can download a new University of Idaho bulletin to learn how to avoid or reduce high soil phosphorus levels in fields receiving manure. The 30-page bulletin, “Mitigating High-Phosphorus Soils,” highlights the environmental and nutrient management issues related to phosphorus on Idaho livestock operations and helps producers meet the legally defined standards for adding phosphorus.

Available at http://www.info.ag.uidaho.edu/pdf/BUL/BUL0851.pdf , the on-line bulletin not only helps livestock operators to be in compliance with the law but to be sure their operation is in long-term balance in terms of phosphorus added to or removed from soil. An essential nutrient for crop and animal production, phosphorus can accelerate nuisance aquatic growth in freshwater, depleting life-sustaining oxygen for fish and producing toxins harmful to fish, shellfish and other animals.

“This isn’t just an engineering publication,” said co-author Brad Brown, a University of Idaho Extension crop management specialist in Parma. “It’s unique in that it covers the entire front of phosphorus-management issues, particularly as they relate to the Idaho statute. For producers whose livestock operations come under the standard for manuring, this pretty well addresses what they need to be concerned about. It should meet a very real need in southern Idaho and other areas.”

The publication presents strategies for balancing phosphorus inputs with outputs, including optimizing phosphorus use efficiency, refining animal feed rations, processing manure, moving manure from surplus to deficit areas, sampling manure prior to application, and refining cropping systems.

Other authors include Mireille Chahine, Mario de Haro Marti and Christi Falen — all current University of Idaho Extension faculty members — and former faculty member Ron Sheffield, now of Louisiana State University. The publication drew from research-based information developed within and beyond Idaho.

A printed version may be available in the future. For more information, contact Brown via phone: 208-722-6701 or e-mail: bradb@uidaho.edu.

Alternative rotation for less-than-ideally drained soils

 

By Tom Kilcer, regional crop and soils specialist,
Cornell Cooperative Extension

 

    Nearly every farm has fields that are less than ideally drained. Some farms switched these fields to reed canary grass with high nitrogen (N) applications. But this system has become uneconomical as N prices nearly tripled over the past five years.
    Another option is to interseed winter forage triticale with red clover, rotated with corn, brown midrib (BMR) sorghum-sudan or teff.
    This is not a perfect crop system but it can boost yields on less-than-ideal soils without breaking the bank trying to buy N fertilizer.

 

Cornell Cooperative Extension in Rensselaer County has been testing alternative crop rotations specifically for these soil types.  The objectives were to:

• produce high yields of high quality dairy forage;

• work the soil minimally to reduce picking stones, while staying off wet soils in early spring and fall;

• rotate crops between grass and broadleaf species to reduce buildup of disease and insects;

• use a legume in the rotation to replace purchased N and supply the grass component of the rotation. 
 

An alternative rotation
    After a summer annual such as corn is harvested in early September, minimum till or aerate the soil, then plant winter forage triticale (a cross between wheat and rye) with a conventional drill or a no-till drill.
    In late February or March, when the ground is frozen, broadcast a good variety of medium red clover at 8 pounds of seed per acre into the stand along with about 75 pounds of N. The N feeds early rapid growth of the winter triticale. The frost-seeded clover will come up under the triticale. 
    Harvest the triticale as high quality forage at flag leaf stage (where the flag leaf shows but NO head is showing). This is about May 18 to 23 in lower Rensselaer County, the same time that intensively managed reed canary grass is ready for harvest.
   Following triticale harvest, with normal rainfall, expect two cuttings of  high quality, high yielding clover. Seeding year clover at Cornell’s trials typically yields 2.2 tons of dry matter (DM) per acre.

 

            For the second year of clover expect 3 to 4 cuttings with yields equal or exceeding the peak years of an alfalfa stand. In Cornell yield trials, second-year clover yielded 4.5 to 5.5 tons DM per acre. By the third year, native grubs will have built up in the clover stand, destroying most of the root system.  You will get a good first cut but the stand will rapidly disappear.

 At this point there are three options to choose from:
    1.  No-till plant a very short season Roundup Ready (RR) corn. Keep in mind that on most fields the first cutting will yield 1.5 to 2 tons of DM even on a runout stand.  This boosts the first year DM per acre to 5.75 to 6.25 tons; or more than 16 to 18 tons of corn silage equivalent. 
   2. No-till BMR sorghum-sudan. No-tilling eliminates most of the stone problems.  It works best with round bale wrapping systems, although it takes a higher level of management and attention to details, thus it is not a crop for everyone.
    3. Apply Roundup and no-till plant teff.  Originally from Ethiopia, teff is a fine-leaved plant that, in a two-cut system, has consistently yielded 3 to 4 tons of DM per acre with only 50 pounds of N per cutting.  It excels in dry weather and makes very high quality hay.  Normally there are two cuttings from this rapidly growing crop.  If no manure is used, it would be excellent feed for dry cows.
 Each of these three choices comes off for the final harvest at the beginning of September and the cycle starts over with a planting of winter forage triticale.

 

 Problems, Pitfalls, and Possibilities
   Each step has issues that you need to manage for this system to succeed.

 

    Triticale.  Triticale MUST be in the ground by Sept. 25, earlier in colder areas, and out of the ground by the end of September to protect soil during the winter and establish yield potential for the next spring.  Our research showed that planting later with a higher seeding rate only wasted seed and still had major yield penalties the next spring.     

 The crop MUST be drilled in 1 to 1.25 inches deep.  Broadcast and harrowed-in, it leads to very poor yields and sometimes complete winter kill. Winter triticale is planted at 125 lbs. of seed per acre.  A corn starter supplying 20 pounds of N plus phosphorous and potash if needed will get the crop off to a good start.
  Heavy manure applications before planting supplies too much N, which produces excessive growth susceptible to being killed by winter diseases.  N needs to be applied in the spring. We have been very successful frost seeding both clover and N.  Both are incorporated by the same freezing-thawing system.
 The biggest problem with frost-seeding both clover and N is to remember to do it in late February or early March.  But if you miss the window, you can still put both on after the frost is out.

 

• Keep an eye on the triticale stand as the flag leaf stage can sneak up on you.  It is ready the same time as intensive managed grass and can go into the same silo.

 The mower should be set with NO shields in the back allowing the tall forage to fly out the back with minimal bunching.  Yields are heavy so if you use a conditioning mower, slow it down to allow the heavier crop to feed through.  Wide-swathed triticale can be ensiled the same day it is mowed, preserving the high sugars the crop naturally contains.  While conditioning does not help the crop to dry, tedding after 1 to 3 hours of drying lifts and loosens the heavy swaths for rapid drydown and same day chopping.
   Forage quality is 4,000 to 4,200 potential pounds of milk per ton of DM, compared to 3,700 to 4,000 potential pounds of milk/ton of DM for high quality corn silage. Triticale still tests high even during wet harvest. Like reeds, triticale has an excellent root system that pumps out a tremendous amount of water, drying the ground and allowing for harvest while minimizing the chance for rutting the field.
    Clover. For haylage, clover has an undeserved reputation as a crop that never dries.   First cut clover starting at the same moisture as alfalfa and mowed wide swath and NOT conditioned dried at the same rate as alfalfa, until about 70% moisture. Tedding clover an hour or two after mowing will move its upper leaves to expose lower levels to sunlight, rapidly drying the crop. But even without tedding, the clover was still ready to chop the same day, only slightly behind the alfalfa.
    One little-known advantage is that the protein in clover is protected, not broken down as with alfalfa. It remains in true protein form which is much more usable by the dairy cow.
   Improved new varieties are much higher yielding than common medium red clover.  No clover will last past the beginning of the third year due to the native grubs that decimate the root systems of clover.

   Short season RR corn. We mean LESS than 80-day corn.   Because short season corn shortens the vegetative stage, plant at 36,000 to 38,000 plants per acre.  A seed protection treatment is highly recommended. After the corn emerges (3 to 4 inches) apply Roundup for season-long weed control. You can also try traditional plowing but at much greater time and fuel cost.

 

Only 30 pounds of N is needed in the starter for sod fields.

 

BMR sorghum-sudan. Kill the sod first to starve clover-eating grubs during the summer and then no-till BMR sorghum-sudan directly into the sod. Round bale wrapping, especially with processing, makes tight, solid bales with excellent fermentation characteristics.  Sorghum-sudan responds to conditioning for the heavy stems.  As with the above crops, a tedding after a couple of hours of drying also works well. 

 

Teff. Teff is a new crop with a C4 photosynthesis like corn and sorghum.  It starts to head about knee high, but the very thick stands produce tremendous yields.  Normally there are two cuttings in a season.  The forage can be dry hay baled, chopped or round bale ensiled. But do NOT mow it to close to the ground on the first harvest.  Regrowth is from leaf tissue. The higher you cut, the faster it regrows. 
   Soil: Most of the wet soils for this rotation have been moldboard plowed when they were too wet sometime in the past 50 years.  The only way to remove the root-limiting pan still there is to deep till.  Then use plant no-till or use the new aerated tillage cropping for  excellent seed beds, good stands and good yields, without having to plow these delicate soils.

 

Based on research trials, we can estimate this rotation’s production:

 

•The triticale and clover will yield 4.45 tons of DM in the seeding year.

• The straight clover will yield 4.5 to 5.5 tons of DM in year two. 

• The first cutting of clover haylage and the yield of the short season corn or BMR or teff will yield 7 tons of DM.

This average of 5.5 tons of DM for the rotation is far above the poor yields many farmers tolerate from wet fields.  A bigger factor is that the DM harvested is as good as or better than that of many well drained fields.

 Contact Tom Kilcer at 518-272-4210. Email tfk1@cornell.edu. Or go to this website http://counties.cce.cornell.edu/rensselaer/agriculture

 

 

USDA report details foreign ag land ownership

USDA’s Farm Service Agency (FSA) released the latest report on foreign holdings of U.S. agricultural land. The publication contains statistics through Feb. 28, 2007, regarding the 21.2 million acres of U.S. agricultural land in which foreign persons hold an interest.
The publication reports that foreign persons have an interest (partial or total ownership) in 1.6% of all privately held U.S. agricultural land and 0.94% of all land in the United States This is a 5.3 million acre increase from 2006. Holdings from 1996 through 2006 were relatively steady.
The report includes a breakdown of land held by foreign persons by the type of acreage:
* Forest land – 64%
* Cropland – 11%
* Pasture and other agricultural land – 25%

The report also lists which countries have foreign persons holding the largest amount of land:
* Canadians hold the largest amount of land: over 8.2 million acres, or 38%.
* Foreign persons from the following three countries collectively hold more than 6.7 million acres, or 31% of the foreign held acres in the U.S.:
* Netherlands, almost 3.9 million acres (18%),
* United Kingdom, over 1.5 million acres (7%), and
* Germany, more than 1.3 million acres (6%).

The report, titled “Foreign Holdings of U.S. Agricultural Land,” is available on the FSA web site at: www.fsa.usda.gov.

Food costs, safety among consumer concerns

U.S. consumers are more concerned about the safety of the food they eat than they are the war in Iraq or global warming according to a new study. The finding is contained in the Center for Food Integrity’s (CFI) annual Consumer Trust Survey.
In addition the survey asked respondents to react to 24 attitudinal statements about the food system. Fewer than 20% of those surveyed strongly agreed that government agencies are doing a good job ensuring the safety of the food we eat.
“Consumers are very concerned about food safety,” said Jan Wilson, president of Gestalt Inc., the international market research firm conducting the study. “Governmental agencies responsible for ensuring the safety of the food supply are not being perceived very favorably.”
The study also asked consumers to rate their level of concern about a series of life events and current situations. Not surprisingly, rising energy costs, the U.S. economy, and the rising cost of food were the top three issues of concern. However, food safety rated higher as a concern than global warming or the war in Iraq (see Table 1).
CFI conducts research annually to benchmark consumer attitudes toward the important issues associated with the U.S. food system. This year’s research explores how much “social license” consumers are willing to grant producers, processors, retailers and restaurants.
Full survey results will be released at the Center for Food Integrity 2008 Food System Summit taking place Oct. 8-9, in Indianapolis. The research also contains consumer attitudes on the issues of immigration, animal well-being and energy/sustainability. More information on the summit, including how to register, is available at www.foodintegrity.org.

Table 1: Summary of Consumer Concern about Issues

Issues                                                                             Mean

Rising Energy Costs                                                        8.37

The U.S. Economy                                                            8.25

Rising Cost of Food                                                         8.09

Rising Health Care Costs                                                  7.73

Personal Financial Situation                                             7.51

Food Safety                                                                      7.03

The War in Iraq                                                                 6.97

Illegal Immigrants Working in the Food System               5.81

Global Warming                                                                5.79

Humane Treatment of Farm Animals                                5.66

The Impact of Immigrants Who are in the                                              Country Legally Working in the Food System                     4.16

Scale:  0 = No Concern        10 = Very Concerned

© 2008, Center for Food Integrity
Number of respondents: 2066

Genomics, cattle health traits researched

Colorado State University research may lead to early identification of animals with less susceptibility to feedlot diseases, especially bovine respiratory disease (BRD). The study is sponsored by Pfizer Animal Genetics and the National Beef Cattle Evaluation Consortium (NBCEC).

“This landmark research is providing us with greater insight into the genetic markers responsible for improved feedlot health, a promising significant breakthrough for the beef industry,” says Nigel Evans, Ph.D., vice president of Pfizer Animal Genetics.

The study design and funding originated from the NBCEC, a group of universities focused on furthering genetic evaluations of beef cattle. The organization had recently completed a pilot study at Iowa State University that showed encouraging results for genetic control of pinkeye, said NBCEC director Dr. John Pollak. As a next step the group decided to focus on the most prevalent disease in feedlot cattle: BRD.

“As an organization, one of our goals has been to identify genetic traits related to animal health, which is difficult on a large-scale industry level,” says Dr. Pollak. “Focusing on animal health, we identified BRD as one of the obvious diseases on which to focus our efforts. We hope the study results will lead to panels of markers indicative of animals less susceptible to BRD.”

Dr. Pollak identified multiple specialists to serve as members of the research team with Dr. Mark Enns of Colorado State University as the lead researcher. The ongoing research combines multiple past study designs to create a unique methodology focused on genetics under commercial feedlot conditions.

“Our goal with this study is to maximize producer profitability through healthier animals, improved animal welfare and the use of effective genetic management tools,” said Dr. Enns. “By identifying key genetic markers, the industry can better develop tools for producers to decrease morbidity and mortality, resulting in more profits for beef producers throughout the industry.”

The study, which began in 2007 and ends next year, involves more than 3,000 steers. All animals originate from one large commercial beef operation and are being fed at a Colorado commercial feedlot. All animals have been genotyped and performance and health traits will be monitored throughout the research while overall health and carcass quality will be charted after harvest.

The first-year data already is being used to discover and identify possible genetic marker panels that are indicative of animals less susceptible to common feedlot diseases. Currently in its second year, researchers are beginning to validate research results.

Data from the study also is being utilized by Pfizer Animal Health Veterinary Medicine Research and Development (VMRD). Pfizer is looking at the synergies between animal health and genetics to develop therapies that will improve the health of the animal, said director of Livestock Pharmaceuticals Jeffrey Watts, Ph.D., Pfizer Animal Health.

“Pfizer believes the Colorado State University research will help us in developing new products which can be tailored for certain management protocols that fit the needs of the animal subpopulations in the feedlot,” said Dr. Watts. “For example, in the future it may be possible to design pharmaceuticals to fit animals based on their genetic predispositions for carcass quality, tenderness and susceptibility to common feedlot diseases.”

“We may find that as we improve animal growth and productivity, animals will remain susceptible to certain diseases,” added Dr. Watts. “From a protocol standpoint we will be able to recommend different management regimens to treat common feedlot diseases and improve the overall performance based on an animal’s specific genetic makeup.”

Pfizer Animal Genetics is a business unit of Pfizer Animal Health, a world leader in discovering and developing innovative animal vaccines and prescription medicines. Pfizer Inc. is the world’s largest research-based pharmaceutical company.

Johne’s Control

Johne’s disease remains one of dairy’s biggest herd health challenges.

By Phil Durst & Dan Grooms

Top scientists from around the country shared Johne’s disease research results at a three-day conference at Michigan State University earlier this year. In addition, a single-day educational conference, “New Horizons in Johne’s Disease Control: Integrating Cutting Edge Research into On-Farm Practice” was held to review practical on-farm applications. Following are summaries of some of the presentations.

Best Management Practices for Control of Johne’s Disease, by Scott Wells and C. Ferrouillet, University of Minnesota.

To assess how commercial dairy producers implemented recommended Johne’s disease control practices, the authors asked producers:

• “How effective are these practices for the control of Johne’s disease?”

• “What are the best control strategies for use in dairy herds?”

They found that while testing and culling of Johne’s-positive cattle and, in some states, vaccination, have their place, management to protect vulnerable calves from exposure to Johne’s-causing bacteria is the most important tool to control the disease.

As in Michigan, Minnesota has been involved with a herd demonstration project for five years. Six Minnesota herds completed a risk assessment at the start of the project, and herd owners determined which control practices they would implement. Annual testing, using both serum ELISA and fecal culture, measured progress. Over the five years of the study, the prevalence of Johne’s disease within the herds decreased from 8% down to 3.1% of cows (using serum ELISA) and from 10% down to 5.6% of cows (using fecal culture).

In addition, surveys of Minnesota producers enrolled in the Minnesota Voluntary Johne’s Disease Control Program showed these producers effectively reduced their Johne’s risk scores (years 1 & 2) and prevalence of cattle testing Johne’s positive (years 1-4) by changing management practices, but risk scores and prevalence of infected animals leveled off thereafter. They concluded that implementing risk control practices (see box for a list of some recommended practices) reduces the rate of Johne’s disease within herds by reducing the number of new infections.

However, even over a five-year period, the disease was not eradicated in any of the herds. It will take more time and a continued commitment to maintain tight Johne’s disease control practices, including ceasing purchase of cattle from herds of unknown Johne’s status, to eliminate the disease.

Consensus Recommendations on Diagnostic Testing for Johne’s Disease (paratuberculosis) in the U.S., by Michael Collins, University of Wisconsin.

A team of experienced Johne’s disease veterinarians set out to define the best course of action regarding Johne’s disease testing in dairy and beef herds based on business type, infection status and prevalence.

The team acknowledged that producers should focus on management as the primary means of Johne’s disease control, with testing used as a secondary tool.

They looked at available testing options based on the accepted sensitivity and specificity of each test, as well as the purpose of the test, including: classifying a herd as infected; controlling the disease; surveillance; eradication; and confirming the disease in herds with no prior confirmed Johne’s disease cases and in herds that are known to be infected. Because each test has strengths and weaknesses, test selection should be based on the objectives of the testing. Considerations included:

Only low-cost tests are sellable to producers.

Speed of test results is over-rated. More important is having the results at the time when the producer needs to make a decision about culling or classifying an animal as “do not breed.”

• Look at every test result quantitatively, considering the state of disease progression may be determined by response to a test.

The authors prepared a table with recommendations for commercial dairy herds, seedstock dairy herds, cow-calf beef herds and seedstock beef herds. For instance, the recommended test to classify a commercial dairy herd as infected is a pooled environmental culture, whereas the recommended test to control disease in the same herd is the ELISA. To confirm a clinical diagnosis of Johne’s disease in a herd with no prior confirmed cases, they recommend a necropsy of animals that die or can be sacrificed, or fecal culture or polymerase chain reaction testing of others.

The full table and explanation is included in the proceedings at www.jdip.org.

MAP Super-shedders: A New Paradigm Shift in Johne’s Disease, by Robert Whitlock, University of Pennsylvania.

Having previously defined Johne’s diseaseinfected cows that are “super shedders” of the bacteria, and knowing that the risk of exposure to bacteria by herdmates on the farm is high, a team working with Dr. Whitlock tested the hypothesis that some cows may ingest the bacteria Mycobacterium avium paratuberculosis (MAP) and subsequently excrete it without becoming infected. By excreting the bacteria as pass-through bacteria, they risk being identified as infected animals when they, according to the hypothesis, are only passive shedders of the organism.

To test their hypothesis, they tested almost 2,300 fecal cultures from 556 cows in three herds in three states. Seventy-eight of those cows were culture positive, for an apparent prevalence rate of 3.5%. Bacteria in cultures from manure samples are measured as colony forming units (cfu) of MAP per gram (gm) of fecal material. Low shedders may have 5 cfu/ gm of manure; moderate shedders may have 50 cfu/gm; and heavy shedders may have 500 cfu/gm. Super-shedders are defined as shedding 10,000 to 10 million MAP bacteria per gram of manure.

In these three herds with a fairly low apparent prevalence of Johne’s disease, 15 cows (some from each herd) of the 78 culture positive cows (19%) were defined as super shedders. A single super-shedder cow puts out bacteria approximately equivalent to seven clinical cases or 160 heavy shedders, or over 2,000 moderate shedders or almost 24,000 low shedders.

These cows account for tremendous numbers of bacteria in the animal’s environment and, although few in number, put many other animals at risk of infection. Therefore, identifying and eliminating super shedders is important in controlling the transmission of Johne’s disease.

Diagnostics and Strain Differentiation of Mycobacterium avium paratuberculosis: Current Tools and Challenges, by Srinand Sreevatsan. University of Minnesota.

The current tests for Johne’s disease are valuable, but limited in sensitivity, the ability to detect subclinically infected animals, determining the stage of the disease and to specifically identify differences in the strain of the disease-causing bacteria.

However, scientific advances, including the recent characterization of the complete genome sequence of a cattle isolate of MAP allow researchers to continue to seek ways to overcome those limitations with new tests and new means of identification.

The immune reaction within an animal in response to an infection has a progression that is well-defined. Research is being conducted to identify bio-markers to help pinpoint the state of the disease.

Bio-markers also may in the development of therapeutics, determining response to therapy and predicting prognosis.

Happy Birthday, Afact

With the backdrop of higher food and energy prices and concerns about future food production capabilities, the American Farmers for the Advancement and Conservation of Technology (AFACT) held its first AFACT Summit in Chicago. From its embryonic start as “Voices for Choices,” a campaign initiated by DairyBusiness Communications, to its official birth just a year ago, the organization now boasts 1,000 dairy producer members who do not take kindly to attacks and restrictions on science and technology in the production of milk and other food. They represent about 1.5 million U.S. cows. There are another 400 members in related farming or agricultural enterprises. AFACT leaders contributed more than $125,000 out of their own pockets to get the organization on its feet, because they believe strongly in their cause.

July’s AFACT Summit brought together regional and national leaders of ag companies with similar interests in preserving access to modern agricultural technologies. The meeting’s main theme was to emphasize how producer advocacy can help reconnect with food retailers and consumers to educate about and protect the use of those technologies, promoting not only the efficiencies of modern agriculture to feed a growing world population, but also to share their passion and values in their pursuit of sustainable and environmentally sound food production.

AFACT is young and, like everyone, must admit to some youthful mistakes. Some early actions were based solely on emotions, after having been backed into a corner by those with far different agendas and motives. But they have learned quickly, and are mature beyond the single candle on their birthday cake.

This is truly a “modern” organization, in that most members have never met. Nearly all business is conducted electronically, in almost weekly teleconferences and daily e-mail communications. They’re using that same electronic technology to combat anti-animal agriculture/ technology activists – and having success (ask them about the Wal-Mart blog site). They also strive to make communication personal, by visiting one-on-one with grocery store managers to discuss marketing practices, and conducting consumer focus groups to find out what consumers “really” think about milk label absence claims. They’ve spent a great deal of time learning about the tactics and methods of those opposed to animal agriculture and technological advances, and refuse to concede the moral “high ground” to them. And, even though many have never met, AFACT leaders have developed a cohesive team with shared passions and values.

They’re also getting more arrows in their quiver. Studies in Europe, at Cornell University and South Dakota State/University of Minnesota (see page 20) show modern, efficient dairies have a smaller carbon footprint per unit of food produced, despite claims to the contrary. A milk composition study compiled at Penn State University showed that despite marketing claims and milk labels, there’s little or no difference in the composition of milk produced conventionally, as “rbST-free” or organically (see page 23). In its early stages, AFACT asked the American Farm Bureau Federation to monitor retail milk prices for regular, “rbST-free” and organic milk.” Those numbers show profits are going somewhere, and it’s not back to producers – many of whom are forced to give up tools which could boost their bottom line.

If you’d like to wish AFACT a “Happy Birthday,” or join its growing organization, visit www.itisafact.org. The group, like cheddar, will get even better with age.

Productivity Cuts Cow numbers, Total Methane

More productive dairy herds

– requiring fewer cows to produce more milk

– have resulted in less overall methane emissions into the atmosphere, according to a new South Dakota State University study.

South Dakota State University Extension dairy specialist Alvaro Garcia, along with James Linn, head of the University of Minnesota department of animal science, looked at the role cattle and dairy cows play in methane emission. Garcia and Linn presented their findings at the 2008 American Dairy Science Association meeting in Indianapolis.

According to the U.S. Environmental Protection Agency, agriculture is responsible for roughly 30% of total U.S. methane emissions. A majority comes from gastro-intestinal fermentation and manure management.

Garcia and Linn compared today’s dairy herds to those of 1924, the first year USDA dairy statistics were compiled. Modern dairy cows weigh more than those of 1924 as a result of genetic selection and a reduced number of mixed breeds, and therefore generate more methane per animal. However, in 2007, there were 9.15 million cows producing an average of 20,231 lbs. of milk per cow annually. In 1924, there were 21.42 million cows with a yearly per-cow average of 4,162 lbs. of milk.

“There were also drastic differences in the production systems. In 1924, more than half of U.S. dairies grazed their cows nearly six months of the year with diets that consisted almost exclusively of supplemental forages,” Garcia said. “The majority of today’s dairy operations confine their animals and feed a diet of roughly 50% grain and 50% forage.”

Dairy cow methane production is associated with total feed intake – the more a cow eats, the more gas she will produce. Average cow feed intake is determined by their production and their genetic drive to produce more milk stimulates them to eat more feed.

In 1924, the average daily production was 11.4 lbs. of milk, with a feed intake of 21.3 lbs. of dry feed. Cows produced just under 0.5 lb. of methane daily. In comparison, 2007 dairy cows produced on average five times more milk – 55.4 lbs. per day – and consumed on average 41.6 lbs. of dry feed. The dairy cow of 2007 produced almost 0.75 lb. of methane per day. Although the results show modern cows produce more methane daily, in 1924 there were 12.3 million more dairy cows in the United States.

“This large number of cows resulted in 40% more total methane emissions when compared to 2007,” said Garcia. “If we look at the ratio, three times more methane was produced per pound of milk in 1924 compared to 2007.”

This research also showed that production efficiency started to change drastically during the mid-1950s, with fewer cows needed to produce more milk. These changes resulted in less total methane production in spite of the increased gas production on a per-cow basis.

Garcia said there are opportunities to reduce methane emissions from dairy cows.

“Feeding grains and their byproducts will continue to be a important practices to reduce methane emissions,” he said. “Regrettably, high grain prices might challenge our ability to economically feed cows for reduced methane emissions. We must stress the importance of high quality forages to increase the efficiency of feed utilization and thus reduce the emission of methane.”

Similarly, the use of production enhancers such as ionophores and growth hormone result in improvements in efficiency.

All these measures should be accompanied by an adequate ration balance according to the nutrient requirements of the different physiological states of the cow, Garcia concluded.

Studies come to defense of dairy technology

Production efficiency cited as one key to reducing dairy’s carbon footprint.

By Dave Natzke

Proponents of dairy technology and sustainability have a new arrow in their quiver. On June 30, the Proceedings of the National Academy of Sciences web site published a Cornell University study demonstrating the use of recombinant bovine somatotropin (rbST) reduces the carbon footprint of milk production.

The study, “The Environmental Impact of Recombinant Bovine Somatotropin (rbST) use in Dairy Production,” is authored by Cornell professor Dale Bauman, post-doctoral research associates Jude Capper and Euridice Castandena-Gutierrez, and Monsanto scientist and Cornell alumnus Roger Cady.

With modern agricultural practices – especially those related to livestock production – coming under increasing pressure, the entire dairy industry is seeking ways to become more “sustainable” and reduce its overall carbon footprint. For example, spearheaded by Dairy Management Inc., producers, processors and marketers recently held a “Sustainability Summit” to address issues from the farm to the consumer (see July 2008 Midwest DairyBusiness, “Make Dairy Industry More ‘Sustainable’,” by Paul Rovey).

However, frequently lost in the rush toward “sustainability” is the need for adequate food production to feed a growing population, and the need for food producers to achieve adequate profitability to stay in business.

According to the Cornell study, as the global population reaches 9 billion people in the first half of the 21st century, the food supply required over the next 40 years will approximately equal the total amount of food produced throughout the history of humankind. U.S. milk production will have to increase to 5.62 billion gallons by 2040 to meet USDA dietary recommendations for three 8-oz. glasses of milk per person each day. The most sustainable way to increase U.S. milk production is to improve production per cow, and assess total population environmental impact per unit of milk produced.

“Sustainability is important in agricultural production, with an emphasis placed on meeting human food requirements while mitigating environmental impact,” said Bauman. “This study demonstrates that use of rbST markedly improves the efficiency of milk production, mitigates environmental impact including greenhouse gas emissions and reduces natural resource requirements such as fossil fuel, water and land use.”

Three models

The study design included three models to predict the environmental impact of using rbST:

1. one examined the impact of increased productive efficiency of individual cows in a producer’s herd.

2. another examined industry-scale adoption of rbST-supplemented cows, a number equal to approximately 15% of the current U.S. dairy herd.

3. another examined the environmental impact of achieving future increases in the future U.S. milk supply required to meet projected population growth and USDA Dietary Guidelines using conventional, conventional with rbST or organic production systems.

Increasing milk production efficiency reduces the feed required per unit of milk by diluting the fixed maintenance feed requirements over more units of milk. This means less manure is produced per unit of milk, and the amount of nitrogen and phosphorus that could potentially run off into waterways is reduced.

The carbon footprint will also decrease when the same milk can be produced with fewer animals and less crop production. “The total reduction in the carbon footprint conferred by rbST supplementation of 1 million dairy cows is equivalent to removing approximately 400,000 family cars from the road, or planting 300 million trees,” the study’s authors said. “Increased milk production efficiency also decreases the energy needed from fossil fuels and electricity required for cropping and milk production.

“The savings in gasoline alone would be sufficient to power approximately 1,550 passenger cars, each traveling an average of 12,500 miles. Further, the total fossil fuel and electricity savings would provide sufficient annual heat and electricity for approximately 16,000 and 15,000 households, respectively.”

More cows are needed to meet projected dietary demand, but with technologies and husbandry practices that increase productive efficiency, that need can be greatly reduced. The authors report that 8% fewer cows are needed in an rbST- supplemented population, whereas organic production systems would require a 25% increase to meet future production targets.

Strong start builds a productive future

Studies show a link between nutrient intake prior to weaning and long-term milk yield.

By Mike Van Amburgh, Emiliano Raffrenato and Bob Everett

Your treatment of calves from the first hour through the first six to eight weeks of their lives could impact their future milk producing ability.

Most dairy producers know the important relationship between calf health and growth and colostrum quality, yield and immunoglobulin (Ig) absorption. Low serum Ig status in calves relates to decreased growth rate and increased morbidity. Some studies even indicate that low serum Ig levels affect milk yield during first lactation.

A 1988 study indicated calves with higher Ig status are able to inactivate pathogens prior to mounting a full immune response. This allows them to maintain energy and nutrient utilization for growth  But calves with low Ig status must first mount an immune response, diverting nutrients to defense mechanisms rather than growth.

How severe is this difference, or for how long does it persist? Data from a 1989 study demonstrated that for each unit of serum IgG content above 12 mg/ml, there was an 18.7-lb. increase in mature equivalent milk yield. This implies calves with lower IgG content were more susceptible to immune challenges, which impacted long-term performance.

A 2005 study suggests the impact of serum Ig levels wasn’t nearly as great, but still affected milk yield and survival through the second lactation. In that study, Brown Swiss calves received either 2 or 4 liters of colostrum just after birth. Researchers monitored the animals for two lactations after calving, making three observations:

1. There was a 30% increase in prepubertal growth rates based on colostrum feeding level under identical feeding conditions.

2. There was a 16% increase in survival to the end of the second lactation of calves fed the 4 liters of colostrum.

3. The surviving calves fed the 4 liters of colostrum produced 2,263 lbs. more milk by the end of the second lactation.

We don’t know if this response is due just to Ig status or other factors in colostrum. But it suggests colostrum quantity is important for long-term productivity, in addition to what we traditionally thought of as immune status.

Early eating, later production Many studies have allowed researchers to look at milk yield from cattle that received more nutrients up to eight weeks of age (see Table 1). In each study, increased nutrient intake prior to 56 days of age resulted in 1,000-3,000 lbs. of additional milk during the first lactation, compared to calves under more restricted feeding during the same period.

In a recent Miner Institute study in Chazy, N.Y., researchers report calves fed approximately 2 lbs. per day of milk replacer produced 1,543 lbs. more milk (at 200 days in milk) than calves receiving 1 lb .of milk replacer powder per day. Calving age wasn’t affected by treatment.

Averaging the studies shown in Table 1, there is a 1,700-lb. response to increasing nutrient intake prior to weaning. Here’s the take-home point: The higher intake levels must be from liquid feed.

Cornell research

We started feeding Cornell’s research herd for greater preweaning weight gains many years ago, and have more than 1,000 weaning weights and 725 lactations with which to make evaluations. We analyzed the lactation data of the 725 heifers with complete lactations, evaluating several factors – birth weight, weaning weight, height at weaning, weight at 4 weeks of age and others – related to early life performance and their milk yield.

Our data shows growth rate prior to weaning has the greatest correlation with first-lactation milk. For every pound of average daily gain (ADG) prior to weaning, the heifers produced approximately 1,000 lbs. more milk.

The range in preweaning growth rates among the 725 animals was 0.52 to 2.76 lbs. per day. Also, 20% of the variation in firstlactation milk production could be explained by growth rate to weaning. This has important ramifications:

The impacts of Ig status and nutrient intake play a significant role in the performance and variation in first lactation milk yield.

More milk will be achieved once we better understand the cause of the variation.

To achieve these milk-yield responses from early life nutrition, calves must double their birth weight by weaning. This means milk or milk replacer intake must be greater than traditional programs for the first three to four weeks of life.

A closer look at some research

In the study by Rincker et al. (2006), control calves were fed a standard 20% crude protein (CP), 20% fat milk replacer and starter, at 1.2% of body weight (BW), to achieve 1-lb. per day growth rate to weaning. The treatment calves were fed a 28% CP, 15% fat milk replacer at 2.1% of BW and a higher protein starter (24.5%) to achieve 1.5-lb. per day gain prior to weaning. All calves were weaned by six weeks and fed similarly from eight weeks through the first lactation. Body weight at calving was not different – 1,265 vs. 1,241 lbs., respectively. Milk yield was followed only through the first 150 days of lactation. Projected 305-day milk yields were 1,100 lbs. greater for the heifers fed for the higher growth rates prior to weaning.

The response in the Moallem et al. (2006) study suggests milk replacer quality and protein status of the animal, post-weaning, were important to achieve the milk yield response.

Calves were fed a 23% CP, 12% fat milk replacer containing soy protein or whole milk. Post-weaning, calves were fed similarly until 150 days of gain, and the diets were protein deficient (~13.5% CP). Starting at 150 days, calves from both preweaning treatments were supplemented with 2% fish meal from 150 to 300 days of life.

Calves allowed to consume whole milk ad lib for 60 minutes, supplemented with additional protein, produced approximately 2,500 lbs. more milk in the first lactation.

In the Pollard et al. (2007) study, calves were fed either a conventional milk replacer (22:20) at 1.25% BW or a 28:20 milk replacer fed at 2% BW for week one of treatment. They received replacer at 2.5% BW from week two to five, and then were systematically weaned by dropping the milk replacer intake to 1.25% for six days.
All calves were weaned by seven weeks of age and, after weaning, managed as a single group and bred according to observed heats. The heifers calved between 24 and 26 months of age with no significant difference among treatments. Calving weights averaged 1,278 lbs. Milk yield on average was 1,841 lbs. greater for calves fed the higher level of milk replacer prior to weaning.

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