INSIDE THIS ISSUE

Dairy Policy and Market Watch, Dr. Cameron Thraen, Milk Marketing Specialist, The Ohio State University
bST Safety Around the World, Dr. Normand St-Pierre, Dairy Management Specialist, The Ohio State University
Testing Milk for rbST, Dr. Normand St-Pierre, Dairy Management Specialist, The Ohio State University
The Safety of Insulin-Like Growth Factor-I (IGF-I), Dr. Normand St-Pierre, Dairy Management Specialist, The Ohio State University
The Environmental Impact of rbST, Dr. Normand St-Pierre, Dairy Management Specialist, The Ohio State University

Dairy Policy and Market Watch
Dr. Cameron Thraen, Milk Marketing Specialist, The Ohio State University (top of page)

Market Watch - 2008

For dairy farmers, the milk price has been outstanding over the past 12 to 13 months. Will this price strength continue into and throughout 2008? Clearly with significantly higher feed, and fuel and energy prices in 2008, it is critical to maintain adequate profitability on farms with hope that market prices do not collapse in the coming months.

To address his question, I will consider where this milk price strength has come from and what may lie ahead. The included table shows the average Class 3 and Class 4 milk price for 2006, 2007, and the first two months of 2008. In the table, you will find the contribution, both in dollars per hundredweight and as a percent of total milk price, by each commodity making up the price. For example, considering 2006, the Class 3 price averaged only $11.88/cwt. The butter market contributed $4.64/cwt (39%), the cheese market $6.26/cwt (53%), and the dry whey market $0.99/cwt (7%). Now look at the second column which shows the averages for 2007. The cheese and whey markets had taken off in an upward soar and contributed $10.51/cwt (58%) and an outstanding $2.39/cwt (14%) to the average Class 3 price of $18.04/cwt, respectively. The 2007 butter market increased modestly and added $5.14/cwt (29%) to the average Class 3 price.

In the lower section of the table, you will find the same dissection of the average Class 4 milk price. Back in 2006 this was only $0.82/cwt less than the Class 3 price. By the end of 2007, the Class 4 price had overtaken the Class 3 price as the all important Class 1 mover, averaging $0.32/cwt more than Class 3. Looking at the table, you can see that the impact of the dramatic rise in the market price of nonfat dry milk, averaging $0.87/lb in 2006 and increasing to $1.88/lb in 2007, was responsible for 72% or $13.22/cwt of the average 2007 Class 4 price of $18.36/cwt.

What lies ahead in the 2008 marketing year?

Now looking to 2008 it is clear that we need to focus on the four commodity prices, butter, cheese, whey, and nonfat dry milk (NDM), to anticipate where the Class 3 and Class 4 milk prices may be headed. With the butter price back down toward levels equal to 2006, we cannot expect this commodity to make a major contribution to either the Class 3 or Class 4 price. Whey has retreated to levels not seen since mid-2006 and is currently under $0.25/lb. Given current supply and demand conditions, I do not expect to see any real help from that commodity in 2008. This leaves cheese and NDM. Cheese is currently staying quite strong with the February 2008 price reported at $1.84/lb. The NDM peaked during December 2007 at the month average price of $2.10/lb. The NDM is currently trading at $1.30/lb on the Chicago Mercantile Exchange.

Why are these two commodity prices staying high? Cheese demand is only fair at these prices. Cheese manufactures are reluctant to increase production with these high milk prices. Cheese inventories are light and this means that cheese manufactures must buy to cover holiday contracts. Cheese export sales are strong with USDA FAS reporting that for the first nine months of the year, exports of cheese and curds are up 37% over the same period last year. We can expect some decline in the cheese price after the holiday season, but if the export demand remains strong, the market should not weaken dramatically. Therefore, the driver for Class 3 is the cheese market where it goes so will the Class 3 price.

Turning to the Class 4 milk price, it is apparent that NDM market has been phenomenal over the past 15 to 16 months. This has been driven by an almost insatiable export demand. Now, we are beginning to see some real weakness in this market. Domestic NDM production and inventories are heavy as could be expected with plus $2/lb prices and domestic and international demand has slowed. According to the USDA FAS, export volumes are fulfilling past contract obligations and new contracts are slow to materialize. Export sales for the first nine months of 2007 have declined by 18% as compared to the same period in 2006. Domestic cheese manufactures will increase NDM use as the price falls below $1.30/lb and this will help provide support. The driver for the Class 4 price is the NDM market. Where the NDM market goes over the next 9 months will determine what happens to the Class 4 price.

For more information on the dairy industry, prices, and policy, link to my OhioDairyWeb 2008 at: http://aede.osu.edu/programs/ohiodairy/

Web links to Milk Marketing Information: Ohio Dairy Web - http://aede.osu.edu/programs/OhioDairy/; eDairy, Inc. - http://www.dairy.nu/

rbST Safety Around the World
Dr. Normand St-Pierre, Dairy Management Specialist, The Ohio State University (top of page)

Summary

• rbST has not been legislatively banned in any country because of human safety concerns.
• Currently, rbST is registered for commercial sale in 20 countries. In addition, 56 countries have confirmed that rbST is safe and pose no human safety threats.
• The current legislation does not allow the use of rbST within European Union (EU) member countries, but it allows imports of milk and dairy products from rbST animals into the EU.
  

Details

• Technically speaking, no country has a regulatory ban on rbST. Registration of rbST for commercial use has simply not been completed in many countries. Some have imposed a legislative ban.
• No country has banned the importation of milk or milk products from the U.S. or from any of the countries where rbST has been approved and registered. Milk from cows supplemented with rbST can be exported anywhere in the world (U.S. Dairy Export Council).
• There are 20 countries that have a current registration of rbST for commercial sale. Chile is the most recent country to grant registration in 2006.
• There are 56 countries that have confirmed that rbST is safe and does not threaten the human food chain; these include Canada and most countries members of the EU.
• Although there are countries in which rbST has not received registration for commercial sale, the process is generally still open. In some countries, however, the process has been suspended or blocked (banned) through a legislative ban, mostly for political and economic reasons.
• The list of national and international scientific/medical/health/government organizations that have confirmed the human safety of milk and meat products from cows supplemented with rbST is very lengthy and include (not an exhaustive list):

  American Cancer Society; American Council on Science and Health; American Dietetic Association (ADA); American Medical Association (AMA); Canadian Animal Health Institute; Canadian Dietetic Association; Canadian Institute of Biotechnology; Canadian Medical Association; Canadian Network of Toxicology Centres; Canadian Pediatric Society; Children's Nutrition Research Center; Baylor College of Medicine; Council on Agricultural Science & Technology; European Union's Committee for Veterinary Medicinal Products (CVMP); Food and Drug Administration (FDA); Food and Agriculture Organization of the United Nations (FAO); Food and Nutrition Science Alliance; Food Marketing Institute; Grocery Manufacturers of America (GMA); Health Canada; Institute of Food Technologists (IFT); International Dairy Food Association (IDFA); Joint FAO and WHO (World Health Organization), Expert Committee on Food Additive (JECFA); National American Wholesale Grocers' Association; National Dairy Council; National Institute of Health (NIH); Royal College of Physicians and Surgeons; The American Academy of Family Physicians Foundation; The Ohio State University - College of Food, Agricultural and Environmental Sciences; Toronto Biotechnology Initiative; University of California - Berkely; University of California - Davis; U.S. Congress Office of Technology Assessment (OTA); U.S. Food and Drug Administration - Response to Citizen Petition on bST; U.S. Dairy Export Council; U.S. Surgeon General Office

Some have erroneously stated that "Codex Alimentarius, the United Nations main food safety body, TWICE decided it could not endorse the safety of rBGH for human health". This statement is incorrect. The Codex Alimentarius Commission was created in 1963 by FAO and WHO to develop food standards, guidelines, and related texts, such as codes of practice under the Joint FAO/WHO Food Standards Programme. The main purposes of this Programme are protecting the health of the consumers, ensuring fair trade practices in the food trade, and promoting coordination of all food standards work undertaken by international governmental and non-governmental organizations. The FAO/WHO has stated very clearly its position regarding the human safety of rbST:

After examining new evidence, an FAO/WHO independent scientific committee has reconfirmed that the treating of cows with the hormone bovine somatotropins (sic), known as BST, to increase milk production is safe. The Committee concluded that there are no food safety or health concerns related to BST residues in products such as milk and meat from treated animals. (http://www.fao.org/news/1998/980301-e.htm)

The Codex Alimentarius never did question the human safety of rbST. Twice it failed to reach a consensus regarding maximum residue limits (MRL) for products from rbST supplemented animals. During its 22nd session, the commission decided to suspend the consideration of the adoption of MRL for bovine somatotropin. The Chairperson of the Committee on Residues of Veterinary Drugs in Foods reported that the Fiftieth Meeting of JECFA had re-evaluated bST and that the previous MRL "not specified" for bST were confirmed when the substance was used in accordance with good veterinary practice. The Committee on Residues of Veterinary Drugs in Foods, however, had been unable to reach a consensus on the adoption of the MRL because (1) some argued that MRL were unjustified based on JECFA 's finding, and (2) due to the lack of defined methods of analysis.

Statements such as "European nations and Canada have banned rbGH to protect citizens from IGF-I hazards" are grossly incorrect. In 1999, the Council of the European Union (a legislative body) decided to definitely ban the possible use of bovine somatotropin (rbST) in the EU. In support of its ban, it invoked animal welfare reasons. Prior to that decision, the European legislators had invoked different reasons, especially the impact on the European dairy policy, with varying success. Concerns over public safety were always cleared by the competent scientific committee, the Committee of Veterinary Medicinal Products (CVMP). In other instances, European Courts found concerns to be unfounded. Despite the scientific finding of safety to human and public health, which should have led to the establishment of a MRL, the EU legislative body decided to ban rbST. The current legislation does not allow the use of rbST within EU member countries, but it allows imports of milk and dairy products from rbST animals into the EU. If consumer safety was a concern, it would be hard to follow the logic of an approach that considers a product unsafe for consumers in the EU if it is administered within the EU, but safe if it comes from animals treated in other countries.

Adapted from "Bovine Somatotropin Safety around the World" by Dr. Terry Etherton, The Pennsylvania State University.

Testing Milk for rbST
Dr. Normand St-Pierre, Dairy Management Specialist, The Ohio State University (top of page)

Summary

• Tests based on monoclonal antibodies cannot distinguish rbST in the presence of the four other variants in milk. The theoretical concentration of rbST in milk under normal use is so low and the rbST molecule is so similar to the non-recombinant variants, that it is unlikely that any antibody-based method, especially monoclonal, will ever be successful at detecting milk from cows supplemented with rbST.
• A test based on changes in the fatty acid binding protein (FABP) appears unlikely to ever differentiate milk from rbST supplemented cows because so many factors affect the maintenance of mammary cells, and thus, FABP.
• It appears unlikely that a rapid, accurate, and sensitive test for detecting rbST supplementation in dairy cows using milk samples will be derived anytime soon.
  
  

Details

1. A paper by Erhard et al. (1994) based on a possible antigenic difference of recombinant and pituitary bovine growth hormone raised the possibility of using monoclonal antibody techniques to test for the presence of rbST in serum and milk of dairy cows. Unfortunately, the technique cannot distinguish recombinant bST in the presence of the four other variants in milk. More recent work has lead to the same conclusion. For example, a recent paper by Castigliego et al. (2007) showed the possibility of testing for some forms of rbST using immunodetection with a sandwich ELISA. The authors, however, concluded that the method's "discrimination ability still cannot provide support for any lawsuit, confirming the difficulty in immunologically discriminating rbST prom pituitary bST, especially if recombinant molecules with extremely reduced differences in primary sequence are involved. In fact, the more recent commercialized molecules overlap with one of the major natural NH2-terminus variants, representing a considerable problem in making an immunologically based assay that will discriminate effectively".
   
   The challenge of developing a test to specifically distinguish rbST in milk is several times more complex than finding any bST due to the fact that there are four natural forms (variants) of bST produced by dairy cows. The rbST in Monsanto's Posilac is derived from one of these variants.

   Monsanto did not put a "tag" on rbST. There is a methionine amino acid in the # 1 position on Monsanto's rbST molecule. It appeared there as a result of the recombinant process and was not removed because it had no impact on biological activity. Because all cows have a minimum of either 2 or 4 variants of bST (and there are actually more variants based on research conducted at Ohio University in the 1990's), each of two different lengths (190 or 191 amino acids), the methionine in the #1 position on Monsanto's rbST molecule can be viewed as either an additional amino acid to one of the 190 amino acid molecules resulting in a 191 variant, or a substitution of the first amino acid in one of the 191 variants. It is not involved in binding or the 3-D structure of the molecule. Because the methionine in the #1 position of the rbST molecule is in a non-biologically active portion of the molecule and does not change the bioactivity of the rbST molecule from its parent bST molecule, the FDA did not require its removal.
   
   The fact that the #1 position is a non-biologically active part of the molecule makes it EXTREMELY difficult to detect any changes that occur there. The challenge is trying to find a miniscule difference in an infinitesimally small amount. The amount of bST in raw milk is so small, (0.5 ng/ml, or 500 parts per trillion; Schams, 1990) it approaches the lower-limit of being detectable at all.

2. More recently, a patent was issued in 1997 to Dr. R. C. Gorewit of Cornell University for a test based on associated changes in a protein referred to as FABP (fatty acid binding protein). The test is based on comparing rates of phorphorylation of FABP. This involves the isolation of globular membranes that surround the milk fat droplets and purifying them by column chromatography techniques. The FABP fraction is then collected and concentrated by ultra-filtration. Finally, samples of the FABP preparation are incubated with radioactive phosphate (gamma 32P-ATP) and the extent of radioactive 32P incorporation is determined. The basis for this test has since been published by Spitsberg and Gorewit (2002). Dr. Gorewit ideas were somewhat speculative and were based on very limited work. Neither he nor anyone else has demonstrated an actual relationship between FABP in milk and use of rbST.

   The FABP is related to maintenance of mammary cells, and thus, varies widely. Factors such as milk yield, persistency of lactation, stage of lactation, pregnancy, parity, breed, diet, season, environmental temperature, and animal health all affect the maintenance of mammary cells. All of these factors would give expected changes in FABP similar to what is speculated to occur with rbST. This patent has since expired due to the owner of the patent failing to pay the renewal fees.

   Any test for rbST would require validation, including reasonable estimates of repeatability, sensitivity, variability, and accuracy. None of these have been reported for the FABP hypothetical method, and it is doubtful whether the actual methods used for FABP could ever meet reasonable minimum standards.

In spite of the huge economic incentive to develop a test for detecting milk from cows supplemented with rbST, such a test has not emerged and is nowhere close on any radar screen. Thus, it appears highly unlikely that a rapid, accurate and sensitive test for the detection of rbST in milk will be derived anytime soon. Also, because all constituents in milk from rbST supplemented cows are in the normal concentration ranges found with non-supplemented cows, it appears very unlikely that a rapid, accurate, and sensitive test to detect rbST use from constituents in the milk of rbST supplemented cows will be found in the near future.

(References are available on request.)

The Safety of Insulin-Like Growth Factor-I (IGF-I)
Dr. Normand St-Pierre, Dairy Management Specialist, The Ohio State University (top of page)

Summary

• The IGF-I in human plasma is found at concentrations that are 10.5 to 77 times greater than that in bovine milk.
• The IGF-I concentration in bovine milk is quite variable regardless of whether the animals are supplemented with rbST or not. Many factors such as herd, stage of lactation, parity, and diet affect IGF-I concentrations to a greater extent than rbST supplementation.
• Compared to gastrointestinal secretions in adults, bovine milk has in fact a very low IGF-I concentration. Daily ingestion from saliva and other digestive secretions in a normal adult equals the amount of IGF-I found in 95 quarts of milk.
• Endogenous daily IGF-I secretions (i.e., body production) equal the IGF-I found in 3000 quarts of milk.
• There has been some reports documenting an association between serum IGF-I and the risk of certain cancers. It is generally thought that the cancer cells are responsible for the elevated serum IGF-I and not the other way around. Regardless, the total daily IGF-I intake from milk is so low compared to endogenous secretions (less than 1% assuming that all IGF-I consumed is absorbed) that it seems highly unlikely that cancer would be directly related to IGF-I intake.

Details

One area of concern regarding the safety of rbST is that IGF-I in milk results in elevated IGF-I levels in humans after they consume milk from cows supplemented with rbST. The Food and Drug Administration (FDA) maintained and continues to maintain that "levels of IGF-I in milk whether or not from rbGH supplemented cows are not significant when evaluated against the levels of IGF-I endogenously produced and present in humans".

• The IGF-I is normally found in human plasma at concentrations much higher than those found in bovine milk (Schaff-Blass et al., 1984). The levels in human plasma range from a low in neonates of 14 ng/mL to a high of 686 ng/mL in late pubertal females. The mean values of IGF-I concentrations in human plasma are between 42 and 308 ng/mL.
• The mean serum IGF-I concentration in cows not supplemented with rbST is approximately 4 ng/mL at mid lactation (Collier et al., 1991). In this survey of 100 bulk tanks from farms not utilizing exogenous somatotropin supplementation, the mean IGF-I concentration was found at 4.3 1.1 ng/mL, with a range of 1.3 to 8.1 ng/mL. In another study (Juskevich and Guyer, 1990), milk samples from 5 commercial dairy herds not supplemented with rbST had a mean IGF-I concentration of 2.54 ng/mL.
• Reported percentage increases in IGF-I concentrations in milk of rbST supplemented cows are deceiving and misleading because the levels of IGF-I in milk are so low prior to any increase. The IGF-I concentration in milk of rbST supplemented cows is increased by 2 to 3 ng/mL (Juskevich and Guyer, 1990; Torkelson et al., 1988), thus leading to the 50 to 100% increase often stated. Nowhere can one find in the scientific literature a 10- fold increase (1000 %) in serum IGF-I concentration from rbST supplementation as has been stated in public comments and various internet sites. In addition, the effect of farm, parity, and stage of lactation have a greater effect on serum IGF-I concentrations than rbST supplementation (Collier et al., 1991).
• The total daily production of IGF-I (the endogenous production) in an adult is approximately 10,000,000 ng/day (Guler et al., 1989). Gastrointestinal secretions in adults are estimated at 357,400 ng/day (Chaurasia et al. 1994; Vander, Sheman and Luciano (ed.), 1990). Thus, the daily IGF-I from saliva and other digestive secretions equal the IGF-I in 95 quarts of milk. The IGF-I from whole body production equal to the IGF-I in 3,000 quarts of milk. Milk is just a very low source of oral IGF-I. In fact, the IGF-I concentration in saliva is more than 50% greater than that of milk.
  
  

Table 1. Volume and IGF-I concentrations in gastrointestinal secretions of human adults.

• The IGF-I comprise one-tenth of one millionth of total milk proteins. It is digested in the gastrointestinal tract like other dietary protein. There is little to no direct absorption of IGF-I (NIH, 1990; Houle et al, 1995; Phillips et al., 1995). In fact, a massive dose of IGF-I administered orally (8.45 µg/day) resulted in an increase of less than 5 nmol/L in serum IGF-I in training athletes (Mero et al. 1997). Interestingly, a one hour training session has a greater impact on serum IGF-I than the oral supplement.
• The IGF-I is normally found in human breast milk in concentrations higher than those found in bovine milk. The IGF-I concentrations in human milk ranged between 13 and 40 ng/mL (Corps et al., 1988; FDA, 2000). These levels are 3.25 to 15.7 times greater than those of bovine milk.
• There has been some reports of increased IGF-I serum concentrations after humans consume milk (e.g., Heaney et al. 1999). The IGF-I increased observed in this study must be viewed in light of the total daily adult endogenous production of IGF-I, which is in the milligram range while the daily levels of IGF-I consumed in milk are in the microgram range - this is a thousand fold difference (FDA, 2000). Even if all the IGF-I in 1.5 liters of milk was directly absorbed - which it is not - the plasma IGF-I would be altered by a maximum of 1%. Well-controlled studies have reported no significant change in serum IGF-I levels over a 2 year period for women supplemented with four 8-ounce glass of milk for the duration of the trial (Storm et al., 1998).
• Some have asserted a connection between increases in levels of IGF-I and breast, prostate, and lung cancer (Chan et al., 1998; Hankinson et al., 1998; Yu et al., 1999). These papers note a possible relationship between increased risks for these cancers and elevated levels of IGF-I, but none of them showed a causal relationship. In fact, one paper states "that the increased IGF-I plasma levels may be part of the phenotype [i.e., expression] of certain types of cancer." Thus, the cancerous cells themselves may promote IGF-I to maintain accelerated cell cycle (FDA, 2000). The presence of oxygen (air) is essential to start and maintain a fire, but it does not cause the fire. In addition, these cancers generally appear much later in life than peak IGF-I which occurs in late puberty. Also, strenuous exercise increases IGF-I concentrations without having any positive association with these cancers.

(References are available on request.)

The Environmental Impact of rbST
Dr. Normand St-Pierre, Dairy Management Specialist, The Ohio State University (top of page)

Summary

• Often forgotten in the rbST debate is the positive environmental impact of technology in general, and rbST in particular.
• A recent study calculated the amount of various pollutants that are not produced from one million dairy cows supplemented with rbST. Manure excretion is reduced by 3.3 billion pounds per year. The emission of CO₂ equivalents is reduced by 1.3 billion pounds per year - the equivalent of over 350,000 family cars.
  

Details

What has often been forgotten in the debate about the use of rbST is the very favorable impact that technologies such as rbST have on our environment. A recent study conducted by Capper et al. (2007) at Cornell University calculated the amount of various pollutants that are not produced and released into the environment from one million dairy cows supplemented with rbST. The numbers are staggering.

Millions and billions of pounds

Nitrogen excretion is reduced by more than 15 million lb/year; phosphorus excretion, by more than 3 million lb/year. The excretion of manure is reduced a phenomenal 3.3 billion pounds per year - that's billion with a "b". The emission of CO₂ equivalents (a form of universal "currency" to express green gas emission) is reduced by 1.3 billion pounds per year. As can be seen in Table 1, rbST has a significant and positive impact on our environment. Viewed this way, rbST is in fact a green technology.

Technology is green

Invariably, technology is being researched and used to address all sort of environmental concerns. Hydrogen fuel cells are being developed to power our cars in the future. High-technology synthetic compounds are being developed to improve the insulation of our homes. In fact, across all other industries, technology is the common denominator to finding green remedies to environmental problems. Technology is green. In dairy, we already have green technologies. They are called artificial insemination, rumen inert fats, synthetic vitamins, teat disinfectants, 3 times-a-day milking, sprinklers, rbST, organic minerals, estrus synchronization, sire proofs, fans, cation-anion balance, rumen buffers, pedometers, direct-fed microbials, rumen-protected amino acids, etc.

Table 1. Current annual resources saved from 1 million rbST-supplemented dairy cows.¹

¹ Adapted from Capper et al., 2007
² Includes methane from enteric fermentation and methane emitted by manure fermentation.
³ Only includes fuel used for cropping.

(References are available on request.)