Virginia Polytechnic Institute and State University

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Dairy Club Recognized as Outstanding Chapter in National Association

The Dairy Club at Virginia Tech earned several awards at the American Dairy Science Association (ADSA) national conference, including recognition as the 2006 Outstanding Chapter in the Student Affiliate Division. This was the fourteenth time since 1980 that the Virginia Tech club has received the award, more than any other participating university club.

The Virginia Tech students were among nearly 120 students and almost 3,000 dairy science professionals from throughout North America who attended the ADSA July 8-11 conference in Minneapolis, MN, and celebrated the organization's centennial anniversary.

The Dairy Club, a student curricular organization in the College of Agriculture and Life Sciences Department of Dairy Science, gives members a chance to learn about the dairy industry and related career opportunities through campus activities and community service. The group has about 85 student members from various academic departments.

In addition to the Outstanding Chapter Award, several students won individual prizes and distinctions. Rena Johnson of Glade Spring , Va. received the Genevieve Christen Award, which recognizes undergraduate students for their demonstrated leadership, academic achievement, industry involvement, and participation in national and local dairy science organization activities.

Casey Marstaller of North Yarmouth , Maine was chosen as the student division's first vice president for the upcoming academic year.

The students ranked in each category for the paper presentations as well. Jeremy Yoder of Gladys , Va. won first place in the dairy production category for his talk, “Why Crossbreed Dairy Cattle?”. The team earned second place in both the dairy foods and original research papers and third place for both its website and chapter yearbook, The Milky Way.

At the annual meeting, Virginia Tech and other students participated in a “Leaders in Training” career symposium and a dairy quiz bowl, where the Virginia Tech panel placed second. Established in 1906, ADSA is a scientific and educational association that serves the dairy and dairy-related industries.

Ranked 11th in agricultural research expenditures by the National Science Foundation, Virginia Tech's College of Agriculture and Life Sciences offers students the opportunity to learn from some of the world's leading agricultural scientists. The college's comprehensive curriculum gives students a balanced education that ranges from food and fiber production to economics to human health. The college is a national leader in incorporating technology, biotechnology, computer applications, and other recent scientific advances into its teaching program.

China 's New Standard on Antibiotic Residues

China currently has around 12 million cows producing 3 tons of milk each per year. The Chinese are estimated to consume about 18kg of dairy produce per capita. The consumption of dairy products in China has grown rapidly in the last 30 years, prompting an increasing drive for food safety and consumer health. The Ministry of Agriculture has drawn up a new national standard on raw milk that will make testing for antibiotics in raw milk compulsory for dairy processors.

Antibiotics are widely used by Chinese dairy farmers to treat infections in their dairy herds and previously, there has been no regulation in place to restrict their use. A recent survey has shown that around 50 percent of milk products on the market contain antibiotic residues. Since residues can reach the milk, people who are allergic to specific antibiotics are at risk. Also, frequent exposure to low level antibiotics can cause microorganisms to become resistant to them, through mutation, so that they are ineffective when needed to fight a human infection.

In the United States and other countries, cows given antibiotics are typically withheld from the milk supply for some days and both farmers and dairy processors carry out routine testing for antibiotics, with serious penalties for those found to be selling milk containing residues. But in China 's major dairy regions, where milk is collected from thousands of small dairy farmers, testing for antibiotics is not standard practice.

For dairy processors supplied by numerous small farmers, the standard could be difficult to meet. However, there is one area that has proven the measures to be workable. In the Guangdong province, the farmers have been controlling antibiotic residues since they began exporting to Hong Kong in the 1980s. This shows that the standard can be implemented across China , says Wang Dingmian, deputy chairman of the Guangdong Dairy Association.
“As long as farmers isolate sick cows and separate the milk during that time from the milk collected during normal days, their milk will not be contaminated by antibiotics. The milk collected during the sick days of the cow is fed to calves, or used to produce condensed milk. There are no technical problems in implementing the measure; all the new standard requires is that dairy companies and farmers change their mindset, and do not risk people's health in exchange for their own benefits.”
In Guangdong , dairy companies buy milk from farmers for 3000 to 3500 yuan per ton, but milk with antibiotic residues sells for just 500 yuan per ton. This gives farmers an incentive to separate milk with antibiotics from normal milk.
However, Guangdong 's milk production accounts for less than 1 percent of the national total.

Ropy Milk: A Quality Defect

Ropy milk was a serious problem prior to the 1960's, and it appears to be recurring more and more often in modern dairy facilities. Improved sanitation and cooling on farms and in plants eliminated the problem in the last century, but the trend toward larger dairy farms, transporting raw milk long distances, and extending shelf life in HTST pasteurized fluid milk products is responsible for the reemergence of ropy milk today.

Ropiness may vary from a slightly increased viscosity to a stringy, slimey characteristic that can cause the milk to be drawn out in long threads. It is caused by mucins that are formed by several different bacteria, so it is not present at milking. It develops due to bacterial growth that occurs during storage. To test for this quality defect, incubate a small sample of milk at temperatures of 60 - 72°F for 24 to 36 hours, then pour from the vial and look for strands of rope or slime.

Ropiness in pasteurized milk can go undetected if the milk is consumed before sufficient bacterial growth has taken place. Some of the organisms that cause this condition are spore formers that survive pasteurization, while other species cause the condition to develop during extended refrigerated storage. Once established in a plant, these microorganisms pose a serious threat to product quality, and rigorous cleaning/sanitizing procedures are required for their removal.