Virginia Polytechnic Institute and State University

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New Tool Helps Dairy Farmers

The Department of Dairy Science at VA Tech has been working to provide dairy farmers across the country with more complete information for selecting bulls for increased herd life of daughters.

Chandraratne Dematawewa, visiting scholar, and Ron Pearson, professor of dairy science, have created an extended lactation curve to improve the productive life measurements used for all dairy cows. Their research has already made an immediate and direct impact on the dairy industry.

Productive life measurements are used by producers to help them select superior bulls that will sire cows that stay in their herd longer, produce milk for a longer period of time, and ultimately create more profit for their operations.

Productive life measures how long a dairy cow stays in the herd over her lifetime when compared to her herdmates. This trait was formerly measured for 305 days (a standard lactation length) for the cow's first five years of life. Although it would be ideal if all cows milk according to industry standards, some cows are not bred at the right time or have longer lactations.

Dematawewa and Pearson knew the values were not as accurate as they could be for cows that milk or live longer than the values accounted for. Their research has resulted in the creation a new curve so that each day a cow produces milk throughout her entire lifetime is used in her productive life value.

“After 305 days, the degree of genetic control determining milk production is reduced,” says Pearson. “Management and other factors are keeping cows in the milking herd. We were looking for a way to allow extra days in the productive life values so that credit was given for the cow's extended days of production but were not counted as much as earlier days in the lactation.”

Creating the new lactation curve was a bit of a challenge. Since lactation curves had only been kept for the first 305 days of all animals' first five years of life, they did not have as many values for longer lactations. Only data from the past 10 years was used. Using the lactation records provided by the USDA from almost a million cows, the research team worked to create a new lactation curve that is 999 days long. In the new curve, each day that a cow is lactating is counted in the productive life measurement so that the cow is given a more accurate value for her complete lifetime.

“Now, a cow is allowed as many days as she has,” adds Pearson. “Each day is weighted individually.”

The new changes have already had direct influence on the industry. Since the new curve is already being used on the farm, the new genetic evaluation for productive life is helping producers make an educated decision about which bulls to select for their herd. The records are now more accurate than those that were in place before.

“Productive life is now more representative of the real values,” says Pearson.

And for the researchers, this project has been a great success. The new lactation curve and weighted days are making direct impacts on the farm by providing more accurate information about the dairy bulls that producers are using.

“What I'm happiest with is that we started this project a year-and-a-half ago and it is already implanted and having an impact on the dairy industry,” Pearson says. “It is already affecting the national productive life values for all breeds and it's neat to be a part of that.”

  HOT TOPICS AND DAIRY ISSUES

High Tech Cheese Plant Comes to Clovis , N.M.

Southwest Cheese LLC is a 50/50 partnership between Glanbia plc and the Greater Southwest Agency (a group formed by dairy cooperatives, Dairy Farmers of America, Select Milk Producers, Zia Milk Producers and Lone Star Milk Producers). The plant became fully operational in September, 2005 and is expected to generate $340 million in annual sales. The impetus for the development of the Southwest Cheese came from the dairy farmers in the area who sought a capable dairy processor company to bring the processing to the milk so that they could ship less milk to neighboring states.
Today New Mexico is the seventh largest milk producing state. DFA's Southwest Area Council estimates that with every load of milk dropped off at Southwest Cheese, a local dairy farmer saves about $1,000 to $2,000 in hauling costs.

Southwest Cheese is one of the first cheese plants to use a combined methane digester/methane recapture system that turns effluent into clean water and methane gas. The digester is made up of lagoons, sand filters, and methane recapture subsystems that can handle the water that results from daily conversion of 7 million pounds of milk into cheese and whey products. That's about 44,000 pounds of cheese and 3,000 pounds of whey protein powder every hour. The treated effluent is nearly indistinguishable from tap water. A portion of the methane from the system is recaptured and used to run one of four boilers used for process steam. The steam from that boiler is used to keep the anaerobic lagoons at 95 °F, and to provide process heat for the cheese and whey processes.
Effluent from the whey process spends 14 days in covered anaerobic lagoons, where seeded anaerobic bacteria consume the biological material and convert it to methane.
The semi-treated water then moves to a series of open aerobic lagoons where it spends another two days. Finally the water is moved to a deep pool sand filter system.

The sub-plant cost Southwest Cheese more than $25 million to build, but it will allow the company to focus on the efficient production of high volumes of cheese without worrying about environmental issues. It will also provide opportunity for expansion in the future. The plant is designed to produce a high volume of cheese so efficiently and effectively that it can elbow into a competitive market with its 40 and 640 pound blocks.

Some of the finished water is used to irrigate the surrounding farmland. What is not used is sent through a dedicated line to the Clovis municipal treatment facility where is commingled with other fully treated water that is then piped to other farm operations for irrigation. With the system in place, the plant actually produces more water than it uses.

Milk is trucked into a 5-bay receiving area that is open 22 hours a day. Approximately 140 tankers are unloaded each day. After testing, milk travels to one of eight 70,000 gallon milk silos. Milk is pasteurized with plate heat exchangers; separation and clarification are done with Tetra Pak equipment, and the pasteurized milk is sent to cold storage surge tanks. On the process floor, batches go to one of 15 horizontal cheese vats (8 dedicated to 640 pound blocks and 7 reserved for the 40 pound block batches) that automatically add rennet and starters.

Once the curd is formed and cut, it travels over a series of three belts where it is milled, drained and salted. The curd is pneumatically conveyed to one of 14 blockforming towers (each tower is 40 feet tall), where a vacuum is applied to help knit the curd and extract remaining whey as blocks are formed. Bags are fitted by hand at the base of each block former and the blocks are sent along conveyers to a Sealed Air bagging system. Cheese is aged on site for about two weeks, then sold directly to cut and wrap and foodservice customers.

Like any large scale cheese plant, Southwest Cheese produces a parallel stream of whey products. Mesa Ingredients Corporation has built a $15 million facility adjacent to the cheese plant that manufactures animal feed from the whey permeate.