*Krissa Welshans holds a bachelor's degree in animal science from Michigan State University and a master's degree in public policy from New England College. Welshans has long been involved in agriculture and has worked with numerous agricultural groups, including the Animal Agriculture Alliance.
GREENHOUSE gas emissions are a popular topic in the media, and animal agriculture has been targeted for its role in contributing to the numbers.
Methane production is a natural part of the digestive process of ruminants. Bacteria in a cow's rumen break down the food in a fermentation process. Two byproducts of this fermentation process are carbon dioxide and methane.
The important task facing animal agriculture is to develop effective, economically feasible and practical greenhouse gas mitigation technologies.
Researchers have been working to find solutions for reducing the emission numbers, and over the past few years, an unusual feed supplement has been found to do exactly that.
According to a study conducted at The Pennsylvania State University, essential oils, which have strong antibacterial properties, are one enteric methane mitigation option that continues to show promise.
Additionally, essential oils have also been studied as potential modifiers of rumen biohydrogenation of dietary lipids, the goal being to enhance the health benefits of meat and milk.
Because essential oils possess antibacterial properties, researchers decided to study numerous plants containing essential oils for their potential as enteric methane mitigation agents.
Dr. Alex Hristov, associate professor of dairy nutrition in Penn State's department of animal science, found that oregano leaves (Origanum vulgare L.) showed anti-methanogenic effects within eight hours post-feeding. Feeding cows between 250 g to 750 g per day, the oregano leaves produced the desired outcome without reducing milk production.
Additionally, the study found that feeding dairy cows oregano also increased feed efficiency by reducing total dry matter intake without altering the composition of milk fatty acids.
When Hristov first started his research more than eight years ago, he screened hundreds of essential oils, plants and various compounds in the laboratory before arriving at oregano as a possible solution. During the experiments, he found that oregano consistently reduced methane production without demonstrating any negative effects.
In the first study, the gas-reducing supplement was found to increase daily milk production by nearly 3 lb. of milk for each cow during the trials. The higher milk productivity for the herd was anticipated, though.
"Since methane production is an energy loss for the animal, this isn't really a surprise," Hristov said. "If you decrease energy loss, the cows can use that energy for other processes, such as making milk."
In his latest study, in addition to verifying results from the first study, Hristov sought to isolate specific compounds involved in the suppression of methane.
Some of the compounds found in oregano, including carvacrol, geraniol and thymol, seem to play a more significant role in methane suppression. After his first study, Hristov said identifying the active compounds is important because pure compounds are easier to produce commercially and are more economical for actual farm use.
Hristov tested graded levels of oregano to investigate the effects of increasing supplementation levels of oregano leaf material on rumen fermentation and methane production, performance of lactating dairy cows and milk fatty acid composition.
Like the previous experiment, methane production data were collected only within eight hours of feeding; the effect of oregano over a 24-hour feeding cycle has not been determined.
The results of the second study, however, confirmed what the first study had found, further solidifying the idea that using oregano as a feed supplement will reduce rumen methane production and will have no negative effect on rumen function, digestibility or animal production.
Hristov reported that, overall, oregano supplementation had positive effects on rumen methane production within eight hours post-feeding and on feed efficiency in dairy cows.
However, he suggested that long-term research experiments are necessary to provide a broader picture of the compound's effectiveness.
Dairy options in schools
A wide range of dairy foods should be available for sale through vending machines, a la carte lines and school stores, the International Dairy Foods Assn. (IDFA) recently suggested to the U.S. Department of Agriculture in comments filed on a proposed rule.
The comments addressed the department's proposal that aims to set nutrition standards for foods and beverages sold apart from reimbursable school breakfasts or lunches. These products are known as "competitive foods."
IDFA commended USDA for its efforts to encourage dairy consumption, noting that "milk, yogurt, cheese, dairy snacks and frozen dairy desserts are all options that can be nutritious and tasty choices for kids."
Specifically, IDFA agreed with USDA's recommendations for low-fat and fat-free milk as beverage options as well as the proposed sugar levels in low-fat and fat-free yogurt and the fat exemption for reduced-fat cheese.
However, IDFA identified a few issues of concern in the proposed rule, such as the method of defining sugar limits for foods. IDFA urged USDA to base the sugar limit on the weight of the finished food rather than on the percentage of calories.
IDFA also recommended that fortified nutrients apply toward meeting the requirements of the nutrition standards and that non-nutritive sweeteners be allowed in all competitive foods and beverages.
The organization's comments addressed the need to reduce sodium limits over time, which it said is similar to the sodium reduction approach now in place for reimbursable school meals.
IDFA also identified some areas where the financial impact of these nutrition standards could be significant. The group pointed out that possible changes to ingredients, labels and distribution methods could all increase costs both to food manufacturers and to schools.
IDFA recommended that the nutrition standards be implemented no sooner than 18 months from the publication of the final rule so schools and suppliers have sufficient time to adjust to the new requirements.
Raw milk petition
Raw milk producers seeking to expand their markets have hit another obstacle: The Food & Drug Administration recently denied a 2008 petition that would have allowed the interstate sale of raw milk.
Many states already allow intrastate sales, but the petition filed by Organic Pastures, citing food safety advancements, sought to open state lines for business.
In the petition, Organic Pastures pointed to improvements in raw milk testing and implied that this would ensure the safety of the product.
"Advances in technology and understanding of microbiology now allow the production of safe raw milk to be a reality and not just a random chance," the petition states.
In rejecting the petition, however, FDA pointed out that specific examples were not supplied to support that statement.
FDA added that "state health departments warn of the danger of raw milk consumption and emphasize that state regulation does not ensure that raw milk is safe and free of pathogens." According to FDA, pasteurization is the only advancement it is aware of that would ensure the safety of raw milk.
To further justify its decision, FDA pointed to reports from the Centers for Disease Control & Prevention showing that states where raw milk sales are legal had more than twice the amount of illness outbreaks as states where raw milk sales are illegal.
Organic Pastures tried to use itself as an example that raw milk sales can be successful without causing outbreaks, but FDA pointed out that the farm actually had been included in seven different recalls within the state from which it operates.
In the petition, Organic Pastures asked that interstate sales be allowed if they are "tested, state inspected, state regulated, (carry) a 'government warning statement' and (are) labeled for retail sales."
FDA concluded, however, that the petition "fails to establish that current testing, state inspection and state regulation programs can adequately mitigate the dangers posed by raw milk."