BAS Tests for Bioactive Compounds in Animal Samples

Feed additives for livestock are a growing industry. For dairy producers, supplements with bioactive, halogenated compounds — known as such for containing halogen atoms like bromoform, iodine, or chlorine — can alter a cow’s gut microbiome in a way that potentially improves feed efficiency and milk yields and reduces the environmental impacts of production.

But developing additives and feeding strategies that are effective, economical, and healthy requires accurate monitoring methods. To that end, Bigelow Analytical Services (BAS) at Bigelow Laboratory for Ocean Sciences now offers standardized analyses of halogenated compounds in a variety of animal and environmental samples.

This new analytical capability will benefit farmers and those in the industry looking to optimize operations by helping them determine feeding amounts and timing, precisely quantify formulations, and monitor the stability of additives in different storage conditions. It will also benefit researchers looking to better understand these complex chemical reactions and regulators seeking to maximize health and safety, by enabling them to detect the build-up of any compounds.

The approach was recently described in the journal Scientific Reports. In the study, researchers monitored the degradation of bromoform into various byproducts over time in samples of fluid from the largest part of a cow’s stomach, called the rumen. They compared the effects of supplementing rumen fluid with direct additions of dissolved bromoform versus with samples of Asparagopsis taxiformis, an alga that naturally contains bromoform.

“If you’re thinking about the optimal dosage of bromoform or another halogenated compound, you’ve got to know how much of the additive you’re feeding, how quickly you’re feeding it, and how, after it’s ingested, it’s released in the rumen,” said Kevin Posman, assistant director of BAS and the study’s lead author. “There’s a lot of potential in seaweed-derived bromoform supplements, and we now have a better analytical approach to quantify that.”

In the study, researchers confirmed that bromoform is degraded within minutes once ingested, though they also found that some of the bromoform broke down into smaller molecules, which appear to have a longer lifespan — roughly 20 times longer — in the rumen. The findings also showed that bromoform is released much more slowly when added within the context of the Asparagopsis supplement. Posman likened it to a “slow-release Tylenol,” which could mean reduced dosing frequency and costs.

The analytical approach described in the paper relies on experimental glass vials that the researchers call the “bottle herd.” Each enclosed bottle is filled with a rotating sample of rumen fluid, incubated at warm temperatures in low-oxygen environments to replicate the conditions of a cow’s stomach. Compared to existing protocols, the team uses a shorter incubation period and measures compound concentrations more frequently to help minimize external disruption to the system and ensure they’re capturing rapid chemical reactions in the data.

“The rumen is such a metabolically active and interesting environment that it’s difficult to replicate outside the cow,” Posman said. “But in these isolated bottles, and with the protocol we established, we’re able to cut out a lot of additional variables and create an environment that’s testable."

In addition to rumen fluid, BAS offers these tests in other relevant matrices, including organ tissue, meat and milk, feces and urine, forage, and water, allowing for a comprehensive analysis of these compounds at all stages of livestock production.

“Rumen fluid and other animal products are very complex matrices to extract these compounds from and routinely and regularly identify them, but Bigelow Laboratory has the core competencies in analytical chemistry that allows for this type of work,” Posman said.

Photo: An image of the experimental bottle herd researchers use to replicate the environment of the cow rumen and test halogenated compounds (Credit: Colby College).