Key Findings
Mycotoxins are toxic compounds that can adversely affect health and milk production in dairy cows that consume myxotoxin-contaminated feed.
A mycotoxin deactivator binder added to animal feed can negate the toxic effects of mycotoxins. This could enable producers to safely use poorer quality feed, increasing efficiency and decreasing potential economic losses brought on mycotoxins. Study results indicate that rumen parameters can be restored by a dietary mycotoxin deactivator, resulting in an improvement of the production of beneficial metabolites and enhancing health and performance of the cows.
About the Co-Author
Nancy Whitehouse, Research Assistant Professor of Agriculture, Nutrition, and Food Systems
Contact information: Nancy.Whitehouse@unh.edu, 603-862-1349
This research was published in the INSPIRED: A Publication of the New Hampshire Agricultural Experiment Station (Winter 2021)
Researchers: N. Whitehouse, H. Robertson, B. Kerns and S. Lynch
Mycotoxins are toxic compounds naturally produced by certain types of molds and pose a serious risk to both humans and animals. Heat, humidity, and rainfall contribute to the growth and spread of mycotoxins. This makes managing and removing mycotoxins from animal feeds difficult. When feed is high in mycotoxin contamination, the overall health and production of dairy cattle are adversely impacted. Two trials were conducted to measure the effect of a mycotoxin deactivator binder, which can negate the toxic effects on lactating dairy cattle when fed a diet high in mycotoxin contamination.
Mycotoxins are toxic secondary metabolites of fungus naturally found throughout the world and in animal feeds (Lagrieco, 2018). They are molecules of low molecular weight that can present toxic responses in both humans and vertebrate animals (Gallo et al., 2015). These fungal toxins are chemically diverse. There are hundreds of known mycotoxins, but only a few have been intensely studied and researched. Mycotoxins exist naturally in the environment, particularly in molds present in forages and silage, however the incidence of mycotoxins throughout a region can vary (Gallo et al., 2015). Fungi present on crops can produce preharvest or postharvest, during handling and transport, storage, ensiling, processing or feeding. Notable mycotoxins include aflatoxins, trichothecenes and fumonisins.
These groups of mycotoxins primarily reside in the kernels of mold-affected grain. They detract from the overall nutritional content by lowering the fat, protein and vitamin content of the grain. In addition to degrading the feed value, these molds can also change the texture, color of the kernels and, in the process, emit odors that cause feed refusal. Mycotoxin deactivators are fed to negate the toxic effects of consuming mycotoxins.
This study tests the effectiveness of a mycotoxin deactivator. All procedures related to animal care were conducted with the approval of the University of New Hampshire Institutional Animal Care and Use Committee. Cows were housed at the Fairchild Dairy Teaching and Research Center in a naturally ventilated tie-stall barn, fed individually, and had continuous access to water. For both trials, 24 multiparous Holstein cows were used with 9 cows being equipped with ruminal cannulas and 15 non-cannulated cows. The treatments were: 1) control diet (Low DDGS), 2) control diet + distillers grains with a high mycotoxin load (High DDGS), and 3) control diet + distillers grains with high mycotoxin load + mycotoxin deactivator (High DDGS+D). Blood, rumen, and milk samples were collected on the last three days of weeks 3 and 6 for trial 1 and weeks 2, 4, 6, 8, and 10 for trial 2. Blood and milk samples were collected from the coccygeal vein at 1000 hours and analyzed for hematological and biochemical parameters.
Table 1 shows the results across treatments. The total mixed ration (TMR) in the High DDGS diets increased zearalenone and deoxynivalenol compared to Low DDGS diets. Cows fed High DDGS had elevated somatic cell score (SCS) compared to Low DDGS, but High DDGS+D showed low SCS in Trial 2. Results show mixed outcomes between trials on leukocytes and monocytes. The rumen parameters showed a significant increase for butyrate and isobutyrate and isovalerate with supplementing High DDGS+D compared to High DDGS. Bacteria and archaea relative abundance were also affected by the mycotoxin contamination, resulting in a higher bacteria:archaea ratio. In Trial 2, the contaminated diets had higher acetate concentrations compared to Low DDGS, and the propionate concentration was lower for the High DDGS+D compared to the Low DDGS and High DDGS diets. This may be due to the longer length of Trial 2, different modes of action that deactivators have, or that mycotoxin T2 and HT2 were present in higher amounts than in Trial 1.
