FROM THE FARM REPORT: SOMETHING IN THE AIR? WHAT'S THE DEAL WITH MATERNAL BOVINE APPEASING SUBSTANCE?

Pheromones are a means of communication within a species, and can be secreted to provide signals between individuals. One example of this is maternal bovine appeasing substance (MBAS), a naturally-excreted pheromone from cows to elicit a calming effect on their offspring by reducing the neuroendocrine response to a threat or stressor.

There are several products that have taken this concept and applied it through the use of a synthetic analog of MBAS to take this technology to the market. These products are indicated to reduce stress during times of management challenge including dehorning, weaning, castration, comingling, processing, transportation, and vaccination. The commercial synthetic MBAS are for use in cattle to be applied topically to the nuchal skin (poll, back of the neck) and the skin above the muzzle. The dose is based on the weight of the animal and is indicated to be 5 mL per location for animals over 200 lb (>90 kg) and 2.5 mL per location for animals less than 200 lb (<90 kg) per one of the US based companies with an estimated cost of $1.50 to 3.00/head/treatment. There is no beef or milk withdrawal time needed when administered according to label directions. A question that might come up is: Does it work?

Many studies have evaluated the use of MBAS in beef cattle operations on production, health, and stress markers in times of stress. A recent meta-analysis (Lean et al., 2025; https://doi.org/10.15232/aas.2025-02712) was conducted to see what the responses have been across studies by pooling all of the information to date from the published literature. This is an important tool, especially with an emerging technology. This meta-analysis included 13 reports and a total of 18 studies, all published since 2019. The studies included a range of initial body weight (88-1400 lb; 40-638 kg) and ages (birth to 810 days of age). Most of the studies focused on weaning or feedlot entry, one evaluated transport stress, and 3 evaluated pasture-fed cattle.

There was no difference in final body weight overall for the meta-analysis, however three studies did show a positive effect of MBAS, and more experiments and sample size could show a benefit. Overall, cattle given MBAS were 3.79 lb (1.72 kg) heavier than the controls. There were some varied responses in average daily gain (with a limited number of studies evaluating this) and indications that there were some benefits at different times throughout the studies but overall, not enough information currently to evaluate this. Furthermore, there was no significant effect on dry matter intake or gain to feed. The impact on health (diarrhea, respiratory disease, and mortality) incidence was a mixed bag and not significant. To evaluate this more completely more animals will need to be included. Individual studies have shown reductions in mortality and diarrhea. Some numerical reductions in pharmaceutical cost for treating respiratory disease were indicated in two individual studies, indicating additional work is needed. Blood cortisol, an indicator of stress, was reduced with MBAS treatment. The mode of action is not entirely known but thought to be through the recognition of the pheromones and creating a cascade from the hypothalamus to reduce the perception of a threat via a reduced neuroendocrine response. This reduction in blood cortisol supports the hypothesis of the mode of action of MBAS and its potential in the cattle industry, however, many questions still remain.

In dairy cattle some studies that have been reported recently include decreases in cortisol and increases in average daily gain for calves that had been disbudded, increased pregnancy per artificial insemination by 12.5%, and increased milk production in transition cows given MBAS compared to controls. These examples highlight the potential for the application of MBAS. but also show that we have a lot to learn. It certainly seems like nature has a specific purpose for animals using pheromones, so if we can understand how we might be able to use these for the benefit of our animals we can help mitigate stressful management practices and their negative impact.

— Sarah Morrison

morrison@whminer.com