Bupleurum Extract – A Heat Stress Antidote?
A popular Chinese herbal supplement is being evaluated as a potential feed additive to mitigate the effects of heat stress in dairy cattle.
Bupleurum is a centuries-old herbal supplement used in Chinese human medicine. It is created from the root of the Bupleurum chinense plant by drying the roots and grinding them into powder.
Asian cultures have long embraced Bupleurum for its perceived liver-cleansing benefits and to treat fevers, colds, and flu. In more recent years, interest in Bupleurum has grown among Western consumers as a tool to support immune health, boost mood, and fight inflammation.
And now, the dairy cow is catching the Bupleurum wave, with interest in using it as a heat stress aid.
In addition to the obvious setbacks in milk production and dry-matter intake, heat stress has been implicated in previous studies in damaging cows’ immune systems; fueling metabolic diseases; changing their hematological (blood) parameters; and inciting disorders related to hormone levels in their serum, causing potential reproductive setbacks.
Changes in circulating water and minerals due to heat stress have also been shown to disrupt osmotic balance and disrupt blood-pressure regulation in cows.
A recent study published in the Italian Journal of Animal Science evaluated 40 lactating Holstein cows in a heat stress setting. Heat stress thresholds in the study were defined as a Temperature-Humidity Index (THI) of 72 and body temperature exceeding 102.2°F. Actual conditions in the three-month study were an average THI of 78.2, and average body temperature was 102.7°F.
Cows were divided into four feeding groups of 10 animals each. The control group received no Bupleurum supplement, while the other three groups received, respectively, powdered Bupleurum extract at 0.25, 0.50, and 1.0 grams/kilogram of dry matter.
In the study, the dose of 0.5 g/kg proved to be effective in improving the hematological parameters of heat-stressed cows. Specifically, those cows had higher red blood cell counts, hemoglobin, hematocrit, and white blood cell count, compared to the non-treated controls.
The 0.5 g/kg dose also decreased blood sodium concentrations and increased calcium and potassium concentrations, and lowered serum cortisol (stress hormone) levels.
Various benefits also were observed at the other dosage levels, and no deleterious effects were observed at any dosage. But the researchers concluded that 0.5 g/kg produced the most collectively beneficial outcomes of supplementing with Bupleurum to help cows cope systemically with heat stress.
For more on heat stress, read:
- Gene Editing Could Improve Heat Tolerance
- Beating the “Summer Slump”
- Feeding Strategies to Mitigate Heat Stress
