Developing proper digestive capacity and healthy structural growth during the pre-weaning period remains a critical priority in dairy cattle management. Young calves undergo a delicate physiological transition from a liquid milk diet to solid feeds, making them susceptible to digestive disturbances and reduced nutrient absorption. Nutritional strategies that encourage higher feed consumption while stimulating internal stomach development are vital for establishing long-term health and future milk production potential. Researchers continuously investigate natural feed additives that can safely enhance gut function without relying on synthetic growth promoters or routine antibiotics.

A research team published a study in the Journal of Livestock Science and Technologies, authored by Radman Bakhtiari, Yadollah Chashnidel, and Mahmoodreza Rezaei Armi. The investigation evaluated how dietary supplementation with agricultural biochar and wood vinegar affects growth performance, body measurements, stomach fermentation characteristics, and gas production parameters in newborn male Holstein calves. The authors randomly assigned forty calves to four distinct dietary treatments: a standard basal control diet, a diet containing half a percent biochar, a diet containing three-tenths of a percent wood vinegar, and a combination diet containing both additives from three days of age until weaning at sixty-six days.

The experimental results demonstrated that wood vinegar supplementation produced pronounced positive effects on feed intake and skeletal development compared to the control group. Calves receiving wood vinegar achieved a significantly higher average dry matter intake of 1.78 kilograms per day compared to 1.60 kilograms per day in non-supplemented groups. Skeletal measurements recorded at three, six, and nine weeks of age revealed consistent structural gains among calves fed wood vinegar. By nine weeks, these animals exhibited greater overall body length, chest girth, abdominal girth, hip-to-pin distance, and pin width, indicating enhanced framework development supported by increased nutrient intake.

Analysis of stomach fluid collected at the conclusion of the trial showed that both biochar and wood vinegar modified internal fermentation dynamics. Supplementation with wood vinegar increased total volatile fatty acid concentrations to 137.6 millimolar compared to 128.7 millimolar in non-treated groups. Furthermore, wood vinegar altered the fermentation profile by increasing the molar proportion of acetate to 55.0 percent while reducing the proportion of butyrate to 8.0 percent. Biochar supplementation alone increased total volatile fatty acids to 139.2 millimolar, but it did not alter individual fatty acid proportions or improve overall feed consumption and body weight gain.

Laboratory gas production testing further confirmed the digestive advantages associated with wood vinegar inclusion in calf diets. Substrates treated with wood vinegar demonstrated higher organic matter digestibility, greater metabolizable energy values, and increased short-chain fatty acid production after twenty-four hours of incubation. The lack of significant statistical interaction between biochar and wood vinegar indicated that each additive functioned independently within the digestive system. The organic acids and natural bioactive compounds present in wood vinegar were identified as the primary drivers behind improved microbial activity and nutrient degradation.

The findings indicate that wood vinegar holds substantial promise as an effective, natural feed additive for young dairy calves. By promoting higher starter feed intake and stimulating favorable stomach fermentation, wood vinegar helps establish a strong foundation for early structural growth and digestive efficiency. While biochar offers modest improvements in total volatile fatty acid production, wood vinegar delivers broader, more comprehensive performance benefits for early calf development. Dairy operations can utilize wood vinegar to optimize pre-weaning nutritional management without introducing negative impacts on feed conversion efficiency.

Source: Bakhtiari, R., Chashnidel, Y., & Rezaei Armi, M. (2026). Effects of biochar and wood vinegar supplementation on growth performance, rumen parameters, and gas production in milk-fed Holstein calves. Journal of Livestock Science and Technologies, 16(1), 19-27.