The study investigated the effects of biochar and urea supplementation on feed intake, milk yield, feed conversion, and methane production in dairy cows. The results showed that the supplementation did not influence any parameter of nutrient balance or feed conversion, indicating that biochar inclusion in dairy cow diets had no impact on dairy cow metabolism or productivity. The study also utilized a 3×3 Latin square design with different feeding groups to determine feed intake and milk production, showing no significant differences in nutrient balance or feed conversion. Additionally, the researchers measured methane production and nutrient digestibility, considering factors such as group, lactation number, days in milk, daily dry matter intake, and concentrate proportion in the ration.