The researchers studied how different grass and soybean mixtures affected the growth and nutrient balance of dairy heifers. They found that guinea grass + soybean produced more biomass, but green panic grass + soybean was more nutritious for the animals. The heifers in the green panic grass + soybean group had higher nutrient digestibility and intake compared to the guinea grass + soybean group. Both mixtures supported the heifers' growth and nitrogen balance, with no significant difference in growth rate between the two groups. Overall, green panic grass + soybean was better for the heifers' nutrition, while guinea grass + soybean had higher biomass production.