Effects of mineral biochar on performance, digestibility and blood parameters in Holstein calves

The objective of this study was to determine the effects of different levels of mineral biochar (MB) on performance, nutrient digestibility, and some blood parameters of Holstein calves. Twenty-seven Holstein female weaned calves (67.66 ± 9.33 kg initial BW) were randomly assigned to one of three experimental diets; contained 0%, 0.35% and 0.70% of mineral biochar in concentrate respectivelyDry matter intake (DMI) and body weight gain were recorded at the end of each week. Blood samples were collected on day 48 and nutrient digestibility was measured at the end of the experimental period (days 46 to 49). Results showed that mean of total body weight gain, final body weight and daily gain were not affected by different levels of MB in diets. There was no difference in average daily dry matter intake of calves consuming different experimental diets; while, feed conversion ratio (FCR) was lower (P = 0.02) in calves fed diets containing MB compared to control group and FCR decreased linearly (P = 0.02) as the level of MB increased in the diet. Apparent total tract digestibility of OM, CP and NDF increased (P < 0.01) with diets containing MB in comparison to control group. Also, blood urea nitrogen, total protein, triglycerides and VLDL were not different across experimental diets, but, calves fed 0.35% MB had lower (p<0.05) blood cholesterol than those fed other diet. It was concluded that using of MB had favorable effects on nutrient digestibility, FCR and blood cholesterol.