The effect of spearmint sativum essence added to starter diet on ruminal fermentation, weaning age and performance of Holstein calves

This experiment was conducted to investigate the effects of spearmint sativum essence added to starter concentrate of Holstein calves. For this purpose, thirty calves (15 male and 15 female) with the mean of 41.3± 0.73 kg birth weight were used in a completely randomized design. The experiment was done from 3 days age to 3 weeks after weaning. Three levels 0 (control), 0.025 and 0.05% of the essence were added to the calves starter concentrate as dry matter (DM) basis. Plasma samples and ruminal fluid were collected at different times. Weight records, feed consumption, fecal score and weaning age were determined. Results showed that the treatments had no significant effect on DM intake and average daily gain during the different weeks of experiment. However, the 0.05% essence increased (P<0.05) alfalfa intake in entire trial. Also, the high level of essence reduced (P<0.05) claves weaning age. During the preweaning period 0.05% essence increased (P<0.05) fecal score, however this effect was not significant in postweaning and entire periods. Plasma parameters and ruminal metabolites were not affected by the essence. It was concluded that 0.05% spearmint essence added to starter concentrate decreased calves weaning age and increased their forage consumption.