The aim of this study was to investigate the effect of wetting the forage part of the starter and adding fiberolytic enzymes and probiotic supplements on ruminal health and fermentation, digestibility and performance of Holstein calves. 60 Holstein female calves (mean birth weight 39.8 ±1.67 kg) were used in five treatments. The first treatment received 8% of dry straw forage in the ration and other treatments with wet forage in the form of 2´2 factorial design with the main effects of adding enzymes and probiotics were performed with 12 replications. Experimental treatments of the factorial section were: 1) calves that received wet forage without enzyme additives and probiotics, 2) calves that received wet forage with enzyme additives and without probiotics, 3) calves that received wet forage without enzyme additives and probiotics And 4) calves that received wet forage with enzyme and probiotic additives. From 3 days to 15 days of age, calves received two servings of 2 liters milk per meal, 16 days to 56 days of age received two servings of 3 liters milk per meal, and then received 3 liters of milk per day until day 59. At 60 days of age, They were weaned. Dry matter intake, rectal temperature, fecal score and were measured every day and body weight were measured every ten days and skeletal growth was measured at the beginning of the experiment, weaning time and at the end of the experiment. On days 35 and 70, ruminal fluid samples were collected from calves by esophageal tube. fecal samples were sampled for digestibility tests on 3 consecutive days before and after weaning. Calf behavior was recorded on 3 consecutive days in the pre-weaning and post weaning period. Data were analyzed using a mixed model of SAS statistical software (version 9.4). The results showed that wetting the starter diet forage increased the initial feed intake (P 0.01), increased daily weight gain in the post-weaning period and the whole period (P 0.01) (P 0.01), increased Dry matter digestibility (P 0.01), increase in some skeletal growth traits such as chest circumference (P = 0.06), body depth (P 0.01), body length (P = 0.04) and stalk height Before weaning (P = 0.02), increased eating behavior (P = 0.04) before weaning increased the total concentration of volatile fatty acids before weaning (P = 0.03). Wetting the feed of the initial feed also caused a significant decrease in the digestibility of soluble fibers in neutral and acidic detergents (P 0.01), (P = 0.02), decrease in pH of ruminal fluid before weaning (P = 0.01), Decreased sleeping behavior after weaning (P 0.01), decreased rumination behavior before weaning (P = 0.04), decreased acetate concentration (P = 0.08) before weaning. Enzymes, probiotics and their interactions in this project had different results. Fiber-degrading enzyme reduced dry matter intake in three periods before and after weaning and the whole period (P = 0.08), (P = 0.07), (P = 0.01). The enzyme also reduced the initial feed intake (P = 0.09), (P = 0.07), (P = 0.01). Fiber-degrading enzymes decreased the digestibility of the consumed dry matter (P 0.01), and increased the digestibility of crude protein (P 0.01). The enzyme reduced skeletal growth in dorsal traits and body depth after weaning (P 0.01), (P 0.01). The enzyme was able to reduce non-nutritional behaviors before and after weaning (P = 0.03), (P = 0.03). Addition of probiotics had effects such as more daily weight gain before weaning (P 0.01) and the whole period (P = 0.08), improvement in weaning weight (P = 0.03) and final weight (P = 0.09). ) Improve the digestibility of crude protein (P = 0.02) and soluble fibers in neutral detergent (P 0.01), decrease ruminal pH before and after weaning (P = 0.05) and (0.03) P), increased propionate production (P = 0.03) and decreased acetate to propionate ratio (P = 0.03). The interaction of enzyme and probiotic increases the digestibility of crude protein (P = 0.08), neutral detergent fibers (P = 0.04), soluble fibers in acidic detergent (P 0.01), effect on some growth traits Skeleton such as sleeping after weaning (P 0.01), eating before weaning (P = 0.04), chewing before weaning (P = 0.04). Keywords : Enzyme, Probiotic supplement, Growth yield, Calf