Eighty eight Holstein cows and their calves were used to evaluate effects of various level of intramammary infections on colostrum quality and calves health. Average somatic cell counts (SCC) in three treatments were 960×10 3 , 2137×10 3 , 5050×10 3 cells/ml. Treatments were arranged in an unbalanced completely randomized design with 3 treatments according to LOG 10 SCC. Maternal Colostrum was fed immediately after birth in amount of 2 L/Feeding. Any calf that did not receive maternal colostrum was removed from the study. Calves blood samples were collected at 0 h, and 3 h after first feeding and 42 d. Dams blood samples were taken immediately after parturition. Volume, density and pH of the first milking was recorded. Calves were housed in individual pens and were fed milk from 3 d until 60 d at 10 % of BW/d. Water and calf starter were offered free choice after 3 d. Calves were weighted at 0 h, 30 d and 60 d. Health and fecal scores were evalueted daily until 42 d. Body length and withers heigth were evaluated at 1 and 60 d. Colostrum analyzed for protein, Lactose, TS, SNF, pH, and IgG. Serum samples IgG was determined. Data were analyzed using MIXED procedure of SAS system. No significant differences due to intramammary infections were detected for colostrum volume, fat, protein, Lactose, density, TS, SNF, and IgG. But pH increased significantly (6.29, 6.36, 6.39 for low, medium and high SCCs, respectively; P 0.05). Calves birth weights, IgG concentrations at 3 h, and 42 d, ADG in Second thirty days after birth, body length and heigth of withers showed no differences among treatments. But ADG in first thirty days were significant (0.181, 0.169, 0.103 for low, medium and high SCCs, respectively; P 0.05). Health and fecal scores were affected by infection. Dams IgG were also affected by infection (18.09, 22.7, 25.14 for low, medium and high SCCs, respectively; P 0.01). Data indicated that intramammary infections can reduce calf health and performance but its effect on colostrum IgG is not significant.
