Aim: This study was carried out to examine growth characteristics of calves (from birth to 12^th month) of Anatolian Black and Brown Swiss Cattles reared in different types of extensive rearing, Şile Region.

Materials and Methods: This study was carried out in 29 Brown Swiss and 71 Anatolian Black between 2011 and 2013 years. Calves were grouped four different extensive rearing types. These were Continuous Pasture Brown Swiss (CPBS), Continuous Pasture Anatolian Black (CPAB), Returned to Housing in Evening Time Anatolian Black (RHETAB) and Returned to Housing in Evening Time Anatolian Black with Additional Feeding (RHETAB with AF), respectively. For determining growth characteristics in calves, data related to live weight, chest girth, body length and shoulder height were taken at birth, in 3^rd month, in 6^th month and in 12^th month, respectively.

Results: According to rearing types birth weights of the calves were 26,07±0,67 kg, 21,24±0,75 kg, 20,64±0,80 kg and 22,12±0,79 kg respectively. There was a statistically difference with respect to birth weight in favor of group one at birth (P<0,01). In 12^th month live weight of the calves were 185,20±5,28 kg, 147,75±5,89 kg, 133,30±6,30 kg and 173,19±6,23 kg in rearing groups respectively. The difference with respect to live weight disappeared between calves of Brown Swiss and Anatolian Black with additional feeding groups (P>0,05).

Conclusion: In Şile Region, Brown Swiss may be preferred against Anatolian Black to obtain more meat production in extensive cattle breeding. During periods of poor pasture quality, it is advisable to perform additional feeding for both Brown Swiss and Anatolian Black.