There are about six million native Cattle in Iran that their characteristics have not been studied yet; therefor, their genetic potential is not properly recognized. Designing fundemental programs for improving the breeding performance of these cattle would be feasible, if their potentials are recognized.
In this work, milk and fat yield, fat percent, reproductive performance and growth rate of Sarabi cattle in the Hakimieh Station and College of Agriculture were studied for five years. Sarabi cattle were reared in the open-shed and the condition of treatments in both stations were the same. Records were standardized for milking days and statistically analyzed. The results are as follows:
1) Conformation: Neck, Head and Forehead length were 45.30, 47.50 and 20.00 cm., respectively. Forehead width in areas of poll, median and between eyes were 18.10, 15.97 and 19.23 cm., in the same order. Height in withers, Barrel girth, Heart girth, ‘oin width, Feet and Legs hight were 122.12, 206.00, 176.98, 68.16 arid 71.94 cm., respectively.
2) The overall mean of actual milk yield in the Hakimieh and the College Stations were 1281.3 and 566.4 and their ranges were 110.7 to 4907.2 .and 98.0 to 1880.Kg. The adjusted milk yield for 305—day were 1887.78 and 1252.61 with the standard deviations of 999.13 and 539.05 Kg. Average fat percent in the Hakimieh station was 4.71, which is close to that of Jersey Breed. Length of the Lactation period was 163.10 day or Hakiniieh and 118.03 days for the College stations. Individual milk yield curves varied substantialy, which may he due to genetic and environmental. factors.
3) The average Age of Heifers at first calving was 35 months with minimum 27 and maximum 48 months. Length of gestation, days open and calving interval were 283.2, 73.2, and 365.6 days, respectively.
4) The average weight of male and female calves were 26.09 and 24.95 Kg. in this study which is equal to those of the Jersey breed. Phenotypic correlation cofficients among birth weight and three month weight and yearling weight were 0.79 and 0.74 respectively. Average daily gain of calves were 460 and 780 gm. during the first three-month and third three-month of age respecfively.
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