The reproductive and productive traits of performance, i.e., age at maturity, age at first conception, age at first calving, days open, service per conception, Calving to first Service Interval (CFSI), calving interval, lactation length, dry period, lactation milk yield and parity are important to find out the actual efficiency of performance (Sattar et al.,2005, Abdel and Alemam, 2008, Tadesse et al., 2010, Alemayehu and Moges, 2014, Haftu Kebede, 2015, Mamun et al., 2015, Mengistu and Wondimagegn, 2018). displayed in regular cycles. The time of sexual maturity depends not only on age but also is the result of the effect of numerous genetic (process of sexual maturation, display of sexual maturity) and environmental factors (nutrition, climate, rearing, housing, care, etc.). After reaching sexual maturity, animals require an adequate period for further body development in which necessary breeding maturity of the animal will occur. The beginning of the breeding maturity is variable and depends mainly on the bodyweight of animals (Smiljakovic et al., 2007, Novakovic et al., 2011). In the case of heifers of high-yielding breeds, sexual maturity is reached at the age of 9-11 months and an average body mass of 250-280 kg (Sejrsen and Purp, 1997). Most of the recommendations refer to the first insemination of heifers at the age of 14 to 15 months and body mass of ≥ 350 kg, in order to achieve age at calving of 24 months (Antov et al., 1998). The age of dairy cattle at first conception is one of the major reproduction properties. Age of calves at first calving depends mainly on age at first conception. Age at first conception is determined by the date of birth and date of first conception (Novakovic et al., 2011). Age at first conception includes the period from the birth of the heifer to the first insemination at the age when the animal has reached breeding maturity enabling it normal gravidity. Age when an animal reaches sexual and breeding maturity have for a long time been in the center of attention of expert and the scientific public in regard to the possibility for shortening of the generation interval. Age at first calving is an important factor influencing the yield and composition of milk (Pirlo et al., 2000). Age at first conception is one of the most important fertility properties in dairy cattle. It has a direct impact on age at first calving since the duration of gravidity has a physiologically constant value. There is a positive relationship between the body mass at first calving and milk yield in the first lactation. This relation is an important basis for defining levels of body development and the age of heifers at first conception/calving. Age at first conception is determined within defined time limits. The bottom limit is the date of birth, and the top limit date of conception (Novakovic et al., 2011). Lactation length is defined as the period between two consecutive calvings during which cows are capable of producing milk or lactating. Many researchers in tropical countries have reported the mean of lactation length (Abdel Rahman and Alemam, 2008). Hatfu Kebede, 2015 reported that the lactation length in his study was shorter than the optimum value of 305 days required to maintain the optimum calving interval of 12-13 months. The shorter lactation length may be due to factors such as improper feeding regimes, inadequate dry period and prevalence of diseases. Dry period It is the period of off milking. Smith (1959) stated that a dry period is necessary in order to accomplish one or more of the following: a) To refresh the body with nutrients that were depleted during lactation. b) To repair and regenerate the alveolar system. c) To gain new stimulation for lactation as the result of parturition following gestation. Thus an optimum dry period is essential for maximum production of milk in the subsequent lactation. The standard length of the dry period is a period of 60 days (Rahman and Alemam, 2008). The dry period of indigenous cows was higher than HF cows which in turn increased lactation length in HF cows (Nahar, 1987, Mamun et al., 2015)