Habtamu, Lemma2020-06-122023-11-082020-06-122023-11-082006-06http://etd.aau.edu.et/handle/123456789/21554This study was conducted in Wolaita Sodo State Dairy Farm from October 2007 to April 2008 to determine the milk yield and reproductive performance and herd life of Jersey cattle and also potential factors affecting these parameters. The Jersey cattle in the study farm were mainly kept on pasture land and with some supplementary feeds. The data recorded and kept by the farm from 1987 to 2007 were used for the study. Data analysis was performed using descriptive statistics and GLM of SPSS (release 11.05, 2002). The factors considered in the model were year of birth, calving and service; season of birth, calving and service; parity number of dam; source of cattle and sex of calves. The results of this study revealed that the overall mean values of lactation milk yield, lactation length and life time milk yield were 1691.59kg (SE=27.55), 318.42 days (SE=3.92) and 5565.19kg (SE=220.03), respectively. Lactation milk yield and lactation length (p<0.001) were significantly affected by year of calving and cattle source. Imported cattle had better lactation milk yield and length than those reared on farm. In addition, lactation length was significantly decreasing with parity number (p<0.001). Life time milk yield was also affected by year of calving (p<0.01). The overall means of age at first service, age at first calving, calving interval, interval between calving and effective service and number of services per conception were 722.24 days (SE=36.4), 1035.21 days (SE=12.59), 450.09 days (SE=6.60), 174.68 days (SE=8.61) and 1.79 (SE=0.06). All the reproductive performance traits were significantly influenced by year of birth, calving or service depending on the type of trait. In addition, age at first service was significantly lower in imported cattle while calving interval was lower in on-farm raised cattle (p<0.001). Calving interval and the interval between calving and effective service were decreasing significantly with parity number (p<0.001). Number of services per conception was significantly lower in short rainy season (p<0.05). The overall mean values for total herd life, productive herd life and effective productive herd life were 2983.74 days (SE=67.98), 2310.11 days (SE=296.91) and 1663.15 days (SE=55.09), respectively. In this case, year of birth had significant effect on total (p<0.001) and effective productive (p<0.01) herd life. Imported cattle had significantly longer total (p<0.01) and productive herd life (p<0.05) than the on-farm reared cattle. The overall mean values for birth and weaning weight were 22.87 kg (SE=0.17) and 108.88 kg (SE=0.67), respectively. Both traits were influenced significantly by year of birth, season of birth, sex of calves and parity number of the dam. Calves born in the long xi rainy season had better birth and weaning weight than the others. There was a trend of increased birth weight of calves as the parity number of the dam increased. From this study it can be concluded that Jersey cattle kept in the study farm had poor milk yield and reproductive performance. The herd life, productive herd life, effective productive herd life and birth and weaning weight of Jersey cattle found in this study are in general good. Inconsistency in management and variations in climatic conditions seem to determine the values for the different traits considered in this study suggesting the need to improve the overall herd management at the study farm.enbirth weightdairyherd lifeJerseyreproductive performanceThesis