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Productivity and profitability of sheep farming are highly influenced by lamb survival and ewe reproductive performance. Thus, this study was conducted to evaluate the survival and reproductive performance of crossbred sheep. Data collected from 2009 to 2018 from Sirinka sheep breeding stations were utilized for this study. Survival analysis was conducted by using Survival Kit 6.12 software with the Weibull model and the general linear model of SAS 9.0 was used to analyze reproductive traits. The overall mean survival rate of Dorper x Tumele crossbred lambs at 3, 6 and 12 months of age were 86.0, 76.6, and 67.9%, respectively. About 46.8% of mortality from the total death was observed during the first 120 days of life. Gastrointestinal parasites, pneumonia and septicemia were the major causes of lamb mortality. Birth weight, birth type, sex and year of lambing were the most important risk factors for survival of crossbred lambs. The overall least-squares means for litter size at birth, litter size at weaning, total litter weight at birth and total litter weight at weaning were 1.10 lambs, 0.94 lambs, 3.28 kg and 15.5 kg, respectively. Birth type, sex and year of lambing were the most determinants of ewe productive traits. Tumele and their crossbred sheep had good mothering ability necessary to successfully raise lambs to weaning. The current crossbreeding program which aims to improving growth performance had a positive influence on the survival rate of lambs. Improvement of environmental in the flock, special care for small lambs and indirect selection based on birth weight would lead to further survival improvement.

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The growth and efficiency-related traits of the Boer x Central Highland goats raised semi-intensively were evaluated. Besides, genetic and non-genetic factors affecting growth and efficiency-related traits were identified. Data were collected over a period of nine years in a flock of Boer crossbred goats and analyzed using general linear model procedure of SAS. The overall least-squares mean live weight at birth, 3-, 6-, 9-and 12 months of age were 2.52 AE 0.01, 9.81 AE 0.13, 13.8 AE 0.15, 17.8 AE 0.19, and 20.5 AE 0.29 kg, respectively. The average weight gains from birth to 3 months, 3 to 6, 6 to 9 and 9-12 months of age were 80.3, 37.5, 41.9, and 31.2 g day À1 , respectively. Boer blood level, birth type, season and year of kidding had a significant effect on growth traits. The overall least-squares mean of Kleiber ratio from birth to 3 months, 3-6 months, 6-9 months, and 9 month to yearling age were 13.99 AE 0.11, 5.23 AE 0.14, 4.66 AE 0.16, and 2.95 AE 0.18, respectively. Parity, birth type, Boer blood level, season and year of birth had a significant influence on the expression of efficiency-related traits (Kleiber ratios) in different growth phases. In terms of growth performance and efficiency-related traits, F2 and F3 crossbred goats did not show any benefit over F1 crossbred goats. Increasing Boer blood level above 50% would be worthless under the existing minimal input production system. Therefore, besides to improving the management of goats, producing the first filial generation would be suitable for medium to high input production systems.

Background: The productivity and profitability of dairy cattle depend largely on reproductive performance. Thus, this study was intended to evaluate the reproductive performance of Jersey cattle raised under semi-intensive management system.Methods: A retrospective analysis consisted of data collected for the last 33 years was conducted. The fixed effects fitted were birth period, calving period, service period, birth season, calving season, service season, parity and genetic group. The general linear model procedure of SAS was used for the statistical analysis of data. Result: The overall least-square means for age at first service (AFS), age at first calving (AFC), calving interval (CI), days open (DO) and the number of services per conception (NSPC) were 22.93±0.22 months, 32.95±0.22 months, 494.16±3.68 days, 221.09±3.73 days and 1.99±0.03, respectively. Year, season and parity had a significant effect on most of the investigated reproductive traits. Imported Jersey cows had an extended CI and DO than farm-bred cows. Besides, the inconsistency of management and variability of climatic variables across year and season seems to have a considerable influence on the reproductive efficiency of cows. Therefore, the improvement in the level of management and selection of parents based on their breeding value would be improve the reproductive performance of Jersey cows.