Research
Review on Major Assisted Reproductive Technologies
Since early period, several reproductive technologies practiced as a prime concern for researchers, employed for genetic improvement of farm animals. This review deals with the assisted reproductive technologies (ARTs) among the known approaches for genetic improvements. This review paper focused on artificial insemination (AI), estrus synchronization, multiple ovulation and embryo transfer (MOET), cryopreservation (freezing) of gametes or embryos and in vitro embryo production (IVEP). Briefly to see, AI is the manual placement of semen in the reproductive tract of the female by a method other than natural mating. AI is the most effective method being used for the genetic improvement of animals. Estrous synchronization is another process of targeting female mammals to come to heat within a short time frame (36 to 96 hours) that is to have a number of females in estrus during a very short period. Superovulation is also a method when an animal is induced (usually through use of injectable hormones) to ovulate multiple ova (the hormonal treatment for harvesting increased number of oocytes from the ovary than normal). Cryopreservation is another technique operated by storing a low temperature for a long-term storage to preserve the structurally intact living cells and tissues for extended period at a relatively low cost. The other ARTs method is embryo transfer, which is carried out on a variety of agricultural animals, to a greater or lesser extent depending on the species. IVEP includes three major steps: in vitro maturation (IVM), in vitro fertilization (IVF) and in vitro development (IVD) of the resulting embryos. In conclusion, animal biotechnologies related to reproduction have contributed too many improvements in agriculturally important traits in livestock. Reproduction lies at the heart of any livestock breeding enterprise and is vital to maintain or increase the number of animals required for production.
Assessment of Livestock Feed Resources in the Farming Systems of Mixed and Shifting Cultivation, Gambella Regional State, Southwestern Ethiopia
The study was conducted with the objective of assessing available livestock feed resources from mixed farming system (MF) and shifting cultivation (SC) in Abobo woreda, Gambella Regional State. The study was done using a formal survey, focus group discussion, secondary data and field observations. Purposive sampling was employed to select 180 respondents (90 from each farming system) that have at least one livestock for the survey data collection. The number of cattle from MF was higher (p<0.05) than that of SC, while the number of goats and chicken from SC were higher (p<0.05) than MF. Natural pasture was the dominant feed resources during the wet season. Crop residue and browse forage species play a significant role during the dry season. The major livestock production constraints in the study area were disease and parasite (67%) followed by feed shortage (50%) and water scarcity (46%). From this study it was concluded that seasonal feed shortage and inefficient utilization are the major problems affecting livestock productivity. Poor conservation practices and lack of knowledge are among the critical constraints for inefficient utilization of available feed resources. In the short term strengthening extension, demonstration and training on effective utilization of available feed resources could play an important role in the improvement of livestock productivity in the area. Follow up evaluation of available feed resources including limiting anti-nutritional factors and animal performance on promising browse and grass species are priority areas of future research.
