Beskrivning och analys av superovuleringsresultat och andra fertilitetsregistreringar vid Nötcenter Viken

Abstract: Recording and analyses of superovulation results and fertility records at the nucleus herd Viken The development of different reproductive technologies aim at increasing the number of progeny per individual parent, and in that improving the possibility of genetic progress. One technique, embryo transfer, have facilitated genetic dissemination and shortened the generation interval also in females. Nötcenter Viken is a company that run embryo collection and embryo transfer in the breeds Swedish Red and Swedish Holstein. It is located outside Falköping. Information is continuously gathered about cows tested at the nucleus herd. It is of interest to know how this information should be used to best improve selection of the cows. The aim of this study was to map out which information, mainly related to fertility, that is gathered, how available it is and how it can bee used in research. This study concentrate mainly on information about flushing results - the number of embryos collected from the donor cows and phenotypic connection with other fertility traits. The study included 761 embryo flushings in 423 animals, (equally divided between Swedish Red and Swedish Holstein), 418 of these animals also had fertility information. The information was gathered during the period January 2004 to October 2006. Information from the year 2003 was not included in the statistical analyses, as those recordings were regarded misleading. The average total number collected embryos and number of transferable embryos per year, showed an improvement during the period 2003-2006. The high standard deviations indicated a large variation in these traits and high repeatabilities suggest that genetic selection may be possible. One explanation to the low results in 2003 is likely a start-up period at Nötcenter Viken, when management routines were not yet were established. Exchange of staff and more effective working routines have resulted in an improvement in flushing results. The 761 embryo flushings resulted in an average of 6.11 collected and 3.55 transferable embryos per collection. The results from only 2006 were 7.13 collected and 4.3 transferable embryos, which show on an increase in the number of embryos. This study did not show any significant effects of flushing result on other fertility traits, when the number of transferable embryos was used as explaining variable in the models for fertility traits. This material neither showed strong or significant correlations or residual correlations between these traits. One explanation may be that the material was too small to show if flushing result and fertility traits affect each other.