Effect of type of insemination on embryonic mortality and stillbirth in dairy cattle and heifers

ABSTRACT

The aim of this work was to evaluate the rate of embryonic mortality in early pregnancy period and rate of stillbirths at calving period in naturally and artificially inseminated dairy cattle and heifers. The study was carried out in October, 2007-November, 2008 in a cattle farm located at Alex desert road, El Behera province. Animals divided into two groups The first one naturally inseminated [20 cows and 8 heifers]. Group two [34 cows and 12 heifers] were artificially inseminated. Pregnancy diagnosis was carried out by ultrasonography on days 28 and 35 then, confirmed rectally on day 45 post insemination. Animals that were pregnant on day 28 but not on day 35 were considered to have undergone embryonic mortality [EM]. The rate of embryonic mortality in Heifers those naturally inseminated had significant variance [p<0.05] from day 35 [0.0] to day 45[16.67%] post insemination rather than artificial insemination on day 35 [12.50%] to day 45[14.29%]. While, cows those naturally inseminated had significant variance [p<0.05] from day 35 [7.69%] to day 45[16.67%] post insemination rather than artificial insemination on day 35 [4.35%] to day 45[4.55%]. Stillbirth in calves without regarding to the type of animals [Cows or Heifers] had significant increase [p<0.05] with natural insemination [33.33%] rather than artificial insemination [22.22%]. In conclusion, the use of AI needs to be mandatory strategies in order to obtain high fertilization rates and maintenance of pregnancy in cattle and consequently lead to reduction of dystocia and improvements in calf health and survival. Future studies should attempt to biotechnologies of AI techniques as well as other traits that contribute to lifetime profitability, because precise knowledge of such parameters is needed to develop efficient and effective dairy crossbreeding systems