evaluation of the antibodies produced in colostrum by the injection of trivalent rota-corona virus and escherichia coli k99 vaccine in pregnant cows

the amount of antibodies produced in colostrum following injection of the trivalent rota-corona virus and e. coli vaccine was evaluated to undrestand the priventive effects of vaccine against calf diarrhea. forthy six and 27 pregnant cows were selected from industrial dairy herds as a treatment and control groups, respectively in urmia iran. a 5 ml trivalent rota-corona virus and e .coli vaccine was injected subcutaneousely in over 7 months pregnant treatment group. after parturition a 50 ml colostrum from both groups was colleced and evaluated for antibodies using competetive elisa method and commercial kits of rota, corona virus and e. coli of 46 vaccinated cows, antibodies in colostrum againt e. coli, rota and corona virus were detected in 71.7%, 100% and 100% and in control group were 14.8%, 100% and 100%, respectively. the percentages of cows with +2 positive to antibodies produced in treatment group were 60.9%, 93.5% and 73.9%, respectively. the highest and lowest inhibition rate in vaccinated cows for e. coli antibodies were 85% and 1%, rotavirus were 59% and 20% and corona virus were 61% and 20%, respecrively. chi-square tests showed significant differeces (p<0.05) between vaccinated and control groups for e. coli antibodies (x=8.31, p<0.05), cows with +2 positive antibodies produced for e.coli and control group (x=11.7, p<0.05), cows with positive and negative to antibody produced for e.coli in control group (x=9.4, p<0.05) and cows with negative to antibodies produced and control group (x=7, p<0.05). there were no significant differences between vaccinated group with rota and corona virus and control group. a 2.2% of calves in treatment group and 7.5% in control group were appeared diarrhea in which the differences was not significant. thus, it is concluded that antibodies produced by the injection of e.coli vaccine in pregnant cows was significantly different from control group, while not for rota and corona virus vaccine. it seems that using monovalent e. coli vaccine is more reliable, economics and practicible in the prevention of calf diarrhea than polyvalent vaccine e. coli, rota and corona virus.