دراسة تشخيصية لبعض مسببات الإسهال المعدية في العجول حديثة الولادة باستخدام اختبار الإليزا المباشر

الملخص EN

The aim of this study was to investigate the prevalences of the some infectious causes of diarrhea and study of the changes in the blood pH, gases concentration and electrolytes in calves affected with diarrhea.

The study was conducted on 341 local breed calves from both sexes, aged between 1– 30 days during the period from November 2010 to March 2011.One hundred and ten calves randomly selected ( 88 calves from 95 animals affected with diarrhea and 22 clinically normal ) used for clinical examination and collection of the fecal samples, while the blood samples were collected from 40 animals (30 calves affected with diarrhea and ten clinically normal animals served as a control group).

The results of the study revealed that the total prevalence rate of diarrhea in calves was 27.8 % .

The main clinical signs of the newborn calves affected with diarrhea included depression, unable to sucking, dehydration and recumbency on one side of their bodies with differences in the means of the respiratory rates , heart rates and body temperature.

The gross examination of the fecal samples revealed that the consistency of fecal samples were soft or watery and varies in color (brown , green , yellow ) with presences of mucus or blood , in addition to bad odor and absence of any relationship between the color of the feces and the types of the causative agents.

By using polyvalent direct ELISA test , the total percentage of the infection with different causes of diarrhea in both single and mixed infections was 75.0 %.

Single infection were more frequently recorded than mixed infection, while only 31.8 % of the fecal samples of clinically normal animals were positive for the single infection.

The prevalence rate of the single infection in the calves affected with diarrhea indicated that the Cryptosporidium parvum was the predominant causative agent , then the percentage of infection with rotavirus and the lowest percentage of infection showed with Enterotoxogenic E.coli (F5).

All the fecal samples of the clinically normal calves were negative for ELISA test except five samples were positive for rotavirus and two samples for the Enterotoxogenic E.coli (F5).

The percentages of the infection with infectious causes of diarrhea either single or mixed were varies with ages of the animals affected with diarrhea