[Evaluation of the correlation between ration physically effective fiber and rumen pH in dairy cattle]

The current definition of subacute ruminal acidosis [SARA] is based on the pH of the ruminal fluid in dairy cattle and ration physically effective fiber could be used as a non-invasive method for prediction of ruminal pH. The purpose of this study was to evaluate the correlation between ration physically effective fiber, measured using old and modified Penn-state particle separator and ruminal pH. The physically effective fiber measured in the ration of 17 rational group [7 fresh and 10 mid lactation cow groups]. Ruminal fluid obtiained by rumenocentesis and SARA affected cows were detected. The physically effective fiber measured by modifed Penn-state particle separator had a correlation with mean ruminal pH of cows [r= 0.595, p= 0.012] and the ratio of subacute ruminal acidosis affected cows in rational groups [r= -0.533, p= 0.027]. The ration of SARA affected mid lactation groups had less physically effective fiber than non affected groups [p= 0.041]. According to our results, the physically effective fiber measured by modifed Penn-state particle separator had more correlation with ruminal pH in dairy cattle and can be used as a predictive index for ruminal pH

Probable occurrence of black leg in a sucker dairy calf: the necessity of providing sufficient maternal antibody in endemic regions

Black leg has been reported in a variety of animals, but is of the most importance in cattle and sheep. A 20 days old Holstein dairy calf was examined because of anorexia and lameness from 2 days ago. The calf was depressed, tachypneic, tachycardic, and had a body temperature of 38.5°C. Both hind limbs proximal to the tarsal joint were markedly swollen, firm and painful. No crepitation was noted on palpation. The calf had bruxism, stiffness of gait and unwillingness to move. At necropsy, massive necrosis of thigh muscles which caused dark discolorated tissue with metallic sheen, large amount of thin sanguineous exuda and abundant gas bubbles were evident in the underlying tissues. Histopathologic examination revealed extensive degeneration and coagulative necrosis of muscle fibers and supported a diagnosis of black leg. No vaccination against Clostridium chauvoei was applied in the herd and the calf did not receive notable maternal antibody. Providing sufficient maternal antibody or early vaccination of the susceptible newborn calves should be considered in the endemic regions

Hemorrhagic bowel syndrome in dairy cattle in Iran: a case report

Hemorrhagic bowel syndrome is a highly fatal intestinal disease of adult dairy cattle with uncertain cause. In a dairy herd in Khorasan Razavi province, Northeast of Iran, two cows showed depression, anorexia, decrease in milk production, ruminal hypomotility, bruxism and dehydration. At necropsy, massive hemorrhage and clot formation was observed within the jejunum and bacterial culture of the intestinal ingesta and lesions showed the presence of a large number of Clostridium perfringens. Subacute ruminal acidosis was detected in fresh and mid-lactation cows. This report shows the possibility of diagnosis of other hemorrhagic bowel syndrome cases in dairy cows in Iran

Prevalence of subacute ruminal acidosis in some dairy herds of Khorasan Razavi province, northeast of Iran

To estimate the prevalence of subacute ruminal acidosis [SARA] in dairy cows, a total of 196 ruminal fluid samples were drawn by rumenocentesis from 10 dairy herds of Khorasan Razavi province, northeast of Iran. Two groups of 12 cows, early lactation and mid-lactation cows were sampled in each dairy herd and ruminal pH was determined immediately using a portable pH-meter. A total of 54 cows [27.6%] were found to be experiencing SARA. No significant differences were found between SARA affected and non-affected cows in ruminal contractions, faecal quality and fat and protein components of milk