Vaccination of the dam by the intramuscular or deep subcutaneous route to prevent neonatal calf enteric colibacillosis.

Comparison of colostrum-induced immunities in calves was made by challenge exposure with Escherichia coli. These calves were delivered of cows which were vaccinated intramuscularly or deep subcutaneously (in the region of the mammary lymph nodes) with strain B44 E coli bacterin during the last trimester of pregnancy. The calf of each cow was allowed to nurse colostrum naturally after birth. Cows vaccinated by either route of administration were capable of providing increased resistance to their calves, via the colostrum, when compared with nonvaccinated cows.

Comparison of treatments for ovine foot rot.

Sheep affected with foot rot were treated by vaccination and/or hour-long footsoaks, without hoof paring. The response to each treatment was obvious, but the cure rate was not satisfactory for eradication efforts. Booster vaccination and hoof paring combined with medication applied topically greatly improved the response to treatment. There was little difference in response to footsoaking or footbathing when hooves were pared.

Effect of epididymitis on semen quality of rams.

To better document the detrimental effect of ram epididymitis (RE) in large range flocks, a study was conducted to determine the correlation of palpable RE lesions and semen quality. Presence of leukocytes in the semen of rams affected with RE also was evaluated and found to correlate positively with RE lesions and inversely with semen quality. Rams with palpable RE lesions usually produced semen of reduced quality; however, some affected rams did produce good quality semen. The mean scrotal circumference varied significantly when rams were analyzed by breed, but not when grouped by RE status or classified by semen quality.

Prevalence and causes of ram epididymitis in Utah.

Palpation of the testicles and epididymides was used to determine the prevalence of ram epididymitis (RE) in Utah range flocks over a 5-year period. Of 62 range flocks examined, 58 had rams with palpable lesions. A comparison was made of prevalence by right vs left testicle involvement, but no significant difference was found. Culling all rams with palpable lesions from the flock progressively reduced the annual incidence, but did not eliminate RE from any flock. Semen and specimens of reproductive tract tissue were obtained from representative flocks for bacterial culture. Brucella ovis was found commonly in range flocks, but was not isolated from RE-affected rams in virgin, ram-producing flocks. In the ram-producing flocks, a gram-negative, pleomorphic rod-type organism was found. It was concluded that RE should be considered as 2 disease entities, based on the finding of 2 causative organisms and the management systems under which those organisms are found. Brucella ovis was the major cause in persistently infected range flocks, whereas the gram-negative pleomorphic rod-type organism is the apparent cause of RE in virgin, ram-producing flocks.

Placental transfer of fluoride in Holstein cows.

Placental transfer of fluoride was studied in 40 Holstein cows and related to a previous 7 1/2 y study for comparative purposes. Animals were randomly assigned to fluoride dosage groups of control, 0.51, 1.31 or 2.66 sodium fluoride/d (10, 25, 50 or 100 ug/g feed). Each animal received the dose daily via gelatin bolus for 4-14 d prior to parturition. Maternal heparinized blood samples were collected before dosing and after parturition. Placental cotyledon and calf blood samples were collected from each animal immediately after parturition. Maternal and calf plasma and placental cotyledon fluorine concentrations were determined. Increased levels of fluoride given to pregnant cows resulted in significantly increased (p less than 0.05) maternal plasma and placental cotyledon fluorine concentrations. Calf plasma fluorine concentrations at birth did not significantly increase in relation to the fluoride treatment level of dams. The data support the concept that under normal circumstances in cattle there is a partial placental barrier to fluoride that operates to limit fluoride concentrations in the fetal circulation and tissues.