In geography and fluvial geomorphology, a thalweg or talweg (/ËtÉËlvÉÉ¡/) is the line of lowest elevation within a valley or watercourse. Under international law, thalwegs can acquire special significance because disputed river borders are often deemed to run along the river's thalweg. 1 Etymology.
However, when they are 3 to 4 months old, they become susceptible to the disease, so all calves should be vaccinated for blackleg by 4 months of age. A revaccination 3 to 6 weeks later according to product label directions is necessary to provide the best protec-tion.lackleg seldom affects cattle older than 2 years of age, most likely due to immunity induced by vaccines or natural exposure. However, sporadic cases do occur in cattle older than 2 years and are often associated with the reuse of needles for multiple injections.
Kids born to does with uncertain vaccination history or with questionable colostrum ingestion within the first 24 hours of birth should be vaccinated at 7 to 21 days of age and then given a booster three to four weeks later. Alternately, tetanus antitoxin (150 - 250 units) can be given at birth or at castration. Breeding bucks, yearlings and other adults should get annual boosters 30 days prior to the breeding season or when others in the herd are given booster vaccines.