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.
Report Abuse. They should be vaccinated with distemper/parvo at 8 and 12 weeks. 16 is optional. They can get one final one at ~1.5 years of age and then every 3 years after that MAX.Distemper and parvo are the only vaccinations they absolutely need.The others (lepto, adenovirus, etc) are not strictly necessary.hey should be vaccinated with distemper/parvo at 8 and 12 weeks. 16 is optional. They can get one final one at ~1.5 years of age and then every 3 years after that MAX.