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.
Calves can be weaned any time after their rumens become functional, that is, when their digestive system can process whole feeds. Bottle-fed calves can be weaned after one month of age, while calves nursing cows are weaned between 3 and 8 months of age. It is usually best to wean at the older age. For comparing weight of calves weaned at different ages, a 205-day weaning weight is sometimes calculated. This â205-day WWâ is the calf weight adjusted for birth date and weaning date, and does not infer that calves should necessarily be weaned at that age.