The retina is a light-sensitive tissue at the back of the eye and is crucial for vision. As RP progresses, the field of vision narrows, a condition known as tunnel vision until only central vision (the ability to see straight ahead) remains. Many people with Usher syndrome also have severe balance problems.
Calves can be ready for weaning by 3 to 4 weeks of age; however, in Penn State studies calves weaned at 3 weeks required extra attention. The increased time and labor required to get these calves eating starter suggest that waiting until 4 weeks of age would be prudent.
How long should you wean a calf for before placing it back on the same pasture with its pregnant mother? The weaning will be done the end of November or the first of December. Calves that have been weaned at about 500 pounds (6 to 7 months of age) will resume nursing their dams after having been separated for several weeks. Several years ago, we did some research in an attempt to reduce milk production in cows by temporarily separating weaning-age calves (7 months old) from their dams.