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.
Lambs should be kept on the same feed before and after weaning until the stress of weaning has past (7-10 days). Feeds containing urea should not be fed for at least 2 weeks past weaning. Lambs weaned at 10 weeks of age will recognize and return to their dams after 2 months of separation. After weaning, twins will stay together for the first few days.