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.
Producers can begin preparing calves for weaning at birth. 1  Consider removing horns and castrating all male calves in commercial operations within the first two weeks of birth.  If not weaned at birth, then at least four weeks prior to weaning reduce calf and operator stress by: