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.
RESEARCH RESULTS An important reason for weaning calves early is to allow the cow to build body reserves for the winter. Cows nursing calves that were weaned late gained 66 pounds between July 15 and September 15 (Table 1), but their gain was 31 pounds less than that of cows from which calves were already weaned.