The popularity of gravity-return skyline logging systems is now increasing in the Western United States. Simplicity seems to be the basis for their success. While two drum yarders are most commonly used, ·some systems, such as the Wyssen, use only a single drum for yarding. Carriages commonly used with these...
At weights of 81.5-90.5 kg, 187 prepuberal crossbred gilts were
subjected to specific environmental stimuli, for up to 17 days, to
determine which stimuli or combinations of various ones would initiate
onset of estrus in prepuberal gilts. The stimuli used were:
movement to new building, mixing or non-mixing of gilts,...
Effects of inbreeding coho salmon (Oncorhynchus kisutch) on
survival during early life history, growth, feed efficiency, and
resistance to gas bubble disease were studied. No effect of inbreeding
could be associated with either F=0.25 or F=0.125. Tetraploidy
may help explain the absence of inbreeding depression at these
levels.
