A study of the fasting metabolism of various breeds of hog: III. Metabolism and surface area measurements.

Abstract

From metabolism experiments carried out on the pigs enumerated in the first paper of this series the following conclusions are drawn:(a) The metabolism in a state of inanition appears to be more a function of a power of the weight than of the true surface area as determined by the photographic method.(b) Hogs born in the summer and autumn of one year appear to show two maxima of metabolism; one almost immediately, as has been observed previously, and another during the following summer, provisionally ascribed to the effect of light on thyroid activity, produced by the intermediary action of the anterior pituitary.(c) Actual, and theoretically computed average growths are shown to agree remarkably well in the case of eleven of the pigs which were treated in an exactly similar manner. Individual growth curves showed no such agreement. This is considered to strengthen the evidence for the writer's previously stated view that nett energy is a statistical rather than a physiological constant.

The interaction between environment and level of feeding for pigs from weaning to bacon weight

“…Nevertheless, it is apparent from the literature that seasonal differences in performance do sometimes exist, but whether or not these are due to fluctuations in environmental temperature or to some other factor such as length of day is not clear. Deighton (1937), from animalcalorimeter studies, concluded that 'hogs born in the summer and autumn of one year appear to show two maxima of (resting) metabolism, one almost immediately. .…”