02636naa a2200241 a 450000100080000000500110000800800410001902400320006010000180009224500880011026000090019852019730020765000090218065000240218965000290221365000100224265000200225265000100227265300140228265300180229670000140231477300660232820755662017-09-14       1946    bl uuuu     u00u1 u    #d7 a10.2527/jas1946.52147x2DOI1 aMILLER, J. C.  aBody temperature and respiration rate, and their relation to adaptability in sheep.  c1946  aBody temperature and respiration rate determinations were made on six uniform breed groups of five ewes each in the summer of 1943 and on seven groups in 1944. Purebred groups consisted of Southdown, Hampshire, Merino and Rambouillet. Crossbred groups consisted of Southdown × Rambouillet, Dorset × Rambouillet and Suffolk × Rambouillet.  Determinations were made at different hours of the day from 8 a.m. to 5 p.m. on each ewe, and average values for each breed group were used for comparisons. Atmospheric temperature and relative humidity recordings were made. With few exceptions Southdown and Hampshire groups in that order showed the highest body temperature and respiration rate at all hours of the day. Rambouillet and Merino groups were quite comparable on body temperature and respiration rate, and somewhat lower than the Southdown and Hampshire groups. The crossbred groups had lower respiration rate than the purebred groups but their body temperature was quite comparable to that of the fine wool breeds (Merino and Rambouillet). Body temperature and respiration rate in purebred groups were influenced more by atmospheric temperature changes than in the crossbred groups. Suffolk × Rambouillet ewes maintained the lowest respiration rate of all groups at all times and were least affected by atmospheric temperature changes. They also maintained a relatively low body temperature which fluctuated very little with atmospheric temperature changes. Merinos showed the lowest body temperature and respiration rate, and the least daily fluctuation among purebred groups. Breeding, growth and health records of the various breed groups in the College flock are in close agreement with their efficiency of heat disposal as measured by these observations. Further investigations on a more extensive scale are necessary before generalizations can be made, but the correlation between thermo-regulatory efficiency and flock record is more than a coincidence.  aEwes  aGenetic correlation  aReproductive performance  aSheep  aBioclimatologia  aOvino  aAdaptacao  aCrossbreeding1 aMONGE, L.  tJournal of Animal Sciencegv. 5, n. 2, p. 147-153, May. 1946.