01943naa a2200193 a 450000100080000000500110000800800410001902400320006010000180009224500690011026000090017952014250018865000090161365000150162265000100163770000190164770000170166677300660168320755222017-09-13       1944    bl uuuu     u00u1 u    #d7 a10.2527/jas1944.32175x2DOI1 aBEESON, W. M.  aSome factors affecting the blood phosphorus level of range ewes.  c1944  aData are presented from a four-year study on the seasonal variation in the blood phosphorus level of range ewes. Blood samples were collected from a group of about 40 Columbia ewes at 3 to 7 different times during the year. Seasonal trends in blood phosphorus level were fairly definite and-variations between seasons were highly significant. Highest blood phosphorus levels were found on the winter and spring ranges, while lowest levels were found at lambing time, in the late summer and fall, and on the winter feed lot. Supplemental feeding of cottonseed cake or oats on the winter range or feed lot increased the phosphorus content of the blood. Blood phosphorus was lower for ewes that had lambed than for ewes that had not yet lambed. Dry ewes had higher blood phosphorus than ewes which were pregnant or were suckling lambs. Ewes with one lamb had higher blood phosphorus than ewes with two lambs. A relationship was found between gain or loss in body weight and blood phosphorus. Ewes which were losing weight tended to have higher blood phosphorus. Blood phosphorus tended to decrease with age.No definite evidence of phosphorus deficiency was found except low blood phosphorus levels. The percentage of ewes having blood phosphorus values of 3.50 mg. or below for the various seasons were 5.30 for the fall range, 2.50 for the feed lot, 20.0 at lambing, 2.7 for the spring range and 10.0 for the summer range.  aEwes  aPhosphorus  aSheep1 aTERRILL, C. E.1 aBOLIN, D. W.  tJournal of Animal Sciencegv. 3, n. 2, p. 175-182, May, 1944.