Ninety-six 7-month-old Hereford heifers (two replicates of 48, one year apart) were individually fed for 2 years a basal ration containing .14% phosphorus on an "as fed" basis, which approxiamted 66% NRC recommendations. Forty-eight of the animals were limited to this low phosphorus (P-) diet. The other 48 (P+) received sufficient monosodium phosphate, top dressed on the basal ration, to elevate phosphorus intake to .36% on an "as fed" basis (174% NRC recommendations). The average daily weight gain for all groups was .45 kg. Feed efficiency was similar for the two groups. There was no evidence of lack of appetite or depraved appetite in either group; nor was there a difference in age of puberty. The P-cattle had a 96% pregnancy rate with 91% live calves compared to 100% and 93%, respectively, for the P+ cattle. These differences were not significant. After 9 months on trial (approximately 16 months of age) no difference in rib bone morphology was discernable from microradiographs. Blood and serum levels of phosphorus temporarily increased in the P+ cattle, but at 16 months of age were comparable to the less fluctuating values in the P-cattle. The phosphorus levels for bone and muscle were similar each year and for each treatment. Urine and fecal phosphorus excretion was significantly higher in the P+ than in the P-cattle.
The succession of fungi colonizing untreated stakes of Pinus radiata sapwood was followed in aboveground, groundline, and belowground zones. The course and speed of the succession in these zones was influenced both by the source of infection and the moisture content of the wood. Aboveground moisture content of the stakes limited development, and colonization by airborne fungi (blue-stain fungi to molds) did not proceed to the stage where decay fungi became established. At groundline and below where the succession of organisms (primary molds to soft-rot fungi to secondary molds and basidiomycetes) was complete, moisture content was more favorable for fungal growth. The succession proceeded more slowly belowground than at groundline because of (1) higher moisture content of the wood and (2) colonization being restricted to soil-borne fungi. Relative frequencies of fungi in each zone are tabulated and discussed. Decay capability tests were made to aid in establishing the role of soft rot and basidiomycetous fungi. The basidiomycetes encountered were not those usually isolated from posts of P. radiata in an advanced state of decay. Comparative studies of the effect of temperature and pH on the growth rate of the various fungi isolated were of little value in explaining the broad bases for the successional trends. Some basic problems remaining in ecological studies of wood-inhabiting fungi are discussed.
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