摘要:

Phosphorus utilization in four laying hens has been studied by means of radiophosphorus (P32), which was incorporated into the laying mash as tricalcium phosphate replacing the bone meal in the diet. The results obtained indicate that, for these four hens:1. The phosphorus that was absorbed appeared in the yolk, white, and shell within 24 hr. after feeding.2. The maximum recovery of P32following a single feeding was within 24 hr. in the case of the shell, 48 to 72 hr. for the white, and 144 hr. (six days) for the yolk.3. A large portion of the unabsorbed phosphorus was excreted within 24 hr. of feeding.4. A considerable quantity of the phosphorus absorbed by the digestive system was found to be stored in the tibiae at least 40 days after feeding.5. The percentage uptake of phosphorus from tricalcium phosphate rose gradually in the egg and became relatively constant in about 14 to 15 days after the first feeding of tricalcium phosphate.

ISSN:1923-4287    

DOI:10.1139/cjr48d-012

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

The general toxicity of 127 synthetic organic compounds was tested against larvae ofMusca domestica,Tribolium confusum, andEphestia kuehniella, and adults ofSitophilus granarius. The compounds were mixed in the insects' food in graded concentrations, and their toxicity was assessed by determination of the median lethal concentrations (LC50) for each of the four species. The most highly toxic compounds were gammexane (the gamma isomer of hexachlorocyclohexane) and chlordane (obtained by distillation of technical chlordane). The toxicity of DDT was on the average one-half of that of the first two compounds, and it was superior to any of the 12 analogues tested. Four chlorinated aliphatic hydrocarbons, namely hexachloropropene, hexachlorobutadiene, and thesymm-and asymm-heptachloropropanes, showed a high toxicity related to their powerful fumigant action. A high level of toxicity was shown by benzyl thiocyanate and its chlorinated derivatives. The nitro compounds dinitro-o-cresol, nitrostyrene, dinitrodimethylbutane and dinitrocyclohexylphenol were especially toxic toSitophilusadults, but were ineffective againstMuscalarvae. Certain aromatic semicarbazones recommended by previous workers gave disappointing results. Of 22 derivatives of morpholine tested, only three showed any degree of toxicity to the four species of insects employed.

ISSN:1923-4287    

DOI:10.1139/cjr48d-013

出版商:NRC Research Press    

年代:1948

数据来源: NRC

摘要:

The direct contact toxicity of 91 synthetic organic compounds was tested against nymphs ofBlatella germanicaand ofOncopeltis fasciatus, and adults ofTribolium confusum. The compounds were dissolved in graded concentrations in benzene–kerosene mixture and sprayed on the insects in a spraying tower. Their toxicity was assessed by determination of the median lethal deposits (LD50) for each of the three species.Taking the results with the three species as a whole, the highest contact toxicity was shown by gammexane and chlordane. Dinitro-o-cresol and dinitrocyclohexylphenol were next in order of effectiveness. These were followed by benzyl thiocyanate and itso- andp-chloro and 2,4-dichloro derivatives. DDT was sixth and methoxy-DDT was 12th on the list of compounds in order of their average effectiveness to the three species. A number of chlorinated aliphatic compounds that were strong fumigants showed no contact toxicity.

ISSN:1923-4287    

DOI:10.1139/cjr48d-014

出版商:NRC Research Press    

年代:1948

数据来源: NRC