R. B. Herrick

Further studies on the acute and subacute toxicity of insecticides to chicks.

Abstract The acute and subacute toxicity to White Leghorn cockerels of 44 organic insecticides were studied. These included 6 phosphates, 6 phosphorothionates, 2 phosphorothiolates, 10 phosphorodithioates, a phosphorotrithioate, 3 phosphonothioates, 3 phosphonodithioates, 2 phosphonotrithioates, 9 carbamates, a carbonate, and a chlorinated hydrocarbon. Symptomology, growth, and blood plasma cholinesterase activity are presented.

Acute and subacute toxicity of apholate to the chick and Japanese quail.

Abstract The acute oral LD 50 of apholate was 246.2 (223.7–271.3) mg/kg to 11-day-old cockerels; 204.4 (176.0–237.3) mg/kg to 14-day-old male Coturnix ; and 179.0 (147.1–217.8) mg/kg to female quail. Single oral doses of apholate in both species resulted in body weight depression, testicular arrest, and leukocytopenia. Continuous administration of apholate in the feed of the chick resulted in a reduction in growth, depression of leukocyte level but no erythrocyte reduction, reduced testis and spleen size, but an essentially normal liver. Microscopic examination indicated increased numbers of immature erythrocytes in the femoral bone marrow, spermatogenic and maturation arrest and atrophy of testicular tissue, and a marked diminution of lymphoid cells in the splenic white pulp. Apholate at equivalent dosages was much more toxic in dry sugar-feed mixes than when added to the feed mix from a chloroform solution.

Acute toxicity of five insect chemosterilants, hemel, hempa, tepa, metepa, and methotrexate, for cockerels

Abstract The acute oral LD50 values in 11-day-old cockerels of the insect chemosterilants, hemel (hexamethylmelamine), hempa (hexamethylphosphoric triamide), tepa (tris(1-aziridinyl)phosphine oxide), metepa (tris(2-methyl-1-aziridinyl)phosphine oxide), and methotrexate (N-(p-(((2,4-diamino-6-pteridinyl)methyl)methylamino)benzoyl)glutamic acid), were calculated to be 341 (314–373), 835 (771–932), 151 (130–169), 329 (306–353), and >1000 mg/kg, respectively. The LD30, LD70, and LD90 values were also computed. Methotrexate at 1000 mg/kg caused no detrimental effects in the treated birds. Leukopenia was marked in birds treated with 300 mg/kg metepa and 125 mg/kg tepa. Hemel at 300 mg/kg caused a moderate leukopenia, but hempa at 600 mg/kg had little or no effect on the number of leukocytes in the blood. Testes growth and spleen size were significantly restricted by treatment. Microscopic examination indicated that hempa at 500 mg/kg was highly inhibitory to testicular development.

Subacute toxicity of apholate to the mature chicken

Abstract Apholate administered to mature chickens at varying levels in the diet from 500 to 5000 ppm produced a significant depression in reproductive performance. Fertility was completely depressed in both cocks and hens. Among males, semen volume, sperm concentration, and sperm motility were greatly depressed. Testis weight of these birds was significantly depressed, and microscopic examination of these tissues revealed degeneration of the cellular elements of the seminiferous tubules. Hens fed apholate-treated diets ceased egg production, and the gonads became highly involuted. Marked leukopenia occurred among apholate-treated males and females. Appreciable changes were not found in erythrocyte numbers except in the case of severe poisoning. Males were more sensitive to high levels of apholate in the diet than females as indicated by the severity of signs of apholate intoxication and greater mortality.