A comparative study of carbofuran metabolism in treated and untreated soils

Soils which have been pretreated with carbofuran can degrade the insecticide more rapidly than untreated soils, with a consequent loss of efficacy. In laboratory studies, soils pretreated with carbofuran were found to degrade the chemical more rapidly than soils which were not so pretreated. When pretreated soils were sterilised, the rate of carbofuran degradation was much reduced, indicating that most of it was due to microbial action. Incubation of pretreated soil with [phenyl-U-¹⁴C]carbofuran led to the rapid disappearance of the parent compound (3 % left after seven days). Most of the ¹⁴C was accounted for as bound residue after seven days, whilst smaller amounts were recovered as carbon dioxide, 3-hydroxycarbofuran, 3-ketocarbofuran, and an unknown metabolite. Incubation of pretreated soil with [carbonyl-¹⁴C]carbofuran led to rapid loss of the parent compound and the recovery of 73% of ¹⁴C as carbon dioxide by five days. Most of the bound ¹⁴C (>90%) arising from [phenyl-U-¹⁴C]carbofuran treatment of pretreated soil was extracted by 1 M sodium hydroxide and about half of the extracted ¹⁴C was precipitated with ‘humic acids’ after acidification. These and other results suggest that the major metabolic route for carbofuran in pretreated soils involves hydrolysis of the ester bond leading to (1) release of carbofuran phenol which rapidly binds to soil organic matter and, (2) release of the carbonyl moiety which quickly degrades to generate carbon dioxide.     

The effect of dose and line on immunisation of cattle with lymphoblastoid cells infected with Theileria annulata

Thirty-one Friesian calves in Morocco susceptible to tropical theileriosis were protected against a lethal sporozoite challenge by prior infection with lymphoblastoid cell lines infected and transformed in vitro by a Moroccan stock of Theileria annulata. The challenge infection of cryopreserved sporozoites killed all four susceptible control calves within 20 days. Four schizont-infected cell cultures at Passage 3 were inoculated at four different doses, 10(8), 10(6), 10(4) and 10(2), into pairs of calves. The recipient animals showed great variation in severity of disease symptoms, which did not show a linear correlation with the cell dose inoculated. The most severe disease symptoms were recorded, prior to challenge, in the 10(2) cell dose recipients; one animal died of acute theileriosis and another had to be treated. One of the four cell lines used was more virulent than the other three. Two years after the completion of this experiment, immunised animals have shown normal productivity traits.     

Effects of age and of early lighting on ovarian function in breeding turkeys

1. Yellow follicle numbers and production of defective egg shells were greater in the early part of the laying period in conventionally-reared turkeys photostimulated at 24 rather than 30 weeks of age. 2. The number of yellow follicles declined with age and were similar in both groups at 40 weeks of age. 3. At 55 weeks of age more birds photostimulated at 24 weeks were out of lay and birds in lay had fewer yellow follicles and more atresia compared with turkeys photostimulated at 30 weeks of age. 4. The numbers of white follicles in the 1 to less than 2 mm size were similar in the two groups at each age. The proportion of white follicles which were atretic was negatively related to the number of yellow follicles, particularly in follicles 5 to less than 8 mm diameter.     

Colony Formation in Culture by Bovine Granulopoietic Progenitor Cells

Calf bone marrow cells cultured in a semi-solid medium of 0.8% methyl cellulose produced colonies of granulocytic cells and macrophages by seven days. A prerequisite for colony growth was the presence of serum obtained from a calf three hours after intravenous injection of endotoxin. Three morphological types of colonies were seen but cell types within these types of colonies did not differ. Cultured cells were identified by morphological and cytochemical characteristics.

Optimum growth occurred when serum from endotoxin stimulated calves and fetal calf serum were present in a volumetric ratio of 7:3. Inhibition of colony growth occurred when endotoxin-stimulated serum was present at greater than optimum concentration. Normal calf serum, fetal calf serum, mouse L-cell conditioned medium and bovine urine did not stimulate significant colony growth when 8.0 x 10⁴ marrow cells were cultured.

There was a linear relationhip between the number of marrow cells in the cultures and the number of colonies produced. Colony forming efficiency ranged from 13 to 59 colonies per 10⁵ cells plated.

The behaviour of calf colony forming units in suspension culture was similar to that reported for mouse colony forming units.