The depletion of insecticides on sheep fleece

Abstract

SUMMARY Sheep have been dipped in various concentrations of aldrin and dieldrin and the rate of loss of insecticide on the wool has been determined using a biological assay method. In one experiment with aldrin, the biological assay method was confirmed by chemical analysis. Depletion is rapid immediately following dipping for a period of 2–4 weeks, after this it is much slower. It has been shown that when dipping is carried out at the normal time, i.e. May to June, the chemical persists for a period of 3–4 months. When sheep are dipped in late July and August, however, the period of protection is much greater. The distribution of insecticide over the fleece has been examined; the area with least pick‐up of insecticide is in the tail region where the wool is coarse. Weather and rate of wool growth could not be correlated with rate of insecticide loss.

Topical Drug Delivery to Cattle and Sheep

“…Many chemicals bind strongly 'to wool (23)(24)(25)(26)(27)(28), and a similar situation must be expected with cattle hair. Thus, they can react with and change (frequently reduce) the thermodynamic activity of drugs that they contact.…”

“…Thus, they can react with and change (frequently reduce) the thermodynamic activity of drugs that they contact. Many chemicals bind strongly 'to wool (23)(24)(25)(26)(27)(28), and a similar situation must be expected with cattle hair.…”

Seasonality in wool growth under semi-arid conditions

“…Ryder & Stephenson (1968) attempted to separate genetic from environmental factors and related such factors as changes in nutrition, light and temperature rhythms as well as environment proper to the observed changes in wool growth. Breed differences were reported by Harrison & Johnson (1961), Slee & Carter (1961) and Doney (1966), thus emphasizing the existence of genetical differences. Other workers have reported seasonality in wool growth in response to seasonal changes in nutrition (Roe, Southcott & Turner 1959;Johnstone, 1955;Lyne, 1964).…”

A method for the detection and measurement of insecticide resistance in larvae of Lucilia cuprina (Wied.) (Dipt., Calliphoridae)

“…In early fly strikes, larvae of Lucilia abrade the skin and feed mainly on the exuding serum. Blood serum has therefore often been employed in larvicide tests against young larvae, with either wool or cotton wool to absorb the serum and toxicant (Hobson, 1937;Du Toit & Fiedler, 1953;Harrison & Johnson, 1961;Greenwood & Harrison, 1965;Shaw & Blackman, 1971). In Queensland this technique is used for testing third-instar larvae of L. cuprina, 48 h old (P.J.…”