The experimental production of krimpsiekte in sheep with Tylecodon grandiflorus (Burm.f.) Toelken and some of its bufadienolides.

Six bufadienolides were isolated from Tylecodon grandiflorus ( Burm .f.) Toelken .

Krimpsiekte and acute cardiac glycoside poisoning in sheep caused by bufadienolides from the plant Kalanchoe lanceolata Forsk.

Three toxic bufadienolides , one characterized as hellibrigenin 3-acetate, have been isolated from Kalanchoe lanceolata Forsk. Typical signs of cardiac glycoside poisoning, involving the gastro-intestinal, neuromuscular and cardiovascular systems, could be induced by drenching the milled plant to sheep. Such signs could also be induced by dosing the bufadienolides to sheep or by injecting them into both guinea-pigs (subcutaneously) and sheep (intravenously).

A rapid quantitative colorimetric determination of blood acetone applied to the assessment of ketosis in fasted pregnant ewes.

A simple, accurate, colorimetric method for determining blood acetone as an adjunct to the enzymic method of estimating the other ketones was developed and tested on a group of fasted pregnant ewes. Acetone reacted with 2-hydroxybenzaldehyde to form a stable coloured complex that followed Beer's Law up to an acetone concentration of at least 4 mg/100 ml of the test solution at 490 nm. While the optimum incubation time of the reaction mixture was found to be 3 h at 40 degrees C, it could also be left to incubate overnight at room temperature.

Glucose turnover, tolerance and insulin response in wethers, ewes and pregnant ewes in the fed and fasted state.

Glucose turnover parameters were obtained in fed and fasted wethers, ewes and pregnant ewes in their 2nd and 3rd trimesters, using a jugular bolus injection of D-glucose-2-3H. Fasting significantly (P less than 0,05) reduced glucose turnover (c. 40%) in both the wether and the non-pregnant ewe.

An accurate, sensitive and reproducible method for the colorimetric estimation of free fatty acids in plasma.

A sensitive and reproducible method permitting the estimation of 0,030-3,000 mM free fatty acids (FFA) in plasma with a standard error of 0,006 5 was developed. The method is based on the extraction of phosphate-buffered plasma with a chloroform-heptane-methanol mixture, formation of the cobalt complex and on the subsequent determination of the metal with 1-nitroso-2-naphthol. The method was used to obtain normal values (mean 0,547 mM range 0,147-1,197 mM) for Merino wethers fed lucerne hay.