Walther H. Ott

Antipyridoxine activity of 2,4-dimethyl-3-hydroxy-5-hydroxymethylpyridine in the chick.

Summary Bioassays with chicks have shown that 2,4-dimethyl-3-hydroxy-5-hydroxymethylpyridine is a very potent inhibitor of pyridoxine. Under the conditions of these experiments, two molecules of the inhibitor were sufficient to offset the vitamin activity of one molecule of pyridoxine. This ratio was found to hold for suboptimal and optimal amounts of pyridoxine given to pyridoxine-deficient chicks.

The isolotion and biological properties of a β-glucanase from B. subtilis

Abstract A purified fraction has been isolated from a crude concentrate obtained from Bacillus subtilis fermentation which was highly active as a β-glucanase in vitro . In chicks on a Washington state barley basal diet, it also produced a significant growth response when fed at a level of 0.000001% of the diet. A comparison of chick growth and β-glucanase activities over a wide range of potencies shows a correlation which indicates that both the in vitro and in vivo activities are due to a single entity. The fraction prepared by extraction, dialysis, ammonium sulfate precipitation and DEAE-cellulose chromatography showed essentially a single peak when examined by free-boundary electrophoresis at pH 6.5. Although the physical-chemical data are insufficient for us to state that the enzyme has been obtained in homogeneous form, the purest sample represents a 2600-fold purification of the β-glucanase activity from the starting concentrate.

Plasma Cholesterol Concentrations in Cockerels and Dogs Treated with Bile Acid Binding Polymer and Cholesterol Synthesis Inhibitors

Summary In normocholesterolemic cockerels the bile acid binding polymer, cholestyramine resin (MK-135), lowered plasma cholesterol concentrations when fed in the diet; the hepatic cholesterol synthesis inhibitor, benzmalecene, lowered cholesterol levels when given by injection, but not when fed in the diet. In combination, their effect was additive. In dogs, feeding of cholestyramine resin plus benzmalecene or triparanol (MER-29) had additive cholesterol-lowering effect.

Effect of Biotin Deficiency on the Course of Plasmodium lophurae Infection in Chicks.

It has generally been assumed that malnutrition decreases the resistance of the organism to malaria. The first experimental evidence to support this view is Tragers 1 , 2 recently published observation suggesting that biotin deficiency increased the severity of certain avian malaria infections. Similarly, Caldwell and György have reported that biotin deficiency will prolong Trypanosoma lewisi infections in the rat. 3 Since we had found, in experiments to be reported soon, that a deficiency in certain dietary factors which have not yet been chemically characterized has a pronounced effect on the course of Plasmodium lophurœ infections in chicks, we were interested in determining whether or not the effect of biotin deficiency on avian malaria was specific. In this communication we are reporting experiments on the relationship of biotin deficiency to the severity of P. lophurœ infections which, although the diets and experimental procedures used differed from those of Trager, confirm his findings on the specific effect of biotin. Experimental. While P. lophurœ infections are more severe in the duck than in the chick the latter species was chosen for the following experiments because much more is known about its nutritional requirements. Because of simplicity and convenience it was decided to produce biotin deficiency for this experiment by adding dried raw egg white to a commercial chick ration. In order to be certain that the addition of egg white proteins did not in itself influence the course of the malaria, a control diet was used in which steamed egg white replaced the raw egg white. To further demonstrate whether or not biotin was the specific factor involved, 0.0001% of crystalline biotin was added to the diet containing dried raw egg white. Twenty-five 9-day-old S.C.W. Leghorn male chicks were set out on each of the following diets:

Antipyridoxine activity of methoxypyridoxine in the chick.

Summary 2-Methyl-3-hydroxy-4-methoxymethyl-5-hydroxymethylpyridine (methoxypyridoxine) has been shown to have the same order of antipyridoxine activity as desoxypyridoxine in chicks. In these experiments, approximately four moles of methoxypyridoxine counteracted the vitamin activity of one mole of pyridoxine when suboptimal or optimal amounts of the vitamin were given to pyridoxine-deficient chicks.

Coccidiosis: Experimental designs involving drug mixtures

Abstract With a drug mixture of a coccidiostat, an antibiotic, and an arsenical, anticoccidial efficacy must not be impaired by the presence of the antibiotic and the arsenical. Efficacy for growth promotion and feed efficiency must be demonstrated separately and additively for the antibiotic and the arsenical in mixtures with a coccidiostat. Coefficients of variability among pens of 100 or 130 broilers per pen over a 7-year period at a research farm were about 2.5% for 8-week weight and 1.5% for feed/gain. The degree of replication required in broiler trials to demonstrate specified improvements as significant at P ⪯ 0.05 was illustrated in a graph. Under these conditions about 15 replications were estimated to be needed to validate a 2% improvement in 8-week weight or a 1.2% improvement in feed/gain.

Influence of source of cholesterol, grade of cottonseed oil, and breed on experimental avian atherosclerosis.

Conclusions 1. White Leghorns and New Hampshire chickens apparently differ in their susceptibility to aortic atherosclerosis when placed on the same atherogenic diet. 2. The atherogenic potential of a high cholesterol diet appears to be influenced by the source of cholesterol and the grade of cottonseed oil used.