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Biomedical subjects

D L Frape

Publications and source records attributed to D L Frape.

28 records · Page 2Linked to original sources
PubMed1982

The use of inert markers in the measurement of the digestibility of cubed concentrates and of hay given in several proportions to the pony, horse and white rhinoceros (Diceros simus).

1. The rate of passage of chromic oxide (Cr) was similar in the pony and rhinoceros. 2. Higher apparent amounts digested were found using 4N-HCl-insoluble ash (AIA) than those determined by Cr, but overall digestibilities were similar for the two species. 3. An abrupt increase in the starch content of the horse diets increased the number of faecal ciliate protozoa. Only when the overall feed intake was increased in horses receiving a high dietary proportion of starch were the numbers depressed. 4. When the rhinoceros received 109 kJ apparent DE per kg bodyweight daily (716 kJ/W0.75 daily) it maintained normal condition.

Animal Feed↗
PubMed1982

The effects of gum arabic, wheat offal and various of its fractions on the metabolism of 14C-labelled aflatoxin B1 in the male weanling rat.

1. Male weanling rats were given for extended periods diets containing gum arabic or wheat offal or various offal fractions. The fractions included two lipid fractions, a water-soluble extract and a modified-acid-detergent (MAD)-fibre extract. The diets contained either low concentrations of aflatoxin B1 (induced rats) or were free from this source of aflatoxin (non-induced rats). The distribution of 14C was then studied after the rats received 14C-labelled aflatoxin B1 in their feed. Blood plasma concentrations of triglycerides, and total cholesterol were also measured. 2. Gum arabic and wheat offal accelerated the rate of passage of 14C through the small intestine and wheat offal very considerably decreased retention time in the large intestine. Both fibre sources increased faecal bulk. However, only wheat offal decreased liver and urinary accumulation of 14C and the effect could be explained entirely by the MAD-fibre fraction of wheat offal. 3. The possible induction of either microsomal enzymes unrelated to the production of mutagenic aflatoxin metabolites, or of extramicrosomal enzymes is discussed; but it is concluded that the main effect brought about by wheat offal on the toxicity and carcinogenicity of aflatoxin can be attributed to a direct influence of the MAD fibre fraction of wheat offal on the intestinal absorption of aflatoxin B1. 4. The relevance of these conclusions to drug safety studies is discussed, because comparable studies may yield differing results, despite a use of diets having the same nutrient composition but differing ingredient composition.

Aflatoxin B1↗
PubMed1981

The effect of dietary fibre sources on aflatoxicosis in the weanling male rat.

1. Two experiments with male weanling rats were conducted in which they received individually and restrictedly either a basal semi-purified diet containing starch as the principal carbohydrate or the same diet to which mixed aflatoxins were added in quantities providing from 0.13 to 0.4 mg aflatoxin B1/kg diet. Various natural ingredients, or semi-purified sources of dietary fibre were substituted for a portion of the starch in the basal diet containing aflatoxin. The diets were fed for 13-14 weeks after which the rats were given ad lib. a commercial rodent diet until they were killed at 109 weeks of age. 2. Two further experiments were conducted in which twenty-four rats in each experiment received the basal diet plus aflatoxin, or diets in which a portion of the starch was replaced by gum arabic or by wheat offal. After 13 or more weeks the absorption, retention and excretion of 14C-labelled aflatoxin B1 was measured in each rat. 3. The addition of gum arabic or wheat bran to the diet decreased the effects of the toxin in the first two experiments, but as measured by several characteristics, only wheat bran provided an effect which persisted during the period when neither it nor the toxin was given. The effects included an apparent reduction in tumour incidence. The change in the content of starch in the basal diet, occurring as a consequence of adding the test ingredients is also considered to be an associated cause of the effects observed. 4. In comparison to starch, wheat offal increased the total 14C in the faeces and the proportion of the total found during the first 48 h after dosing. Rats receiving starch excreted more 14C in their urine and retained more 14C in their livers. The differences between gum arabic and starch were not significant as measured by 14C excretion and retention. Liver size as a proportion of carcass weight was less in rats receiving wheat offal or gum arabic, and rats receiving wheat offal had a lower incidence of fat-loaded hepatocytes. 5. The interaction of dietary toxins, or drugs, with the ingredient composition of diet may affect animal response even when the diets are adequate and similar in nutrient composition. This may be of significance both in drug-safety studies and in animal production.

Aflatoxin B1↗
PubMed1980

The effects of long-term feeding of soya flour on the rat pancreas.

Rats were fed raw and heated soya flour for up to 2 years. The rats fed raw soya flour all developed pancreatic hypertrophy and hyperplastic and adenomatous nodules. Four of 26 rats fed raw soya flour continuously and 1 of 5 rats fed raw soya flour for 2 days each week developed pancreatic cancer. Preheating the soya flour seemed to protect against the pancreatic hyperplastic and neoplastic changes.

Adenoma↗
PubMed1975

Recent research into the nutrition of the horse.

The majority of recent experiments in equine nutrition relates to the metabolism of protein, non-protein nitrogen, carbohydrate, calcium and phosphorus. An understanding of the significance of the nitrogen cycle is emerging in which there is a two-way movement of compounds across the wall of the G.I. tract. Some quantitative estimates of the role of microflora in this process have been made for comparison with similar processes in ruminants. However, the pathway by which the microflora contributes to the nitrogen economy and the extent to which this occurs is not established in the horse. It is well established that both glucose and volatile fatty acids are common substrates in tissue metabolism; but in contrast to evidence in the ruminant the ratio of starch to fibre in the diet does not affect the efficiency fo fibre digestibility. This, and similar observations, are explicable in terms of the anatomy of the G.I. tract of the horse. There is a scarcity of information on the secretion of digestive enzymes by the horse and on the relationship between intestinal function and certain digestive upsets. Furthermore, there is an urgent need for accurate clinical evidence for the significance of calcium and phosphorus nutrition to the development of leg abnormalities in horses. The irrelevance, for diagnosing purposes, of estimates of serum Ca and P is concluded, especially where no other relevant information is available. Haematological procedures, of diagnostic value in this respect, are available for use at least in controlled clinical conditions.

Amino Acids↗