Letter to the Editor Dietary Factors Affecting Rats Used in Aging Research: A Reply

An experiment was carried out with kid goats of the Granadina breed to identify the dietary factors affecting voluntary feed intake of the kid goat and those that additively could determine its body composition. The animals used were from birth to 61 d of age, fed ad lib. on different milk replacers containing 200, 240 and 280 g crude protein/kg DM and 200, 240 and 280 g fat/kg DM, thus giving nine dietary treatments. The utilization of the milk replacers and the animals' body composition were determined by balance and slaughter trials. There were significant positive effects of protein concentration of the milk replacers on component digestibilities, energy metabolizability, feed intake, empty-body weights, empty-body composition and protein and fat retention. The concentration of fat in the milk replacers also had a significant positive effect on the digestible and metabolizable energy concentration of the diets and on fat retention. The relationships existing between feed intake and diet composition (concentration of digestible protein, metabolizable energy and digestible protein:metabolizable energy ratio) as well as between empty-body composition or protein and fat retention and diet composition, were examined. From these it was deduced that feed intake was significantly influenced by the digestible protein concentration of the diets. The higher the digestible protein concentration the higher the feed intake up to a maximum digestible protein concentration value. As the digestible protein concentration of the diets was the dietary factor which significantly influenced feed intake, this also significantly influenced the body composition and the protein and fat retention. The protein concentration of the feed at which metabolizable energy intake in these animals would be greatest was estimated to be 347 g/kg DM.

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Dietary Factors Affecting Experimental Models of Nutritional Encephalomalacia

Poultry Science ◽

10.3382/ps.0610084 ◽

1982 ◽

Vol 61 (1) ◽

pp. 84-93 ◽

Cited By ~ 2

Author(s):

YOSEF DROR ◽

IDO BARTOV

Keyword(s):

Experimental Models ◽

Dietary Factors ◽

Factors Affecting

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OBSERVATIONS ON PROTEIN DIGESTION IN VIVO: II. DIETARY FACTORS AFFECTING THE RATE OF DISAPPEARANCE OF CASEIN FROM THE GASTROINTESTINAL TRACT

Canadian Journal of Biochemistry and Physiology ◽

10.1139/o59-167 ◽

1959 ◽

Vol 37 (12) ◽

pp. 1475-1491 ◽

Cited By ~ 14

Author(s):

Carl Peraino ◽

Quinton R. Rogers ◽

Minoru Yoshida ◽

Mou-Liang Chen ◽

Alfred E. Harper

Keyword(s):

Gastrointestinal Tract ◽

Food Intake ◽

Dietary Factors ◽

Protein Digestion ◽

Dietary Carbohydrate ◽

Factors Affecting ◽

Single Meal ◽

Protein Free Diet ◽

Stomach Emptying

The effects of various dietary changes on the emptying of solids and nitrogen from the stomach and on the disappearance of nitrogen from the gastrointestinal tract of rats trained to consume a single meal daily are described. When the animals were fed 5 g of food the presence of casein in the diet caused a general deceleration of stomach-emptying and altered the shape of the stomach-emptying curve. The presence of 50% of casein in the diet did not result in an accumulation of nitrogen in the intestine much above the amount found when a protein-free diet was fed. When dextrin was the dietary carbohydrate the diet emptied from the stomach as a homogeneous mixture, whereas when sucrose was the dietary carbohydrate the casein emptied from the stomach more slowly than did the other components of the diet. Raising the dietary level of fat to 50% caused a general deceleration of emptying and abolished the above-mentioned carbohydrate effect. No delay in stomach-emptying due to the presence of casein in the diet was noted when only 1.5 g of diet was fed. As the level of food intake was raised the total quantity of nitrogen emptying from the stomach per unit time increased although a greater percentage of the amount ingested emptied from the stomach when the level of food intake was low.

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Effects of Dietary Taurocholate, Fat and Protein on the Storage and Metabolism of Dietary beta-Carotene and alpha-Tocopherol in Ferrets

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831.75.2.133 ◽

2005 ◽

Vol 75 (2) ◽

pp. 133-141 ◽

Cited By ~ 5

Author(s):

Sundaresan ◽

Marmillot ◽

Liu ◽

Mitchell ◽

Grundel ◽

...

Keyword(s):

Plasma Concentrations ◽

Beta Carotene ◽

Retinyl Palmitate ◽

Dietary Factors ◽

Alpha Tocopherol ◽

Tissue Storage ◽

Factors Affecting ◽

Fat Diets ◽

High Protein Diets ◽

Protein Diets

Dietary factors affecting tissue storage of beta-carotene (BC), alpha-tocopherol (alpha-T), and retinol (ROL) in mammals include taurocholate, protein, and fat. Few studies have examined the effects of these factors on the storage of BC, retinyl esters, and alpha-T in a mammalian system that is similar to humans. The main objective of the study was to investigate the effects of taurocholate (TC), fat, and protein on the absorption and metabolism of BC and alpha-T in ferret tissues. Three 4-week experiments were conducted using groups of 5–6 ferrets per treatment. All diets contained 0.2% BC. In Experiment 1, taurocholate was fed at concentrations of 0, 0.5, or 1%. Effects of two concentrations of dietary fat (6 and 23%) and three concentrations of protein (10, 20, and 40%) were also studied in Experiments 2 and 3, respectively. Tissues were analyzed for BC, retinoids, and alpha-T by high-pressure liquid chromatography (HPLC). Taurocholate enhanced hepatic and plasma concentrations of BC (2.3- to 3-fold), retinyl palmitate [(RP) 3.2- to 9.5-fold], retinyl stearate [(RS) 2.9- to 6- fold], and hepatic alpha-T (6- to13- fold) at p < 0.05. High-fat diets elevated hepatic BC, RP, RS, and retinyl linoleate (RL) concentrations (2- to 3.6-fold, p < 0.05). In contrast, high-protein diets lowered hepatic RL 1.8-fold and alpha-T 8-fold (p < 0.05). Our results indicate the importance of taurocholate, fat, and protein in achieving adequate levels of vitamins A and E in mammals.

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