Effect of animal and vegetable fats and proteins on distribution of cholesterol in plasma and organs of young growing pigs.

Young, growing pigs were fed for 8 wk diets containing either soy protein isolate or ground beef as the main protein source and soybean oil or beef tallow as the main fat source to examine effects of types of dietary protein and fat on cholesterol distribution between blood plasma, plasma lipoproteins and body organs. Type of dietary protein did not influence concentrations of a) cholesterol in plasma, b) low-density-lipoprotein (LDL) cholesterol, c) high-density-lipoprotein (HDL) cholesterol or d) cholesterol in several organs of pigs. Pigs fed tallow had greater concentrations of plasma cholesterol and LDL and HDL cholesterol than did pigs fed soybean oil. Ratios of HDL to LDL were not altered by dietary fat. Cholesterol concentrations were greater in heart, skeletal muscle and viscera of pigs fed soybean oil than in those fed tallow. Plasma cholesterol varied reciprocally with cholesterol in several tissues. Thus, dietary beef and soy protein isolate had similar effects on cholesterol concentrations in plasma, LDL, HDL and organs, whether pigs consumed soybean oil or beef tallow as a major fat source. Soybean oil, however, exerted a hypocholesterolemic effect, irrespective of major source of dietary protein.

Effects of dietary calcium, vitamin D3, and corn supplementation on growth performance and mineral metabolism in young goats fed whole milk diets.

Twenty-four male goats, approximately 2 to 4 wk of age, were allotted to four dietary treatments in a 2 X 2 factorial design and were fed a basal milk diet at 12.5% body weight for 20 wk. Vitamin D3 was added to the milk in two different amounts with and without supplemental CaCO3. At the end of wk 7, corn was added to all diets at 1% body weight. Over 20 wk, average daily gain was unaltered by addition of Ca or vitamin D3 to the diet. When corn was added to the diet, gains increased from 48 to 180 g/d. Plasma Ca concentrations were not affected by dietary treatment. Supplemental Ca decreased plasma Mg concentrations. Corn supplementation curtailed a depression in plasma Mg and seemed to prevent a whole milk-induced hypomagnesemia. Fecal excretion of all minerals measured was increased in goats fed supplemental Ca. Dietary Ca increased urinary Ca but decreased urinary Mg. Percentage of apparent absorption of Ca, Mg, and total ash was lower in Ca-supplemented goats, as was apparent retention of Ca and Mg. The physiological responses reported suggest the goat as a potential research model for mineral metabolism studies in other ruminants.

Vitamin D3 and D3 metabolites in young goats fed varying amounts of calcium and vitamin D3.

Twenty-four male goats, 2 to 4 wk of age, were allotted to four dietary treatments in a 2 X 2 factorial design and, for 20 wk, were fed a milk diet at 12.5% body weight. Treatments varied in amounts of supplemental calcium and vitamin D3. Daily allowances per kilogram body weight were: 9.4 IU vitamin D3 (basal), 9.4 IU vitamin D3 plus 406 mg calcium carbonate (basal plus Ca), 940 IU vitamin D3 (basal plus D3), and 940 IU vitamin D3 plus 406 mg calcium carbonate (basal plus Ca plus D3). At the end of wk 7, a corn supplement was added to all diets at 1% body weight daily. Addition of vitamin D3 to the diet resulted in a dramatic increase in plasma concentrations of vitamin D3. Goats in the basal plus D3 and basal plus Ca plus D3 groups had nearly 100 X greater concentrations of vitamin D3 than goats in the basal and basal plus Ca groups. When greater amounts of vitamin D3 were fed, dietary calcium interacted to decrease plasma vitamin D3 concentrations. Plasma concentrations of 25-hydroxyvitamin D3 were unaffected by additional dietary calcium but were increased by dietary vitamin D3, increasing sixfold to seven-fold in the basal plus D3 and basal plus Ca plus D3 groups. Supplemental calcium resulted in decreased plasma 1,25-dihydroxyvitamin D3. No signs of vitamin D toxicity were noted. The physiological responses reported implicate the goat as a potential animal model for vitamin D research in dairy cattle.

Dietary calcium and vitamin D: risk factors in the development of atherosclerosis in young goats.

Effects of supplemental dietary calcium and vitamin D on lipid distribution and aortic mineralization were examined in young goats. Twenty-four goats, 2-4 wk of age, were allotted one of four dietary treatments for a 20-wk period and fed a basal milk diet (Basal), a calcium-supplemented diet (Basal + Ca), a cholecalciferol-enriched diet (Basal + D3) or a diet with both calcium and cholecalciferol (Basal + Ca + D3). Goats in the Basal + Ca group had plasma cholesterol concentrations that were 16.6% of those of the Basal group. Percentage absorption and fecal excretion of total lipids were unaffected by dietary treatment. Generally, total lipid and cholesterol concentrations were unaltered in liver, other viscera and carcass tissues. Dietary cholecalciferol increased concentrations of cholesterol and total lipid in aortas, whereas dietary calcium decreased total lipids in aortas. Concentrations of calcium, magnesium and total ash were increased in aortas by dietary treatment, with a marked increase observed in the Basal + Ca + D3 group. Sudan IV and gross calcium staining in aortas revealed both lipid and mineral deposition that confirmed composition data. A high intake of vitamin D accompanied by excessive intake of calcium seems to accelerate the development of atherosclerosis. Supplemental calcium with normal amounts of vitamin D, however, is hypocholesterolemic and seems protective against the atherogenic process.

Effects of dietary calcium and fat on cholesterol in tissues and feces of young goats.

To examine the effects of amount of calcium and type of fat in the diet on distribution of cholesterol in plasma, several tissues and feces, 4-week-old goats (6 females and 18 males) were fed isocaloric diets consisting of goat milk supplemented with cholesterol and 1) soybean oil, 2) tallow, 3) soybean oil and CaCO3 or 4) tallow and CaCO3 for 20 weeks. Plasma cholesterol increased initially in all animals; plasma and lipoprotein cholesterol concentrations, however, were not affected by dietary fat or calcium. Goats fed CaCO3 excreted more calcium and ash in their feces and had greater cholesterol and fat concentrations in their livers. Neutral steroid, but not bile acid, excretion was greater in soybean oil-fed goats than in goats fed tallow. Soybean oil-fed goats had greater cholesterol concentrations in the viscera (minus liver) and tended to have greater cholesterol concentrations in the carcass and whole body. Aortas of soybean oil-fed goats exhibited greater fat deposition. In summary, dietary fat, but not calcium, significantly altered cholesterol disposition in young goats by affecting cholesterol deposition in tissues and excretion in feces, without a concomitant change in plasma cholesterol.

Vitamin A inhibits some aspects of systemic disease due to local x-radiation.

We have previously reported that supplemental vitamin A ameliorates the stress response to a wide variety of noxious agents. The present study was carried out to determine how supplemental vitamin A influences the course of radiation sickness in C3H female mice subjected to 3000 R irradiation of one lower hind limb. All mice ingested a chow diet containing about 13,000 units of vitamin A/kg diet (about half as preformed vitamin A and half as beta-carotene) which supports normal growth, development, and reproduction of normal mice. One hundred fifty thousand units of vitamin A/kg chow was added for the vitamin A supplemented mice. All mice ate and drank ad libitum. The supplemental vitamin A feeding was begun either 3 days before radiation or immediately after radiation. There were no significant differences in the effects of these two regimens. The supplemental vitamin A prevented the weight loss, moderated the adrenal hypertrophy, prevented the thymic involution, and lessened the lymphopenia due to radiation. We conclude that supplemental vitamin A has both prophylactic and therapeutic benefits in radiation-induced disease.

The effects of supplemental dietary cholesterol and exercise on blood cholesterol and atherosclerosis in the goat.

The objective of this experiment was to determine the effects of supplemental dietary cholesterol and treadmill exercise on blood plasma cholesterol and development of atherosclerosis in young goats. Eighteen two-week-old goats, assigned to four groups for 22 weeks, were fed 100 g whole milk and, after 14 weeks, 50 g corn and cob meal daily/kg body weight. The four groups received, respectively, 250, 175, 100 and 25 mg cholesterol/kg body weight daily in the milk. From week 10 to week 22 of the experiment half of the goats in each group were exercised on a motorized treadmill at a rate of 6.4 km/h for 15 min daily, five days per week. Addition of cholesterol to the diet increased the mean plasma cholesterol in each of the four groups, but between-group comparisons were statistically significant for only the 250-mg group versus the 25-mg group. Exercise had no effect on plasma cholesterol. Analysis of serial blood samples of 16 of the goats during one day of the experiment indicated no significant diurnal variations. Six males, three exercised and three nonexercised, were sacrificed; all had extensive aortic sudanophilia. Histological preparations from sudanophilic areas of all aortas showed areas of intimal thickening composed of foam cells. These same areas stained strongly for lipid with Oil Red 0. No histological evidence of calcium deposition or fibrous plaques was found.