The effect of adding cholesterol to laying hen diets as powder or predissolved in fat.

An experiment was conducted to determine if adding supplemental cholesterol to the feed or first adding it to the supplemental fat source of laying hen diets would result in differences in egg yolk and liver cholesterol levels. Five levels of cholesterol (0, .5, 1, 2, and 4%) and three levels of animal tallow (0, 4, and 8%) were used. The diets were randomly assigned and fed for 35 days to individually caged hens within each of six replicates. Eggs laid on or near Days 0, 7, 14, 21, 28, and 35 were used for cholesterol analysis. Liver cholesterol, egg production, and feed intake were also assessed. Mixing cholesterol with the fat source before feed incorporation did not promote higher yolk or liver cholesterol levels and were essentially the same as the method in which powdered cholesterol was added directly to the feed. A linear increase in yolk and liver cholesterol was observed with 0, .5, and 1% dietary cholesterol. Yolk cholesterol also increased linearly during the first 14 days of cholesterol administration. Further increases in yolk cholesterol, however, were not obtained with either the higher levels of dietary cholesterol or the extended feeding times.

Response of broiler chickens to addition of bacitracin methylene disalicylate and roxarsone to diets containing halofuginone.

Studies were conducted at six locations over a 7-yr period to evaluate the response of broiler chickens to bacitracin methylene disalicylate (BMD) and roxarsone in the presence of diets containing 3 ppm halofuginone/kg feed. Treatments consisted of a 2 x 2 factorial arrangement with 0 or 55 mg BMD and 0 or 50 mg roxarsone/kg feed. These additives were fed beginning with day-old chicks and were removed 6 days before termination of the study, which varied in length from 48 to 56 days among locations. Body weights were significantly improved (P less than .05) by the addition of either BMD or roxarsone with a significant interaction (P less than .05) between BMD and roxarsone. Roxarsone improved body weights only in the presence of BMD. Feed utilization was significantly (P less than .05) improved by addition of either BMD or roxarsone, with no interaction between the two products.

Production performance of White Leghorn layers fed lactobacillus fermentation products.

A series of trials was conducted to determine if adding a Lactobacillus fermentation product (LAC) to the feed of laying hens would improve their production performance. Feeding a liquid, nonviable LAC product to either cage or floor housed laying hens did not improve hen-day egg production, feed efficiency, nor egg size during a 48 week experimental period. Laying hens fed a dried, nonviable LAC product did not show any improvement in hen-day egg production nor feed efficiency compared with laying hens fed no LAC or zinc bacitracin. Addition of a viable LAC product to ratios of differing protein levels did not improve hen-day egg production, livability, or egg size of laying hens.

Influence of probucol ((4,4'-isopropylidine dithio)-bis(2,6-di-t-butyl-phenol)) on egg yolk cholesterol content and performance of laying hens.

Addition of the hypocholesteremic agent Probucol ((4,4'-isopropylidine dithio)-bis(2,6-di-t-butyl-phenol)) to the diet of laying hens at up to 1% significantly reduced egg yolk cholesterol content (mg/g yolk) without impairment of rate of egg production, egg weight, shell strength, albumen quality, or other production related parameters. Dietary concentration of .1% Probucol significantly reduced yolk cholesterol within 2 weeks after feeding. Higher concentrations did not further reduce yolk cholesterol. Probucol at .025% reduced egg yolk cholesterol within 4 weeks after feeding, but after 8 weeks of feeding, eggs from hens fed .025% Probucol did not differ significantly in yolk cholesterol from those fed the basal unsupplemented diet. This suggests possible adaptation in cholesterol synthesis by the laying hen.

Enhanced incidence of leg abnormalities in reovirus WVU 2937-infected chickens fed various dietary levels of selected vitamins.

Five experiments were conducted to evaluate the incidence of leg abnormalities of 4-, 6-, and 8-week-old reovirus WVU 2937-infected and uninfected chickens fed diets containing 20%, 100%, or 200% of the 1977 National Research Council nutrient requirements (NRC-77) of poultry for manganese, biotin, niacin, choline, or folic acid. Reovirus infection significantly elevated the incidence of leg abnormalities in the biotin-, niacin-, and folic-acid-deficient chickens and decreased the incidence of leg abnormalities in choline-deficient chickens. Reovirus-infected male chickens had a significantly greater incidence of leg abnormalities than reovirus-infected female chickens in the biotin, niacin, and folic acid studies. No sex differences in the incidence of leg abnormalities were observed in uninfected chickens. The incidence of leg abnormalities decreased with increasing dietary levels of biotin, niacin, choline, or folic acid in all chickens except reovirus-infected male chickens in the biotin study. In the manganese study, neither reovirus infection nor dietary level had any effect on the incidence of leg abnormalities in male or female chickens.

Severity of tenosynovitis in reovirus-infected chickens fed various dietary levels of choline, folic acid, manganese, biotin, or niacin.

Five experiments were conducted to determine the incidence and severity of tenosynovitis in tendons distal to the tarsal joint in 4-, 6-, and 8-week-old reovirus WVU 2937-infected chickens fed diets containing 20%, 100%, or 200% of the 1977 National Research Council nutrient requirements (NCR-77) of manganese, biotin, niacin, choline, or folic acid. Male chickens, but not female chickens, fed 20% or 100% or the NRC-77 level of folic acid had consistently higher lesion scores of tenosynovitis than male chickens fed the 200% NRC-77 level of folic acid. Increasing dietary manganese levels from 20% to 200% NRC-77 reduced the severity of tendon swelling in 6- and 8-week-old male chickens and appeared to increase the severity of tendon swelling in 8-week-old female chickens. Male chickens fed 20% of the NRC-77 required level of biotin had numerically more severe tenosynovitis at 6 weeks of age and significantly more severe tenosynovitis at 8 weeks of age than male chickens fed 100% and 200% of the NRC-77 level of biotin. Increasing dietary choline levels from 20% to 200% of the NCR-77 required level increased the severity of tenosynovitis numerically at 6 weeks of age and significantly at 8 weeks of age. When data were pooled across diet, male chickens had significantly more severe tenosynovitis than female chickens at 4, 6, and 8 weeks of age in the choline experiment and at 4 and 6 weeks of age in the folic acid experiment. Differences in the severity of tenosynovitis of individual treatment means (sex X diet X infection interaction means) occurred at only the 20% or 100% NRC-77 level of choline or folic acid. Male chickens also had more severe tenosynovitis than female chickens when fed 20% of the NRC-77 required level of manganese for 6 or 8 weeks.

Production performance of white Leghorn layers limited fed.

Three trials were conducted to determine if the age at start of limited feeding or the amount of time laying hens were given to consume feed could be used to reduce feed intake without affecting egg weight (EW) or egg production. The age at start of limiting feed did not affect hen-day egg production (HDEP) or EW in any trial. In Trial 2, a significant difference in HDEP due to feeding times at 26 weeks of age was observed. Laying hens fed 7 hr/day at 26 weeks of age had a significantly lower HDEP than any other feeding time. Limited feeding in Trials 1 and 2 significantly decreased feed consumption, body weight gain (WG), and EW when compared with laying hens fed ad libitum. No difference in HDEP or EW was observed due to limited feeding in Trial 3. Laying hens fed 9 or 10 hr/day gained significantly less weight than laying hens fed ad libitum (Trial 3). Limited feeding did not improve feed efficiency in any trial. No consistent improvement in mortality could be attributed to limited feeding.

The effect of constant ambient temperature and ration on the performance of sexed broilers.

Two trials involving 480 Cobb color-sexed broiler chicks were conducted to determine the effect of various constant ambient temperatures on the performance of broilers. Temperatures in Trial 1 were 18 and 29 C and in Trial 2 were 24 and 35 C. The interacting effect of dietary energy (3.142 or 3.252 kcal ME/g of diet) and protein (16, 19, or 22%) on performance criteria was also examined within each trial. There was no indication of selective consumption of any of the ratios at any temperature. Differences in feed consumption observed in either trial were totally contributed by temperature effect. Within a trial, and irrespective of temperature treatment, the rate of growth and feed consumption of the females were less than that of the males. Males and females responded equally to the ambient temperature; there was no significant sex X temperature interaction in Trials 1 or 2.

Effects of blood sampling by cardiac puncture on subsequent body weights of broilers.

The effects of blood sampling via cardiac puncture in broiler chicks 2 to 4 weeks of age on subsequent body weights were examined in three experiments. No differences were found in chicks bled or stabbed with 18, 22, or 25-gauge needles when compared to chicks not blood sampled. However, male chicks bled at both 2 and 3 weeks of age with a 25-gauge needle demonstrated elevated body weights at 8 weeks of age when compared to chicks not blood sampled.

Diet and exercise in middle-aged men.

Effects of an anaerobic exercise program on serum lipids and lipoproteins in sedentary male subjects were studied for 12 weeks. No dietary changes were made, and individuals were encouraged to maintain their body weight. Increase in lean body weight, decrease in percent body fat, and unchanged total body weight occurred in subjects participating in the resistive weight training program, while the men's serum cholesterol and low-density lipoprotein-cholesterol decreased and their high-density lipoprotein-cholesterol increased. Lipid profile improvements were attributed to exercise.

Total serum cholesterol and urinary dehydroepiandrosterone in humans.

The relationship between urinary excretion of dehydroepiandrosterone (DHEA) and total serum cholesterol was evaluated in an epidemiological study of coronary risk factors. The results of this study show statistically significant negative correlation (r = -0.238; P -0.014) between the urinary excretion of DHEA (mg/g creatinine) and total serum cholesterol. Total serum cholesterol (r = 0.278) and to a lesser extent. DHEA (R = 0.021) were found to be correlated with age. However, it was determined that the correlation between serum cholesterol and urinary DHEA was not attributable to the effect of age, since the partial correlation coefficient between serum cholesterol and urinary DHEA adjusted for age (r = 0.240) was found to be statistically significant (P less than 0.05). Negative but non-significant correlations were also found between urinary excretion of DHEA and many of the accepted risk factors for coronary heart disease.

Effect of exercise on lipid metabolism of rats fed high carbohydrate diets.

Two experiments were conducted to determine whether high carbohydrate diets or exercise would have a greater influence on certain parameters of lipid metabolism. Male Fischer rats were used in both experiments, separated into exercise and sedentary groups, and fed either a high sucrose (63%) or a high starch (63%) diet. There were no differences in body weight or food consumption between the two diets. Exercise resulted in a highly significant increase in food consumption in both experiments. Rats fed sucrose had a higher serum cholesterol value than rats fed starch. Diet did not influence serum triglycerides but the rats on excercise had significantly lower serum triglycerides than the sedentary rats. Liver weight was significantly larger in rats fed sucrose. Sucrose caused an increase in the activity of both glucose-6-phosphate dehydrogenase and malic enzyme activities in liver tissue, whereas exercise caused an increase in the activity of these enzymes in adipose tissue.

Metabolic effects of exercise. I. Effect of exercise on serum lipids and lipogenesis in rats.

To evaluate the metabolic effects of exercise, three groups of exercised male rats were compared to their sedentary controls at the end of 10 wk of voluntary exercise in rodent activity cages. Exercises rats consumed more food than sedentary rats but had greater weight gain only at the higher levels of activity. Exercised rats had significanlty lower serum triglycerides and higher values of adipose tissue alpha-glycerophosphate dehydrogenase activity. At higher levels of physical activity, the exercised rats enhibited larger adrenal glands and lower values of hepatic glucose-6-phosphate dehydrogenase. It is concluded that specific levels of voluntary exercise are needed to achieve specific metabolic effects.

Metabolic effects of exercise. II. Residual metabolic effects of exercise in rats.

This report described the duration of changes in serum lipids, adrenal weight and hepatic G-6-PD activity in rats following the termination of 10 weeks of voluntary activity in a revolving drum. Exercised rats had lower weight gain, larger adrenal glands, lower serum cholesterol, lower serum triglycerides and lower liver glucose-6-phosphate dehydrogenase (G-6-PD) activity than the sedentary controls. The differences between exercise and control rats in adrenal gland weight, body weight and G-6-PD tend to disappear within 3 wk after termination of the exercise. These experiments provide evidence that exercise can affect lipid metabolism and have a beneficial effect on the lowering of serum lipids. It also shows that this effect will persist for up to 3 wk after the exercise is terminated, under the experimental conditions of this study.