Egg Cholesterol Content Research Articles

Cholesterol content in eggs produced by hens divergently selected for body weight (Short Communication)

Abstract. In this work the cholesterol content of chicken eggs produced by two lines (high and low weight) representing the 31st generation of selection for divergent growth was studied. Divergent selection for body weight at 8 weeks of age resulted in changes in egg size and consequently in the weight of egg components. Higher values (P≤0.001) were observed in eggs from the high weight (D+) line for egg weight, albumen, yolk and shell weight. Percent yolk was greater (P≤0.001) and percent albumen was lower (P≤0.001) in eggs from the low weight (D−) line. Eggs from the D− line contained lower (P≤0.001) cholesterol content (mg/ egg, mg/g yolk, mg/g yolk dry matter) than eggs from the D+ line but when cholesterol was expressed in milligrams per gram of egg or per gram of edible egg, differences between the two lines were not significant. Divergent selection for body weight changed the albumen : yolk ratio and a change of this type affected the grams of cholesterol per gram of yolk values.

Fatty acid profile and cholesterol content of egg yolk from chickens fed diets supplemented with purslane (Portulaca oleracea L.)

The aim of the present study was to evaluate the effects of purslane on egg production, egg weight, feed efficiency, yolk fatty acid composition, and egg cholesterol content in laying hens. Sixty 80-week-old layers were allocated randomly to receive diets supplemented with 0 (control), 10 g kg(-1) or 20 g kg(-1) dried purslane for 84 days. Egg weights and egg production in the groups were recorded daily, whereas feed intake was measured weekly. Diet supplemented with 20 g kg(-1) purslane significantly decreased body weight of the chickens compared to the control. Inclusion of purslane at the level of 10 g kg(-1) or 20 g kg(-1) into the diet significantly (P < 0.05) improved egg weight compared to the control. Chickens fed the diet including 20 g kg(-1) purslane had a significantly (P < 0.05) higher egg production and improved feed efficiency compared to the control. Cholesterol content of eggs from the hens fed 0, 10 or 20 g kg(-1) did not differ and was 10.45, 9.51 or 9.51 mg g(-1) dried egg yolk, respectively. Inclusion of purslane at the level of 20 g kg(-1) into the diet significantly (P < 0.05) increased omega-3 fatty acids such as C18:3(omega-3) and C22:6(omega-3). The ratio of omega-6 to omega-3 also was significantly (P < 0.05) lower in the eggs from chickens fed 10 g kg(-1) or 20 g kg(-1) purslane supplemented diets compared to the control. This study showed that adding dried purslane to the diet of laying hens significantly increased egg production and egg weights although there was no reduction in the egg cholesterol concentration. This study also showed that inclusion of purslane into diet enriched eggs with omega-3 fatty acids and decreased the ratio of omega-6/omega-3 in the yolk.

The effect of fermentation of sludge with Neorospora sp. on the egg performances and quality of laying hens.

The purpose of this research is to produce enriched eggs (high concentration in protein, amino acid and β-karoten) but law in lipid and cholesterol content. An experiment was conducted to study the utilization of fermented palm oil sludge (LSF) using neurospora sp for layer. The present study was done based on Randomized Design in which 100 layer were distributed to five treatment group as follow: Layers were fed diet with (0, 5, 10, 15 and 20% LSF). Experimental results showed that LSF significantly (P 0.05). LSF reduced egg smell, improved taste of egg and yolk colur (P < 0.05). Protein and fat, contents of eggs were significantly reduced (P < 0.05) and cholesterol content of eggs was significantly reduced (P < 0.01). Utilization LSF increased the content of β-karoten yolk (P < 0.01), and modified the composition of amino acid in yolk. In conclusion, utilization of LSF improved egg quality, reduced egg cholesterol dan lipid and modified the composition of amino acid in yolk. Key Words: Palm Oil Sludge, Neorospora sp, Egg Quality

Effects of dietary yeast autolysate (Saccharomyces cerevisiae) on performance, egg traits, egg cholesterol content, egg yolk fatty acid composition and humoral immune response of laying hens

The objective of this study was to determine the effects of dietary yeast autolysate on performance, egg traits, egg cholesterol content, egg yolk fatty acid composition, lipid oxidation of egg yolk, some blood parameters and humoral immune response of laying hens during a 16 week period. A total of 225 Hyline Brown laying hens, 22 weeks of age, were allocated equally to one control group and four treatment groups. Yeast autolysate (Saccharomyces cerevisiae, InteWall) was used at levels of 1, 2, 3 and 4 g kg(-1) in the diets of the first, second, third and fourth treatment groups respectively. Dietary treatments did not significantly affect body weight, feed intake and egg traits. Yeast autolysate supplementation increased egg production (P < 0.001) and egg weight (P < 0.001) and improved feed efficiency (P < 0.05). Yeast autolysate at levels of 2, 3 and 4 g kg(-1) decreased egg yolk cholesterol level as mg g(-1) yolk (P < 0.01) and blood serum levels of cholesterol and triglyceride (P < 0.05) and increased antibody titres to sheep red blood cells (P < 0.01). Total saturated fatty acids and the ratio of saturated/unsaturated fatty acids increased (P < 0.01) and total monounsaturated fatty acids (P < 0.001) decreased with yeast autolysate supplementation. Dietary yeast autolysate at levels of 2, 3 and 4 g kg(-1) had beneficial effects on performance, egg cholesterol content and humoral immune response. It is concluded that 2 g kg(-1) yeast autolysate will be enough to have beneficial effects in laying hens.

Effect of Cooking Method on the Cholesterol Content of Chicken Eggs

Effect of Cooking Method on the Cholesterol Content of Chicken Eggs

Effect of plant sterol-enriched diets on plasma and egg yolk cholesterol concentrations and cholesterol metabolism in laying hens

Egg exists as a major dietary source of cholesterol in Western diets. In North America, laying hen diets are usually devoid of cholesterol when diets are formulated to exclude animal-based products. Hence, laying hens meet their physiological cholesterol requirement through de novo synthesis. Plant sterols exert a cholesterol-lowering effect in humans by interfering with intestinal sterol absorption. However, it is unknown whether plant sterol supplementation could be effective in reducing intestinal reabsorption of biliary cholesterol in laying hens, thus modulating whole body cholesterol in favor of lower plasma and yolk cholesterol content. The current study was designed to investigate the effect of diets enriched with 0, 0.5, 1, and 2% plant sterols on cholesterol absorption, synthesis, as well as plasma, liver, and egg yolk cholesterol concentrations in laying hens. After 8 wk of plant sterol intervention (first 2 wk were acclimatization), feed intake, BW, egg weight, egg yolk weight, egg production, Haugh units, liver mass, plasma, and hepatic cholesterol concentrations did not differ as a function of plant sterol supplementation. Egg cholesterol concentrations (mg/g) fluctuated during the 6-wk experimental period. At wk 6, a minor reduction in egg yolk cholesterol concentration (mg per g of yolk, P<0.05, vs. control) was observed in hens fed 1 and 2% cholesterol-enriched diets, respectively. However, such result failed to affect total egg cholesterol content. No statistical difference was observed across treatments over 6 wk. Neither cholesterol absorption rates nor synthesis differed as a function of treatment. Results suggested that overall cholesterol content in egg yolk was not affected by feeding hens plant sterol-enriched diets over 6 wk.

Effect of feeding flax and two types of antioxidants on egg production, egg quality, and lipid composition of eggs

SUMMARY The present study was conducted to investigate the effect of feeding flaxseed and 2 types of antioxidants [α-tocopherols (Toc), butylated hydroxy toluene (BHT)] at 3 levels (50, 100, and 150 IU or mg/kg) on production performance, egg quality, fatty acid profile, Toc, and egg cholesterol content. Twenty-four 1-wk-old ISA Brown Leghorn laying hens (n = 96) were kept in cages and were fed a corn- and soybean meal-based diet for 56 d: control (no flax, no antioxidant), 10% flax with no antioxidant, or 10% flax + antioxidants. The flax-based diets had no effect on egg production, egg weight, egg mass, or feed conversion (P > 0.05) when compared with the control diet. Feed intake was reduced in hens fed the flax diets (P 0.05). Lower levels of saturated fat were observed in eggs of hens fed the flax + Toc and flax + 50 mg of BHT diets when compared with hens fed the other diets (P 0.05). Inclusion of Toc led to more than 4.5- to 12-fold increases in Toc in eggs from hens fed flax-based diets. These data demonstrate that eggs with increased n-3 fatty acids and Toc can be produced by minor diet modifications without affecting egg quality parameters.

Effects of temperature and dietary sterol availability on growth and cholesterol allocation of the aquatic keystone speciesDaphnia

Enhanced water temperatures promote the occurrence of cyanobacterial blooms, which may be detrimental to aquatic herbivores. Especially, the often-dominant crustaceans could be negatively affected because cyanobacteria are deficient in phytosterols, which are required by the crustaceans to form the membrane component cholesterol, which in turn plays a role in thermal adaptation. Here, we determined the influence of temperature on growth, reproduction and the allocation of dietary sterol into somatic tissues and eggs of the keystone species Daphnia magna raised along a dietary cholesterol gradient. Mass-specific growth rates of D. magna increased with the increasing availability of dietary cholesterol up to an incipient limiting level, which increased with increasing temperature. This indicates a higher demand for cholesterol for growth at higher temperatures and may explain the consistently smaller clutch sizes of reproducing females at the highest temperature. The cholesterol content of the individuals increased with increasing dietary cholesterol; this increase was enhanced at higher temperatures, indicating a higher demand for cholesterol for tissues and probably specifically for membranes. Surprisingly, the daphnids showed different allocation strategies with regard to temperature and dietary sterol availability. The cholesterol content of eggs was enhanced at higher temperature, which suggested that females allocate more cholesterol to their offspring, presumably to ensure sufficient egg development. When dietary cholesterol was limiting, however, females did not allocate more cholesterol to their eggs. Our data suggest that during cyanobacterial blooms, a potential dietary sterol limitation of Daphnia can be intensified at higher water temperatures, which can occur with global warming.

Laying performance and egg quality of blue-shelled layers as affected by different housing systems

Blue-shelled eggs are gaining popularity as the consumption demand diversifies in some countries. This study was carried out to investigate the laying performance and egg quality of the blue-shelled egg layers as well as the effects of different housing systems on egg production and quality traits. One thousand pullets from Dongxiang blue-shelled layers were divided into 2 even groups and kept in different housing systems (outdoor vs. cage). Daily laying performance was recorded from 20 to 60 wk of age. External and internal egg quality traits were examined at 26, 34, 42, and 50 wk. Yolk cholesterol concentration and whole egg cholesterol content were measured at 40 wk of age. Average laying rate from 20 to 60 wk for the cage (54.7%) was significantly higher than that of outdoor layers (39.3%). Among all of the egg quality traits, only eggshell color was affected by housing system. Interaction between housing system and layer age was found in egg weight, eggshell color, eggshell ratio, yolk color, and yolk weight. Meanwhile, cholesterol concentration in yolk was 8.64 +/- 0.40 mg/g in the outdoor eggs, which was significantly lower than that of eggs from the cage birds (10.32 +/- 0.48 mg/g; P < 0.05). Whole egg cholesterol content in the outdoor eggs (125.23 +/- 6.32 mg/egg) was also significantly lower than that of eggs from the caged layers (158.01 +/- 8.62 mg/egg). The results demonstrated that blue-shelled layers have lower productivity in the outdoor system than in the cage system. Blue-shelled layers have lower egg weight, larger yolk proportion, and lower cholesterol content compared with commercial layers. In a proper marketing system, lower productivity could be balanced by a higher price for the better quality of blue-shelled eggs.

Effects of dietary black cumin seed (Nigella sativa L.) on performance, egg traits, egg cholesterol content and egg yolk fatty acid composition in laying hens

AbstractBACKGROUND: The objective of this study was to determine the effects of dietary black cumin seed on performance, egg traits, egg cholesterol content and egg yolk fatty acid composition in laying hens during a 12 week period. For this purpose a total of 160 Lohmann Brown laying hens 36 weeks of age were allocated to four dietary treatments with one control group and three treatment groups. Black cumin seed (Nigella sativa L.) was used at the level of 5, 10 and 15 g kg−1 in the diets of the first, second and third treatment groups, respectively.RESULTS: Dietary treatments did not significantly affect body weight, feed intake, egg production, egg quality characteristics and blood parameters. Diets containing 10 and 15 g kg−1 black cumin seed increased egg weight (P &lt; 0.01), improved feed efficiency (P &lt; 0.01) and decreased egg yolk cholesterol, saturated fatty acids (% of total fatty acid methyl esters) and the ratio of saturated to unsaturated fatty acids (P &lt; 0.05) compared to the diet of control group.CONCLUSION: Dietary black cumin seed at the level of 10 and 15 g kg−1 had beneficial effects on egg weight, feed efficiency, egg cholesterol content and egg yolk fatty acid composition. Therefore it can be used at the level of 10 and 15 g kg−1 in the diets of laying hens. Copyright © 2009 Society of Chemical Industry

The effect of dietary fat on the fatty acid composition and cholesterol content of Hy-line and Warren hen eggs

The present study analyzed the effect of dietary fat and strain on the fatty acid and cholesterol contents of eggs over a 20 month-period. Hy-line and Warren hens received three consecutive 7% lipid diets in which the basal constituents of the diet supplied 3% of the fats while the remaining 4% was composed of fats, oils or oleins added to progressively increase polyunsaturated fatty acid (PUFA) levels, while decreasing dietary levels of both saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA). In general, the percentages of most fatty acids in egg lipids were affected by changes in dietary lipids but not by the strain. Data suggest the existence of a dietary threshold for elaidic acid to appear in eggs. Mufa decreased and total PUFA increased throughout the study. The cholesterol egg content was higher at the animal fat plus soybean oil than at the animal fat or the olein plus soybean oil blend. Overall, results showed that changes in dietary lipids influenced fatty acid composition and hence atherogenic and thrombogenic indexes much more than the strain.

Single food focus dietary guidance: lessons learned from an economic analysis of egg consumption

BackgroundThere is a large body of literature evaluating the impact of various nutrients of eggs and their dietary cholesterol content on health conditions. There is also literature on the costs of each condition associated with egg consumption. The goal of the present study is to synthesize what is known about the risks and benefits of eggs and the associated costs from a societal perspective.MethodsA risk apportionment model estimated the increased risk for coronary heart disease (CHD) attributable to egg cholesterol content, the decreased risk for other conditions (age-related macular degeneration (AMD), cataract, neural tube defects, and sarcopenia) associated with egg consumption, and a literature search identified the cost of illness of each condition. The base 795 case scenario calculated the costs or savings of each condition attributable to egg cholesterol or nutrient content.ResultsGiven the costs associated with CHD and the benefits associated with the other conditions, the most likely scenario associated with eating an egg a day is savings of $2.82 billion annually with uncertainty ranging from a net cost of $756 million to net savings up to $8.50 billion.ConclusionThis study evaluating the economic impact of egg consumption suggests that public health campaigns promoting limiting egg consumption as a means to reduce CHD risk would not be cost-effective from a societal perspective when other benefits are considered. Public health intervention that focuses on a single dietary constituent, and foods that are high in that constituent, may lead to unintended consequences of removing other beneficial constituents and the net effect may not be in its totality a desirable public health outcome. As newer data become available, the model should be updated.

The effects of different levels of L-carnitine and fat on performance and egg quality of laying hens

L-carnitine is used as feed additive in poultry diets to increase yield and to improve feed efficiency. The major role of L-carnitine appears to be the transport of long-chain fatty acids into mitochondria for ƒÀ oxidation. This experiment was carried out to determine the effects of two levels of fat (10 and 30 g kg-1 DM) and two levels of L-carnitine (0 and 250 mg kg-1) on performance, egg quality, and blood parameters of laying hens in a factorial arrangement (2~2) with completely randomized design with six replicates and four laying hens in each replicate. During the experiment feed intake, egg weight, egg production, feed conversion ratio, and some blood parameters (triglyceride, cholesterol, LDL, HDL), egg quality (albumen height, egg shell thickness, egg shell breaking strength), and cholesterol content of eggs were measured. Results of this experiment indicated that supplementation of L-carnitine in laying hens diets had not significant effect on performance, cholesterol content of eggs, but decreased the levels of triglyceride, cholesterol, LDL in blood serum and increased albumen height of eggs significantly (p

The cholesterol content of eggs produced by the Slovenian autochthonous Styrian hen

The cholesterol content of eggs produced by the Slovenian autochthonous Styrian hen in comparison with eggs of the Isa Brown, reared in two different rearing systems, was determined. Eggs were collected four times during the year. The cholesterol content was determined by the enzymatic-spectrophotometric method. The influence of genotype, in two different rearing systems, on the cholesterol content in eggs was studied. The cholesterol content determined in eggs from cages was 13.1 ± 0.43 mg g −1 yolk of the Styrian hens as compared to 11.4 ± 0.49 mg g −1 yolk of Isa Brown hens. The cholesterol content determined in free range eggs was 13.6 ± 0.22 mg g −1 yolk of the Styrian hen and 11.8 ± 0.30 mg g −1 yolk of Isa Brown.

Effects of feeding fermented fish on egg cholesterol content in hens

This study was conducted to investigate the effects of feeding fermented fish (FF) to layers on laying performance, and polyunsaturated fatty acid and cholesterol levels in eggs and plasma. A total of 96, 13-week-old Babcock B380 pullets were used in this study. They were randomly assigned to four numerically equal groups with eight replicates per treatment, three birds per replicate. All the birds were housed in individual cages. The dietary treatments were: Control diet, without FF; FF3 diet containing 3% (w/w) FF, FF6 diet containing 6% (w/w) FF and FF9 diet containing 9% (w/w) FF. The study was carried out for 16 weeks inclusive of two weeks of adjustment. Weekly feed intake and egg production were recorded. Blood plasma cholesterol and fatty acid profiles were assayed at the end of the experiment. FF did not enhance (P > 0.05) egg mass but (P < 0.05) decreased egg weight slightly. However, egg yolk cholesterol and plasma cholesterol concentrations were reduced (P < 0.05) by FF. The n-6:n-3 fatty acids ratio in the egg yolk (Control = 7.9, FF9 = 6.2) and plasma (Control = 10.6, FF9 = 6.2) were decreased by feeding FF. Moreover, FF was able to increase (P < 0.05) the docosahexaenoic acid (DHA) concentrations in egg yolk and plasma. In conclusion, this study demonstrated that FF increased DHA and reduced egg yolk cholesterol in poultry eggs.

The effects of housing systems and age of hens on the weight and cholesterol concentration of the egg

The effects of laying hen age and the housing of laying hens in conventional cages, enriched cages, litter system and outdoor system on egg weight and yolk and egg cholesterol concentration were studied. ISA brown laying hens were used in the experiment. The characteristics were measured at 39, 50, 59, 68 and 75 weeks of age. Fifteen eggs were always collected from each housing system. In total, 300 eggs were analyzed. There were not any significantly different results in the eggs from the hens living in the different housing systems or from the age of laying hens on the weight of eggs. But the housing system and the age of hens had a significant (&lt;i&gt;P&lt;/i&gt; &amp;le; 0.01) effect on both yolk and egg cholesterol concentration. The concentration of yolk and egg cholesterol was the lowest (&lt;i&gt;P&lt;/i&gt; &amp;le; 0.01) in the enriched cages (12.5 mg/g yolk and 211.2 mg/egg) and the highest in the litter technology (14.1 mg/g yolk and 242.6 mg/egg). Further, there was a significant (&lt;i&gt;P&lt;/i&gt; &amp;le; 0.01) influence of the interaction between the housing system and the age of hens on egg weight and on yolk and egg cholesterol concentration.

Correlations between breeder age, egg cholesterol content, blood cholesterol level and hatchability of broiler breeders

1. The research was carried out to investigate correlations between breeder age, egg cholesterol content, blood cholesterol level and hatchability of broiler breeders. 2. Egg cholesterol content increased with increased breeder age. The mean yolk cholesterol contents (mg per g yolk) were 10·47 ± 0·28, 15·34 ± 0·65 and 15·64 ± 0·71 mg/g at 28, 45 and 65 weeks of age, respectively. 3. There were positive correlations between yolk weight and yolk cholesterol content (mg/g yolk) (r = 01·941; P < 0·01) and egg cholesterol content (mg/egg) (r = 0·980; P < 0·01). 4. Negative correlations were found between egg yolk cholesterol content and hatchability of fertile eggs (r = −0·345; P < 0·05), fertility ratio (r = −0·609; P < 0·01) and hatchability of total eggs (r = −0·574; P < 0·01). 5. The mean blood cholesterol levels were 165·1 ± 11·04, 166·5 ± 11·97 and 179·5 ± 11·33 mg/dl at 28, 45 and 65 weeks of age, respectively.

Effect of Canola Oil on Cholesterol and Fatty Acid Composition of Egg-yolk of Laying Hens

This experiment was conducted to determine the effect of a dietary Calcium Soap of Fatty Acids (CSFA) and canola oil on cholesterol and omega-3 fatty acids content of the egg. A total of 120 Hy-line white layer (24-week old) were randomly divided into four experimental treatments with six replicates (5 hens per cage) and arranged in a completely randomized design. The experimental period lasted eight weeks and during this period, the birds had free access to feed and water. Experimental diets consisted of: 1) basal diet; 2) basal diet with 1% calcium soap of fatty acids; 3) basal diet with 3% canola oil and 4) basal diet with 5% canola oil. Egg weight, egg-yolk and egg white weights, yolk and egg cholesterol concentrations, linolenic and docosahexaenoic acids (DHA) content of the yolk were measured. Egg and egg white weights were not significantly different (p>0.05) among treatments. Adding 3% canola oil and 1% CSFA had no significant effect on egg-yolk weight, but addition of 5% canola oil showed significant effect on egg-yolk weight (p 0.05). Canola oil at 3 and 5% increased the percentage of linolenic acid by 2.7 to 4.73 folds to give levels of 3.43 and 6.02 percent of total fatty acids, respectively. Canola oil increased DHA content of the egg (p<0.05). By adding 3 and 5% canola oil, the percentage of DHA increased by 8.73 and 9.8 folds compared with the control diet, respectively. Canola oil at 3 and 5% increased percentage of total omega-3 fatty acids by 3.3 and 4.75 folds (4.72 vs 6.80%) as compared with the control diet (1.43%). Based on the results it seems that adding 5% canola oil to the laying hen diet based on corn and soybean meal, can increase omega-3 fatty acids content of egg-yolk which may have beneficial roles on human health.

Lipid Profile and Fatty Acid Composition of Two Silurid Fish Eggs

The lipid content and the composition pattern of the lipid class including fatty acid composition in the eggs of two different Indian silurid cat fishes Ompok pabda and Wallagu attu have been examined. The lipid content of O. pabda and W. attu (on dry basis) are about 14.7% and 17.8% respectively. The major lipid classes are phospolipid (PL) and triacylglycerol (TAG). The O. pabda egg lipid contains more PL while the W. attu egg lipid contains more TAG. Phosphatidylcholine (PC) constitutes the major phospholipid followed by phosphatidylinositol (PI). PI represents in about 31.7% and 21.3% of total PC in O. pabda and W. attu respectively while phosphatidylethanolamine (PE) (about 28.0%) is significantly higher in the egg of W. attu than O. pabda (9.6%). Cholesterol content in egg of O. pabda is also higher (about 9.6%) than W. attu (4.1%). The lipids are rich in polyunsaturated fatty acids (PUFAs) and they are mainly concentrated in the respective PL fractions. Among PUFAs the arachidonic acid (20:4 n-6 AA) is present at about 9.3% in both egg PL. Eicosapentaenoic acid (20:5 n-3 EPA) is significantly lower in egg lipids of both W. attu (1.8%) and O. pabda (3.2%), whereas docosahexaenoic acid (22:6 n-3 DHA) is predominantly higher (14.6% and 18.1% in W. attu and O. pabda respectively) in their PL fractions.

Reducing shell egg cholesterol content. I. Overview, genetic approaches, and nutritional strategies

In laying hens, cholesterol is primarily biosynthesized in the liver and incorporated into vitellogenin (VTG) and triglyceride-rich very low density lipoprotein (VLDL) particles, which are secreted into the bloodstream and subsequently taken up by growing oocytes via receptor-mediated endocytosis. VLDL and VTG are then intracellularly transformed into yolk, constituting ∼60% and 24% of yolk dry matter and ∼95% and 5% of yolk cholesterol, respectively. During the past four decades, research efforts directed toward reducing shell egg cholesterol content have centred on genetic selection or alteration of the laying hens' diet with various nutrients, natural products, non-nutritive factors, or pharmacological agents. The present paper will provide a justification for low-cholesterol egg production, primarily in the context of the heterogeneity of response to dietary cholesterol in humans, and will review cholesterol metabolism in the laying hen, avian embryonic cholesterol needs, and genetic and nutritional approaches to chicken egg cholesterol reduction. A subsequent paper will provide a comprehensive overview of the use of non-nutritive dietary factors and select pharmaceuticals as egg cholesterol-lowering agents, and will discuss emerging strategies for lowering the cholesterol content of shell eggs.