Effects of chronic ingestion of south Louisiana crude oil on mallard ducklings.

South Louisiana crude oil was fed to duckling mallards (Anas platyrhynchos) in concentrations of 0.025, 0.25, 2.5, and 5.0% of the diet from hatching to 8 weeks of age to assess the effects of chronic oil ingestion during early development. Growth was depressed in birds receiving a diet containing 5% oil but there was no oil-related mortality. Diets containing 0.25, 2.5, and 5.0% oil impaired avoidance behavior of 6-day-old mallard ducklings when compared with controls or ducklings fed 0.025% oil, but had no effect on open-field behavior of 7-day-old ducklings. Liver hypertrophy and splenic atrophy were gross evidence of the pathological effects of oil in birds on the 2.5 and 5.0% oil diets. Biochemical lesions that occurred included elevation of plasma alanine aminotransferase and ornithine carbamyl transferase activity. Hepatocyte hypertrophy and bile duct proliferation in the liver were noted in birds fed the 2.5 and 5.0% oil diets and tubular inflammation and degeneration in the kidney were noted in birds fed the 5.0% oil diet.     

Effect of dietary tung oil on the growth and lipid metabolism of laying hens

The influence of dietary tung oil, containing a high level of alpha-eleostearic acid (cis-9, trans-11, trans-13-octadecatrienoic acid, EA) on growth, egg production, and lipid and fatty acid compositions in tissues and egg yolks of laying hens was studied in White Leghorn hens. Forty-week-old hens were divided into three groups of eight birds each and fed diets containing 0, 0.5, or 1.0% tung oil for 6 wk. The average body weight, feed consumption, rate of egg production, and weights of eggs and yolks were not affected. The weight of adipose tissue was remarkably small in hens fed tung oil, whereas the yolk lipid content did not change. Triglyceride level in heart and adipose tissue decreased in hens fed tung oil, and the level of linolenic acid (C18:3) in all tissues was decreased. Alpha-EA was not almost deposited in the tissues and egg yolk of hens fed tung oil, but conjugated linoleic acid (CLA) was detected in all tissues and egg yolks. The level of CLA in the tissues was significantly higher with increased dietary tung oil. The order of CLA level in tissue lipids was adipose tissue>liver>heart>breast muscle. Especially, the level of CLA in the lipids of adipose tissue and egg yolks of hens fed 1.0% tung oil was 2.0% of the total fatty acid. These results supposed that dietary tung oil affected the lipid metabolism of laying hens and could modify the lipid and fatty acid composition in tissues and eggs.     

The ability of laying hens to regulate phosphorus intake when offered two feeds containing different levels of phosphorus

The ability of laying hens to adjust their intake of available P (AP) was investigated with a maize-soyabean diet fed to forty-eight individually caged birds in a 2 x 4 factorial experiment. From 19 to 25 weeks of age (phase 1) twenty-four birds were fed a normal-P (NP) diet (2.2 g AP/kg DM) and twenty-four were fed a low-P (LP) diet (1.1 g AP/kg). LP eggs were lighter (51 v. 54 (SEM 1.0) g; P<0.05), providing evidence that the LP diet was deficient in AP. From 25 to 28 weeks of age six hens from each phase 1 treatment were fed either the NP or LP diet alone or a choice of the LP and NP feeds or a choice of the LP feed and a phytase-supplemented (PP) feed (LP diet with 400 microbial phytase units/kg). With a choice of the NP and LP feeds, the hens fed the LP diet in phase 1 ate a smaller proportion of the LP feed (34 (SEM 12.0) %) than the hens fed the NP diet in phase 1 (72 (SEM 12.0) %; P<0.05), showing that P deficiency influenced subsequent selection for AP, i.e. an appetite for P was demonstrated. In those birds offered the LP and PP feeds, the presence of phytase in one of the two feeds significantly alleviated the effect of P deficiency on egg and body weights. The proportion of the LP diet chosen was not significantly affected by phase 1 treatment; it was not necessary for the hens to eat more than 50 % of PP feed.     

Eggshell thinning in ring doves exposed top,p′-dicofol

Ring doves (Streptopelia risoria) were brought into breeding condition and, after laying two clutches of two eggs each, were fed one of three experimental diets containing either 33.4 ppm dicofol (1, 1-bis(p-chlorophenyl)-2,2,2-trichioroethanol), 37 ppmp,pi DDE (2,2-bis (p-chlorophenyl)-1,1 dichloroethylene), or no toxicant (control). Mean shell thicknesses of eggs produced on experimental diets were: control, 156 x; DDE, 145 ; and dicofol 142 . Birds fed DDE produced eggs with shells a mean 5.6% thinner than pre-treatment eggs, while birds fed dicofol produced eggs with shell means 7.2% thinner. No change in shell thickness was found in eggs from control doves. Analysis of covariance revealed a statistically significant effect of decreasing eggshell thickness over time in doves fed DDE and dicofol diets but not in control birds. Egg production was significantly lower in both dicofol-fed and DDE-fed birds when compared with controls. Control birds produced a mean of 1.97 eggs per clutch. Dicofol- and DDE-treated birds produced 1.88 and 1.79 eggs per clutch, respectively. The proportion of eggs found cracked or broken in the nest was greatest in birds fed dicofol, with 16.9% of all eggs broken or cracked, compared to 7.9% of eggs from the DDE group and 5.7% of eggs from control group. Selected eggs were analyzed for residues of dicofol, dichlorobenzophenone (DCBP), and DDE in the yolk. For the birds fed the dicofol diet, DDE residues in treatment eggs ranged from 0.036 to 0.119 ppm wet weight. DDE residues in pre-treatment eggs ranged from 0.013 to 0.080 ppm. Dicofol residues ranged from 2.62 ppm to 22.58 ppm. DCBP residues ranged from 2.55 to 17.68 ppm. Only residues of dicofol showed a significant correlation with percent shell thinning.     

Shell thinning and reproductive impairment in black ducks after cessation of DDE dosage

Captive black ducks (anas rubripes) were fed dietary DDE [1,1-dichloro-2,2-bis (p-chlorophenyl)ethylene] at 10 ppm (dry weight; about 2 ppm on a natural diet basis) for 2 breeding seasons, then untreated feed for 2 succeeding years. Residues of DDE in the carcasses of adults declined 90% during the 2-year clean-up period. Following 2 years of dietary DDE, mean residues in eggs reached 64.9 ppm. Even after 2 years on clean feed, DDE residues in the eggs averaged 6.2 ppm or 9.5% of the mean DDE level reached after 2 years on treated feed. Shells of eggs from treated hens were about 20% thinner than shells of eggs from controls. Stoppage of DDE dosage resulted in progressively thicker shells, yet even after 2 years on untreated feed hens laid eggs with shells about 10% thinner than control hens. After DDE was removed from the diet, DDE residues in the eggs decreased, shell thickness increased, and reproductive success improved. Hens previously exposed to DDE, but then fed clean feed for 2 years, still produced significantly fewer surviving ducklings than did control hens.     

不同类型多不饱和脂肪酸对产蛋鸡免疫功能及肝脏脂质过氧化的影响

目的 :　研究不同类型多不饱和脂肪酸 (PUFA)对产蛋鸡体液免疫功能、淋巴细胞前列腺素 E2 合成及机体脂质过氧化的影响。方法 :　 360只 60 w龄的海兰褐产蛋鸡随机分为 1 0个处理组 ,各组试验日粮为 :对照组 (不添加油脂 ) ;鱼油三个添加水平 (1 %、3%、5% ) ;胡麻油三个添加水平 (2 %、4%、6% ) ;玉米油三个添加水平 (2 %、4%、6% )。结果 :　添加不饱和油脂均可以提高血清抗体效价 ,其中鱼油和胡麻油添加组与对照组相比差异显著 (P<0 .0 5) ;添加玉米油组的血清溶菌酶含量显著低于其它油脂添加组和对照组 (P<0 .0 1 ) ;添加鱼油和胡麻油组的外周血淋巴细胞 PGE2 的合成量显著低于添加玉米油组 (P<0 .0 5) ;不同水平多不饱和脂肪酸的添加影响了肝脏组织脂质过氧化分解产物丙二醛 (MDA)的含量 ,随着不饱和油脂添加量的提高 ,MDA含量呈上升的趋势 ,但是 6%玉米油组显著低于鱼油 5%添加组 (P<0 .0 5)。结论 :　在本试验条件下 ,产蛋鸡日粮中添加不同类型的多不饱和脂肪酸可以影响动物的免疫反应和肝组织脂质过氧化作用     

Effects of methylmercury on approach and avoidance behavior of mallard ducklings

Summary Mallard ducks were fed a control diet or a diet containing 0.5 or 3 ppm mercury (as methylmercury dicyandiamide) based on the dry feed. These mercury diets are approximately equivalent to 0.1 and 0.6 ppm mercury in a natural succulent diet. I measured for the ducklings the approach behavior in response to a tape-recorded maternal call and the avoidance of a frightening stimulus.There were no significant differences among controls and ducklings from mercury-treated parents in the percentage of ducklings that approached the tape-recorded call. Control ducklings, however, moved back and forth toward the call more than ducklings from mercury-treated parents and also spent more time in the end of the runway near the loudspeaker than ducklings whose parents were fed a diet containing 0.5 ppm mercury.Compared to control ducklings, ducklings from parents fed a diet containing 0.5 or 3 ppm mercury were hyper-responsive in the test of avoidance of a frightening stimulus.Mallard eggs collected in the wild have been found to contain levels of mercury exceeding the 1 ppm (wet-weight) found in the eggs of hens fed a diet containing 0.5 ppm, but there are no reports of mallard eggs collected in the wild that were found to contain as much mercury (6 to 9 ppm) as eggs from hens fed a diet containing 3 ppm mercury. On a dry-weight basis, the concentration of mercury in the eggs was about 6 times as great as that in the feed for ducks fed the 0.5 ppm mercury diet and about 6 to 9 times as great for ducks fed the 3 ppm mercury diet.     

Hormonal responses to protein restriction in two strains of chickens with different growth characteristics

The hormonal response to protein restriction was studied in breeds of chickens with different rates of growth and body size. Fast-growing (broiler) chicks and lighter-weight (White Leghorn) birds were fed isoenergetic 5% (low) and 20% (control) protein diets ad libitum starting at 2 wk of age. At 4 wk of age, one-half of each group continued receiving the initial diet, while the other half was fed the alternate diet for two additional weeks. Growth was decreased in birds fed the low protein diet due to restriction of protein, sustained low feed intake and hence possibly insufficient energy for growth. Birds fed low protein diets had higher plasma growth hormone (GH) concentrations (325% in Leghorns and 233% in broilers) compared with controls. Plasma concentrations of somatomedin-C in protein-restricted Leghorn and broiler chicks were only 50 and 34% of those of controls, respectively. Similarly plasma concentrations of thyroxine (T4) and triiodothyronine (T3) were reduced in protein-deprived birds compared with those fed adequate protein. Plasma T3 concentrations of restricted birds were 48 (Leghorns) and 47% (broilers) of those of controls, whereas plasma T4 concentrations were 44 (Leghorns) and 41% (broilers) of those of controls.     

Olive oil prevents the adverse effects of dietary conjugated linoleic acid on chick hatchability and egg quality

Dietary conjugated linoleic acid (CLA) decreases yolk 18:1(n-9), induces chick embryonic mortality and alters egg quality. A study was conducted to determine whether olive oil would prevent these adverse effects of CLA. Hens (15 per treatment) were fed diets containing 0.5 g corn oil/100 g (CO), 0.5 g CLA/100 g (CLA), 0.5 g corn oil plus 10 g olive oil/100 g (CO + OO) or 0.5 g CLA plus 10 g olive oil/100 g (CLA + OO). After 74 d of feeding, hens were placed on CO for 10 d. Hens were artificially inseminated weekly. For hatchability studies, fertile eggs were collected daily, stored at 15 degrees C for 24 h and then incubated. After 6 d of feeding, embryonic mortality rates were 15, 100, 8 and 16% in the CO, CLA, CO + OO and CLA + OO groups, respectively. When CLA-fed hens were fed the CO diet, hatchability improved to that of the CO group within 7 d. For fatty acid analysis, three eggs were obtained at the 7 d of feeding. Relative CLA levels of yolk from CO-, CLA-, CO + OO- and CLA + OO-fed hens were 0.11 +/- 0.01, 1.91 +/- 0.16, 0.08 +/- 0.04 and 0.69 +/- 0.07 g/100 g fatty acids, respectively. The ratios of 16:0/16:1(n-7) and 18:0/18:1(n-9) of yolk from CLA-fed hens were approximately 1- and approximately 1.5-fold greater, respectively, compared with those fed CO. OO prevented CLA-induced increases in 16:0 and 18:0 and the decrease in 18:1(n-9) in yolk. Fertile eggs were stored at 4 degrees C for 2 or 10 wk and analyzed for pH or mineral levels. Dietary CLA caused abnormal pH changes of albumen and yolk when eggs were stored at 4 degrees C. The pH of yolk and albumen from CO-fed hens after 10 wk of storage was 6.12 +/- 0.12 and 9.06 +/- 0.03, respectively, versus 7.89 +/- 0.25 and 8.32 +/- 0.16, respectively, in eggs from CLA-fed hens. OO prevented CLA-induced abnormal changes in the pH of albumen and yolks. Eggs from CLA-fed hens had greater iron, calcium and zinc concentrations and lower magnesium, sodium and chloride concentrations in albumen relative to those from hens fed CO. OO prevented CLA-induced mineral exchange between yolk and albumen, presumably by reducing the yolk saturated fatty acids, which are believed to disrupt the vitelline membrane during cold storage. This study suggests that the adverse effects of CLA may be due to the increased level of saturated fatty acids. However, because the addition of olive oil also lowered egg CLA content, the direct role of egg CLA on egg hatchability and quality cannot be ruled out.     

Dietary protein concentration regulates the mRNA expression of chicken hepatic malic enzyme

Chicken hepatic malic enzyme activity varies with dietary protein content. The mechanisms responsible for this alteration in activity are unclear. In a series of four experiments, broiler chicks were allowed free access for 1.5, 3, 6 or 24 h to a low (13 g/100 g diet), basal (22 g/100 g diet) or high (40 g/100 g diet) protein diet. The diets were isocaloric and had equal concentrations of dietary fat. Hepatic malic enzyme mRNA expression and enzyme activity as well as total liver lipid concentration were examined for each experimental duration. There were no differences in the expression of the mRNA for malic enzyme at 1.5 h, but at 3, 6 and 24 h, malic enzyme mRNA expression was significantly (P < 0.05) reduced in chicks fed the high protein diet and significantly enhanced in chicks fed the low protein diet compared with chicks fed the basal diet. Hepatic malic enzyme activities and total lipid concentration were not different among the chicks fed the different diets at 1.5 and 3 h. At 6 and 24 h, malic enzyme activity and total liver lipid concentration were both significantly greater in birds fed the low protein diet compared with levels in the birds fed the other two diets. In birds fed the high protein diet, malic enzyme activity and total liver lipid concentration were significantly reduced at 24 h compared with birds fed the basal diet. In a final experiment, the observed differences in malic enzyme mRNA expression at 6 h were confirmed when chicks were given access to isocaloric diets with the same protein levels as the initial 4 experiments, but with the dietary concentration of carbohydrate held constant. The results suggest that previously observed alterations in the activity of malic enzyme, which were correlated with dietary protein intake, are due to rapid changes in the mRNA expression of this enzyme.     

Effects of dicofol on mallard eggshell quality

Dicofol is an organochlorine acaricide structurally similar to DDE and there is concern that it may effect avian reproduction. Effects of dietary dicofol on mallard (Anas platyrhynchos) egg production and eggshell quality were evaluated; the mallard is moderately sensitive to DDE shellthinning toxicity. Hens in egg production were fed either 0, 3, 10, 30, or 100 g/g dicofol for 42 days (the formulation of dicofol contained <0.1% DDT-related impurities). A positive control study was also conducted in which mallard hens in egg production were fed 0, 3, 10, and 100 g/g DDE for 42 days. Egg weight, shell thickness, shell strength, and dried shell weight were measured for all eggs produced. Egg production was not affected by dicofol diets but the percentages of cracked and soft-shelled eggs from birds on the 100 g/g dicofol diet were significantly (p < 0.05) greater. Shell strength, thickness, and weight were negatively related to dicofol dietary concentrations. Shell quality was reduced after one day of treatment with some dicofol diets. Effects of similar character and magnitude were observed in eggs from positive control birds fed DDE.Mention of trade names or commercial products does not constitute endorsement or recommendation for use.     

富含EPA浓缩鱼油抑制血小板聚集的机理探讨

流行病学和实验室资料均提示富含EPA鱼油(简称鱼油)具有抑制血小板聚集和抗血栓形成的作用。本文主要探讨鱼油抑制血小板聚集的机理。实验分别将大鼠和家兔随机分成4组:正常组、高脂组、鱼油组、橄榄油组。按各自不同饲料喂养3个月以后,4组大鼠血浆TXB_2/6-酮-PGF_(1a)比值分别为1.4,2.2,1.0,1.7。鱼油组血小板内cAMP含量明显高于高脂组(P<0.05)。鱼油组血清总胆固醇值、血浆TXB_2、5-羟色胺(5-HT)、钙离子浓度、纤维蛋白原含量及血液粘度(低切)均明显低于高脂组(P<0.05)。鱼油组血浆、血小板、心肌及肝脏中EPA、DHA含量明显高于其它3组(P<0.001)。以上结果提示,鱼油抑制血小板聚集和血栓形成的机理可能是,鱼油中的EPA和DHA等高不饱和脂肪酸纳入细胞膜后竞争抑制花生四烯酸(AA)代谢,减少血小板TXA_2生成和释放,降低血中TXA_2/PGI_2比值,同时增加血小板内cAMP含量,稳定血小板功能,减少5-HT,钙离子等具有促聚活性物质释放。另外,鱼油降低血脂、血浆纤维蛋白原含量及血液粘度,从而改善血液流变性,使血小板本身及其周围环境得以改善,防止血小板聚集和血栓形成。     

Cholesterol-lowering in hamsters fed rice bran at various levels, defatted rice bran and rice bran oil.

This study was conducted to determine the relative cholesterol-lowering effects of several levels of full-fat rice bran in hamsters. In addition, the separate effects of defatted rice bran and/or crude rice bran oil were investigated at levels equivalent to those present in 43.7% full-fat rice bran. Diets containing 10.9, 21.8, 32.8 or 43.7% full-fat rice bran, 35% defatted rice bran and/or 9% rice bran oil were fed to 4-wk-old male hamsters. All diets contained 10% total dietary fiber, 9% fat and 3.2% nitrogen; hypercholesterolemic diets contained 0.3% cholesterol; two diets were cholesterol-free, i.e., 10% cellulose and 43.7% full-fat rice bran. After 21 d, plasma and liver cholesterol, plasma triglycerides and liver weights were significantly greater in hamsters fed the 10% cellulose diet with 0.3% cholesterol compared with those fed the cholesterol-free cellulose diet. In animals fed cholesterol-free diets, plasma cholesterol values were significantly lower in those fed the 43.7% full-fat rice bran diet than in those fed the cellulose diet. In animals fed cholesterol-containing diets, plasma and liver cholesterol were significantly lower in animals fed the 43.7% full-fat rice bran diet than in those fed the cellulose diet. Plasma cholesterol reductions were significantly correlated to the level of rice bran in the diet. In cholesterol-fed hamsters, total liver cholesterol content was significantly lower in those fed the defatted rice bran diet with rice bran oil compared with those fed the cellulose diet. Full-fat rice bran was the only treatment that significantly lowered both plasma and liver cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hepatic lipid metabolism in domestic fowl as influenced by dietary cereal

The influence of dietary cereal on hepatic lipid metabolism was studied in adult Japanese quail and mature female chickens fed isoenergetic and isonitrogenous corn-soy and wheat-soy diets ad libitum. Hepatic lipid accumulation and rate of biosynthesis were significantly higher in birds fed the corn-soy diet. The differential response to the cereals was seen in ovipositing females but not in mature male quail. There were no significant concomitant changes in body composition, egg production, egg weight, body weight, feed, and energy intake. Results of sequential changes in hepatic lipid metabolism showed that reduction in liver fat was significant 2 to 3 weeks after feeding the wheat diet and was due to a significant reduction in rate of lipogenesis and the amount of triacylglycerols deposited. Plasma levels of free fatty acids and glucose were not significantly altered by the dietary regimes in laying hens. In Japanese quail fed the corn-soy diet, plasma glucose was elevated and there was evidence of impaired glucose tolerance. In vitro rate of oxidation of labeled palmitate was significantly higher in liver homogenates from birds fed the corn-soy diet. Addition of carnitine to the incubation mixtures resulted in an increase of equivalent magnitude for both treatments. Liver hemorrhages were observed in laying hens but not in Japanese quail. Addition of myo-inositol to the corn diet for Japanese quail failed to significantly alter hepatic lipid accumulation. These studies show that differences in liver lipid accumulation due to corn and wheat diets are related to changes in rate of lipogenesis.     

Evidence for a critical period during late gestation when maternal dietary carbohydrate is essential for survival of newborn rats

Two experiments were designed to test the hypotheses that 1) maternal dietary carbohydrate is required on d 20-21 of gestation (gd 20-21), when fetal liver glycogen is accumulating, to ensure the postnatal survival of the newborn rat pup and that 2) the lack of maternal dietary carbohydrate during this critical 2-d period will cause high neonatal mortality. Pregnant dams were fed one of two lipid-based, carbohydrate-restricted experimental diets. In experiment 1, the primary energy source was soybean oil; the diets contained no added glucose but contained 4% glucose-equivalents as lipid-glycerol. In experiment 2, the major lipid component was food-grade oleic acid; this diet was supplemented with 4% glucose. A crossover design was used. For gd 0-19, dams were fed either the high carbohydrate diet (62% glucose) or one of the carbohydrate-restricted diets (4% glucose or 4% lipid-glycerol); beginning on gd 19 and through neonatal d 7 (nd 7), the opposite diet was fed. For controls in each experiment, a high carbohydrate diet (62% glucose) and the respective carbohydrate-restricted diets were fed throughout pregnancy. The results showed that restriction to 4% glucose equivalents beginning on gd 20 resulted in high first-day neonatal mortality that was comparable in magnitude to nd-1 mortality rates in dams fed the carbohydrate-restricted diets throughout pregnancy. Repletion with the high carbohydrate, control diet after gd 19 significantly reduced mortality. These experiments demonstrate that maternal dietary carbohydrate beginning in late gestation is essential for the postnatal survival of rat pups.     

Identification of volatile sulfur derivatives released from feathers of chicks fed diets with various levels of sulfur-containing amino acids

Physical changes are observed in the feathers of chickens fed diets with high levels of methionine or cysteine. Chicks were fed diets chemically analyzed to contain 21% crude protein, 0.35% methionine and 0.37% cystine (basal) supplemented with DL-methionine [0.063 (control), 0.25 or 1.45%] or L-cysteine (0.203%). At 3 wk of age, the birds were weighed and the feathers scored for softness. Feather strength (i.e., force-displacement curves) was determined on feathers from the pectoral tract. A significant (P less than 0.05) reduction in body weight and an increase in feather softness were seen when chicks fed the control diet and those fed the diet with 1.45% added methionine were compared. Chicks fed the diet supplemented with 0.203% L-cysteine produced the strongest feathers; those fed diets supplemented with 1.45% DL-methionine produced the weakest feathers. Volatile sulfur compounds released from the feathers were trapped as dinitrophenyl (DNP) thioethers and were analyzed by thin-layer chromatography, high pressure liquid chromatography and mass spectrometry. More bound sulfide (P less than 0.05) was recovered from feathers of chickens fed the diet supplemented with 1.45% methionine than from feathers of chickens fed the other diets. The feather softness score was correlated (r = 0.5; P less than 0.05) with bound sulfide. Thus, consumption of a diet with a level of methionine that is approximately three times the requirement resulted in decreased growth, elevated sulfide bound to the feathers and soft, weak feathers.     

The effect of dietary cholesterol level on lipid status and initiation of atherosclerosis in Japanese quail

The effect of variations in dietary cholesterol level on the development of hyperlipidemia, tissue cholesterol status and incidence of atherosclerosis was investigated in male Japanese quail of strain SEA (Susceptible to Experimental Atherosclerosis). Groups of 12, five-week-old, birds were fed one of four purified diets. The basal diet contained (weight %): soyprotein, 35; beef tallow, 10; glucose, 46; three atherogenic diets were prepared by replacing glucose with 0.25, 0.5 and 1.0% cholesterol in the basal diet formula. After 4 weeks, birds were killed and serum, thoracic aortae, brachiocephalic arteries, and liver were taken for analysis. Serum cholesterol was increased (relative to basal values) by 15, 127 and 229% for birds fed the 0.25, 0.5 and 1.0% cholesterol diets respectively; increases were due to elevations of cholesterol in the very low density lipoprotein (VLDL) and low density lipoprotein (LDL) fractions. Hepatic and arterial cholesterol levels increased with increasing dietary cholesterol levels, but there were significant, between-group differences in the case of liver cholesterol only. Lesion incidence was 0, 8, 43 and 50% for birds fed the basal, 0.25, 0.50 and 1.0% cholesterol diets respectively. The small dot-like, yellow lesions were found predominantly in the right brachiocephalic artery and to a lesser extent in the thoracic aorta; no lesions were found in the left brachiocephalic artery. The extreme rapidity with which Japanese quail of strain SEA develop early atherosclerotic lesions makes them an attractive animal model for studying the early development of atherosclerosis in man.     

Effects of quantity and unsaturation of dietary fat on serum components in normal and diabetic Macaca nigra.

Dietary fat affects serum lipids independently of dietary cholesterol. Normal and diabetic monkeys (Macaca nigra) were fed cereal-based, specially formulated diets with either a low fat (LF = 2.5%) or a higher fat (13.2%) content; the latter had varying concentrations of safflower and coconut oil to attain greater polyunsaturation (SFO) or saturation (CCO) in the diets. Dietary cholesterol was less than 0.01%. Serum triglyceride concentrations were greatest when monkeys consumed the LF (higher carbohydrate) diet and lowest when they consumed the SFO diet. Concentrations were greater in diabetic than in normal monkeys fed the LF and SFO diets, but both groups had similar concentrations when fed the CCO diet. Cholesterol levels in diabetic monkeys were only slightly higher than in normals regardless of diet; in both groups, levels were lowest when the LF diet was fed and highest when the CCO diet was fed. The quantity of fat had a greater effect on serum cholesterol than did the degree of polyunsaturation. In both groups, triglyceride concentrations correlated significantly with VLDL protein, and cholesterol levels correlated with LDL protein. Thus the responses of Macaca nigra to dietary fat manipulation depend upon both the diet fat content and composition as well as the normal or diabetic metabolic state of each monkey.     

ω-3多烯脂肪酸在鸡蛋蛋黄中的积累研究

目的：研究ω－３多烯脂肪酸对鸡蛋蛋黄中ＥＰＡ、ＤＨＡ含量的影响。方法：以含鱼油１％～８％的饲料饲喂商用蛋鸡９周。结果：气相色谱分析测试结果显示,在１～４周内,鸡蛋蛋黄中ＥＰＡ含量有明显下降,而ＤＨＡ含量则上升１～４倍,其中尤以添加８％的鱼油组最为显著。在５～９周内,蛋黄中ＥＰＡ含量在较低浓度范围内波动,而ＤＨＡ则仍呈上升趋势。     

Reversal of the promotional effect of high-fat diet on mammary tumorigenesis by subsequent lowering of dietary fat

Female Sprague-Dawley rats were given 7,12-dimethylbenz(a)anthracene at 50 days of age to induce mammary tumors, and beginning one week later were fed a high-fat, semipurified diet containing 20% sunflowerseed oil to promote tumor development. After another 7 weeks, when one third of the rats had palpable mammary tumors, the rats were randomly assigned to five groups of 31 animals each, with the same number of tumor-bearers in each group. One group was continued on the high-fat diet, another was given a fat-free diet, and the three remaining groups were fed diets containing 10% lard, butter, or coconut oil, respectively. During the next 29 weeks, rats fed the diets containing 0% or 10% fat developed significantly fewer tumors than those continued on the 20% fat diet. The diets containing 10% fat suppressed tumorigenesis at least as effectively as the fat-free diet. Rats fed the 10% butter and 10% lard diets had growth rates comparable to those fed the 20% sunflowerseed-oil diet throughout, and evidence of essential fatty acid deficiency was seen only in rats on the fat-free diet. These results provide additional evidence that high-fat diets promote development of mammary cancer and suggest that reducing the level of dietary fat might help to prevent the development and recurrence of breast cancer in humans.