Effect of fungal enzyme mixture supplementation of various fibre-containing diets fed to broiler chicks 2: On blood,liver and kidney total lipids,triacylglycerols and cholesterol

Broiler chicks of both sexes were fed formulated rations containing different fibre types with and without supplementation with crude and pure microbial enzymes in order to determine the effect on the lipids of the blood, liver and kidney. Results shown enzyme supplementation to greatly and significantly affect total lipid, free fatty acids, triglyceride and cholesterol levels of the blood, liver and kidney relative to the age of the birds and the type of fibres. By day 42, the total blood lipid of the unsupplemented diet rose to the highest level (22.4 mg/l), that of the kidney (3.62 mg/g) and the liver (185.7 mg/g). Enzyme supplementation, however, brought about reduction of these values with the diet containing all the fibres – wheat bran, corn bran, palm kernel meal and coconut meal giving the lowest values of the total lipids, free fatty acids, triglycerides and cholesterol on day 42 for the blood, liver and kidney, respectively. The pure forms of the enzymes applied directly to the feed gave more highly significant effects than the crude forms fed through water. Interaction effects between the various forms of the enzyme and the mode of application were also statistically significant.     

Influence of probiotic supplementation on blood parameters and growth performance in broiler chickens

Effects of commercial probiotic (Bactocell®) on growth performance and blood parameters were evaluated. A total of 800 one day-old Ross broiler chicks were raised over 42 days. Chicks were wing-banded, weighed individually and randomly allocated into four equally major groups each having two replicates. Chicks of group 1 (control group) were fed the starter and finisher diets that did not supplemented with probiotic. The chicks of groups 2, 3, and 4 were fed the control starter and finisher diets supplemented with 1.6 g, 1 g and 0.8 g of probiotic per kg feed, respectively. Weekly body weight, feed consumption and feed conversion were measured. Blood parameters at 1, 4 and 6 weeks of age including packed cell volume (PCV), haemoglobin (Hb), total protein, albumin, total lipid and cholesterol were determined. All birds were kept under similar environmental, managerial and hygienic conditions. The results of the current study revealed that there was no significant change for Hb and PCV concentrations among different groups at all studied times. Also, total protein, lipids and albumin concentrations were not affected by probiotic supplementation. Chicken fed a diet containing various levels of probiotic showed a significant decrease (p ⩽ 0.05) in cholesterol concentration compared to control group. Probiotic supplementation significantly increased the body weight and daily weight gain of broiler chicks at late ages (3–6 weeks). Also, the birds fed on probiotic levels 1 and 0.8 g/kg diet exhibited higher body weight among chicken groups at 6 weeks of age. Improved feed conversion was noticed in birds fed a diet supplemented with probiotic. There was no significant difference in mortality rate among groups. We concluded that use of selected commercial probiotic resulted in improved performance parameters and reduced serum cholesterol in broiler chickens. Moreover, supplementation of the probiotic to broilers in the levels of 1 and 0.8 g/kg diet was found to be better than control and 1.6 g/kg level indicating that increasing dietary probiotic level does not has the best performance.     

Effects of Dietary Polychlorinated Biphenyls and Protein Level on Liver and Serum Lipid Metabolism of Rats

The effects of polychlorinated biphenyls (PCB) and dietary protein level on the liver and serum lipid metabolism of rats were studied. Rats were fed an experimental diet containing 7 or 30% casein with or without 0.1 % PCB for 24 days. Dietary PCB increased the level of triglyceride, phospholipid and cholesterol in the liver. The accumulation of triglyceride and cholesterol in liver was markedly increased with a low protein diet. The incorporation of injected ³H₂O into liver cholesterol was increased by PCB, but not affected by the dietary level of protein. The incorporation of the tracer into liver fatty acids was not increased by PCB intake. Dietary PCB also raised serum cholesterol and phospholipid, while PCB decreased triglyceride level, especially in rats on low protein diet. In addition, PCB intake clearly raised serum high density lipoprotein and diminished very low density lipoprotein. In the low protein group, PCB markedly repressed the incorporation of ³H₂O into serum lipids. The results suggest that the hepatic lipids accumulation by the addition of 0.1 % PCB to a low protein diet might be mainly ascribed to a repression in the transport of triglyceride from liver to blood. KEY WORDS: PCB, dietary protein, liver lipids, serum lipoprotein.     

The influence of three days or three weeks of force feeding on the transport of plasma lipids in young female chickens (Gallus gallus L.).

1. Ten-week old broiler females were force-fed (FF) for 3 days or 3 weeks. 2. Control livers were lighter in weight and contained less total lipid, neutral lipid and phospholipid than either FF group, which did not differ. 3. Radioactivity incorporated into liver neutral lipid fractions from 1-[14C]acetate injection was greater in birds FF 3 weeks than controls. Those FF 3 days were intermediate. In all groups, the triglyceride fraction contained 90-94% of isolated radioactivity, the cholesterol fraction 4-8% and the cholesterol ester fraction 1-2%. 4. Plasma lipids were elevated in the birds FF for 3 weeks, but not in those FF 3 days. After injection of 1-[14C]acetate, plasma lipid specific radioactivities were not different between the 3 groups at 20 and 60 min post injection, but were greater in the controls at 120 min.     

Eucalyptus leaves powder,antibiotic and probiotic addition to broiler diets: effect on growth performance,immune response,blood components and carcass traits

The study was conducted to investigate the effects of different levels of eucalyptus powder (EP), virginiamycin and probiotic on performance, immunity, blood components and carcass traits of broiler chickens. A total of 250, 1-day-old male broiler chickens (Ross 308) were randomly allocated to five treatments with five replicates and 10 chicks each, as a completely randomized design. The dietary treatments consisted of: basal diet (BD), BD+0.25% EP, BD+0.5% EP, BD+0.01% of diet probiotic (Protexin), BD+0.02% of diet antibiotic (virginiamycin). Dietary supplementation did not affect feed intake, BW gain (BWG) and feed conversion ratio (FCR) during starter and grower phases, but BWG and FCR were affected during the finisher and whole periods (P<0.05).The highest BWG and lowest FCR were obtained in birds fed with virginiamycin and 0.5% EP. Dietary supplementation significantly increased the relative weight of carcass and breast (P<0.05). Treatments had no effect on relative weights of internal organs and small intestine except for bursa that increased by treatments. Relative length of jejunum also increased by treatments (P<0.05). Antibody production against sheep red blood cells did not changed in primary titer (day 35), but it significantly increased in secondary titer (day 42) by 0.5% EP. White blood cell counts were increased and cholesterol decreased by dietary supplementation (P<0.05). In conclusion, the results of this study showed that 0.5% EP served as a useful replacement for antibiotic and would improve performance and immune response of broiler chickens.     

Effects of Dietary Glutathione on Plasma and Liver Lipid Levels in Rats Fed on a High Cholesterol Diet

The effects of dietary glutathione (GSH) on plasma and liver lipid concentrations were investigated with rats fed on a high cholesterol diet. When graded levels of GSH, 0.75 to 5.0%, were added to the 25% casein basal diet, the plasma total cholesterol level was significantly decreased and the HDL-cholesterol level was inversely increased in all addition levels without influence on the growth of animals except for the 5% addition level; the dietary addition of 5% GSH markedly depressed the growth and food consumption of rats and caused a slight diarrhea. Plasma triglyceride and phospholipid levels were decreased by the dietary addition of GSH. The contents of cholesterol and triglyceride in the liver were decreased as the dietary addition level of GSH was increased. The dietary addition of a mixture of glutamic acid, cysteine and glycine, or cysteine alone corresponding to 2.5% GSH resulted in a cholesterol-lowering effect which could not be distinguished from the effect of GSH in rats fed on the 25% casein diet. When 1.5% GSH was added to a low (10%) casein diet, the plasma cholesterol-lowering effect of GSH was also observed and the effect was comparable to that of cysteine. These results indicate that dietary-added GSH has a plasma and liver cholesterol-lowering efficacy and that this effect is largely attributable to the cysteine residue of GSH rather than to the tripeptide itself or the other amino acid residues.     

Effect of T-2 toxin on growth, performance and haematobiochemical alterations in broilers

Administration of dietary T-2 toxin in 120 days old broiler chicks led to significant lower body weights and increase in feed conversion ratio from 2nd week of age. There was significant reduction in haemoglobin and packed cell volume in T-2 toxicated birds at 4 ppm level only. The other hematological parameters like TEC, TLC and absolute leucocyte count did not showed any variation due to T-2 toxin in feed. Significant reduction in serum total protein and cholesterol levels and rise in serum uric acid and LDH levels of broilers were observed due to dietary T-2 toxin. The result suggests that T-2 toxin is toxic to broilers even at very low concentrations.     

Plasma lipoprotein profiles in broiler chicks (Gallus domesticus): effects of early overfeeding

1. Twenty-eight day old broiler chicks gavage fed for 22 days consumed 40% more feed and gained 100-110 g more than control birds. 2. Normal feeding resumed on day 41, by day 63 feed intakes and body weights of overfed and control birds were equal. 3. Moderate differences in lipid compositions of LDL and VLDL were observed at 41 and 50 but not at 63 days. 4. In contrast to mammals where early over feeding predisposes to adult obesity, lipoprotein profiles and ad lib feeding patterns of chicks are not readily altered by dietary measures.     

Effects of dietary chromium picolinate and peppermint essential oil on growth performance and blood biochemical parameters of broiler chicks reared under heat stress conditions

A study was conducted using 240 female day-old broiler chicks to evaluate the effects of dietary chromium picolinate (CrPic), peppermint essential oil (P.mint), or their combination on growth performance and blood biochemical parameters of female broiler chicks raised under heat stress conditions (HS, 23.9 to 38 °C cycling). Average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) were obtained from 1 to 42 days of age. Furthermore, at the end of the experiment (day 42), birds were bled to determine some blood biochemical parameters and weighed for final body weight (BW). ADFI, ADG, and BW were not influenced significantly by dietary CrPic and P.mint (P?>?0.05). A significant interaction between dietary CrPic and P.mint on FCR (P?=?0.012) was detected. FCR significantly decreased in chicks fed the diet including both CrPic and P.mint compared with the CrPic group. Significant interaction between dietary P.mint and CrPic on serum concentrations of triglycerides, glucose, and albumin were observed (P?<?0.05), but the other measured blood biochemical parameters were not statistically affected by dietary treatments (P?>?0.05). The serum concentrations of glucose, triglycerides were decreased (P?<?0.05) in broilers fed the diet including both CrPic and P.mint. Plasma chromium (Cr) content increased significantly (P?<?0.05) in birds fed the CrPic-included diet compared with the control group (P?<?0.05). From the results of the present experiment it can be concluded that dietary supplementation with combined P.mint and CrPic could have beneficial effects on some blood biochemical parameters of female chicks reared under heat stress conditions.     

Investigation on the effect of different levels of dried sweet orange (Citrus sinensis) pulp on performance,carcass characteristics and physiological and biochemical parameters in broiler chicken

Utilization of agricultural by-products in animal nutrition is a matter of great concern. Dried sweet orange (Citrus sinensis) pulp (DCSP) is a potential source of valuable nutrients and natural antioxidants for poultry feed. In the experiment, a feeding trial was conducted in order to investigate the effect of different levels of dried orange residues in diet on broiler growth performance, carcass characteristics, blood metabolites, humoral immunity, and cecum microbial population. A total of 200 one day experimental broiler chicks were distributed into a completely randomized design (CRD) which included 5 dietary treatments with 4 replicates per each treatment and 10 birds fed in each replicate. The experimental treatments consist of a control group (without additive), 0.5%, 1.0%, 1.5%, and 2% of DCSP (residue) in diet. Weight gain, feed intake and feed conversion ratio (FCR) were measured. Blood parameters and carcass traits were measured in the postnatal 35th day. The highest level of dried orange residues in treatment 5 (T5) had significantly increased the feed intake and body weight of broilers in groups and overall during the rearing period (P > 0.05). Different levels of dried orange residues had no significant effect on chicken FCR. Using of dried orange residues significantly decreased the liver and abdominal fat of broilers (P < 0.05). T5 has also significantly lower level of triglyceride than the control (T1) and treatment 2 (T2) (P < 0.05). In conclusion, the use of dried orange residues improved some performance (e.g. feed intake and body weight gain), decreased liver and abdominal fat and also serum triglyceride level in broiler chicken.     

Clostridium perfringens challenge and dietary fat type affect broiler chicken performance and fermentation in the gastrointestinal tract

The aim of the present work was to examine how different fats commonly used in the feed industry affect broiler performance, nutrient digestibility and microbial fermentation in the gastrointestinal tract of broiler chickens challenged with virulent Clostridium perfringens strains. Two experiments were carried out, each including 480-day-old male broilers (Ross 308), which were randomly distributed to eight experimental groups using six replicate pens per treatment and 10 birds per pen. In Experiment 1, birds were fed diets containing soybean oil, palm kernel fatty acid distillers, rendered pork fat and lard. In Experiment 2, birds were fed diets containing rapeseed oil, coconut oil, beef tallow and palm oil. In both experiments, the birds were either not challenged or challenged with a mixture of three C. perfringens type A strains. Irrespective of the fat type present in the diet, C. perfringens did not affect broiler chicken body weight gain (BWG) and mortality in either of the two experiments. The BWG was affected by dietary fat type in both experiments, indicating that the fatty acid composition of the fat source affects broiler growth performance. In particular, the inclusion of animal fats tended to improve final BW to a greater extent compared with the inclusion of unsaturated vegetable oils. In Experiment 2, irrespective of the dietary fat type present in the diet, C. perfringens challenge significantly impaired feed conversion ratio in the period from 14 to 28 days (1.63 v. 1.69) and at 42 days (1.65 v. 1.68). In both experiments apparent metabolizable energy values were affected by dietary fat type. Irrespective of the fat type present in the diet, C. perfringens challenge decreased the digesta pH in the crop and ileum, but had no effect in cecal contents. Moreover, in Experiment 1, total organic acid concentration in the ileum was two to three times lower on soybean oil diets as compared with other treatments, indicating that C. perfringens as well as dietary fat type significantly affects microbiota activity in the broiler chicken gastrointestinal tract.     

Effect of early feed restriction on physiological responses,performance and ascites incidence in broiler chickens raised in normal or cold environment

Intensive selection of broilers for faster growth and better feed efficiency resulted in greater susceptibility to metabolic disorders such as ascites syndrome, which is one of the major causes of mortality and economic loss in broiler industry. Whereas cool temperature is one of the primary triggers for ascites, early feed restriction (FDR) significantly alleviates its incidence and mortality. However, little is known about effects of FDR, cold environmental temperature and their interaction on physiological responses in broiler chickens. For this purpose, 320 one-day-old male broilers were divided into two treatment groups of Ad libitum (Ad) and feed restricted (FR) with eight pen replicates each. Chickens in FR group underwent feed access limitation from days 7 to 14 of age. On day 21 half of the birds (four pens) in each group exposed to the cold temperature (CT) and the other half (four pens) continued at normal temperature (NT). Average daily feed intake, average daily weight gain and feed conversion ratio (FCR) were measured at days 7, 14, 21, 28 and 42. At 39 and 46 days of age two chicks with a BW around the pen average were selected from each pen and slaughtered after collecting blood samples. Then, relative weight of internal organs and right ventricle weight per total ventricle weight (RV : TV) ratio were calculated. Compared with NT group, CT birds had higher daily feed intake and FCR (P<0.05) from day 28 to 42. Cumulative ascites mortality in CT chickens was higher (P<0.001) than NT chicks. Within the CT group, ascites mortality in FR chickens was reduced (P<0.001) to 1.25% compared with 8.75% in Ad chicks. Birds in CT group had significantly (P<0.05) thicker right ventricle and greater relative weight of heart, hematocrit and triiodothyronine concentration. However, none of these parameters were affected by FDR. Under cold stress conditions, FDR reduced activity of alanine aminotransferase and aspartate aminotransferase (P<0.05). Serum triglyceride, cholesterol, high-density lipoprotein and total protein were not influenced by either temperature or feeding regimen. In conclusion, these findings suggest that FDR reduces ascites incidence mainly by allowing better development of internal organs, which helps them to cope with the high metabolic pressure and suffer less damage.     

Effects of supplementation with vitamin E on the performance and the tissue peroxidation of broiler chicks and the stability of thigh meat against oxidative deterioration

Two experiments were conducted: Expt 1 determined the optimal allowance of vitamin E in the diet for broiler chicks aged 0–3 weeks; Expt 2 investigated the effects of different dietary levels of vitamin E (α-tocopherol) on the performance and the oxidative stability of thigh meat of broiler chicks during storage. In Expt 1, 1-day-old 900 broiler chicks were allocated to five treatments, each with six replicates (cages) of 22 as-hatched chicks for performance evaluation, and another cage of 45 male chicks for determining plasma and hepatic α-tocopherol and thiobarbituric acid reactive substances (TBARS) concentration in blood and liver. The basal dietary α-tocopherol concentration was 13 mg/kg, and the five α-tocopherol acetate supplementation levels were 0, 5, 10, 50 and 100 mg/kg. For 0–3-week-old broiler chicks fed with maize–soya bean meal–soya oil type diet, supplementation of vitamin E did not influence the feed intake, but tended to improve growth and feed utilization, however there was no significant correlation between performance and vitamin E supplementation level. Significant positive correlations existed between dietary supplemental vitamin E level and plasma or hepatic α-tocopherol concentrations (P<0.05), and a negative correlation with hepatic TBARS levels no matter at what age (11, 16 and 21 days). In Expt 2, 2200 broiler chicks were randomly allocated to five treatments with four replicates (pens) in each. Chicks were fed ad libitum five pellet diets supplemented with vitamin E at 5, 10, 20, 50 and 100 mg/kg of diet, respectively. The basal dietary α-tocopherol level of grower and finisher diets were 7 and 6 mg/kg, respectively. Supplementation of vitamin E tended to improve growth and feed utilization of birds during 0–3 weeks of age, but the performance from 0 to 6 weeks of age were not influenced. The hepatic α-tocopherol concentrations of 6-week-old chicks linearly increased with the dietary vitamin E levels (R²=0.98, P<0.001). The content of TBARS in the thigh meat over 4 days of storage under 4°C was significantly decreased by increasing dietary vitamin E level (P<0.05). There was a significant inverse relationship between TBARS value in the thigh meat and the dietary vitamin E level (R²=0.93, P<0.01). Supplementation of vitamin E significantly improved the meat quality stability substantially against oxidative deterioration. Comparing the hepatic α-tocopherol levels of chicks in Expts 1 and 2, total allowance of dietary α-tocopherol of 20–30 mg/kg could sustain relatively constant hepatic α-tocopherol level at round about 2–2.5 μg/kg.     

Fate of Mycobacterium tuberculosis inside rate peritoneal macrophages in vitro

Streptozotocin-induced diabetic rats were maintained on 0.5% curcumin containing diet for 8 weeks. Blood cholesterol was lowered significantly by dietary curcumin in these diabetic animals. Cholesterol decrease was exclusively from LDL-VLDL fraction. Significant decrease in blood triglyceride and phospholipids was also brought about by dietary curcumin in diabetic rats. In a parallel study, wherein diabetic animals were maintained on a high cholesterol diet, the extents of hypercholesterolemia and phospholipidemia were still higher compared to those maintained on control diet. Curcumin exhibited lowering of cholesterol and phospholipid in these animals also. Liver cholesterol, triglyceride and phospholipid contents were elevated under diabetic conditions. Dietary curcumin showed a distinct tendency to counter these changes in lipid fractions of liver. This effect of curcumin was also seen in diabetic animals maintained on high cholesterol diet. Dietary curcumin also showed significant countering of renal cholesterol and triglycerides elevated in diabetic rats.In order to understand the mechanism of hypocholesterolemic action of dietary curcumin, activities of hepatic cholesterol-7a-hydroxylase and HMG CoA reductase were measured. Hepatic cholesterol-7a-hydroxylase activity was markedly higher in curcumin fed diabetic animals suggesting a higher rate of cholesterol catabolism. (Mol Cell Biochem 166: 169-175, 1997)     

Influence of 1,3-butanediol on blood glucose concentration and pancreatic insulin content of streptozotocin-diabetic rats.

Male rats were made diabetic by intravenous administration of 75 mg/kg of streptozotocin and were fed, via a pair-feeding regimen, high-fat diets +/- 1,3-butanediol (BD) at 13.5 and 27% of the dietary calories for 30 days and 31 days, respectively. 1,3-Butanediol was added to the diets primarily as a replacement for fat. Food consumption and rat weight were recorded daily. Whole blood glucose concentrations were determined weekly. At sacrifice, liver, pancreas and epididymal fat pads were excised and blood samples were collected. Liver was analyzed for protein and lipid; pancreas was weighed and analyzed for insulin; fat pads were weighed and discarded; and blood was analyzed for glucose and lipid. The 13.5% BD diet increased the beta-hydroxybutyrate, acetoacetate and cholesterol concentrations, decreased the glucose concentration in blood, and increased the insulin content of the pancreas. The BD diets did not affect the concentrations of phospholipid, triglyceride, cholesterol and fatty acid in the liver; fatty acid concentrations in the blood; or the epididymal fat pad weight. The results suggest that BD produced a slight amelioration of the diabetic condition, which may have resulted from an increased capacity of the pancreas to synthesize insulin. In addition, the data provide further evidence suggesting that in the rat BD is oxidized to the ketone bodies, beta-hydroxybutyrate and acetoacetate.     

Effectiveness of sodium bentonite and two commercial products as aflatoxin absorbents in diets for broiler chickens

Three hundred day-old commercial broiler chicks were reared in 10 groups to examine the effects of indigenous sodium bentonite (SB) as a sodium bentonite simple, sodium bentonite + gention violet and sodium bentonite + acetic acid on two levels 0.5 and 1% of feed, along with two market products Sorbatox and Klinofeed on two levels of aflatoxin 0 and 100 mcg/kg. Each group was replicated three times. The aflatoxins (AF) were incorporated in a standard commercial broiler ration and fed to chicks for 6 week. Body weight and feed consumption was recorded weekly. At the end of the experiment two birds from each group were slaughtered to note the relative weight of heart, liver, gizzard and dressing percentage. Titre against Newcastle disease (ND) was monitored at day 21st, 28th, 35th and 42nd of the experiment.Statistical analysis indicated that aflatoxin in diet negatively affected (P<0.05) all the parameters. Chicks receiving aflatoxin-contaminated diet had suppressed body weight, feed consumption and FCR value, which was significantly improved with the addition of 0.5% simple sodium bentonite. The relative weight of liver (5.34%), heart (0.72%), gizzard (2.05%) and mortality (40%) increased significantly with the addition of 100 mcg/kg aflatoxin and were restored to 3.57, 0.57, 1.43 and 16.6%, respectively, with the dietary inclusion of 0.5% simple sodium bentonite. However, dressing percentage significantly decreased (51.7%) when diet (B) was supplemented with 100 mcg/kg aflatoxin as compared to the diet where no aflatoxin was added (diet A). The titre against Newcastle disease (ND) also showed poorest results by addition of aflatoxin which also improved by inclusion of 0.5% simple sodium bentonite. Addition of indigenous sodium bentonite gave overall better results than the market products and between two levels of indigenous sodium bentonite, 0.5% level gave better results than 1%.     

Comparison of the novel compounds creatine and pyruvateon lipid and protein metabolism in broiler chickens

The effects of pyruvate (Pyr), creatine pyruvate (Cr-Pyr) and creatine (Cr) on lipid and protein metabolism were compared in broiler chickens. A total of 400 1-day-old male birds (Aconred) were allocated to four groups, each of which included four replicates (25 birds per replicate). Treatments consisted of unsupplemented basal diet (Control), basal diet containing 2% Pyr, basal diet containing 3% Cr and basal diet containing 5% Cr-Pyr. Cr-Pyr and Pyr significantly decreased the hepatic triglyceride and serum total cholesterol concentration (P < 0.01). Cr-Pyr markedly increased the serum non-esterified fatty acid and high-density lipoprotein cholesterol concentrations (P < 0.05), whereas the expression of carnitine palmitoyl transferase I (P < 0.05) and peroxisome proliferators-activated receptor-α (P < 0.01) mRNA in the liver were both decidedly enhanced in the Cr-Pyr group. The relative leg muscle weight was higher in the Cr-Pyr group than in the control group, whereas the serum uric acid content and hepatic glutamic-oxaloacetic transaminase activity were lower in the Cr-Pyr and Cr groups (P < 0.05), respectively. Muscle insulin-like growth factor I (P < 0.05) expression was enhanced, and the myostatin (P < 0.01) mRNA level was reduced in both the Cr-Pyr and Cr groups. In addition, Cr-Pyr did not alter body weight or the feed conversion ratio. These results indicate that, compared with Pyr and Cr alone, Cr-Pyr has a bifunctional role in broiler chickens, in that it influences both lipid and protein metabolism.     

Effects of dietary conjugated linoleic acids on lipid metabolism and antioxidant capacity in laying hens

To examine the effects of dietary conjugated linoleic acids (CLA) on lipid metabolism and antioxidant capacity in laying hens, Hy-Line Brown layers (n = 384, 52 weeks old) were randomly allocated to one of four dietary treatments. Each treatment had six replicates of 16 hens each. All birds were assigned to a corn-soybean meal-based diet containing a mixture of CLA at 0%, 1%, 2% or 4% for six weeks. With increasing dietary CLA, egg weight and feed intake decreased, and yolk colour was darkened. Feed efficiency was improved at 1% and 2% dietary CLA. Serum triglyceride concentration was significantly reduced by CLA in a dose dependent manner. A linear decrease in total cholesterol and low-density lipoprotein cholesterol, and an increase in high-density lipoprotein cholesterol levels were observed after CLA supplementation. With increasing dietary CLA, the deposition of two major isomers of CLA (c9, t11; t10, c12) in yolk lipids increased linearly, the proportion of saturated fatty acids increased and monounsaturated fatty acids decreased significantly. The proportion of polyunsaturated fatty acids was highest at 1% CLA. Compared to the control, CLA supplementation significantly increased the activities of superoxide dismutase and glutathione peroxidase, inhibited hydroxyl radicals and superoxide anion production, and decreased the malonaldehyde concentrations in both serum and liver. The results demonstrated that dietary CLA meliorated serum lipid profiles and enhanced the antioxidant capacity of laying hens.     

Effect of coix on plasma, liver, and fecal lipid components in the rat fed on lard- or soybean oil-cholesterol diet

To determine the influence of dietary coix on lipid metabolism, the effect of coix on plasma, liver, and fecal lipid components was studied using Sprague-Dawley male rats. All rats were divided into four groups, and the rats of each group were fed the coix-lard diet, coix-soybean oil diet, or the respective control diets (containing 1% cholesterol each) for 27 days. Plasma and liver cholesterol levels in the coix-lard diet group significantly decreased as compared with those in the control group, whereas there was no effect on the fecal excretion of cholesterol. The decreases in the concentrated liver triglyceride and the increases in the fecal excretion of triglyceride were found in coix-soybean oil diet group. Moreover, liver and fecal phospholipid levels in both coix diet groups significantly increased. But there were no significant changes in plasma and fecal bile acids in either coix diet group. These results suggest the possibilities that coix may have an inhibitory action on cholesterol synthesis in liver, a facilitating effect on biliary excretion of triglyceride, and an acceleratory action on phospholipid synthesis in liver.     

Metabolic effects of low aflatoxin B1 levels on broiler chicks

The effects of daily ingestion of aflatoxin B1 (AFB1) on growth, feed intake, plasma glucose, plasma cholesterol, plasma amino acids, plasma albumin, plasma ceruloplasmin, muscle amino acids, liver lipid, and bone strength were studied. For 3 weeks, beginning at an age of 2 days, broiler chicks were dosed daily per os with 50 or 100 micrograms of AFB1 per kg of body weight. Body weight and feed consumption were recorded daily, and metabolic responses were determined at 3 weeks. Treatment with AFB1 did not significantly alter body weight or feed intake. Relative liver weight showed a significant increase at the highest dose, with a significant concomitant increase in liver lipid and decrease in hepatic zinc. Relative spleen and heart weights were not affected by the toxin. Plasma glucose and cholesterol were significantly elevated at the highest dose. AFB1 significantly decreased plasma lysine and histidine and significantly increased muscle histidine, arginine, and valine. AFB1 decreased plasma albumin and markedly increased plasma ceruloplasmin. Dimensions of the long bones (femur and tibiotarsus) were not altered by the toxin. However, AFB1 caused a significant linear decline in the resistance of bone to breakage ("bone breaking strength"). The results indicate that low levels of AFB1 reduced bone strength in broiler chicks. The alterations in blood parameters indicated that AFB1 can disrupt metabolism even at low levels.