Effects Of Different Lipid Sources Research Articles

Effects of different dietary lipid sources on tissue fatty acid composition, serum biochemical parameters and fatty acid synthase of juvenile mud crabScylla paramamosain(Estampador 1949)

A 6-week study was conducted to determine the effects of different lipid sources in pelleted diets on juvenile mud crab Scylla paramamosain. Five isonitrogenous and isolipidic diets containing 8% level of fish oil (FO), lard (LD), safflower oil (SO), perilla seed oil (PO) or mixture oil (MO; VFO:VSO:VPO = 1:1:1), and a live food of marine bivalve Potamocorbula rubromuscula as the control diet (CF), were fed to groups of 25 juvenile crabs (average initial weight 7.4 g, carapace width 3.5 cm) in triplicate. The results showed that crabs fed MO had the highest survival (P < 0.05). The moisture content was significantly higher in crabs fed LD, SO and PO (P < 0.05). Crabs fed SO exhibited the lowest crude protein and lipid (P < 0.05). Ash contents were obviously lower in LD group (P < 0.05). Highest total lipid in the hepatopancreas and muscle was in LD and FO group respectively. Glucose, total cholesterol and low-density lipoprotein were higher while high-density lipoprotein was lower (P < 0.05) in LD group. Tissue fatty acid compositions were consistent with those in diets. FO and MO diets had the same depression effect like CF on fatty acid synthase activity and mRNA expression in the hepatopancreas. The results of this study indicated that FO and mixed oil are suitable for preparation of pelleted diets with better effects for juvenile S. paramamosain compared with live food, and the ratio of n-6/n-3 fatty acids in pelleted diets must be <1.

Intake and performance of confined crossbred heifers fed different lipid sources

The objective of this study was to evaluate the effect of different lipid sources on nutrient intake, performance, development and carcass characteristics of heifers raised in confinement. Twenty-one crossbreed heifers (Nellore × Santa Gertrudis × Braunvieh) received 600 g/kg forage composed of corn silage and 400 g/kg concentrate with a 58.0 g/kg fat content in the total diet. The following lipid sources were used: soybeans, protected fat (Megalac-E®) and soybean oil. The experimental design was completely randomized, with three treatments and seven replicates, and the means were compared by the Tukey test at 5%. The protected fat diet resulted in a greater intake of dry matter (8.80 kg/d) when compared with the other diets. The animals that were fed the protected fat diet had a higher average daily weight gain and slaughter weight. Feed conversion and protein efficiency rate were not influenced by lipid sources. Carcass yield was not influenced by the different diets.

Dietary fats with increased ratio of unsaturated to saturated fatty acids enhance absorption of carotenoid and vitamin E by increasing both efficiency of micellarization and lipoprotein secretion.

Although it is well established that dietary fat promotes the bioavailability of carotenoids and other dietary lipophiles, insights regarding the effects of different lipid sources on processes associated with absorption of these plant compounds remain unclear. We previously reported that triacylglycerides (TG) with higher ratios of unsaturated to saturated fatty acids (FA) increased the efficiency of micellarization of carotenes. Here we examined the influence of FA composition of TG on uptake of β‐carotene (BC), lutein (Lut) and αTC and their basolateral secretion in chylomicrons by Caco‐2 cells. Differentiated Caco‐2 cells were pretreated 4h/d for 4d by apical exposure of cultures to mixtures of saturated, mono‐unsaturated and poly‐unsaturated FA similar to those present in butter (76:24:0) and olive(12:74:14), canola(9:56:35) and soybean oil (16:24:60). On the following day, micelles containing βC, Lut and αTC were included along with the FA mixtures in apical medium. Uptake of test compounds was unaffected by micelle FA composition, whereas micelles rich in unsaturated FA strongly promoted basolateral secretion of BC, Lut and αTC. The number and size of chylomicrons (total TG and TG to apoB48/100 ratio) also were significantly increased by chronic exposure to micelles with FA composition mimicking vegetable oils. Therefore, it appears that ingestion of TG enriched in with unsaturated FA enhances bioavailability of carotenoids and αTC by increasing micellarization during digestion and transepithelial transport by absorptive epithelial cells. Supported by USDA NRI Grant # 2007‐02313 and OARDC.

Utilization of different dietary lipid sources at high level in herbivorous grass carp (Ctenopharyngodon idella): mechanism related to hepatic fatty acid oxidation

Herbivorous grass carp (Ctenopharyngodon idella) has been reported to exhibit low capacity to utilize high dietary lipid, but different lipid sources might affect this limited capacity. In order to compare the effects of different lipid sources with different lipid levels, juvenile grass carp were fed one of nine diets containing three oils [lard, plant oil mixed by maize and linseed oil, and n-3 high unsaturated fatty acid-enriched (HUFA-enriched) fish oil] at three lipid levels (20, 60 and 100 g kg(-1) dry diet) for 8 weeks. Decreased feed intake, poor growth performance, hepatic pathology and higher blood lipid peroxidation were found in 60 and 100 g kg(-1) fish oil groups. Conversely, in lard and plant oil groups, even at 100 g kg(-1) dietary lipid level, feed intake and growth performance did not decrease, despite histological observation revealed hepatic pathology in these groups. Plasma triglyceride and cholesterol contents increased significantly in all 100 g kg(-1) dietary lipid groups. In the comparison of hepatic FA beta-oxidation among three oil groups at 60 g kg(-1) dietary lipid level, impaired mitochondrial and peroxisomal FA oxidation capacity was observed in fish oil group. The results confirmed the relatively low capacity of grass carp to utilize high dietary lipid, and furthermore excess HUFA intake will result in more serious adverse effects than other FA.

The effects of different lipid sources on performance of Koi carp (&lt;i&gt;Cyprinus carpio&lt;/i&gt;) L fingerlings

A feeding experiment was carried out to determine the effect of different dietary lipid on the growth and survival of Koi carp (Cyprinus carpio) L fingerlings. Four experimental diets were formulated such that they contained groundnut oil, shea butter oil and palm oil respectively. The control contained no oil. Each diet was fed to a group of 20 fingerlings in a glass aquarium in a completely randomized design. The fingerlings with an initial average weight of 2.6 grams were fed twice daily for 58 days after which their final weights were recorded. The fingerlings fed with groundnut oil diet had the highest mean weight gain. There was no statistical difference (P>0.05) in the survival rate of the experimental fish. The highest feed conversion ratio of 41.0% was obtained with groundnut oil and closely followed by palm oil (28.0%). Keywords: groundnut oil, shea butter oil, palm oil, koi carp, fingerlings Animal Production Research Advances Vol. 1(1) 2005: 45-49

Production and extraction of an extracellular lipase from the entomopathogenic fungus Metarhizium anisopliae

A lipase from a Brazilian strain of Metarhizium anisopliae was investigated. The effect of different lipid sources added to basal medium was verified to improve enzyme production. Biomass was highest for sunflower oil (21.88 mg/ml), however lipase specific activity was highest for olive oil (108.38 U/mg). In the presence of surfactants, the highest lipase activity occurred when SDS and Tween 80 were added after 50 h M. anisopliae growth. SDS (4.54±0.46 U/ml) and Tween 80 (4.15±1.13 U/ml) were the best surfactants. The best temperature for lipase production was 32 °C. This is the first report investigating lipase production by an entomopathogenic fungus.

Dietary effect of different high-fat diet on rat liver stereology.

Dietary habits are considered to be responsible for a fatty liver. The aims of this work are to study the effects of different lipid sources on rat hepatic structure. Twenty 21-day-old to 18-month-old male rats were fed one of the following diets: soybean oil, canola oil, lard and egg yolk (LE), or canola oil+lard and egg yolk (CA+LE). The blood serum triglyceride samples were analyzed. The following hepatic biometry and the stereology parameters were determined: densities of volume (V(v)) and surface (S(v)), absolute volume (V) and surface (S) of the hepatocytes (h), fat globules (g), and hepatic sinusoids (s), and numerical density of the hepatocytes (N(v)[h]). The largest values of V(v)[h], S(v)[h], V[h], and S[h] were found in the LE group. However, the largest values of V(v)[g], S(v)[g], and S[g] were found in the CA+LE group, and the smallest values of those parameters were found in the LE group. On the other hand, V[g] was larger in the CA+LE group. V(v)[s] and V[s] were larger in the LE group and smaller in the CA+ LE group. Long-term administration of canola oil or soybean oil resulted in similar effects on hepatocytes, hepatic sinusoids, and fat globules. Long-term administration of lard and egg yolk attenuates hepatic fat accumulation and increases hepatic sinusoids. The administration of the canola oil and lard and egg yolk mixture increases hepatic fat accumulation, reducing the hepatic sinusoids.

Dietary fat source regulates ob gene expression in white adipose tissue of rats under hyperphagic feeding.

This work was designed to investigate the effect of different lipid sources on ob gene expression and serum leptin levels in rats with two different feeding protocols: (1) free access to food; or (2) energy-controlled feeding. Male Wistar rats were fed diets containing 40 % energy as fat (olive oil, sunflower oil or beef tallow), for 4 weeks. In Expt 1 rats had free access to food, and in Expt 2 rats were fed a controlled amount of food (16 g/d, equivalent to 300 kJ/d). Insulin and leptin were determined by ELISA and ob mRNA by Northern blot. When rats had free access to food, ob mRNA levels were higher in animals fed either olive oil or sunflower oil than in those fed beef tallow. In marked contrast with feeding ad libitum, no differences were found among dietary fat groups in rats fed energy-controlled diets. When both feeding protocols were compared, free access to food induced an increased expression of ob mRNA in perirenal and/or epididymal adipose tissues from rats fed either olive oil or sunflower oil, but not from rats fed beef tallow. Dietary lipid type did not induce modifications in serum leptin concentrations. A tendency to higher serum leptin levels was observed more in rats with free access to food than in rats fed energy-controlled feeding. No differences were found in insulin levels. Dietary fat type importantly affects ob mRNA expression in rat white adipose tissue under hyperphagic conditions. Further study is needed in order to elucidate the mechanism underlying this effect.

Lipoprotein lipase and lipogenic enzyme activities in adipose tissue from rats fed different lipid sources.

This work was designed to study the effect of different lipid sources on the activities of lipoprotein lipase and lipogenic enzymes in adipose tissue from rats fed ad libitum or energy-controlled diets. Male Wistar rats were fed diets containing 40% of energy as fat (olive oil, sunflower oil, palm oil or beef tallow), for 4 wk. Under ad libitum feeding no differences were found among dietary fat groups in final body weight, adipose tissue weights and total body fat. Under energy-controlled feeding, despite isoenergetic intake, rats fed the beef tallow diet gained significantly less weight than rats fed the other three diets. Beef tallow fed rats showed the lowest values for adipose tissue weights and total body fat. When rats had free access to food no effect of dietary lipid source on lipogenic enzyme activities was found. In contrast, under energy-controlled feeding rats fed the beef tallow diet showed significantly higher activities of glucose-6-phosphate dehydrogenase and fatty acid synthase than rats fed the other three diets. Heparin-releasable lipoprotein lipase activity in perirenal and subcutaneous adipose tissues was not different among rats fed olive oil, safflower oil, palm oil or beef tallow. When comparing both adipose tissue anatomical locations, significantly higher activities were found in subcutaneous than in perirenal fat pad independently of dietary fat. In conclusion, under our experimental protocol, lipogenesis in rat adipose tissue does not seem to be affected by dietary fat type.

Differential effects of diets that provide different lipid sources on hepatic lipogenic activities in rats under ad libitum or restricted feeding

This work was designed to study the effect of different lipid sources on hepatic lipogenic enzyme activity in rats fed ad libitum or energy-controlled diets. Male Wistar rats were fed diets containing 40% of energy as fat (olive oil, sunflower oil, palm oil, or beef tallow) for 4 wk. In experiment 1 rats had free access to food, and in experiment 2 rats were fed a controlled amount of food. In both experiments, rats fed the olive oil diets had higher activities of glucose-6-phosphate dehydrogenase, malic enzyme, fatty acid synthase, and acetyl-CoA carboxylase ( P < 0.05) than rats fed the other fats. It is unlikely that this effect could be attributed to the stimulation by insulin or triiodothyronine because serum values did not differ among the groups. Enzymatic activities were positively and significantly correlated with liver triacylglycerol content, but not with serum triacylglycerol levels. No interaction between lipid source and feeding protocol was found. Oleic acid and components in olive oil other than fatty acids, such as phytosterols, may account for the effects of dietary fat on lipogenic enzyme activity.

Effects of different lipid sources in total parenteral nutrition on whole body protein kinetics and tumor growth.

This study examined the short-term effects of three total parenteral nutrition solutions, each containing a different lipid source, on host and tumor protein metabolism in a rat cancer model. Each diet contained 220 kcal/kg per day, including 2 g of nitrogen/kg per day and 50% of nonprotein calories as either a structured lipid of medium-chain triglycerides and fish oil, a physical mix of medium-chain triglycerides and fish oil, or Liposyn II, a long-chain triglyceride. A 3-day intravenous feeding infusion began on day 7 after tumor implantation. Tumor growth rate, nitrogen balance, energy expenditure, and plasma albumin, glucose, and free fatty acids were measured, and whole body protein kinetics and fractional synthetic rates in liver, muscle, and tumor tissues were assessed using a constant infusion of 14C-leucine. The results revealed that tumor growth rate was slowed in structured lipid-fed animals (p = .06, one-way analysis of variance) with significant increases in rates of tumor protein synthesis and tumor protein breakdown (p < .001, one-way analysis of variance). Although muscle fractional synthetic rates were significantly decreased in tumor-bearing animals (p < .05, two-way analysis of variance), the rates in structured lipid-fed animals were restored. Nitrogen balance improved significantly in structured lipid-fed animals. The results demonstrate that the source of lipid in total parenteral nutrition solutions can influence tumor and host protein metabolism, and that a structured lipid composed of medium-chain triglycerides and fish oil seems to improve protein metabolism in host tissue without stimulating tumor growth.