Effects of dietary conjugated linoleic acid, fish oil and soybean oil on body-fat deposition and serum lipid fractions in broiler chickens

An experiment was conducted on broiler chickens to study the effects of dietary fats rich in conjugated linoleic acid (CLA), fish oil (n-3 rich oil), soybean oil (n-6 rich oil), polyunsaturated fatty acids (PUFAs) alone or in dual mixtures, as well as palm oil as a more saturated fat on tissue fat deposition and serum lipid concentrations of broiler chickens. The fat included in the experiment's diets is a dose of 7% for single fats and 3.5 + 3.5% for the dual mixtures. The conjugate linoleic acid (CLA) supplement used in this study was LUTA-CLA 60, containing 60% CLA, so that dietary inclusion of 7 and 3.5% LUTA-CLA 60 were supplied with 4.2 and 2.1% CLA, respectively. The chickens fed diets containing palm oil, soybean oil or fish oil as the only dietary fat deposited more fat in breast tissue compared with other groups (P < 0.05). The highest fat in thigh tissue was observed in birds fed 7% fish oil (P < 0.05). The CLA containing diets resulted in fatter liver tissue (P < 0.05). The diets containing 7% fish oil effectively decreased the lipid content of chicken's liver (P < 0.05). The fish oil and soybean oil as n-3 and n-6 rich sources, respectively demonstrated a comparable reduction in the serum cholesterol and low density lipoprotein (LDL) concentrations (P < 0.05), while the 7% CLA diet increased serum high density lipoprotein (HDL) level (P < 0.05). The results of this study showed that dietary fish oil, and CLA effectively increased fat content of meat and liver tissues, respectively; and the dietary soybean oil and fish oil were more effective on reducing serum undesired lipoproteins, as compared with CLA.Key words: CLA, PUFA, body fat deposition, serum lipids and broiler chickens

Conjugated linoleic acid: a potent fatty acid linked to animal and human health

Conjugated linoleic acid (CLA) is a mixture of isomers of linoleic acid (C18:2 n-6), which is mostly found in the ruminant meat and dairy products. The CLA is known to have many potential health benefits, and considered a potent powerful fatty acid, which is linked to animal and human health. The present work aims to discuss the source and production, mechanism of action, and effects of CLA on humans, poultry and ruminants by reviewing the recent studies carried out on CLA. Despite most of recent studies indicating beneficial effects of CLA on improving body weight control parameters, its effects on reducing risk factors of cardiovascular diseases (CVD), inflammation, blood glucose and insulin are still controversial, and need to be further studied in different hosts

Effects of Conjugated Linoleic Acid, Fish Oil and Soybean Oil on PPARs (α & γ) mRNA Expression in Broiler Chickens and Their Relation to Body Fat Deposits

An experiment was conducted on broiler chickens to study the effects of different dietary fats (Conjugated linoleic acid (CLA), fish oil, soybean oil, or their mixtures, as well as palm oil, as a more saturated fat), with a as fed dose of 7% for single fat and 3.5 + 3.5% for the mixtures, on Peroxisome Proliferator-Activated Receptors (PPARs) gene expression and its relation with body fat deposits. The CLA used in this experiment was CLA LUTA60 which contained 60% CLA, so 7% and 3.5% dietary inclusions of CLA LUTA60 were equal to 4.2% and 2.1% CLA, respectively. Higher abdominal fat pad was found in broiler chickens fed with a diet containing palm oil compared to chickens in the other experimental groups (P ≤ 0.05). The diets containing CLA resulted in an increased fat deposition in the liver of broiler chickens (P ≤ 0.05). The only exception was related to the birds fed with diets containing palm oil or fish oil + soybean oil, where contents of liver fat were compared to the CLA + fish oil treatment. PPARγ gene in adipose tissue of chickens fed with palm oil diet was up-regulated compared to other treatments (P ≤ 0.001), whereas no significant differences were found in adipose PPARγ gene expression between chickens fed with diets containing CLA, fish oil, soybean oil or the mixture of these fats. On the other hand, the PPARα gene expression in liver tissue was up-regulated in response to the dietary fish oil inclusion and the differences were also significant for both fish oil and CLA + fish oil diets compared to the diets with palm oil, soybean oil or CLA as the only oil source (P ≤ 0.001). In conclusion, the results of present study showed that there was a relationship between the adipose PPARγ gene up-regulation and abdominal fat pad deposition for birds fed with palm oil diet, while no deference was detected in n-3 and n-6 fatty acids, as well as CLA on PPARγ down regulation in comparison to a more saturated fat. When used on its own, fish oil was found to be a more effective fat in up-regulating hepatic PPARα gene expression and this effect was related to a less fat deposition in liver tissue. A negative correlation coefficient (−0.3) between PPARα relative gene expression and liver tissue fat content confirm the anti-lipogenic effect of PPARα, however, the change in these parameters was not completely parallel

Effects of conjugated linoleic acids, fish oil and soybean oil on the growth performance, carcass traits, lipid characteristic and PPARs mRNA expression in broiler chickens

The conjugated linoleic acids (CLA) are known to decrease hepatic lipid deposition and overall lipid metabolism in selected animal models. These properties can be employed to reduce body fat accumulation in food animals, as in broiler chicken. In fact, every 1 % decrease in the chicken’s body fat would result in the average Malaysian eating 300 g less fat for a year from chicken meat, based on per capita chicken meat consumption figures for 2010. However, the anti-lipogenic effects of CLA are variable and complicated because of the differences in animal species, diet composition and possibly their interactions with other dietary fatty acids. We hypothesized that CLA effects on fat metabolism in broiler chickens could be altered by the presence of dietary n-3 and n-6 fatty acids. Hence, fish oil (rich source of n-3 fatty acids) and soybean oil (rich source of n-6 fatty acids) were used in this trial. This study aimed to investigate the effects of dietary conjugated linoleic acids, fish oil, soybean oil and their mixtures, as well as palm oil on broiler chickens. A total of 560 day-old Ross 308 male broiler chickens allotted randomly into 7 equal treatment groups and used in 42 days experimental period. All chicks were fed a starter corn-soybean meal-based diet for 10 days. The treatment diets used were adjusted to be isocaloric and isonitrogenous comprising the corn-soybean meal plus specific dietary fat supplements consisting of conjugated linoleic acid (CLA), fish oil, soybean oil, palm oil or their combinations. The dietary fats were included in the experimental diets at 7% for single fats and 3.5% + 3.5% for dual mixes, and because of the lower metabolisable energy of palm oil as compared to PUFAs, its inclusion rate was about 12%. The conjugated linoleic acids supplement used in this study was LUTA-CLA 60, containing 60% conjugated linoleic acid. Therefore the dietary inclusions of 7 and 3.5% LUTA-CLA 60 were effectively supplying 4.2 and 2.1% CLA, respectively. The treatment groups were 7% soybean oil (SO), 7% LUTA-CLA 60 (CL), 7% fish oil (FO), 3.5% LUTA-CLA 60+ 3.5% soybean oil (CLSO), 3.5% fish oil + 3.5% soybean oil (FOSO), 3.5% LUTA-CLA 60 + 3.5% fish oil (CLFO) and 12% palm oil (PO). The experimental diets were used at grower (11-28 d) and finisher (29-42 d) phases and performance data were collected for each period. Tissue and serum sampling was carried out at the end of experiment (42 d). The high level of palm oil inclusion in the diet did not adversely affect chicken’s feed intake or growth rate. The lowest weight gains were recorded for birds from FO and CL groups during the grower (24.2 g/b/d) and finisher (50.9 g/b/d) phases, respectively. The FO diet also reduced the feed intake of chickens (34.5 g/b/d) while dietary conjugated linoleic acids had no effect on feed intake regardless of its dosage and combinations with other fats. It was also found that palm oil supplemented at about 12 % (w/w) increased the weight of abdominal fat pads significantly (%2.4 of live weight), while higher conjugated linoleic acids content of the CL group increased post slaughter liver weights (%3.3 of live weight) (P<0.05). Lipid contents of the breast tissues were higher in the PO (%2.46), SO (%2.02) and FO (%2.02) groups (P<0.05) versus others (%1.11-1.55). Birds from the FO group had the highest amount of fats in their thigh muscles (%3.94) (P<0.05). Fish oil was more effective in reducing serum undesired lipoproteins (comparable effect with soybean oil), and CL diet enhanced serum favourite HDL fraction. It was also evident that conjugated linoleic acids in combination with soybean oil or fish oil resulted in less fat accumulation in both thigh and breast tissues, as compared to birds treated with soybean oil or fish oil only. Deposition and enrichment of longer chain n-3 fatty acids were also higher in the breast tissue of birds treated with conjugated linoleic acid in combination with fish oil (275 mg/100 g meat) as compared to the fish oil only treatment (254 mg/100 g meat). The treatment oils demonstrated different effects on PPAR genes. The PPARγ gene was up-regulated significantly in the PO group, whereas the levels of adipose PPARγ gene expression were no different across treatments containing conjugated linoleic acids, fish oil, soybean oil or the mixture of these fats. On the other hand PPARα gene expression in the liver tissue was up-regulated in response to dietary fish oil inclusion and the differences were significant for both FO and CLFO treatments compared to PO, SO and CL treatments. In conclusion, the results of the present study showed that the dietary 7% fish oil or 4.2% CLA supplements reduced broiler chicken performance. This combination resulted in the enrichment of n-3 in chicken meat. The combination of CLA with soybean oil on the other hand increases the CLA levels in the chicken meat. The PPARα gene demonstrated anti-lipogenic effects when it is upregulated in the presence of CLA. Changes in the abdominal fat deposition in broiler chickens could be attributed to both PPARα (in hepatocytes), and PPARγ in adipocytes. Lower abdominal fat deposition was achieved by up-regulating the PPARα (of hepatocytes), in tandem with the down-regulation of PPARγ in the adipocytes

Effects of dietary combination of conjugated linoleic acid with fish oil or soybean oil on fatty acid composition of broiler meat

An experiment was conducted to investigate the effects of dietary conjugated linoleic acid (CLA), fish oil (n-3 rich), soybean oil (n-6 rich) or their respective mixtures as well as palm oil as a more saturated fat on the fatty acid profile of breast and thigh tissues in broiler chickens. The dietary fats were included in the experimental diets at 7% for single fats and 3.5% + 3.5% for dual mixed fats. Because of the lower metabolisable energy content of palm oil, its inclusion rate was about 12%. The results of the present study showed that the high CLA and fish oil dosage adversely affected the growth rate, carcass yield and general performance. However, the incorporation of dietary soybean oil as n-6 fatty acid source can moderate these adverse effects. The combinations of CLA + fish oil and CLA + soybean oil resulted in more effective enrichment of chicken meat with n-3 polyunsaturated fatty acids and CLA, respectively. Therefore, it seems that this kind of enrichment of chicken meat is not always in a dose-dependent manner and could be affected by the associated dietary fat composition

Effect of Dietary Garlic Meal on Histological Structure of Small Intestine in Broiler Chickens

This study was conducted to evaluate the effect of garlic (Allium sativum) meal on the intestinal mucosal morphology of broiler chickens between 21 and 42 days of age. A total of 1800, 21 days old Ross 308 broiler chicks were weighed and randomly allotted into 0, 0.125, 0.25, 0.5, 1 and 2% dietary garlic meal groups of each 100 birds. Experimental diets were formulated by addition of each level of garlic meal to commercial finisher mash diet (CP : 20.45%, ME : 3,130kcal/kg), and fed ad libitum for 21d. At day 42, 15 chicks from each treatment were randomly killed to obtain intestinal samples.Villus height, epithelial thickness, goblet cell numbers, crypt depth and the ratio of crypt depth to villus height in each intestinal segment were compared using a light microscope. Garlic meal as a feed additive significantly enhanced villus height and crypt depth and decreased epithelial thickness and goblet cell numbers in duodenum, jejunum and ileum of birds. Fundamentally, jejunum and ileum revealed an almost similar morphological alteration to that in the duodenum except that dietary garlic meal supplement resulted in an increase in the ratio of crypt depth to villus height in duodenum but a decrease in jejunum and ileum. In present study, small intestinal morphological changes in chickens due to dietary garlic meal supplement demonstrate that absorptive process could be activated by garlic meal as an antibiotics alternative growth promoter

Effects of dietary conjugated linoleic acid (CLA), n-3 and n-6 fatty acids on performance and carcass traits of broiler chickens

An experiment was conducted on broiler chickens to study the effects of conjugated linoleic acid (CLA), fish oil, soybean oil or their mixtures (at 7% for single and 3.5% + 3.5% for mixtures) as well as up 12% dosage of palm oil, on the performance and carcass traits of broiler chickens. The chicks fed 7% fish oil or 7% CLA diets were found to have the most inferior weight gain in grower and finisher phases, respectively. A significant reduction in feed intake was observed with diets containing 7% fish oil. However, adding CLA to the diets regardless of the associated dietary fat, did not affect birds feed intake. The dietary fish oil and CLA adversely affected the feed conversion ratio as well as carcass yield. Dietary palm oil (at 12% level) and CLA (at 7% level) increased the abdominal fat pad and liver weights, respectively. The results of this study show that the high dosage of fish oil or CLA can reduce broiler chickens performance but their combination with soybean oil as n-6 fatty acid source can moderate these adverse effects