Effect of dietary conjugated linoleic acid on body composition and energy balance in broiler chickens

High-energy diet does not overcome the negative impact of conjugated linoleic acid on young broiler performance

The aim of this study was to evaluate the effect of conjugated linoleic acid (CLA) supplementation in diets with different energy levels in broiler performance. Birds were offered a starter (1-21 d), grower (22-35 d) and finisher (36-42 d) diets; wherein soybean oil was replaced by CLA. The study consisted of a 3 × 2 factorial arrangement with two CLA levels (0 and 1%) and three energy levels (3050, 3100 and 3150 ME kg-1 diet). During the grower and finisher periods, birds were fed diets with same energy level and CLA supplementation was maintained the same. Growth performance was assessed weekly, and carcass and cuts yield were assessed at 42d. Interaction effect of CLA by energy level was observed in broiler performance and carcass yield throughout the study (p > 0.05). During the overall period (1-42 d) broiler performance was not affected by CLA (p > 0.05).However, CLA supplementation (1%) decreased weight gain (p < 0.05) at 21d, regardless of energy level, with no effects on feed intake and feed conversation rate (p > 0.05). The increase in dietary energy was not able to compensate the negative effect on growth performance of broilers supplemented with 1% CLA at the starter period.

Overcoming the Bitter Taste of Oils Enriched in Fatty Acids to Obtain Their Effects on the Heart in Health and Disease

Fatty acids come in a variety of structures and, because of this, create a variety of functions for these lipids. Some fatty acids have a role to play in energy metabolism, some help in lipid storage, cell structure, the physical state of the lipid, and even in food stability. Fatty acid metabolism plays a particularly important role in meeting the energy demands of the heart. It is the primary source of myocardial energy in control conditions. Its role changes dramatically in disease states in the heart, but the pathologic role these fatty acids play depends upon the type of cardiovascular disease and the type of fatty acid. However, no matter how good a food is for one's health, its taste will ultimately become a deciding factor in its influence on human health. No food will provide health benefits if it is not ingested. This review discusses the taste characteristics of culinary oils that contain fatty acids and how these fatty acids affect the performance of the heart during healthy and diseased conditions. The contrasting contributions that different fatty acid molecules have in either promoting cardiac pathologies or protecting the heart from cardiovascular disease is also highlighted in this article.

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 the 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.

Effect of Conjugated Linoleic Acid Feeding on the Growth Performance and Meat Fatty Acid Profiles in Broiler: Meta-analysis

The effect of conjugated linoleic acid (CLA) feeding on growth performance and fatty acid profiles in thigh meat of broiler chicken was investigated using meta-analysis with a total of 9 studies. Overall effects were calculated by standardized mean differences between treatment (CLA fed) and control using Hedges’s adjusted g from fixed and random effect models. Meta-regression was conducted to evaluate the effect of CLA levels. Subgroups in the same study were designated according to used levels of CLA, CP levels or substituted oils in diets. The effects on final body weight, weight gain, feed intake and feed conversion ratio were investigated as growth parameters. Total saturated and unsaturated fatty acid concentrations and C16:0, C18:0, C18:2 and C18:3 concentrations in thigh meat of broiler chicken were used as fatty acid profile parameters. The overall effect of CLA feeding on final weight was negative and it was only significant in fixed effect model (p<0.01). Significantly lower weight gain, feed intake and higher feed conversion ratio compared to control were found (p<0.05). CLA feeding on the overall increased total saturated fatty acid concentration in broilers compared to the control diet (p<0.01). Total unsaturated fatty acid concentration was significantly decreased by CLA feeding (p<0.01). As for individual fatty acid profiles, C16:0, C18:0 and C18:3 were increased and C18:2 was significantly decreased by CLA feeding (p<0.01). In conclusion, CLA was proved not to be beneficial for improving growth performance, whereas it might be supposed that CLA is effective modulating n-6/n-3 fatty acids ratio in thigh meat. However, the economical compensation of the loss from suppressed growth performance and increased saturated fatty acids with the benefit from enhanced n-6/n-3 ratio should be investigated in further studies in order to propose an appropriate use of dietary CLA in the broiler industry.

Dietary combination effects of conjugated linoleic acid and flaxseed or fish oil on the concentration of linoleic and arachidonic acid in poultry meat

This study was conducted to determine the effects of the combination of dietary conjugated linoleic acid (CLA) and n-3 fatty acids on the linoleic acid (C18:2n-6) and arachidonic acid (C20:4n-6) concentrations of broiler chicken breast and thigh muscles. One hundred and twenty broilers were raised to 6 wk of age. All chicks were fed a basal corn-soybean meal diet containing 5 different fat sources at an inclusion level of 2% total fat: 1) CLA, 2) flaxseed oil, 3) menhaden fish oil, 4) CLA and flaxseed oil, and 5) CLA and menhaden fish oil. Eight broilers from each treatment were processed at 4 and 6 wk of age. Breast and thigh muscle samples were collected and analyzed for total fat content and fatty acid composition. The results showed that broilers from the CLA and fish oil treatment had lower arachidonic acid concentrations in both breast and thigh muscles than those fed the flaxseed oil diet or the CLA and flaxseed oil diet (P < 0.05). The arachidonic acid concentration and n-6:n-3 ratio of breast and thigh samples from the menhaden fish oil diet were similar to those of the CLA and fish oil diet (P > 0.05), but the inclusion of linoleic acid into chicken thigh muscles of broilers fed the CLA and menhaden fish oil diet improved significantly when compared with that of the diet containing menhaden fish oil only. Thus, the combination of CLA and menhaden fish oil is recommended to reduce the concentrations of linoleic and arachidonic acids in broiler chicken breast and thigh muscles.

Body compositional changes and growth alteration in chicks from hens fed conjugated linoleic acid

Effects of feeding conjugated linoleic acid (CLA) to hens on progeny chick development and composition at hatch (NHC) and three weeks of age (TWC) were assessed. CLA (0 or 0.5%, composed of mixed isomers of cis-9,trans-11 or trans-10,cis-12-CLA) was fed to hens with either safflower (SO) or olive oil (OO) (3 or 3.5%) to assure successful hatch for 2 weeks prior to collection for incubation. Maternal CLA feeding had no effect on hatchability, but improved egg fertility (p < 0.05). Maternal feeding of CLA with SO increased 21 day-old progeny growth, while CLA with OO decreased growth (oil*CLA, p < 0.05). In 25 day-old chicks (TWC), but not NHC, maternal CLA decreased the proportion of total body water (p < 0.05) and increased body ash (p < 0.05). While monounsaturated fatty acids were decreased and saturated fatty acids increased in eggs and NHC from hens fed CLA, no differences in fatty acid composition were observed in chicks at 25 days of age from hens fed CLA. Maternal CLA feeding resulted in the presence of c9,t11 and t10,c12-CLA in NHC, but only c9,t11 in the TWC. In conclusion, hens fed CLA led to improved fertility and altered body composition at 3 weeks of age.