Effects of various dietary n-3 / n-6 fatty acid ratios on the performance and body composition of broilers

Abstract

Different combinations of saturated and unsaturated fatty acids were fed to broilers to establish their effect on the fatty acid composition of the broiler carcass and the abdominal fat pad. Six combinations of Canola acid oil (CAO, high levels of C18:3n-3 and monounsaturated fatty acids) and Famarol acid oil (FAO, high levels of C18:2n-6 and saturated fatty acids) were included in the broiler diets from one day of age to six weeks of age, viz. 100% FAO, 80% FAO-20% CAO, 60% FAO-40% CAO, 40% FAO-60% CAO, 20% FAO-80% CAO, 100% CAO. There were no statistically significant differences between dietary groups in weight gain (1.71 ± 0.059 kg) or feed conversion ratios (1.97 ± 0.051 g feed/g gain). No significant differences between treatments were found in the moisture (66.20 ± 0.112%), protein (17.63 ± 0.484%), lipid (15.92 ± 1.507%) and ash (0.95 ± 0.115%) concentration of the carcasses, nor in the moisture (28.77 ± 0.112%), protein (3.03 ± 0.484%), lipid (63.32 ± 9.789%) and ash (0.45 ± 0.135%) concentrations of the abdominal fat pads. With the increase in dietary CAO levels, the mean percentages of C18:2n-6 and C20:4n-6 in the carcasses decreased respectively with 1.78% units from 20.88% and 0.35% units from 1.05%, whilst C18:3n-3 and longer chain n-3 fatty acids such as C20:5n-3 and C22:6n-3 increased respectively with 2.25% units from 1%, 0.1% units from 0.1% and 0.67% units from 0.2%. The same tendency was seen in the abdominal fat pads where C18:2n-6 and C20:4n-6 decreased respectively with 1.55% units from 20.75% and 0.98% units from 1.2% with an increase in dietary CAO, whilst C18:3n-3, C20:5n-3 and C22:6n-3 increased respectively with 2.13% units from 1.15%, 0.45% units from 0.03% and 0.95% units from 0.05%. The n-3/n-6 ratio in the carcasses and abdominal fat pads increased respectively with 0.16% units from 0.06% and 0.19% units from 0.06% with an increase in dietary CAO. These results clearly indicate that dietary CAO enriched with α-linolenic acid lowered the saturated fatty acid concentrations in broiler carcasses and abdominal fat pads with 4.88% units and 10.63% units respectively, and increased the monounsaturated fatty acid concentrations with 3.87% units and 7.25% units, respectively and polyunsaturated fatty acid concentrations with 1.02% units and 2.38% units, respectively. The results of this experiment showed that substitution of Famarol oil with Canola oil in broiler diets can increase the ratio of n-6 to n-3 fatty acids in broiler carcasses and abdominal fat pads to 5:1, a ratio more suitable for human health. Increasing the level of n-3 fatty acids in the diets was also effective in reducing the level of saturated fatty acids in the carcasses and abdominal fat pads of broiler chickens resulting in "healthier" chickens.

Effects of the replacement of corn oil with linseed oil on fatty acid composition and the expression of lipogenic genes in broiler chickens

“…Conversion of ALA (18:3n-3) to EPA (20:5n-3) involves sequential ∆6-desaturation, chain elongation, and ∆5-desaturation. EPA is, in turn, converted to DPA (Olomu and Baracos 1991;Lopez-Ferrer et al 1999;Coetzee and Hoffman 2003). As several reports (Haug et al 2007;Ponte et al 2008;Qi et al 2010), our study (Table 7) showed that reducing dietary 18:2n-6/18:3n-3 ratio linearly increased the enrichment of EPA and DPA, which implied that dietary n-3 PUFAs gave rise to higher tissue levels of EPA and DPA in a dosage-dependent manner.…”

“…In this study, the ARA (20:4n-6) levels of treatments containing corn oil with different proportions (CO, CL1, and CL2, enriching with LNA) were higher than that of LO group in breast muscle, but the ARA (20:4n-6) levels were similar among CO, CL1, and CL2 groups, which suggested that dietary LNA (18:2n-3) could increase ARA deposition in meat in a dosage-independent manner. LO group had the lowest ARA (20:4n-6), which also reflected that high amounts of ALA (18:3n-3) could decrease the conversion of LNA (18:2n-6) to ARA (20:4n-6) (Coetzee and Hoffman 2003;He et al 2009). …”

Effect of dietary lipid sources on lipid oxidation of broiler meat

“…It has been recorded that chickens could modify their lipid profile within a week after replacement of the dietary lipid source (Lopez-Ferrer et al, 2000). There is, therefore, considerable potential for the manipulation of the fatty acid profiles of poultry tissue by dietary means, thus to increase the supply of omega-3 (n-3) polyunsaturated fatty acids (PUFA) suitable for human consumption (Coetzee & Hoffman, 2002). Researchers illustrated that by feeding the relevant dietary unsaturated fatty acids, both polyunsaturated/saturated (PUFA/SFA) ratio (Warnants et al, 1998) and omega-6/omega-3 (n-6/n-3) ratios (Wood et al, 1999) of animal adipose tissue could be altered to fall within the dietary guidelines.…”

Effects of dietary fish oil and flax seed on cholesterol and fatty acid composition of egg yolk and blood parameters of laying hens

“…Eggs and poultry meat rich in omega-3 fatty acids can be produced by using feed ingredients rich in omega-3 fatty acids. In general, studies have been conducted to determine the effects of different omega-3 fatty acids sources in diets on the cholesterol and fatty acid composition of egg yolk and South African Journal of Animal Science 2003, 33 (4) 267 © South African Society for Animal Science meat (Caston & Leeson, 1990;Cherian & Sim, 1991;Hammershøj, 1997;Coetzee & Hoffman, 2002;Komprda et al, 2003). However, studies with regard to the effects of omega-3 fatty acids on blood cholesterol are lacking.…”