Effect of type and level of fish oil supplementation on yolk fat composition and n-3 fatty acids retention efficiency in laying hens

Abstract

1. Laying hen performance and yolk fat fatty acid (FA) concentrations were evaluated with respect to the inclusion in the diet of different sources and levels of marine fish oil (MFO). 2. Twelve diets were arranged factorially, with three sources (MFO1, MFO2_EPA, MFO3_DHA) and four levels of inclusion (15, 30, 45 and 60 g/kg) of MFO. 3. Type of diet had little effect on egg production traits, although laying rate and shell thickness slightly decreased at the highest level of MFO supplementation. 4. An increase in level of inclusion of MFO from 15 to 60 g/kg linearly increased concentrations of C20:5 n-3, C22:5 n-3, C22:6 n-3 and total n-3 FA in yolk fat, but greatly impaired their efficiencies of deposition (g retained/g ingested). 5. An interaction between type and dietary concentration of MFO was found, as the reduction in efficiency of retention of n-3 FA in egg fat with level of MFO was less when the proportion of n-3 in total FA decreased or when that of DHA in total n-3 FA increased. 6. MFO3_ DHA was more efficiently used for total n-3 FA yolk deposition than MFO2_EPA at a similar total n-3 FA intake. 7. Dietary inclusion of MFO reduced LC n-6 FA yolk fat content, which additionally decreased the ratio between total n-6 and total n-3 FA in egg fat. 8. Regression equations were calculated in order to predict efficiency of retention and n-3 FA concentration of yolk fat in the range of diets studied.

Influence of different dietary oil sources on performance and fatty acid profile of egg yolk in laying hens

“…The inclusion of up to 60 g/kg menhaden oil (containing 110 g/kg EPA and 90 g/kg DHA) in laying hen diets yielded eggs containing approximately 150-200 mg DHA/egg and 45-60 mg EPA/ egg (Gonzales-Esquera and Leeson, 2000). Similar results have been reported by Cachaldora et al (2006). Linseed is one of the n-3 PUFA source, which has a high LNA content, while, sunflower seeds are rich in linoleic acid (LA; 18:2n-6) (Filardi et al, 2005).…”

“…The amount of AA in egg yolk significantly (P<0.01) decreased by FO and this was concomitant with increasing the contents of DHA in egg yolk fat, so that n-6 FA was decreased and n-3 FA was increased similary as in Baucells et al (2000) and Cachaldora et al (2006). This phenomenon was probably due to the greater utilization of Δ-6 desaturase in the n-3 FA with respect to the n-6 pathway.…”

“…There is also evidence, that hens have a unique ability to deposit dietary lipid into the egg yolk, which makes the egg a potential source of polyunsaturated fatty acids (PUFAs) (Filardi et al, 2005). So during the past two decades have been demonstrated the desirable changes in the lipid profile of egg yolks by dietary supplemented with marine or oilseed oils (Van Elswyk, 1997;Milinsk et al, 2003;Cachaldora et al, 2006). It should be mentioned that the inclusion of n-3 PUFA promotes a qualitative change in the yolk FA profile and reducing the n-6/n-3 ratio to a more beneficial level with regards to the human nutritional needs (Simopoulos, 1998).…”

Quality characteristics of <i>n</i>-3 polyunsaturated fatty acid-enriched eggs

“…The contents of stearic acid (C18:0) and oleic acid (C18:1) of eggs from hens fed diets 1 and 2 are similar compared with the control diet; this was also reported by Cachaldora et al (2006). The high contents of EPA and DHA should be pointed out, since these are the two most important essential fatty acids for human health (Vaccaro et al, 2005).…”

“…This effect on yolk colour was reported in studies concerning enriched eggs (González-Esquerra and Leeson, 2000;Cachaldora et al, 2006). Although these authors also described other negative effects (shell thickness and lower egg weights), in this work and, as shown above, these negative effects were not found.…”