Fatty acid profile in linseed oil and different experimental diets
All the experimental diets of laying hens were iso-nitrogenous and iso-caloric (Table 1).
The linolenic acid content (Table 2) in linseed oil was 50.72% and content was lowest in control diet and highest in 3.5% linseed oil supplemented diet.
The results of fatty acid compositions in linseed oil were in good agreement with
Oliveira et al. (2010) and
Yi et al., (2014). On the other hand,
Soliman and Afifi (2020) revealed that linolenic acid content in linseed oil is 54.38% which was higher than the present study and
Altacli et al., (2022) reported that linseed oil contain 25% linolenic acid which was very much lower than the present study.
Hen-day egg production and feed intake
The hen-day production (Table 3) was not found to be significant (P>0.05) among all the groups on supplementation of linseed oil at different levels in layers diet when compared to control group.
Goncuglu and Ergun, (2004) observed that supplementation of linseed oil at a level of 1, 2, 3 or 4% of the diet had no effect on the laying performance of hens and egg production was similar in laying hens receiving linseed oil up to 4% which was in good agreement with the findings of present investigation. The feed intake (Table 4) was lower in the group supplemented with 3.5% level (P<0.05) linseed oil, however upto 2.5 % supplementation of linseed oil did not affect the feed intake.
The reduced feed intake in T
4 group might be due to smell on inclusion of high level of oil.
Promila et al. (2017) reported that feed intake was decreased on inclusion of 3%, 3.5 % and 4% level of linseed oil in hen’s diet.
Alaqil and Buhaya, (2022) found reduced feed intake on inclusion of linseed oil at 2, 3 and 4% level in hen’s diet. However, feed consumption as well as feed conversion ratio was not affected by dietary incorporation of flaxseed oil up to 2 and 3% in broiler chickens (
Panda et al., 2015 and
Bharath et al., 2017).
Different fatty acid profile in egg yolk
The level of myristic acid, palmitic acid, stearic acid, oleic acid, palmitoleic acid and behenic acids were lower (P<0.01) in T
4 group compared to control group at both 30
th and 40
th week of age (Table 5 and 6).
The present study was good agreement with
Promila et al., (2017) and
Omri et al. (2019) who also observed reduced myristic acid, palmitic acid, stearic acid, oleic acid, palmitoleic acid and behenic acid on inclusion of linseed oil or linseed in the layer diets. On the contrary,
Petra et al., (2012) reported that myristic acid, palmitic acid, stearic acid and oleic acid increased on incorporation of 3% linseed oil. Highest linoleic acid concentration in egg yolk was found in T
1 group followed by T
2, T
3 and T
4 group. It might be due to decreased concentration of the oleic acid in the linseed incorporated diets. Previous studies by
Shakoor et al., (2020) and
Altacli et al., (2022) reports also support the results of the present study. Linolenic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentration in the egg yolk was highest in T
4 group followed by T
3, T
2 group and lowest in control group at both 30
th and 40
th week of age. Increased EPA and DHA might be due to high amount of linolenic acid in the diet as because it is the precursors of EPA and DHA. It is established that the dietary supplementation of flax seed oil linearly increases the percentages of heptadecanoic acid, eicosatrienoic acid and DHA in egg yolks (
Seyyed and Hasan, 2018). Further,
Bean and Leeson, (2003) reported that brown hens deposited more (P<0.01) DHA into their eggs, whereas white hens deposited more LNA into their eggs.
The omega 3 fatty acid content (Table 7 and 8) and Poly Unsaturated Fatty Acid were significantly (P<0.01) higher in T
4 group followed by T
3 and T
2 group and lowest in T
1 group at both 30
th and 40
th week of age.
It was revealed that inclusion of different levels of linseed oil in the diet of laying hens increased the omega 3 fatty acid content in the egg yolk. Significant reduction of omega 6: omega 3 fatty acid was observed in the groups on supplementation of different levels of linseed oil. It was highest (P<0.01) in T
1 group followed by T
2, T
3 and lowest in T
4 group at 30
th and 40
th week of age. Similar findings were also observed by
Keten (2019) and
Petra et al., (2012) who also reported that the addition of linseed oil to the diet of laying hens increases the content of n- 3 PUFAs, such as linolenic acid, EPA and DHA. Further, the value total Saturated Fatty Acid (SFA) and Mono Unsaturated Fatty Acid (MUFA) content in the egg yolk was higher (P<0.01) in T
1 group and lowest in T
4 group in both 30
th and 40
th week of age. Similar findings also reported by
Promila et al., (2017) that total SFA were decreasing with addition of linseed oil in the diet of laying hens.
Cost of production
Local available feed materials were used for formulation of different diets. Costs of diet per kg for different experimental diets were (Rs.) 32.16, 34.97, 37.57 and 40.37 for T
1, T
2, T
3 and T
4 diet respectively. Production cost of one egg for different treatment groups were (Rs.) 7.80, 8.67, 9.08 and 9.69 for T
1, T
2, T
3 and T
4 respectively.