Influence of Dietary Palm Oils, Palm Kernel Oil and Soybean Oil in Laying Hens on Production Performance, Egg Quality, Serum Biochemicals and Hepatic Expression of Beta-Carotene, Retinol and Alpha-Tocopherol Genes

Simple Summary Limited reports on dietary oil effects in poultry have focused on palmitic acid-, carotenoid- and vitamin E-rich palm oils and medium-chain fatty acid-rich kernel oil. This study explored the effects of dietary crude palm oil (CPO), red palm oil (RPO), refined palm oil (RBD), palm kernel oil (PKO) and soybean oil (SBO) in laying hens. The various oils had no effect on hen-day egg production (HDEP), egg weight, feed intake, feed conversion efficiency (FCR) and egg quality parameters such as shell thickness, shell weight and the percentage of these shell characteristics. Higher egg freshness is indicated by higher albumen height and Haugh unit with dietary CPO inclusion. The RPO and CPO increased the color of the egg yolk as determined by the higher RCF (Roche color fan) and redness (a*) and yellowness (b*) values. Higher serum ALP was observed after feeding the PKO and SBO diets. Dietary CPO and RPO contributed to higher beta-carotene in feed, liver and yolk that improved egg yolk color. No difference in retinol and alpha-tocopherol of serum, liver and yolk was observed. However, a difference was observed in the retinol gene expression in the liver. In conclusion, feeding laying hens with different saturated fatty acids did not influence the production performance and egg quality. Despite being used for many decades, there is a lack of poultry research investigating the effects of dietary palmitic, carotenoid and vitamin E-rich palm oils and medium-chain fatty acid-rich PKO. The current study aimed to elucidate the influence of different dietary oils in layers on production performance, egg quality, serum biochemicals and expression of genes related to beta-carotene, retinol and alpha-tocopherol in the liver. A total of 150 Hisex brown laying hens were fed diets containing CPO, RPO, RBD, PKO or SBO at a similar level for 16 weeks. Different oils did not affect egg production performance and egg quality. CPO improved the freshness of eggs. CPO and RPO enhanced egg yolk color. There was no influence of different oils on serum biochemicals except greater serum ALP in PKO and SBO. CPO and RPO contributed to greater beta-carotene in feed, liver and yolk. There was no difference in retinol and alpha-tocopherol of serum, liver and yolk. However, the liver RBP4A gene was upregulated in CPO and PKO, and the CYP26A1 gene was downregulated in palm oils and PKO. In conclusion, palmitic-rich saturated fatty acids in palm oils and MCFA-rich PKO did not negatively affect egg production performance and quality compared to oil with high unsaturated fatty acids.

Automated summary

This study investigated the effects of different dietary oils on laying hens and found that they did not affect egg production performance and egg quality. However, dietary crude palm oil (CPO) improved egg freshness, and both CPO and red palm oil (RPO) enhanced egg yolk color. Additionally, CPO and RPO increased the levels of beta-carotene in feed, liver, and yolk.