Abordagem meta-analítica para identificar os melhores protocolos publicados para enriquecimento de ovos com ômega-3

Abstract

Eggs enriched with omega-3 have been gaining relevance because they are an easily accessible source of this essential fatty acid, because they are free from religious or cultural restrictions on their consumption, because they are present in numerous recipes and, mainly, because they have an affordable market price. However, the impact of the enrichment protocol on the internal and external characteristics of eggs still requires more objective investigations. Thus, the objective of this study was to answer, based on a systematic review and meta-analysis, whether supplementing the diet of commercial laying hens with omega-3 modifies not only the fatty acid profile of eggs, but also the weight and production of eggs and the feed conversion of the bird. A systematic review of the literature was carried out in several databases on the reference date of 12/07/23. Of the 1,835 articles retrieved, 17 fully met the eligibility criteria and were included in the meta-analysis. These studies included a population of 3,423 hens, mostly brown birds (n=1,758), with supplementation starting between 19 and 22 weeks (n=1,384), evaluated for more than 8 weeks (n=1,891) and supplemented with a mixed animal and vegetable source (n=944), followed by microalgae (n=794) and fish oil (n=588). Overall, dietary supplementation with omega-3 significantly increased the omega-3 concentration in the egg (p<0.001) but decreased both egg weight (p=0.007) and egg production (p=0.040). The feed conversion of the hens was not affected (p=0.075). Heterogeneity between studies was significant (p<0.004) for all variables, except egg weight (p=0.211). Meta-regression and subgroup analysis were performed to identify significant causes of heterogeneity. The intensity of the response of weight and egg production to supplementation was moderated by the genetics of the hens and by the source and concentration of omega-3 in the diet. The concentration of omega-3 in the egg was moderated by the source and concentration of omega-3 in the diet. It is concluded that there is evidence in the literature that feeding hens with omega-3 sources results in higher concentration of omega-3 in the eggs, but decreases weight and egg production.