Supplementation of Boswellia serrata and Salix alba Extracts during the Early Laying Phase: Effects on Serum and Albumen Proteins, Trace Elements, and Yolk Cholesterol

SIMPLE SUMMARY: Consumers’ attention to sustainability and animal welfare has increased, strengthening the demand for eggs produced through alternative and extensive farming methods. At the same time, the need to reduce antibiotics has fostered the use of alternative dietary supplements. The aim of this research was to study the effects of botanical extracts from Boswellia serrata (Bs) and Salix alba (Sa) on serum and albumen proteins, serum iron and zinc, and egg cholesterol in Leghorn hens, during the critical phase of the onset of laying. The supplementation did not alter the protein profile of egg albumen and the cholesterol content of egg yolk. For the serum and albumen protein profile, no significant differences were observed between control and supplemented hens. Overall, this study confirms that the dietary supplementation with phytoextracts did not negatively affect the physiological variations in serum proteins and, therefore, can be safely used as a treatment to prevent inflammatory states during the early laying phase. ABSTRACT: Extracts from Boswellia serrata (Bs) and Salix alba (Sa) are used as supplements in poultry feed. The aims of this research were to study the possible effects of dietary supplementation with Bs and Sa extracts on serum and albumen proteins, zinc and iron, and yolk cholesterol content in Leghorn hens during the critical phase of the onset of laying. A total of 120 pullets, 17 weeks of age, were assigned to two groups (control (C) and treated (T), n = 60 each). The T group received a supplement containing Bs (5%) and Sa (5%) for 12 weeks. The study lasted 19 weeks. Serum proteins were fractionated using agarose gel electrophoresis (AGE) and SDS–polyacrylamide gel electrophoresis (SDS–PAGE). Trace elements were determined in serum using atomic absorption spectrometry, and yolk cholesterol was determined using a colorimetric test. No significant differences were observed between control and supplemented hens for the analyzed biochemical indices. Moreover, the supplementation with phytoextracts did not negatively affect the physiological variations in serum proteins; therefore, it can be safely used as a treatment to prevent inflammatory states at onset and during the early laying phase.