Submitted to: Poultry Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/1/2009
Publication Date: 9/1/2009
Citation: Park, S.W., Burnham, M.R., Branton, S.L., Gerard, P.D., Womack, S.K., Peebles, E.D. 2009. Influence of Supplemental Dietary Poultry Fat on the Yolk Characteristics of Commercial Layers Inoculated Before or at the Onset of Lay with F-Strain Mycoplasma gallisepticum. Poultry Science. 88(9):1883-1887. Interpretive Summary: Mycoplasma gallisepticum (MG) infection of commercial laying hens has been estimated to cost the table egg industry $140 million annually. Efforts to reduce these losses have included the use of live MG vaccines which have been shown reduce early egg production and to also affect egg yolk total lipid, yolk cholesterol and fatty acid concentrations of laying hens. Poultry fat (PF) at 1.5% of the diet was found to alleviate the early reduced egg production from 20 to 26 weeks of age (WOA). In the present study dietary supplementation with 1.5% poultry fat in layers vaccinated with F strain MG was not effective in modulating the effects of an FMG inoculation at 12 WOA on hen egg yolk characteristics between 24 and 58 WOA and further, the combined effects of PF supplementation and FMG inoculation on performance do not influence egg yolk characteristics.
Technical Abstract: The effects of F-strain Mycoplasma gallisepticum (FMG) inoculation and 1.5 % supplemental dietary poultry fat (PF) on the egg yolk characteristics of commercial layers between 24 and 58 wk of age were investigated. Sham and FMG inoculations were administered at 12 (before lay) and 22 (early in lay) wk of age and dietary treatments (basal control diets and basal control diets with 1.5 % supplemental PF) were initiated at 20 wk of age. Yolk lipid concentration was reduced at 24 wk of age in birds that had been inoculated at 12 or 22 wk of age with FMG. Also, the use of 1.5 % supplemental PF increased percentage of yolk weight and yolk:albumen ratio across age and inoculation treatment. Concentrations of yolk palmitic acid increased and those of oleic and linolenic acid decreased when sham inoculations were given at 22 rather than at 12 wk of age. However, FMG inoculations given at 22 rather than at 12 wk increased palmitoleic acid and decreased stearic acid yolk concentrations. At 12 wk of age, FMG inoculations also decreased yolk palmitoleic, oleic, and linolenic acid concentrations while causing increased yolk stearic and arachidonic acid levels when compared to sham inoculations. Furthermore, 1.5 % supplemental PF decreased concentrations of palmitic and oleic acid and increased those of linoleic acid in the yolk between 24 and 58 wk of age. In conclusion, despite the interaction of 1.5 % supplemental PF with the prelay inoculation of FMG on early (18-26 wk) layer performance noted in a previous report, the effects of a prelay FMG inoculation and 1.5 % supplemental PF on the egg yolk characteristics examined in the current study were independent of each other. This would suggest that 1.5 % supplemental PF is not effective in modulating the effects of an FMG inoculation at 12 wk of age on hen egg yolk characteristics between 24 and 58 wk of age, and that the combined effects of PF supplementation and FMG inoculation on performance do not influence egg yolk characteristics.