Dietary L-Glutamine affects Eggshell Quality in the Post-Peak Laying Period

Abstract

In the current study the hypothesis that 1.0% dietary inclusion of glutamine (Gln), a conditionally essential amino acid that influences protein synthesis and shows anti-osteoporotic effect, can influence eggshell quality was tested on laying hens in the post-peak laying period. A 30-week-old Bovans Brown hens were randomly assigned to control group or group supplemented with Gln in the form of alpha-ketoglutarate (10 g/kg) with 12 replicate cages (2 hens/cage) in each group. The experimental period lasted for 30 weeks, from the 31st to the 60th week of age of hens, when eggs were collected and selected eggshell quality indices were determined. While Gln supplementation had no effect on egg geometry and eggshell cracking force, the analysis of eggshell quality showed an increase of the eggshell thickness (P<0.01), porosity (P<0.01), eggshell specific surface (P<0.001) and positive changes in other mechanical parameters (decrease of eggshell stiffness and Young’s modulus, P<0.05 and P<0.01, respectively; increase of work needed to crack the eggshell, P<0.05). Changes in eggshell mineral composition, including an increase of Ca content (P<0.001), were also observed. In conclusion, the current study showed a beneficial effect of Gln on the eggshell thickness, calcification, and some mechanical parameters.

Assessing Bone Health Status and Eggshell Quality of Laying Hens at the End of a Production Cycle in Response to Inclusion of a Hybrid Rye to a Wheat–Corn Diet

“…Additionally, as mentioned above, egg deformation under a load in different egg planes was the only mechanical parameter that changed following xylanase supplementation in the current study. Therefore, it could be assumed that the observed effect of enzyme supplementation to different diets on egg deformation might have been due to changes in the mammillary layer and eggshell microstructure [51,52]. This should be verified by future studies.…”