Shrimp head meal in laying hen rations and its effects on fresh and stored egg quality

in order to determine the effects of shrimp (penaeus spp.) by-product meal (sbm) on performance parameters, physical quality and sensory evaluation of fresh and stored eggs, 120 white leghorn hens, 42 weeks old, were distributed in 4 replicates of five treatments (0, 10, 15, 20 and 25% sbm). at 28 days of the assay, eggs were collected from each treatment to evaluate physical quality at 0, 15 and 30 days of storage at 4 and 20oc. a factorial design of 5×3×2 was used. there were no statistical differences in performance parameters (p>0.05). average egg weight was higher (64.08g) with 15% sbm, without any detectable effect due to storage time. haugh units (hu) decreased in eggs stored at 20oc (15 and 30 days), but not at 4oc. yolk color was reduced in treatments with sbm as compared with the control and was also altered by storage time at 20oc. eggshell weight was not affected by storage conditions or by the treatments. no differences (p>0.05) in eggshell thickness and sensorial evaluation (yolk color and taste) were found. it is concluded that the differences found were caused by storage time and temperature, not by the inclusion of sbm in laying hens？ rations.