This study explored the advantageous effects of Bifidobacterium bifidum-based postbiotic and egg yolk powder on performance parameters, serum biochemical profile, antioxidant/ oxidant capacity, and gut histomorphology of boiler chickens. A total of 320 day-old Ross-308 unsexed broiler chicks were randomly allotted to four experimental groups, and each group was replicated four times with 20 birds per replicate. The control group was fed a basal diet. The postbiotic (PB), egg yolk powder (EYP), and PB + EYP groups received the following supplements in addition to their basal diet: 0.3% PB, 3.5% EYP, and 0.3% PB + 3.5% EYP, respectively. Feed intake, except in weeks three and four, was non-significant among the experimental groups. Significantly higher body weight of the birds throughout the experiment, and higher body weight gain for the first three weeks, were recorded in the treatment groups compared to the control group. Treatment groups had a significant effect on European production efficiency factor (EPEF) performance index (PI), and feed conversion ratio (FCR). Treatment groups had a lowering (P<0.05) effect on triglycerides. The total antioxidant capacity was significantly higher in the treatment groups. With respect to gut histomorphology, significantly better villus height and crypt depth of small intestine segment, with a notably higher VH: CD ratio in the ileum, were observed in the PB+EYP group. The results of the present study demonstrate that supplementing broiler chickens with postbiotic and egg yolk powder alone or in combination can improve the performance, triglycerides, total antioxidant capacity, and intestinal histomorphology.

To Cite This Article: Waqas M, Salman M and Ahmad NA, 2026. Effects of postbiotic and egg yolk powder supplementation on the growth performance, serum biochemical profile, antioxidant capacity and gut histomorphology of broilers. Pak Vet J. http://dx.doi.org/10.29261/pakvetj/2026.015