Effect of different synbiotic administration methods on growth, carcass characteristics, ileum histomorphometry, and...

To combat enteric infections and antibiotic resistance in the poultry industry, researchers seek alternatives such as probiotics, prebiotics, and synbiotics as growth promoters. Synbiotics support probiotic growth through the supply of essential nutrients. The study's objectives were to assess the most effective delivery methods for synbiotics and evaluate their growth, histomorphometric, and hematological impacts on Cobb-500 broilers.

Two studies, independently conducted, employed a completely randomized design. One hundred and eighty viable eggs in the first trial were assigned to three groups: Control (T1), sterile water (T2), and synbiotic in sterile water (T3). On the 21^st day of hatching, hatchability, day-old body weights, and ileum samples for histomorphometric analysis were recorded. In the second trial, out of 500 viable eggs, 200 eggs were fed in ovo with synbiotics (PoultryStar® sol, Biomin Singapore Pte Ltd, Singapore) on 17.5 days and 300 were set aside without in ovo injection. The treatments were control (T1), in water synbiotic (T2), in ovo synbiotic (T3), combination of in ovo synbiotic and synbiotic in feed (T4), and synbiotic in feed only (T5). On 21 and 42 days, blood, ileum, and visceral organ samples were collected for laboratory analysis. Data on weight gain, daily feed intake, and water consumption were recorded for 42 days.

The initial experiment's results revealed a decrease in hatchability, slight weight increase, and significant intestinal morphological changes with the use of an in ovo synbiotic. Applying synbiotic through various methods in the second trial yielded better growth results, lower blood cholesterol, and significantly longer (p < 0.05) villi on 21 days.

Using the in ovo method to administer synbiotics lowered hatchability. Use of synbiotics with any method or in combination enhances growth, ileum structure, dressing yield, feed efficiency, and cholesterol levels in blood. Synbiotics enhance gut health and overall performance in broilers when used through diverse approaches.