Effects of different feed additives and antibiotic growth promoter on the immune response, tibia bone characteristics, meat quality and growth performance of Ross 308 broiler chickens

Abstract

Introduction: The effects of different feed additives as antibiotic replacement on the growth
performance, immune response, tibia characteristics and meat quality of broilers were
investigated.
Materials & Methods: In this experiment, 540 one-day-old male broiler chickens of Ross 308
strain were randomly distributed into 6 treatments with 6 replicates per each. The experimental
treatments were 1) a control group (corn-soybean meal diet), 2) control group + 0.25 g/kg
antibiotic as growth promoter (Lincomycin), 3) control group + 1 g/kg herbal extract (contains
garlic, thyme, turmeric, lemon balm), 4) control group + 3 g/kg medium chain fatty acids (contains
a mixture of caproic, caprylic, capric, and lauric acids), 5) control group + a mix of 1.5 g/kg
prebiotic (MHF-Y) and 0.2 g probiotic (Lactofeed) and 6) 1 ml/L essential oils in drinking water
(contains ferula gummosa, eucalyptus, clove, peppermint, thyme, fennel, ajwain and satureja).
Results: The results showed that the instars of fourth larval instars of flour moth were susceptible
to all isolates of M. anisopliae. The most virulent isolates were MTA with approximately 90%
mortality on A. kuehniella. The most virulent isolates were MTA with 0.42×106 conidia/ml LC50
on A. kuehniella while the least virulent isolate was MTV 4.3×109 conidia/ml LC50 on A.
kuehniella. However, the highest relative weight of spleen and total ash of tibia observed in
broilers which received medium chain fatty acids. experimental treatments had no effect on the
meat quality.
Conclusion: It can be concluded that feed additives may improve growth performance and some
of the immune and tibia traits in broiler chickens.