Hematological, Histological, and NMR Analysis of Meat Quality and Growth Performance of Broilers Fed with Probiotics Bacillus licheniformis-Supplemented Poultry Feed.

The present study evaluated the effect of probiotics (Bacillus licheniformis) on the growth pattern, hematological parameters, metabolic profile, and meat quality of broiler birds. Total of 75 Ross 308 broiler chicks were divided into three groups (25 broilers in each) and fed with poultry feed supplemented with probiotics (15 g/ton of feed for starter diet and 35 g/ton for grower diet), antibiotic (amoxicillin 900 mg/ton of feed) and basal poultry feed, respectively, for 5 weeks. The broilers of control group exhibited higher feed conversion rate (FCR), i.e., 1.932 ± 0.10 followed by the FCR of antibiotic group (1.84 ± 0.10) and probiotic (1.714 ± 0.10) group broilers. It indicated that the chicks fed with probiotic rich feed gained more weight while ingesting comparatively less quantity of feed. The difference in weight of body organs (heart, liver, spleen, and gallbladder) among all groups showed no significant change (p > 0.05). However, significant difference of intestinal length was observed; control group with longest intestine (213.5 ± 15.22 cm) and probiotic group with shortest intestine of length 194 ± 5.51 cm. Moreover, probiotics group showed an improved temperature (30.75 ± 1.75 °C) and pH (6.05 ± 0.05) in meat after 20 min of slaughter. The breast muscles of probiotic group chickens exhibited greater cooking loss, yellowness (b*) (13.15 ± 2.23) and lightness (L*) (53.9 ± 1.6) with reduced redness (a*) (12.305 ± 1.35) and shear force (17.265 ± 0.82) compared to the control and antibiotic-treated group. The histological examination of probiotics group chickens pectoral muscles indicated significant (p < 0.05) increase in fascicle diameter (654.08 ± 5.55 µm) and fiber density (29.26 ± 0.65 n/µm) of meat compared to the antibiotics and control group. Probiotic-treated chickens showed improved intestinal health while the blood glucose level of the probiotics group chicken was reported to be higher. Metabolic analysis of leg and breast meat of chickens fed with probiotics supplemented feed with 600 MHz 1H-NMR spectra revealed 23 identified metabolites, of which seven metabolites (carnitine, phenylalanine, histidine, O-acetylcarnitine, omega 3 fatty acid, uridine, lactate) were only reported in probiotics group. The findings suggest that B. licheniformis enhances growth, carcass yield, organ weights, meat quality, and overall health of broiler birds. Consequently, Bacillus licheniformis can be utilized as a substitute growth promoter instead of antibiotics.