The Influence of Lactococcus and Bacillus Species Probiotics on Performance, Energy Utilization, Intestinal Ecosystem of Broiler Chickens

Abstract

Antibiotics as growth promoters (AGP) has been prohibited, which has a detrimental impact on poultry performances. The prohibition is based on its negative impacts such as antibiotic residue and antimicrobial resistance. Alternative feed additives should be developed to replace the use of AGP in poultry production. Hence, the study aimed to evaluate the effects of combined dietary probiotics L. lactis D1813 and B. licheniformis D3270 on broiler performance, energy utilization, intestinal morphology, and microbial population. A total of 600 one-d-old Lohmann broiler chicks of 300 males and 300 females were used and reared for 35 days. Chicks were distributed into 6 groups (100 birds, 5 replicates of 20 birds) in a completely randomized design. The treatment diets were basal diet with 0.1% different supplementations: T1= CaCO<inf>3</inf> (w/w) (control), T2 = L. lactis at 108 CFU/g, T3 = B. licheniformis spore at 108 CFU/g, T4 = combination of L. lactis at 108 CFU/g and B. licheniformis spore at 108 CFU/g, T5 = B. subtilis spore at 108 CFU/g, and T6 = B. amyloliquefaciens spore at 109 CFU/g. At the pre-starter, the dietary combination T4 yielded lower (p < 0.05) feed conversion ratios compared to the T6 group. Broilers fed L. lactis showed higher body weight gains (p < 0.05) than those fed T5 and T6 groups. All treatments had no significant effect on broiler performance in starter, grower, cumulative periods, as well as E. coli and lactic acid bacteria populations. The combination of L. lactis and B. licheniformis improved (p < 0.05) villus height. The highest villi surface, true metabolizable energy (TME) value (p < 0.05) were recorded in the L. lactis group. In conclusion, the combination of L. lactis D1813 and B. licheniformis D3270 increases feed efficiency in the pre-starter period compared to the B. amyloliquefaciens group. This probiotic combination is unable to achieve the effectiveness of L. lactis in improving villi surface area, TME, and TMEn values. All probiotics have similar effects on the E. coli, LAB population, and broiler performance in the starter, grower, and cumulative periods. © 2022,Advances in Animal and Veterinary Sciences. All Rights Reserved.