The Effects of Acidifier Inclusion in the Diet on Growth Performance, Gastrointestinal Health, Ileal Microbial Population, and Gene Expression in Broilers

Abstract

The purpose of this study was to investigate the effects of acidifier on broilers' performance. A total of 648-day-old broilers were assigned to four treatments (0, 1, 2, and 3 g/kg acidifier in the diet). In the grower period, the acidifier inclusion resulted in a higher average daily weight gain (ADWG) than in the control. On the 40th day of age, 3 g/ kg of acidifier increased ADWG and average daily feed intake (ADFI). The highest ADWG was observed in the 3 g/kg of acidifier treatment for the whole period. Orthogonal contrast between acidifier and control indicated that cholesterol and high-density lipoprotein (HDL) concentration in the serum was lower in the acidifier-fed broilers. Inclusion of 2 and 3 g/kg of acidifier reduced Salmonella population in the ileum. Adding 2 and 3 g/kg acidifier to the diet increased crypt depth compared to other treatments. Weight and length of the tibia were also significantly increased by acidifier. The quadratic effect showed that the acidifier had a significant effect on the tibio-tarsal index. The mRNA expression of PPARγ and Toll-Like Receptor 4 (TLR4) genes in the ileum of broilers that were fed 3 g/kg acidifier was significantly higher than in other treatments. Fatty Acid-Binding Protein 1 gene showed a significant enhancement effect by the acidifier: with increasing levels of acidifier, its expression also increased. In conclusion, the acidifier improved the performance, upregulated the expression of ileal fatty acid-binding protein 1 (FABP1), TLR4, and PPARγ genes, as well as increased the tibia length, and reduced the Salmonella population in the ileum.