Effect of acetic acid supplementation on intestinal histomorphology, immunity and performance of broilers

The present study was conducted to investigate the effect of supplementation of different levels of acetic acid on performance, hematology, blood metabolites and intestinal histomorphology, and immunity of broilers. One hundred eighty day old broiler chicks were purchased from local hatchery and were reared in a group for one week. After one week, one hundred twenty broiler chicks of middle weight range were picked up randomly and divided into 12 experimental units (10 chicks/each). These units were further allotted to 4 treatment groups (T1, T2, T3 and T4). Treatment T1 was served as control i.e. without any supplementation. However, treatment T2, T3 and T4 were supplemented with acetic acid @ 0.1%, 0.2% and 0.3%, respectively. Experiment was conducted from 1-42 days under uniform managemental conditions, while first week was adaptation period. Acetic acid supplementation significantly improved weight gain (6.05-9.61%), feed conversion ratio (5.31-11.59). Effect of acetic acid showed non-significant effect on feed consumption. Feed consumption was minimum under treatment T4 (0.3% acetic acid). Overall acetic acid supplementation at 0.3% level improved bird's performance during 2-6 weeks of age. Slaughtered data showed that dressing percentage exhibited non-significant effect by supplementing acetic acid. Supplementing acetic acid significantly increased intestinal length (1.43-5.82%), intestinal weight (5.66-23.23%) and showed significant decrease in pH of proventriculus (2.46-6.82%) and gizzard (5.98-11.55%) as level of acid increased. The best results were found under T4 (0.3% acetic acid). On the other hand acetic acid supplementation did not have any significant effect on pH of duodenum, jejunum and ileum segments of small intestine. By increasing the levels of acetic acid in broilers feed, villus height, crypt depth, villus surface area of duodenum were increased significantly from 1.76-5.34%, 10.43-13.96% and 15.29-31.96% respectively. Use of acetic acid significantly increased jejunum's villus height (2.60-21.04%), villus surface area (18.35-38.35%) but did not showed any significant effect on its crypt depth. Ileum villus height and crypt depth was increased (6.37-12.96% and 11.57-34.64% respectively) by using acetic acid in broiler feed; however its villus surface area was not effected at any used level of acetic acid. As level of acetic acid increased (0.1 %, 0.2% and 0.3% respectively) in feed, it exhibited significant increase in lymphocyte concentration (3.60-7.19) and showed significant decrease in heterophil/lymphocyte ratio (2.63-7.89%). Supplementation of acetic acid revealed non-significant effect on red blood cells, white blood cells, heterophil, packed cell volume, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. Acetic acid supplementation at the level of 0.3% showed significant effect on serum calcium, serum phosphorus, serum total protein, serum globulin, antibody titer against Newcastle disease and antibody titer against Infectious Bursal disease. While it exhibited non-significant effect on serum albumin and albumin/globulin ratio. In conclusion, acetic acid supplementations in broiler feed revealed positive effect on performance, intestinal histomorphology, some hematological parameter, blood metabolites and immunity.