Effects of the in ovo administration of L-ascorbic acid on tissue L-ascorbic acid concentrations, systemic inflammation, and tracheal histomorphology of ross 708 broilers subjected to elevated levels of atmospheric ammonia

Authors: MOUSSTAAID, A - Mississippi State University; FATEMI, S - Mississippi State University; LEVY, A - Dsm Nutritional Products, Ltd; Purswell, Joseph - Jody; Olanrewaju, Hammed; BAUGHMAN, B - Mississippi State University; MCNULTY, K - Mississippi State University; GERARD, P - Clemson University; PEEBLES, E - Mississippi State University

Submitted to: Poultry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/29/2023
Publication Date: 3/31/2023
Citation: Mousstaaid, A., Fatemi, S.A., Levy, A.W., Purswell, J.L., Olanrewaju, H.A., Baughman, B., Mcnulty, K., Gerard, P.D., Peebles, E.D. 2023. Effects of the in ovo administration of L-ascorbic acid on tissue L-ascorbic acid concentrations, systemic inflammation, and tracheal histomorphology of ross 708 broilers subjected to elevated levels of atmospheric ammonia. Poultry. 2:158-173. https://doi.org/10.3390/poultry2020014.
DOI: https://doi.org/10.3390/poultry2020014

Interpretive Summary: High atmosphric amonia (NH3) concentrations result in several negative effects on broiler health and overall performance. Due to the rapid growth of modern broiler strains, and their high metabolic requirements, young chicks are more susceptible to elevated NH3 concentrations, especially during the first 28 days of the growth cycle. The objective of this study was to investigate the effects of the in ovo administration of L-ascorbic acid (L-AA) on the eye and liver L-AA concentrations, plasma nitric oxide and mineral concentrations, and tracheal histomorphology 'of Ross 708 broilers subjected to 50 ppm of atmospheric NH3 levels for 3 weeks. The 4 in ovo treatments that were administrated at 17 day of injection were: non-injected (control), saline-injected (control), or saline containing 12 or 25 mg of L-AA. The results of the current study revealed that in ovo administration of 12 mg L-AA improved tracheal histomorphology and reduced tracheal infection, while it had no effects on systemic inflammation during an elevated atmospheric NH3 challenge. In conclusion, the in ovo injection of 12 mg of L-AA was effective in overcoming the negative effects of elevated areal NH3 concentrations on tracheal histomorphology. Further research is needed to determine the physiological and immunological mechanisms that may be involved in local improvements in the tracheal histomorphology of broilers subjected to chronic exposures to elevated levels of aerial NH3.

Technical Abstract: Effects of the in ovo injection of L-ascorbic acid (L-AA) on tissue L-AA concentrations, systemic inflammation, plasma mineral concentrations, and tracheal histomorphology 'of Ross 708 broilers subjected to elevated atmospheric ammonia (NH3) levels after hatch were investigated. The 4 in ovo treatments were: non-injected (control), saline-injected (control), or saline containing 12 or 25 mg of L-AA. The in ovo treatments were applied at 17 days of incubation by injecting a 100 µL volume of each pre-specified treatment into the amnion. At hatch, 12 male chicks were randomly allocated to each of 12 replicate battery cages belonging to each treatment group. The cages were arranged in a randomized complete block design within a common room. All birds were exposed to 50 ppm of NH3 through 35 days of posthatch age (doa) and the concentration of NH3 in the room was recorded every 20 seconds. At 0, 7, 14, 21, and 28 doa, one bird from each cage was randomly selected for determinations of liver and eye L-AA concentrations at 0, 7, 14, 21, 28 doa; plasma nitric oxide concentrations at 0, 14, 21, and 28 doa; and plasma calcium and trace mineral concentrations at 0 and 21 doa. Tracheal histomorphology evaluations were performed at 0, 21, and 28 doa. 'There were no significant treatment differences for plasma nitric oxide and mineral concentrations, as well as liver and eye L-AA concentrations at any of the time intervals. The in ovo injection of either 12 or 25 mg of L-AA decreased tracheal attenuation incidence at 0 doa in comparison to the non-injected or saline-injected control groups. Furthermore, tracheal inflammation was significantly reduced at 28 doa in response to the in ovo injection of 12 mg of L-AA whencompared to the non-injected or saline-injected control groups. These results indicate that the in ovo injection of L-AA resulted in a decrease in tracheal inflammation when broilers were subjected to elevated atmospheric NH3.