Effects of the in ovo injection of various levels of L-ascorbic acid (L-AA) on the performance and corneal erosion incidence in Ross 708 broilers exposed to 50 parts per million (ppm) of atmospheric ammonia (NH₃) after hatch were determined. A total of 1440 Ross 708 broiler embryos were randomly assigned to 4 treatments: non-injected (control), 0.85% sterile saline-injected (control), or saline containing 12 or 25 mg of L-AA. At hatch, 12 male chicks were randomly assigned to each of 48 battery cages with 12 replicate cages randomly assigned to each treatment group. All birds were exposed to 50 ppm of NH₃ for 35 d and the concentration of NH₃ in the battery cage house was recorded every 20 s. Mortality was determined daily, and mean body weight (BW), BW gain (BWG), average daily BW gain (ADG), and feed intake, as well as feed conversion ratio (FCR), were determined weekly. From 0 to 35 d of post-hatch age (doa), six birds from each cage were selected and sampled for eye erosion scoring. Incidences of corneal erosion were significantly higher at 21 and 28 doa in comparison to those at 14 and 35 doa, and at 21 doa, birds in the saline-injected group exhibited a higher incidence of corneal erosion compared to all other treatment groups. The in ovo injection of 12 mg of L-AA increased BWG (p = 0.043) and ADG (p = 0.041), and decreased FCR (p = 0.043) from 0 to 28 doa in comparison to saline-injected controls. In conclusion the in ovo administration of 12 mg of L-AA may have the potential to improve the live performance of broilers chronically exposed to high aerial NH₃ concentrations, but further study is needed to determine the physiological and immunological factors that may contribute to this improvement.

The effects of 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 four in ovo treatments included 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 the 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 at 35 days of posthatch age (doa), and the concentration of NH₃ in the room was recorded every 20 s. At 0, 7, 14, 21, and 28 doa, one bird from each cage was arbitrarily selected and euthanized 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, and for liver and eye L-AA concentrations at each sampling timepoint. In ovo injection of either 12 or 25 mg of L-AA decreased tracheal attenuation incidence at 0 doa compared to the non-injected or saline-injected control groups. Furthermore, the percentage of mild tracheal inflammation scores was lower at 28 doa in response to the in ovo injection of 12 mg of L-AA compared to the non-injected or saline-injected control groups. These results indicate that in ovo injection of 12 mg of L-AA reduces tracheal inflammation in broilers subjected to elevated atmospheric NH₃.

Background: Stocking densities could have a significant impact on birds when reducing or eliminating antimicrobials (antibiotic-free; ABF) in poultry diets. This study investigated the effects of stocking densities on growth performance and carcass characteristics of broilers fed antibiotic-free diets grown to 3 kg. Methods: A total of 888 1-d-old Ross × Ross 708 chicks were randomly distributed into 24 pens. The treatments were four stocking densities including 29, 33, 39 and 42 kg of BW/m2; each treatment was represented by six replicates. Treatments were blocked within the room to account for any variations in room conditions. Treatment assignments were randomized within each block. Used bedding was obtained from commercial farms to simulate commercial conditions and litter microflora. Birds were fed antibiotic-free (ABF) diets and provided a three phase-feeding program (Starter: 0-14 d, Grower: 15-28 d and Finisher: 29-42 d). Feed and water were provided ad libitum. Birds and feed were weighed on 1, 14, 28 and 42 d of age to measure growth performance. On d 43, 10 (5 males and 5 females) birds from each pen were processed to determine weights and yields. Result: The BW and BW gain, live weight, carcass weights and carcass yield percentage were not affected by stocking density. Also, mortality was not affected by stocking density. However, FI and FCR for the starter period were significantly elevated (P less than 0.001 and P less than 0.001, respectively) at lower stocking densities, but were not different for the remainder of the growout. In conclusion, stocking densities evaluated from 29 to 42 kg/m2 with appropriate environmental management has a negligible effect on overall production and processing yield in ABF broilers.

Light impacts layer hen's welfare and production. This study investigated the effects of a novel LED light system on blood physiological variables in laying hens. In each of the two trials, 320-layer pullets were allocated to 16 groups of 20 birds. Treatments included the prototype LED lighting (two rooms) and the conventional 2700 K LED bulbs (two rooms). On each sampling day, blood samples were collected and analyzed immediately. Results show that only a few physiological variables were affected by treatments, but age had effects on most examined variables. No effects of treatments or age on plasma corticosterone signify a similar level of physiological stress.