The objective of this research was to determine the optimal level of an encapsulated butyric acid (ButiPEARL) based on the performance of male Cobb broilers reared to 42 d of age and to investigate its effects on intestinal morphology. Experiment 1 ( EXP 1: ) consisted of 4 treatments with 12 replicate pens that contained 45 broilers, and Experiment 2 ( EXP 2: ) consisted of 6 treatments with 8 replicate pens that contained 50 broilers. Birds were weighed by pen on d 0, 21, 35, and 42. In EXP 1, the treatments were as follows: 1) control ( C: ); 2) C + 100 g ButiPEARL/ton; 3) C + 200 g ButiPEARL/ton; and 4) C + 300 g ButiPEARL/ton. In EXP 2, the treatments were identical to EXP 1, with 2 additional treatments: 5) C + 400 g ButiPEARL/ton and 6) C + 500 g ButiPEARL/ton. In EXP 1, two 42-d-old broilers per pen were randomly selected for duodenal and jejunal tissue collection. Only the samples from the broilers fed the C or 300 g ButiPEARL treatments were analyzed for histology in EXP 1. For EXP 2, on d 21 and 35, two broilers per pen were randomly selected for duodenal, jejunal, and ileal tissue collection. For EXP 1 and 2, BW gain increased linearly with increasing butyric acid levels (P < 0.027 and P < 0.001, respectively). For EXP 1 and 2, feed conversion linearly improved with increasing butyric acid from 0 to 42 d (P < 0.001 and P < 0.001, respectively). In EXP 1, there were no differences in any intestinal morphology at 42 d between broilers fed the C or 300 g ButiPEARL treatments. In EXP 2, there were no differences in villus height at 21 or 35 d of age with any level of butyric acid. Based on the results of this research related to BW gain and feed conversion, the recommended optimum dosage level for ButiPEARL in broilers reared to 42 d of age is up to 500 g/ton.

The effects of the in ovo administration of vitamin D 3 ( D 3 ) and its metabolite, 25-hydroxyvitamin D 3 ( 25OHD 3 ) , on the performance, breast meat yield, and inflammatory responses of broilers fed commercial diets were investigated. Live embryonated Ross 708 broiler hatching eggs were randomly assigned to one of the following 5 in ovo injection treatments at 18 d of incubation: 1) noninjected; 2) diluent; diluent containing 3) 2.4-μg D 3 , 4) 2.4-μg 25OHD 3 , or 5) 2.4-μg D 3 + 2.4-μg 25OHD 3 . A 50-μL solution volume of each prespecified treatment was injected into each egg using an Inovoject multiegg injector. At hatch, 18 male chicks were randomly assigned to each of 30 floor pens. The BW, BW gain, feed intake, and feed conversion ratio of the birds were determined in each dietary phase. At 14, 28, and 39 d of posthatch age ( doa ), plasma α-1-acid glycoprotein ( AGP ) levels in 1 bird in each of 6 replicate pens per treatment were determined at 14 and 39 doa. The pectoralis major and minor weights of those same birds were also determined. The remaining birds were processed at 43 doa, and the weights of their processing parts were determined. At 39 doa, the in ovo injection of 25OHD 3 alone decreased plasma AGP concentrations in comparison with the noninjected, diluent, and D 3 -alone treatment groups. In addition, birds that received 25OHD 3 alone had a greater BW at 42 doa than birds in the noninjected, diluent, and D 3 -alone treatment groups. At 39 and 43 doa, breast meat yield was increased in response to the in ovo injection of 25OHD 3 alone in comparison to all other treatments. These results indicate that the in ovo injection of 2.4 μg of 25OHD 3 resulted in an improvement in the performance and inflammatory responses of broilers. A reduction in the inflammatory response subsequent to the in ovo injection of 2.4 μg of 25OHD 3 may have led to an increase in broiler performance.

Effects of the dietary and in ovo administration of L-ascorbic acid (L-AA) on the performance, plasma nitric oxide, and eye L-AA concentrations of Ross 708 broilers were investigated. At 17 days of incubation, live embryonated hatching eggs were randomly assigned to a non-injected or sham-injected (100 μL of saline) control group, or a group injected with either 12 or 25 mg of L-AA suspended in 100 μL of saline. Chicks received a commercial diet with or without 200 mg/kg of supplemental L-AA and were randomly assigned to each of 6 replicate floor pens in each in ovo injection-dietary treatment combination. Weekly live performance variables through 14 days of post hatch age (doa) and the eye weights in both sexes at 0, 7, and 14 doa were determined. At 0 and 14 doa, plasma nitric oxide levels and eye L-AA concentrations of one bird of each sex in each pen were determined. Dietary supplemental L-AA decreased feed intake and growth between 0 and 7 doa, but from 8 to 14 doa; all birds fed supplemental L-AA had a lower feed conversion ratio. At 14 doa, male chicks had higher eye L-AA concentrations and lower plasma nitric oxide levels when treated in ovo with 12 mg of L-AA. In conclusion, dietary L-AA may be used to improve feed conversion in the second week of broiler post hatch growth. However, the in ovo administration of 12 mg of L-AA can increase male eye L-AA concentrations and is effective in reducing their general inflammatory response.

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.

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.