Effects of the In Ovo Injection of L-Ascorbic Acid on Broiler Hatching Performance.

Effects of the in ovo injection of various concentrations of L-ascorbic acid (L-AA) on the hatchability and retention levels of L-AA in the serum of broiler embryos were investigated. A total of 960 Ross 708 broilers hatching eggs were randomly divided into four treatment groups: non-injected control, saline-injected control, and saline containing either 12 or 25 mg of L-AA. At 18 days of incubation (doi), injected eggs received a 100 µL volume of sterile saline (0.85%) alone or containing one of the two L-AA levels. Percentage egg weight loss was also determined from 0 to 12 and 12 to 18 doi. Hatch residue analysis was conducted after candling to determine the staging of embryo mortality. At approximately 21 doi, hatchability of live embryonated eggs (HI) and hatchling body weight (BW) were determined. Blood samples were taken at 6 and 24 h after L-AA in ovo injection to determine serum L-AA concentrations. Serum L-AA concentrations, HI, and hatchling BW did not differ among all treatment groups. However, chicks in the non-injected group had a higher (p = 0.05) embryonic mortality at hatch in comparison to those in the 12 mg of L-AA in saline and saline alone treatment groups. These results suggest that the in ovo injection of high levels of L-AA (12 and 25 mg) does not negatively affect HI or serum concentrations of L-AA but has the potential to promote embryonic livability. Further research is needed to determine the retention time of L-AA in the other tissues of broilers, including the cornea of the eye, in response to different levels of supplemental L-AA.

Effects of the In Ovo Vaccination of the ts-11 Strain of Mycoplasma gallisepticum in Layer Embryos and Posthatch Chicks.

The transmission of the ts-11 strain of Mycoplasma gallisepticum (MG) vaccine (ts-11MGV) between incubated eggs and between hatchlings that was administrated via in ovo injection, and its subsequent effects on their posthatch performance were evaluated. Marek's disease diluent alone (sham-injected) or containing either 3.63 × 101, 102, 103, or 104 cfu of ts-11MGV was manually in ovo-injected into the amnion on 18 days of incubation. Egg residue analysis, percentage incubational egg weight loss, hatchability of viable injected eggs, and hatchling body weight (BW) were assessed. Selected hatchlings from each treatment replicate group were swabbed in the choanal cleft for MG DNA detection. Female chick live performance was also assessed through 21 days of posthatch age. Unexposed control sentinel chicks were allocated to each treatment replicate group to assess horizontal transmission. Birds were later swabbed and bled respectively, for detection of MG DNA and IgM production at 21 days posthatch. In all birds, no MG DNA was detected and SPA tests for IgM were negative. Among all variables, only 0 to 21 day BW gain was significantly affected by treatment and was lower in the 3.63 × 104 ts-11 MGV treatment in comparison to all the other treatments. Because ts-11MGV does not exhibit vertical or horizontal transmission capabilities under commercial conditions, it may not be a good candidate for in ovo injection.

Proteome profile of the pipping muscle in broiler embryos.

This study is the first proteomics analysis of the muscularis complexus (pipping muscle) in chicken (Gallus gallus) broiler embryos. We used differential detergent fractionation and nano-HPLC-MS/MS analysis to identify 676 proteins from all cellular components. The identified proteins were functionally classified in accordance with their involvement in various cellular activities.

Assessment of the effects of electromagnetic field modification on egg-laying hens in commercial flocks as indicated by production measures.

OBJECTIVE: To assess the effects of electromagnetic (EM) field modification by use of Nufield EM field modification (NEFM) units on egg-laying hens in commercial flocks as indicated by production measures, including hen-day mortality rate (HDMR) and eggs per hen housed (EHH). ANIMALS: 16 commercial flocks of egg-laying hens. PROCEDURE: 5 caged commercial table egg layer flocks (Single Comb White Leghorns) successively housed at the same location during a 6-year period were exposed to NEFM. There were 7 hens/cage (317 cm2 of floor space/bird). At the same site, 11 concurrent non-NEFM-exposed flocks (4 genetically different strains) were sequentially housed. All 16 flocks underwent the same feed and management practices. For each NEFM- and non-NEFM-exposed flock, HDMR and EHH were compared with their respective national breeder goals (BG), defined as the reasonable genetic potential expressed under optimal management and environmental conditions. Furthermore, the HDMRs and EHHs of the NEFM- and non-NEFM-exposed flocks were compared. RESULTS: Mean HDMR and EHH of the NEFM-exposed flocks was 36.9% less and 4.96% greater than the relevant BG, respectively. Mean HDMR and EHH of the non-NEFM-exposed flocks was 12.6% and 0.49% greater than the relevant BG, respectively. Compared with the 11 non-NEFM-exposed flocks, the NEFM-exposed flocks collectively had a 47.6% decrease in HDMR and 1.33% increase in EHH. CONCLUSIONS AND CLINICAL RELEVANCE: Results strongly suggest that application of NEFM in commercial egg-layer flocks improves production measures, which has important welfare implications as well as gross economic advantage.