A novel lighting system using high-frequency differential photostimulation developed for layer chickens was assessed for its effects on physiological response. In each of the 2 trials, a total of 320 ten-wk-old layer pullets were randomly allocated to 16 groups with 20 birds/group. Birds were weighed and randomly assigned to each of 4 cage banks in each of 4 rooms. Experimental treatments included the prototype LED lighting system and conventional 2700K LED bulbs. Photoperiod for the prototype system was 24L:0D per the manufacturer's recommendations and photoperiod for the conventional system followed the Hy-Line Management Guide. Blood samples (3 mL) were collected from the brachial wing vein into heparinized syringes within 45 s after birds were caught from 8 randomly selected birds per room for a total of 32 birds at each blood sampling day of placement, prior to point of lay, and at the termination of the study for a total of 96 birds. Plasma was separated from blood samples by centrifugation and used to determine the concentration of biochemical parameters and enzyme activities using an ACE-AXCEL automatic analyzer. Also, estradiol, follicle stimulating hormone, corticosterone, melatonin, T3, and T4 levels using Tosoh A1A-360 automatic analyzer. Results show that only uric acid (UA) and estradiol were affected by treatments. However, woa had significant effects on most examined variables. Plasma corticosterone was not affected by treatments and woa, indicating absence of physiological stress. In conclusion, using high-frequency LED lighting in layer hen houses does not negatively affect layer hens’ welfare.

Previous trials in which layers were in ovo-vaccinated against strain F Mycoplasma gallisepticum (FMG) showed that nearly 50% of the birds produced IgM antibody against FMG at 6 wk of age (WOA). Standard FMG vaccination application at 9 or 10 woa, result in this percentage at approximately 15 woa. This study investigated when FMG in ovo-vaccinated birds initiate a humoral immune response prior to 6 wk, and if sex influences this response. Hy-Line W-36 embryonated eggs were either not vaccinated (controls) or in-ovo vaccinated with a 50 µL volume of a 10-6 dilution of Poulvac MycoF vaccine (Zoetis). For each treatment group, 384 straight-run chicks were reared. At hatch and at 2, 3, 5, 7, 14, 21, and 28 d post-hatch, 54 birds per treatment were individually weighed and a blood sample was collected for Mycoplasma gallisepticum (MG) IgM antibody detection. ELISA was run on blood samples at 14, 21, and 28 d to distinguish IgG antibody production. At each age, BW was not different between vaccinated and control chicks (all P > 0.19). Males, however, outweighed females starting at d 5 (P = 0.02). Mortality was 1.0% for the control birds and 12.2% for the FMG birds during the first 2 wk. The majority (72.3%) of the mortalities in the FMG group were male. The percentage of control and FMG in ovo-vaccinated birds with IgM antibody production was 0% and 1.9% on d 7, 0% and 31.5% on d 14, 1.9% and 55.9% on d 21, and 0% and 60.6% on d 28, respectively. IgG antibody production in the FMG in ovo-vaccinated birds was 0.0% at 14 d, 2.9% at 21 d, and 21.2% at 28 d of age. All control birds tested negative for FMG-IgG production. In conclusion, the earliest detection of MG antibodies after in ovo vaccination with live FMG occurred at 7 d. Male layer chickens were more susceptible to the effects of an in ovo FMG vaccine than females.

Consumption of poultry meat has increased dramatically due to the relative price-competitiveness as compared to other meat products. The rapid growth and increased production efficiency of modern genetic strains is perceived to negatively impact the welfare of the animal. Hematological analyses such as acid-base balance provide a thorough evaluation of the welfare in both animals and humans. This study investigated the effects of feeder space availability on welfare of broilers grown to heavy weights using blood physiological variables. The study was a randomized complete block design. In each of the 2 trials, a total of 1,440 one-d-old Ross × Ross 708 chicks (straight-run) were obtained from a commercial hatchery. Chicks were equally and randomly allocated to 32 pens based on feeder space treatment. Treatments were 4 different feeder space allocations: 2.3 (Single feeder), 2.30, 4.60, and 6.90 cm/bird. To maintain uniform bird:feeder floor space, 3 feeders were installed in each pen, except for the single feeder pen. Blood samples (3 mL) were collected from the brachial wing vein of 3 birds per pen on d 27 and 55, which were then analyzed immediately for whole blood physiological variables. The remaining blood samples were centrifuged to collect plasma that was used for corticosterone and thyroid hormones analysis. Results show there was no effect of feeder space on most of the selected physiological variables, but age had significant effects on most of the examined variables. However, all observed changes were within physiological ranges. Plasma corticosterone and blood glucose were not affected by feeder space and age, indicating absence of physiological stress. The results are in broad agreement with those reported in the literature and on homeostatic variation of broilers grown to heavy weights. In conclusion, expanding feeder allowance does not enhance the welfare of broilers grown to heavy weights.

Consumer concern about rapid growth and increased production efficiency is perceived to negatively impact the welfare of the animal. This study investigated the effects of feeder space availability on welfare of broiler chickens reared to 56 d of age on biochemical, enzymatical, and electrolyte parameters. The study was a randomized complete block design. In each of the 2 trials, a total of 1,440 one-day-old Ross x Ross 708 chicks (straight-run) were obtained from a commercial hatchery. Chicks were equally and randomly allocated to 32 pens based on feeder space treatment. The 4 feeder space treatments were 2.3 cm/bird with one feeder per pen and 2.3, 4.6, and 6.9 cm/bird with 3 feeders per pen and retain uniform bird:feeder floor space, 3 feeders were installed in each pen, except for the single feeder pen. Blood samples (3 mL) were collected from the brachial wing vein of 3 birds per pen on d 27 and 55. The collected blood samples were centrifuged for plasma to determine the electrolyte levels, bio-chemical concentrations, and enzyme activities. Results show that only uric acid was affected by feeder space while age had significant effects on most examined variables. Plasma corticosterone and glucose were not affected by feeder space and age, indicating absence of physio-logical stress. In conclusion, expanding feeder allowance does not enhance welfare of broilers reared to 56 d of age.

In ovo administration of a live-attenuated F-strain Mycoplasma gallisepticum vaccine (FMG) has proven to be a promising alternative vaccination route for layer chickens to combat M. gallisepticum (MG) infections. Its practical application within current in ovo vaccination procedures, employing a disinfection step after each injection, has been uncertain. The objective of this experiment was to determine the ability of FMG to survive the in ovo disinfection step to elicit a posthatch immune response. In 2 trials, layer eggs were in ovo-vaccinated with or without the disinfection step between injections. Utilizing an Embrex Inovoject M machine, treatments included noninjected eggs, diluent-injected eggs with or without a disinfection step, and eggs vaccinated with an FMG vaccine with or without a disinfection step. Ninety hatched chicks per treatment in both trials were raised to 6 wk of age and swabbed in the choanal cleft for FMG detection via PCR and were bled for IgM (serum plate agglutination) and IgG (ELISA) testing for detection of antibody production against MG. The percentage of birds in which FMG was detected at 6 wk of age were similar among both FMG vaccination treatments in both trials (overall 89.4% without and 91.6% with disinfectant step). Birds vaccinated with FMG also developed antibody responses regardless of employment of the disinfection step. These results indicate that FMG survives the disinfection step employed by commercial machines and can be readily applied to current commercial procedures of in ovo vaccination with no detriment to vaccine efficacy.

Effects of dietary Original XPC (XPC) in commercial layer pullets challenged with the virulent, low passage R strain of Mycoplasma gallisepticum (R-low MG) were investigated. Hy-Line W-36 pullets sourced from MG-clean breeders were fed a basal diet with or without (CON) XPC (1.25 kg/metric ton) from hatch until 12 wk of age (woa). At 8 and 10 woa, half of the birds in each dietary treatment were challenged with R-low MG. Body weight was recorded at 3, 8, and 12 woa, and ovary, ceca, and bursa weights were recorded at 3 and 12 woa. Blood samples were taken immediately before the initial R-low MG challenge at 8 woa and again at 12 woa to test for IgM and IgG antibody production against MG. All birds were evaluated for MG lesion scores at 12 woa. Regardless of challenge, inclusion of XPC in the diet did not significantly alter BW at 3 or 8 woa or relative organ weights at 3 or 12 woa. However, at 12 woa, BW of XPC-fed birds, regardless of challenge was significantly (P = 0.0038) heavier than CON by 25.7 g. All birds tested negative for MG antibodies before the 8 woa challenge. Respective percentage serum plate agglutination and ELISA positive birds at 12 woa were 0 and 0% (CON, nonchallenged), 1.4 and 0% (XPC, nonchallenged), 100 and 47.2% (CON, challenged), and 100 and 50.0% (XPC, challenged). Diet did not signifi-cantly affect ELISA titers, but they were significantly (P < 0.0001) increased due to challenge. Furthermore, lesion scores were significantly higher for R-low MG-challenged birds (P = 0.0012), and dietary treatment with XPC in challenged birds numerically reduced MG lesion scores from 0.278 to 0.194. In conclusion, although dietary XPC did not significantly alter the humoral immune response, antibody titer levels, or severity of MG lesions in layer pullets that were or were not challenged with R-low MG, it led to an increase in their rate of growth through 12 woa.

Objective: This study investigated the effects of recommended stocking densities and dietary antimicrobial inclusion of male broilers grown to 35 days of age on selected hemato biochemical and enzymatical variables.Materials and Methods: In each study, a total of 1024 1-day-old Ross×Ross 708 male chicks were randomly distributed into 32 pens based on 4 assigned stocking density treatments.The treatments consisted of 4 densities (27, 29, 33, 39 kg mG 2 ) and 2 diets (AGP+, ABF) arranged in a 4 × 2 factorial with eight replicates.Conventional (antimicrobial-growth-promoters, AGP+) and antibiotic free (ABF) diets were equally assigned to each pen with feed and water provided ad libitum.Blood samples were collected from the brachial wing vein of 3 birds per pen on d 15, 28 and 35.The collected blood samples were centrifuged to separate the plasma and used to determine the concentration of biochemical parameters and enzyme activities using an ACE-AXCEL automatic analyzer.Results: Results show that only uric acid (UA) was affected by stocking density.However, in comparison to broilers fed the ABF diet, broilers with AGP+ had higher significant (p<0.05)effects on albumin (ALB), total protein (TP), alkaline phosphatase (ALP), Gamma-glutamyl transferase (GGT), Ca 2+ and K + along with lower total bilirubin (TBILI).The results are in broad agreement with those reported in the literature and contribute to our knowledge of blood metabolites and homeostatic variation in developing male broilers.Conclusion: The results indicating that stocking densities up to 39 kg mG 2 with appropriate environmental management regardless of antimicrobial addition in the diets may be suitable for both poultry integrators and contract growers to enhance broilers production efficiency without compromising the welfare of broilers grown to 35 days of age.

Highlights Male broilers showed significant preference for whole pellets as compared to a 50:50 (by mass) mixture of pellets and fines and 100% fines. Broilers preferentially consumed pellets from the mixed diets, with 65% of the mixed diet consumed as pellets. Changes in feeder location did not affect preferences, and locations of preferred feed forms were readily re-acquired after re-positioning. Variation in pellet content may reduce effective feeder space through increased competition for pellets. Abstract. Post-starter phase broiler diets are almost universally pelleted during the manufacturing process to improve nutrient density, handling characteristics, and live performance. Low pellet durability, transportation, and on-farm handling and distribution can result in pellet destruction, ultimately resulting in variation in pellet distribution in a wire-auger feeding system. Given that poultry selectively feed to meet nutritional needs, the variation in pellet distribution observed in commercial feeding systems may result in a reduction in effective feeder space through increased competition for pellets. The objective of this study was to determine the effect of mixtures of feed form and location on feed consumption patterns in broilers. Feed form treatments included 100% pellets (P), a 50:50 mix (M) of pellets and fines (by mass), and 100% fines (F). A total of 264 broilers were randomly allocated to each of six rooms at 37 days of age and provided with each of the three feed form treatments in separate feeders. Feeder locations were rotated every three days, allowing each feed form treatment to be located in all three feeder positions. Overall mean consumption rates for each feed form treatment were significantly different (p = 0.0001) with 70.3%, 21.3%, and 8.1% for the pellet only, mixed, and fines diets, respectively, and a pooled SEM of 0.02%. No significant differences were found for feeder position (p = 0.12) or test period (p = 0.91). Broilers were able to reliably re-acquire the position of preferred feed form treatments after each location change Keywords: Feeding systems, Housing design, Poultry.

Effects of dietary Original XPC (XPC) on 17 selected blood variables in commercial layer pullets challenged with the virulent, low-passage R strain of Mycoplasma gallisepticum (RlowMG) were investigated. Hy-Line W-36 pullets sourced from M. gallisepticum–clean layer breeders were fed a basal diet with XPC (1.25 kg/metric ton) or without from hatch until 12 wk of age (woa). At 8 and 10 woa, half of the birds in each dietary treatment were challenged with RlowMG. Blood samples were taken immediately before the initial RlowMG challenge at 8 woa and again at 12 woa (4 wk after challenge). At 8 woa, blood pH was lower and glucose concentration was higher in the preassigned challenge treatment groups. At 12 woa, the concentration of oxygen dissolved in the blood was significantly lower in the RlowMG-challenged group than the unchallenged group of birds regardless of dietary treatment. The RlowMG challenge significantly increased blood carbon dioxide partial pressure, calcium, sodium, anion gap, osmolality, glucose, and corticosterone levels but significantly decreased blood oxygen partial pressure, oxyhemoglobin concentration, concentration of oxygen dissolved in the blood, chloride, and pH levels. Because blood pH and glucose concentration at 8 woa were examined before challenge, their baseline values were biased with respect to challenge treatment before treatment was applied. However, the lack of a significant main effect due to diet at 8 woa for blood pH and glucose concentration, along with the other 15 blood variables, indicate that the baseline data with respect to dietary treatment were unbiased, allowing for real dietary effects to be accurately assessed. In conclusion, layer pullets challenged with RlowMG undergo a stress response associated with changes in various physiological blood variables, and a decrease in pH and increase in carbon dioxide partial pressure, in association with a lack of change in bicarbonate, indicates that the stress response caused by the RlowMG challenge was associated with respiratory acidosis. Nevertheless, feeding XPC did not influence the effects of challenge treatment on these postchallenge physiological blood values.

Effects of light sources, photoperiods, and strains on growth performance, carcass characteristics, and health indices of broilers grown to heavy weights (>3 kg) were evaluated. The experimental design was a 4 × 2 × 2 factorial treatments consisting of 4 light sources [incandescent (ICD, standard), compact fluorescent light, neutral light emitting diode (Neutral-LED), and cool poultry specific LED (Cool-poultry specific (PS)-LED)], 2 photoperiods (regular/intermittent [2L:2D], and short [8L:16D]), and 2 strains (A, B). In each trial, chicks of 2 different strains from different commercial hatcheries were equally and randomly distributed into 16 environmentally controlled rooms at 1 D of age. Each room was randomly assigned one of 16 treatments from day 1 to 56 D of age. Feed and water were provided ad libitum. Birds were provided a 4 phase-feeding program (starter, grower, finisher, withdrawal). Birds and feed were weighed on 1, 14, 28, 42, and 56 D of age for growth performance. On day 56, a total of 20 (10 males and 10 females) birds from each room were processed to determine weights and yields. The BW, BW gain, live weight, and carcass weight of birds reared under PS-LED were higher (P < 0.05) in comparison with birds reared under ICD, but feed intake, feed conversion ratio, mortality, and carcass characteristics were not affected by treatments. Also, broilers subjected to the short/non-intermittent photoperiod had the lowest (P < 0.05) growth performance and carcass characteristics compared with values obtained for regular/intermittent photoperiods. In addition, strain was significant (P < 0.05) for most of the examined variables. Feed conversion, fat, tender, and yield were not affected by treatments. There was no effect of photoperiod, light sources, or their interactions on mortality. This study shows positive impacts on alternative light sources when compared to ICD along with regular/intermittent photoperiod in commercial poultry facilities rearing the 2 strains used in this study, thereby reducing energy costs and optimizing production efficiency without compromising the welfare of broilers grown to heavy weights.

In ovo vaccination is currently being considered as a means of delivery for live Mycoplasma gallisepticum (MG) vaccines. This study was performed to determine the transmissibility of strain F MG (FMG) from in ovo-vaccinated chicks to non-vaccinated pen mates. Eggs from an MG clean flock were incubated together for 18 D, at which point all live embryonated eggs were either not injected or administered a dilution of an FMG vaccine at 106 CFU per dose, 1 × 104 CFU per dose, 1 × 102 CFU per dose, or 1 CFU per dose. Non-injected eggs were hatched in a separate incubator. Ten non-injected, sentinel birds, and 1 in ovo-vaccinated FMG chick were placed in each of 32 isolation units located in 2 replicate rooms (8 replicates per dose). At 6 wk of age, surviving birds that had been vaccinated in ovo were removed, swabbed for FMG detection by PCR, and bled for serum plate agglutination (SPA) and ELISA testing for the presence of antibodies against MG (1, 2, 6, and all 8 in ovo-vaccinated chicks in the 106, 104, 102, and 1 CFU dosages). At 12 wk of age, the remaining sentinel birds were likewise sampled. No sentinel birds died. The in ovo-vaccinated birds that survived to 6 wk were serologically positive except for 5 birds in the 1 CFU treatment. The percentages of MG-positive sentinel birds and sentinel birds with antibody production against MG at 12 wk from each unit were not different between all MG dosages (P = 0.48, PCR; P = 0.77, SPA; P = 0.85, ELISA). Body weights of the in ovo-vaccinated chicks at 6 wk of age (P = 0.43) and the sentinel birds at 12 wk of age (P = 0.95) were each not affected by FMG treatment. These findings indicate that layer chickens in ovo vaccinated with a live-attenuated FMG vaccine were capable of transmitting FMG to other chicks with which they were in direct contact.

Replacing outdated incandescent light sources provides the opportunity to modify lighting systems according to the needs of different species and according to their spectral sensitivity. Providing a lighting environment geared towards poultry vision may improve bird welfare and blood physiological homeostasis. The influence of two LED light sources (red-supplemented vs. un-supplemented) adjusted to either human spectral sensitivity (lux) or poultry spectral sensitivity (CLUX) was investigated on selected blood physiological variables of male broilers. A total of 960 1-d-old male chicks were randomly distributed into 16 environmentally controlled rooms (60 chicks/room). Birds were provided a diet formulated to meet NRC recommendations with feed and water provided ad libitum. The treatments consisted of two LED light sources (red-supplemented (RS) vs. un-supplemented (WL)) adjusted to either human spectral sensitivity (CIE) or poultry spectral sensitivity (CLUX) arranged in a 2 × 2 factorial. Blood samples were collected from the brachial wing vein of six birds per room on d 21, 28, 42, and 56, which were then analyzed immediately for whole blood physiological variables. Blood plasma samples were analyzed for corticosterone. In comparison to broilers reared under RS, broilers reared under WL had lower levels of pO2, SaO2, angap, and Osmo, which were within physiological ranges. Also, birds reared under CIE had lower levels of Na+, which were also within the physiological range. In addition, blood glucose and plasma corticosterone concentrations were not affected by treatments, suggesting an absence of physiological stress. In conclusion, it is suggested that minor differences in lighting programs such as lighting source should not be expected to compromise broilers welfare, but rather is primarily an economic decision driven by capital and operation costs.

Recent catastrophic disease events have highlighted the need for improved disease prevention measures. Improved biosecurity and vaccination programs can aid in reducing animal population and economic losses. Performance of a prototype automated whole-house spray vaccination system was evaluated over 3 flocks in a commercial breeder pullet house. Birds were spray vaccinated for infectious bronchitis virus (IBV) and Newcastle disease virus (NDV) using the automated system in one house and with a typical backpack blower-based sprayer in another house for comparison. Results showed that the automated system improved both seroconversion and geometric mean titer (GMT) as compared to the backpack spray crew. Mean GMT for both IBV and NDV were more than doubled (2.4× and 8.6×, respectively); seroconversions were also significantly improved for IBV (69.4 vs. 39.8%) and NDV (69.6 vs. 17.6%). Adoption of an automated whole-house spray vaccination system may provide significantly improved protection for loose-housed poultry when compared to backpack sprayers while improving biosecurity through minimizing human-to-bird contact.

We evaluated the influence of light sources and photoperiod on blood physiological variables in four trials. In each trial, 720 1-d-old Ross x Ross 708 chicks were randomly distributed into 12 environmentally controlled rooms (30 males/30 females/room). The experimental design was a 4 x 3 factorial treatments consisting of four light sources [incandescent (ICD, standard), compact fluorescent, neutral light emitting diode, and cool poultry-specific-filtered LED] and three photoperiods [long/continuous (23L:1D), regular/intermittent (2L:2D), and short/non-intermittent (8L:16D)] from d8-d56 at 50% relative humidity. Birds were fed the same diet, while feed and water were provided ad libitum. Blood samples were collected from the brachial wing vein on d 14, 28, 42, and 56 of age and analyzed immediately. Light sources had significant (P 0.05) effects on body weight (BW), and some of the selected blood physiological indices except Hb, Hct, Ca2+ angap, glucose, and corticosterone. Also, the photoperiods had significant (P 0.05) effects on BW and most of the selected blood physiological indices except HCO3-, angap, glucose, corticosterone, and T-4. However, all these changes were still within the normal acid-base homeostasis and physiological ranges of this species. Acid-base regulation during the short photoperiod exposure had not deteriorated despite higher pCO(2) that consequently decreased blood pH, due to a respiratory acidosis. Plasma corticosterone and glucose concentrations were not affected by treatments, suggesting an absence of physiological stress. It was concluded that the three LED light bulbs evaluated could be suitable for replacement of ICD along with the regular/intermittent photoperiod. Commercial poultry facilities can thereby reduce energy costs and optimize production efficiency without compromising the welfare of broilers grown to heavy weights (>3kg).

Effects of light sources and photoperiod on growth performance, carcass characteristics and health indices of broilers were investigated in 4 trials. In each trial, 720 1-day-old Ross × Ross 708 chicks were randomly distributed into 12 environmentally controlled rooms (30 males/30 females/room). The experimental design was a 4 × 3 factorial treatments consisted of 4 light sources [incandescent (ICD, standard), compact fluorescent (CFL), neutral light-emitting diode (Neutral-LED), and cool poultry-specific filtered LED (Cool-PSF-LED)] and 3 photoperiods [long/continuous (23L:1D), regular/intermittent (2L:2D), and short/non-intermittent (8L:16D)] from d8-d56. Birds were fed the same diet, while feed and water were provided ad libitum. Birds and feed were weighed on 1, 14, 28, 42, and 56 d of age for growth performance. Mortality was recorded daily and feed conversion was adjusted for mortality. Immune response was determined on d 28 to 35, whereas other welfare indices were performed on d 42, 43, and 49. At 56 d of age, 10 male and 10 female birds from each room were randomly selected and processed to determine weights and yields. The BW, BW gain, live weight, and carcass weights and yields of birds reared under Cool-PSF-LED were increased (P ≤ 0.05) in comparison to birds reared under ICD, but FI, FCR, and mortality were not affected. Moreover, broilers subjected to the short/non-intermittent photoperiod had the lowest (P ≤ 0.05) BW, BW gain, FI, live weight, carcass weight, and pectoralis major and minor weights compared to other 2 photoperiods. There was no effect of treatments on some carcass characteristics. There was no effect of treatments on welfare indices, suggesting that the light sources evaluated did not compromise welfare of heavy broilers. It was concluded that the 3 light sources evaluated in this study may be suitable for replacement of ICD light source along with regular/intermittent photoperiod instead of long/continuous photoperiod in poultry facilities to save energy utilization, thereby reducing the total cost of production.

Commercial layer hens reared on multi-age hen complexes are vaccinated during pullet rearing to combat production losses due to the bacteria Mycoplasma gallisepticum (MG). In this study, the potential to in ovo vaccinate layer chickens against MG was investigated. Layer embryos were administered a dosage of a live attenuated strain F MG (FMG) vaccine at 18 d of incubation and raised for 6 wk for initial post-hatch evaluation in 2 replicate trials. Treatments included control non-injected eggs, eggs injected with diluent, a non-diluted dosage, a 10-2 dilution, a 10-4 dilution, and a 10-6 dilution. A subset of chicks were swabbed for detection of FMG in the trachea at hatch. At 6 wk of age, birds were swabbed again for FMG detection and a blood sample was tested for MG antibody production. Hatch was depressed in the non-diluted dose group (P < 0.0001). Strain F MG was detected at hatch in the trachea in each FMG injection treatment, with decreasing numbers of positive chicks in the lower dosage groups. Mortality during the first 2 wk post-hatch was 3.5% (trial 1) and was 11.7% (trial 2) in the 10-6 dilution treatment, with all other FMG treatments experiencing a high rate of mortality (>50%). Birds in the in ovo FMG treatments had detectable FMG and antibody production at 6 wk. There were no differences in percentage positive birds (P > 0.3 for all tests) or ELISA titers (P = 0.079) between the FMG treatments. Body weight at 6 wk of age was diminished with increasing FMG dose (P < 0.0001). The lowest dose tested was found to be the most practical, causing the least mortality, least weight loss, and a humoral immune response in the majority of the birds. Further work is needed to evaluate how this in ovo vaccine, promoting immunity earlier, would compare to a standard post-hatch vaccination against an MG challenge scenario through a lay cycle.

Infectious agents and their associated diseases can be significant barriers in the production of poultry and zoonotic agents associated with poultry flocks can ultimately endanger consumers. To this end, poultry producers employ a variety of strategies to minimize associated risks. Disinfectants are widely utilized in the poultry industry to limit encounters with avian pathogens and zoonotic agents. These disinfectants are readily applied by a variety of means to both equipment and facilities to reduce pathogenic populations and minimize their associated risk. While a variety of disinfectants and application means are currently available, the search for more efficacious products and technologies continues. Recently, technology has been developed that may be applicable to the poultry industry for pathogen reduction. The NebuPure™ disinfecting system was developed as a means to decontaminate facilities harboring human pathogens. The system utilizes a novel dispersal unit to suspend an electrochemically activated solution in enclosed facilities and allows for largely automated decontamination. To test the NebuPure™ disinfecting system for poultry-related applications, a research facility was seeded with plate cultures of the avian respiratory pathogen Mycoplasma gallisepticum (MG). The facility was then treated with the NebuPure™ disinfecting system with exposure times of 1 or 4 h. Following incubation, no growth was observed among exposed plates, while control plates were 100% positive for MG. The research demonstrates the efficacy of the NebuPure™ disinfecting system for disinfecting MG-contaminated facilities and indicates that the system may be used against other poultry-associated pathogens.

Mycoplasma gallisepticum (MG) is a bacterial pathogen that causes production losses in layer chickens. To combat MG, multiage layer facilities vaccinate pullets by either spray or eye-drop vaccination. The objective in this study was to evaluate the use of in ovo vaccination as a potential alternative for MG vaccination. Layer embryos at 18 d of incubation were either not-injected (control), or were hand-injected with either commercial Marek's disease vaccine diluent alone or with a high, medium, low, or very low dosage of a live attenuated strain F (FMG) vaccine suspended in the commercial diluent. Hatch success and residual egg embryonic mortality were determined after 23 d of incubation. Six hatched chicks per treatment were swabbed for the detection of FMG at 4 different sites (trachea, mouth and esophagus, yolk sac membrane, and the lumen of the duodenal loop) via real-time PCR. Embryos were found to be administered 106 CFU per dose in the high treatment, 104 CFU/dose in the medium treatment, 102 CFU/dose in the low treatment, and between 5.06 and 5.93 CFU/dose in the very low treatment. Hatch of embryonated eggs was decreased by the medium and high doses (P = 0.02). These embryos died while pipping. No FMG was detected in the control and diluent-injected chicks. In the FMG treatments, FMG was found in all sites and dosages, with a greater number of positive chicks found in the higher FMG dosage treatments. These findings indicate the potential practicality of vaccinating layer embryos with FMG by in ovo injection based on the observed hatch success at lower dosages. Also, once injected into the amnion, the bacteria are present in the upper respiratory and gastrointestinal tracts as well the yolk sac membrane and the small intestine of hatchlings. Future research will need to ascertain the effects of FMG administered by in ovo injection on posthatch immunity and mortality.