In ovo administration of the Marek's disease vaccine in conjunction with 25-hydroxyvitamin D3 and its subsequent effects on the performance and immunity-related characteristics of Ross 708 broiler hatchlings1,2,3.

The combined effects of the in ovo injection of commercial Marek's disease vaccine (MDV) and various levels of 25-hydroxyvitamin D3 (25OHD3) on the hatch variables, immunological measurements, and gene expression of Ross 708 hatchling broilers were investigated. A total of 5 in ovo injection treatments that were applied at 18 d of incubation (doi) included: 1) noninjected (control); or a 50 µL solution volume of 2) MDV alone; or MDV combined with 3) 0.6 µg of 25OHD3; 4) 1.2 µg of 25OHD3; or 5) 2.4 µg of 25OHD3. At hatch, hatchability of set and live embryonated eggs, hatchling body weight, hatch residue analysis, serum IgY and alpha-1 acid glycoprotein (AGP) concentrations, and the expression of genes related to immunity (INFα, INFß, INFγ, TLR-3, and TLR-21) and vitamin D3 activity (1 α-hydroxylase, 24 hydroxylase, and vitamin D receptor) were determined. No significant treatment differences were observed for hatchability of set and live embryonated eggs, or for serum IgY and AGP concentrations. However, hatchling body weight was higher when MDV was combined with either 1.2 or 2.4 µg of 25OHD3 than when MDV was provided alone or in combination with 0.6 µg of 25OHD3. Also, in comparison to the noninjected treatment group, the expression of the genes for 1 α-hydroxylase and 24 hydroxylase was improved when MDV was combined with either 1.2 or 2.4 µg of 25OHD3. Lastly, expression of the genes linked to viral detection (TLR-3) and antibody production (INF-ß) was increased in those treatments that contained any level of 25OHD3. These results indicate that in comparison to controls, the effects of MDV were observed to be greater on hatchling BW and splenic gene expression when it was administered in combination with the 1.2 or 2.4 µg doses of 25OHD3. Further research is needed to determine the posthatch effects of the administration of various levels of 25OHD3 in combination with MDV.

Effects of the in ovo injection of an Escherichia coli vaccine on the hatchability and quality characteristics of commercial layer hatchlings.

In the commercial egg industry, avian pathogenic Escherichia coli (APEC) can lead to significant economic loss. The Poulvac E. coli vaccine (PECV) is a commercially available attenuated live vaccine commonly applied via spray or drinking water to protect against losses associated with colibacillosis. The PECV has not been tested in layer hatching eggs using in ovo injection. Therefore, the purpose of this experiment was to determine the effects of injecting 50 µL of different doses of the PECV into Hy-Line W-36-layer hatching eggs on the hatchability and quality characteristics of hatchlings. At 18 d of incubation (DOI), treatments included 1 noninjected and 1 diluent-injected control. Furthermore, PECV treatments included a full dose (4.4 × 108E. coli CFU) or serial dilutions of the full dose to produce 4.4 × 106, 4.4 × 104, or 4.4 × 102 CFU doses of E. coli. In ovo injections targeted the amnion. Percent hatchability of live embryonated eggs (HI), percent residue eggs, hatchling mortality, and female chick whole and yolk-free BW, relative yolk sac weight, and body length were among the variables examined. Treatment significantly (P < 0.0001) affected HI, with HI being highest in the control groups (97.3% in the noninjected and 94.2% in the diluent-injected), and with HI values being 89.0, 88.9, 84.4, and 71.2% in the 4.4 × 102, 4.4 × 104, 4.4 × 106, and 4.4 × 108 CFU E. coli dose treatments, respectively. The percentage of live embryos that did not complete hatch but that pipped internally (P = 0.024) or externally (P < 0.0001) were significantly affected by treatment, with percentages being highest in the 4.4 × 108 CFU treatment. Female chick body length was significantly (P < 0.0001) affected by treatment and was longer in both control groups and in the 1 × 102 CFU E. coli treatment in comparison to all other treatments. Yolk-free female chick BW was significantly (P = 0.034) affected by treatment and was lower in the 4.4 × 106 CFU and 4.4 × 108 CFU treatments when compared to the diluent-injected control group. An increase in the E. coli concentration administered in the amnion of embryonated layer hatching eggs at 18 DOI decreased hatch success and female chick yolk-free BW and body length.

Utilizing in ovo telemetry to examine the effects of reduced incubation temperature on broiler embryo temperature and subsequent hatchability.

The current commercial broiler embryo experiences a rapid metabolism and growth rate and may produce more heat than those of the past. Consequently, it may be beneficial to lower standard incubation temperature for commercial broiler hatching eggs. The purpose of this experiment was to determine if lowering incubation temperature at 12 d of incubation (DOI) would affect embryo temperature (ET) in embryonated Ross 708 broiler hatching eggs. From 0 to 12 DOI, eggs were incubated under standard conditions (37.50°C dry bulb, 29.76°C wet bulb). At 12 DOI, temperature transponders were aseptically placed on the inner air cell membrane to measure air cell temperature (ACT) as an estimate of ET in 120 eggs. The eggs were then randomly assigned to 4 separate still-air incubators, each containing 30 eggs. Two replicate incubators were maintained at a standard (STRT; 37.5°C) or low (LTRT; 35.6°C) temperature treatment between 12 and 21 DOI. A significant positive correlation existed between incubator air temperature (IAT) and ACT across temperature treatment and in the STRT. However, IAT was not significantly correlated with ACT in the LTRT. A significantly higher ACT was observed in the STRT than in the LTRT for 88% of the readings taken between 12 and 21 DOI. Percent egg weight loss (PEWL) between 13 and 17 DOI did not significantly differ between temperature treatments. From 13 to 17 DOI, there was a significant positive correlation between PEWL and ACT in the STRT, however, no significant correlation occurred between PEWL and ACT in the LTRT. Percent hatch of fertile eggs containing live embryos at 12 DOI was 93.3% in the STRT and 100% in the LTRT. However, time of hatch occurred 14 to 19 h later and hatchling BW was lower in the LTRT than in the STRT. Although lowering IAT at 12 DOI may improve hatchability, an associated delay in hatch and a decrease in hatchling BW may not be commercially acceptable.

Onset of the humoral immune response of layer chicks vaccinated in ovo with strain F Mycoplasma gallisepticum vaccine and evidence of male-biased mortality.

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.

Effects of the in ovo injection of vitamin D3 and 25-hydroxyvitamin D3 in Ross 708 broilers subsequently challenged with coccidiosis. I. performance, meat yield and intestinal lesion incidence1,2,3.

Effects of the in ovo administration of vitamin D3 (D3) and 25-hydroxyvitamin D3 (25OHD3) on broiler intestinal lesion incidence, performance and breast meat yield after a coccidiosis challenge were investigated. On each of 10 incubator tray levels, 10 Ross 708 broiler hatching eggs were randomly assigned to each of the following 5 in ovo injection treatments administrated at 18 d of incubation (doi): 1) noninjected; 2) diluent; diluent containing either 3) 2.4 µg D3 (D3), 4) 2.4 µg 25OHD3 (25OHD3), or 5) 2.4 µg D3 + 2.4 µg 25OHD3 (D3+25OHD3). A 50 µL solution volume was injected into each egg using an Inovoject multi-egg injector. Four male chicks were randomly assigned to each of 80 battery cages in each of 2 rooms. Half of the treatment-replicate cages (8) in each room were challenged with a 20× live coccidial vaccine at 14 d of age (doa). One randomly selected bird from each of 4 treatment-replicate cages was scored for coccidiosis lesions before and 2 wk after challenge. Mean BW, BW gain (BWG), feed intake, and feed conversion ratio were determined for all birds from 0 to 14, 15 to 28, and 29 to 41 doa. Carcass weight, and the absolute and relative (% of carcass weight) weights of carcass parts were determined in 3 birds per treatment-replicate cage at 42 doa. Hatchability of live embryonated injected eggs and hatch residue were not affected by treatment. Across challenge treatment, birds in the 25OHD3 treatment group experienced an increase in BWG between 29 and 41 doa when compared to the D3 or diluent-injected birds. Furthermore, pectoralis major muscle percentage tended (P = 0.059) to increase in birds belonging to the 25OHD3 treatment in comparison to birds in the D3 or diluent-injected treatments. These results indicate that regardless of challenge treatment, 2.4 µg of 25OHD3 may increase the BWG and breast meat yield of birds relative to those that only received an injection of commercial diluent.

Effects of the in ovo injection of vitamin D3 and 25-hydroxyvitamin D3 in Ross 708 broilers subsequently fed commercial or calcium and phosphorus-restricted diets. II. Immunity and small intestine morphology1,2,3.

Effects of the in ovo injection of vitamin D3 (D3) and 25-hydroxyvitamin D3 (25OHD3) on the immunity and small intestine morphology of broilers fed calcium and phosphorus-restricted diets were investigated. At 18 d of incubation (doi), live embryonated Ross 708 broiler hatching eggs were in ovo-injected with a 50 µL solution of one of the following treatments using an Inovoject multiegg injector: 1) diluent (control); diluent containing either 2) 2.4 µg D3; 3) 2.4 µg 25OHD3; or 4) 2.4 µg D3 + 2.4 µg 25OHD3. At hatch, 18 randomly selected male broilers belonging to one of the 4 in ovo injection treatments were placed in each of 12 floor pens and were fed either a commercial diet or a diet restricted by 20% in calcium and available phosphorus (ReCaP) content for the starter, grower and finisher dietary phases. Concentrations of plasma IgG and IgM at 14 d of age (doa) and α-1-acid glycoprotein at 40 doa were determined. Bursa, liver, spleen, duodenum, jejunum, and ileum weights were recorded at 7, 14, and 40 doa and small intestine histology was evaluated at 14 and 40 doa. Blood and organ samples were randomly collected from 1 bird in each of the 6 replicate pens within each of the 8 (4 in ovo x 2 dietary) treatment groups. Plasma IgG levels were higher in 25OHD3 than in diluent or D3 in ovo-injected birds. At 14 doa, a higher jejunal villus length (VL) to crypt depth (CD) ratio (RVC) was observed in birds that were in ovo-injected with 25OHD3 alone as compared to all other in ovo injection treatments. At 40 doa, ileal VL increased and jejunal CD decreased in commercial diet-fed birds compared to ReCaP diet-fed birds. In conclusion, the in ovo injection of 25OHD3 alone increased the immune response and improved the small intestine morphology and subsequent nutrient uptake of Ross 708 broilers. However, a ReCaP diet was observed to be detrimental to their small intestine morphology.

Effects of the in ovo injection of vitamin D3 and 25-hydroxyvitamin D3 in Ross 708 broilers subsequently fed commercial or calcium and phosphorus-restricted diets. I. Performance, carcass characteristics, and incidence of woody breast myopathy1,2,3.

Effects of the in ovo-injection of vitamin D3 (D3) and 25-hydroxyvitamin D3 (25OHD3) on broiler performance, carcass characteristics, and woody breast myopathy (WBM) incidence were investigated. Live embryonated Ross 708 broiler hatching eggs (2,880) were randomly assigned to one of the following in ovo injection treatments: (1) diluent (50 µL); diluent (50 µL) containing either (2) 2.4 µg D3; (3) 2.4 µg 25OHD3; or (4) 2.4 µg D3 + 2.4 µg 25OHD3. Eggs were injected at 18 d of incubation (doi) using an Inovoject multiegg injector. At hatch, 18 male chicks were randomly placed in each of 6 replicate pens belonging to each in ovo injection and, dietary treatment combination. Birds were fed either a commercial diet or a diet restricted in calcium and phosphorous (ReCaP) content by 20% for the starter, grower and finisher dietary phases. Broiler performance was determined in each dietary phase and breast muscle yield was also determined at 14 and 40 d of age (doa). At 41 and 46 doa, birds were processed for determination of WBM, carcass weight, and the absolute and relative (% of carcass weight) weights of various carcass parts. Compared to birds fed the commercial diet, birds fed ReCaP diets experienced a reduction in performance from 14 to 40 doa, in breast meat yield at 41 and 46 doa, and in WBM at 41 and 46 doa. At 14 and 40 doa, breast meat yield in birds that received an in ovo injection of 25OHD3 alone was higher compared to birds that received diluent alone or a combination of D3 and 25OHD3. Lower WBM incidence in ReCaP-fed birds was associated with a lower breast weight. An increase in breast meat yield in response to 25OHD3 alone may be due to improved immunity and small intestine morphology. However, further study is needed to determine the aforementioned effects.

Research Note: Effects of the in ovo injection of organic zinc, manganese, and copper and posthatch holding time before placement on broiler body temperature during grow out.

Effects of the in ovo injection of organic microminerals (OM) (zinc, manganese, and copper) and posthatch holding time (HT) on the daily body temperature (bt) of broilers during grow out were determined. The hatching eggs from a Ross 708 breeder flock at 32 wk of age were incubated under standard commercial conditions. At 17 d of incubation, eggs were randomly allocated to 3 in ovo OM injection treatment (TRT) groups, and at 21 d of incubation, male hatchlings were randomly allocated to 2 posthatch HT treatment groups. Eggs were either not injected or were in ovo injected with diluent only or diluent containing the OM mixture. A 0-hour HT group had immediate access to water and feed, and a 24-hour HT (24HT) group contained birds that were kept in transport baskets in their pens without access to feed and water for 24 h before being released. Fifteen male birds were placed in each of 36 litter floor pens in a temperature-controlled facility. Approximately 2 birds in each of 6 replicate pens belonging to each TRT-HT combination had temperature transponders inserted subcutaneous in the mid-dorsal region of the neck. All birds were brooded under standard commercial conditions and had ad libitum access to feed and water after their respective HT. The bt of the same birds were determined daily at the same time each day beginning at hatch and ending on 39 d of posthatch age (AGE). There were no significant main or interactive effects involving TRT or HT for bt. However, there was a significant (P ≤ 0.0001) main effect because of AGE. A general increase in bt occurred during the 39 d grow out period. At hatch, bt was 40.54 ± 0.056°C and at AGE 39 was 41.46 ± 0.055°C. Under standard brooding conditions, a general increase in bt occurred in the Ross 708 broilers. However, these birds did not exhibit a significant bt response to TRT or a 24HT before placement.

Effects of administration of an in ovo coccidiosis vaccine at different embryonic ages on vaccine cycling and performance of broiler chickens,.

Use of a live coccidiosis vaccine has become an increasingly common method to control coccidiosis, especially in antibiotic-free broiler production. The Inovocox EM1 vaccine (EM1) is recommended for the vaccination of embryonated broiler hatching eggs between 18.0 and 19.0 d of incubation (doi). This allows for earlier acquisition of immunity to wild-type coccidia. However, it is unclear whether the difference in embryo age at the time of in ovo injection can influence the effect of the vaccine during grow-out as well as if the growth performance of broiler chickens is affected. Therefore, the objective of the study was to evaluate the effects of 2 injection ages (18.5 and 19.0 doi) and 3 injection types (noninjected, diluent, and vaccine) in a 3 × 2 factorial design, consisting of 10 replicates per treatment (60 treatment-replicate groups). There was a significant effect of injection age on BW at 0, 14, and 35 d after hatch, with a difference in the BW of birds belonging to the 18.5 and 19.0 doi groups up to day 35 after hatch. There was a significant effect of injection type on BW gain, feed intake, and FCR between 0 and 28 d after hatch. Between 0 and 35 d, FCR was lower in the vaccine-injected group in comparison with the noninjected and diluent control groups. Furthermore, total intestine coccidia and lesion indices were higher in the vaccine-18.5 treatment group in comparison with the diluent-18.5 treatment group at 28 d. In conclusion, hatchling weight was affected by injection age, and this subsequently affected growth performance. Furthermore, intestinal coccidia cycling peaked at 28 d, resulting in a reduction in growth performance through 28 d and subsequent compensatory growth by 35 d. There was no significant difference in coccidiosis cycling between the vaccine-18.5 and vaccine-19.0 doi treatment combination groups.

Improvement in the performance and inflammatory reaction of Ross 708 broilers in response to the in ovo injection of 25-hydroxyvitamin D3.

The effects of the in ovo administration of vitamin D3 (D3) and its metabolite, 25-hydroxyvitamin D3 (25OHD3), 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 D3, 4) 2.4-µg 25OHD3, or 5) 2.4-µg D3 + 2.4-µg 25OHD3. 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 25OHD3 alone decreased plasma AGP concentrations in comparison with the noninjected, diluent, and D3-alone treatment groups. In addition, birds that received 25OHD3 alone had a greater BW at 42 doa than birds in the noninjected, diluent, and D3-alone treatment groups. At 39 and 43 doa, breast meat yield was increased in response to the in ovo injection of 25OHD3 alone in comparison to all other treatments. These results indicate that the in ovo injection of 2.4 µg of 25OHD3 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 25OHD3 may have led to an increase in broiler performance.

Effects of dietary Original XPC on selected blood variables in layer pullets challenged with Mycoplasma gallisepticum,.

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 in broiler hens of genetic lines differing in fertility, biotin supplementation, and age on relative abundance of oviductal transforming growth factor-ß and carbonic anhydrase mRNA transcripts.

There was evaluation of effects of biotin administration on oviductal abundance of transforming growth factor-ß (TGF-ß) and carbonic anhydrase (CA) mRNA transcript in younger and older broiler hens of relatively lesser and greater fertility lines. Additionally, effects of biotin supplementation on attenuation of age-related subfertility were evaluated. Hens from the relatively greater (Line D, n = 60) and lesser (Line B, n = 60) fertility rate line were randomly assigned to three treatment groups. Biotin was not or was administered in drinking water from 30 to 33 (younger age) and 53 to 56 (older age) wk of age to have access to no biotin (T0), or 0.3 (T1), or 0.45 (T2) mg/L of biotin. There was assessment the relative oviductal abundances of TGF-ß and CA mRNA transcript abundances. Supplemental biotin and age had no effect on the relative abundance of oviductal TGF-ß mRNA transcript in hens of Line D. There, however, was a ten-fold greater abundance of TGF-ß in hens of the T0 group of Line B compared with Line D. Relative abundance of TGF-ß mRNA transcript was greater in younger hens of Line B; however, biotin supplementation of older hens of the T2 group of Line B resulted in a similar TGF-ß abundance to that of younger hens. Inconstant with the TGF-ß abundance, CA abundance in hens of Line B was not affected by supplemental biotin or bird age. Overall, differences in TGF-ß or CA abundances did not affect fertility of broiler hens.

Effects of source and level of in ovo-injected vitamin D3 on the hatchability and serum 25-hydroxycholecalciferol concentrations of Ross 708 broilers.

Effects of the in ovo injection of vitamin D3 (D3) and 25-hydroxycholecalciferol (25OHD3) on broiler embryo serum 25OHD3 concentrations, hatchability, and hatchling somatic characteristics were determined. Eggs from a 35-wk-old commercial Ross 708 broiler breeder flock were set in a single-stage incubator with 11 treatments represented on each of 8 incubator tray levels (blocks). Each treatment group within a flat on each tray level contained 30 eggs. Control treatments were noninjected and diluent injected. Vitamin treatments were commercial diluent containing 0.6 µg D3, 0.6 µg 25OHD3, 0.6 µg D3 + 0.6 µg 25OHD3, 1.2 µg D3, 1.2 µg 25OHD3, 1.2 µg D3 + 1.2 µg 25OHD3, 2.4 µg D3, 2.4 µg 25OHD3, or 2.4 µg D3 + 2.4 µg 25OHD3. At 432 h of incubation (hoi), 50-µL solution volumes were injected. Blood samples were collected at 462 hoi for serum 25OHD3 analysis, and hatchability of injected live embryonated eggs (HI) was determined at 492 and 516 hoi. At 516 hoi, hatchling yolk-free BW and weights of the liver and yolk sac were determined. Percentage of yolk moisture and dry mater was calculated. At 492 and 516 hoi, HI did not differ between treatments. Embryos that received 1.2 µg or more of either vitamin D3 source alone or in combination had higher serum 25OHD3 concentrations than those that were injected with diluent alone or diluent containing 0.6 µg of D3. Hatchlings that received 1.2 or 2.4 µg of 25OHD3 had higher percentage of yolk dry matter or lower percentage of yolk moisture levels than noninjected controls and those that received D3 alone at any level. These results indicate that the in ovo injection of either vitamin D3 source at levels equal to or higher than 1.2 µg resulted in serum 25OHD3 concentrations that were higher than that of noninjected controls. In addition, the in ovo injection of 1.2 µg or higher of either vitamin D3 source did not negatively affect broiler HI or chick quality.

Growth and humoral immune effects of dietary Original XPC in layer pullets challenged with Mycoplasma gallisepticum.

Effects of dietary Original XPC (XPC) in commercial layer pullets challenged with the virulent, low passage R strain of Mycoplasma gallisepticum (Rlow 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 Rlow 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 Rlow 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 significantly affect ELISA titers, but they were significantly (P < 0.0001) increased due to challenge. Furthermore, lesion scores were significantly higher for Rlow 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 Rlow MG, it led to an increase in their rate of growth through 12 woa.

Effects of stage of broiler embryo development on coccidiosis vaccine injection accuracy, and subsequent oocyst localization and hatchling quality.

Control of coccidiosis in broiler chickens continues to pose challenges to commercial poultry producers, especially in an era of increased consumer demand for antibiotic-free broiler production. As a result, coccidiosis vaccines are now commonly used in rotation programs to achieve effective coccidiosis control. Inovocox EM1 vaccine (EM1) is a coccidiosis vaccine that allows for earlier immune acquisition through oocyst cycling, which reduces the effects of wild-type coccidia. The EM1 vaccine is administered to embryonated broiler hatching eggs between 18 and 19 D of incubation (doi). In the U.S., commercial broiler hatcheries vaccinate embryonated eggs at either 18.5 or 19 doi. However, it is unclear whether a difference in embryo age at the time of in ovo injection can impact the actual site of vaccine delivery. In addition, it is unclear where oocysts eventually become localized within the embryo following the in ovo injection of EM1. Therefore, the objective of this study was to determine the effects of stage of embryonic development on the actual deposition site of the EM1 vaccine oocysts when they are in ovo injected and to subsequently investigate the movement and eventual location of EM1 oocysts after in ovo injection. Because all eggs were injected at the same time, a 12-h difference in set time was a means to derive 18.5 and 19.0 incubation age of injection (IAN) treatments. The experimental design was a 3 injection treatment (noninjected, diluent-injected, and vaccine-injected) × 2 IAN factorial. There was a significant main effect of IAN on site of vaccine oocysts delivery, and subsequent hatching chick quality. Qualitative histological evaluation revealed the oral uptake of vaccine oocysts through the amnion, with their subsequent presence in the gizzard and intestinal lumen by 24 to 36 h postinjection. In conclusion, physiological development influenced the site of injection, and oocysts imbibed along with the amniotic fluid in late stage broiler embryos are subsequently transported to the gastrointestinal tract.

Occurrence of horizontal transmission in layer chickens after administration of an in ovo strain F Mycoplasma gallisepticum vaccine1,2,3.

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.

Sperm characteristics of Chukar partridge (Alectoris chukar) breeders as affected by the addition of calcitriol to the semen extender.

This study was carried out to determine the effect of supplementing the semen extender with calcitriol on in vitro sperm characteristics in Chukar partridges. A total of 60 male Chukar partridges were habituated for semen collection by abdominal massage. Pooled ejaculates from several males were extended (1 to 5 v/v ratio) in the Sexton's diluent containing 0, 24, 48, 96, or 192 µg calcitriol/mL. These concentrations represented 0-, 2-, 4-, 8-, and 16-fold levels of the mean seminal calcitriol concentration, respectively. A total of 12 subsamples from each treatment group were kept at 4 to 5°C or 19 to 24°C for 4, 24, or 48 h. The percentages of motile sperm, live sperm, abnormal sperm, incidence of hypoosmotic swelling (HOS), and thiobarbituric acid reactive species (TBARS) concentrations were determined. The data were analyzed by the xtmixed procedure of STATA software. The percentages of motile sperm, live sperm, abnormal sperm, and seminal TBARS were affected by calcitriol (P < 0.05). There was no effect of treatments on HOS (P > 0.05). There was an interaction effect between calcitriol, storage time, and storage temperature on sperm motility, sperm viability, and seminal TBARS. Supplementation of the diluent with 96 µg calcitriol/mL resulted in the highest sperm motility at 4°C. Also, the same treatment group recorded the highest sperm viability and lowest seminal TBARS at 19 to 24°C. Supplementing the diluent with calcitriol had beneficial effects on spermatozoa; however, the fertility rate of spermatozoa extended in calcitriol-supplemented diluent needs to be determined before the procedure can be recommended for use in artificial insemination programs.

Effects of in ovo injection of L-ascorbic acid on growth performance, carcass composition, plasma antioxidant capacity, and meat quality in broiler chickens1,2,3.

The current study was designed to investigate the effects of the in ovo injection of different dosages of L-ascorbic acid (AA) on posthatch growth performance, carcass characteristics, plasma antioxidant capacity, and meat quality in broiler chickens. A total of 2,220 Ross 708 broiler hatching eggs containing live embryos at 17 D of incubation were subjected to 1 of 6 treatments (trt): non-injected control, saline-injected control, or saline containing 3, 6, 12 or 36 mg of AA. An Inovoject m semi-automatic multi-egg injector was used to inject a 100 µL volume of sterile saline (0.85%) alone or containing the different AA dosage into each egg. After hatch, 14 male hatchlings from each trt group were randomly selected and placed in each of 10 replicate floor pens for growth performance evaluation through 45 D posthatch. Chicks from the 3 and 6 mg AA trt groups had a higher average daily BW gain and a higher feed intake compared to the saline-injected control group during the grower phase. Chicks in the 12 mg AA trt group exhibited a better feed efficiency in the late finisher phase and the entire growing phase than those in the saline-injected control group. Higher thigh and leg percentages were observed in chicks from the 3 and 6 mg AA trt groups than in the non-injected control group. Compared to the non-injected or saline-injected control groups, birds in the 12 mg AA trt group were observed to have a lower plasma malondialdehyde content during the grower and finisher phases, and breast muscle tenderness was elevated in chicks from the 36 mg AA trt group. Taken together, these results suggest that the in ovo injection of AA (3 to 12 mg per egg) have lasting positive effects on the posthatch growth, leg muscle development, and systemic antioxidant capacity of broilers. Higher injected dosages of AA (36 mg per egg) may also have the potential to improve broiler meat quality.

Comparative effects of in ovo versus subcutaneous administration of the Marek's disease vaccine and pre-placement holding time on the intestinal villus to crypt ratios of Ross 708 broilers during early post-hatch development1,2,3.

Villus to crypt ratio (VCR) is used to quantify the microanatomical response of the intestine to various treatments. In early age chickens, comparative effects of the in ovo (i.o.) and s.c. methods of administration (moa) of the Marek's disease (MD) vaccine on 2 types of measurement of small intestinal VCR at 0 and 4 h post-hatch (poh) were investigated. The effects of moa and 4 and 18 h pre-placement holding times (pht) on the VCR measurements at 168 h (7 d) poh were also investigated. In the jejunum of the small intestine, a standard method for VCR determination, based on 10 villus and crypt length measurements, was utilized for the calculation of villus to crypt length ratio (VCLR). In that same region, a single histomorphometric determination of the crypt and total mucosa areas using image analysis software was also used. Subtraction of the crypt area from the total mucosa area provided the villus area, allowing for calculation of the villus to crypt area ratio (VCAR). Across 0, 4, and 18 h of poh bird age, the VCLR of birds that received an s.c. vaccination was higher in comparison to that of those that received an i.o. vaccination. The highest and lowest VCAR values were observed in the s.c. treatment at 0 h poh and in the i.o. treatment at 4 h poh, respectively. Furthermore, at 168 h poh, VCLR values in the 18 h pht and s.c. vaccination group were higher than those in the 4 h pht and s.c. vaccination or 18 h and i.o. vaccination groups. In conclusion, the effects of pht and MD vaccine moa on VCR were dependent on the use of either the VCLR or VCAR method of measurement. However, regardless of method, s.c. injection overall led to a higher VCR through 4 h poh in Ross 708 broilers, and the effects of moa on VCLR at 168 h were influenced by pht.

Early post-hatch survival and humoral immune response of layer chickens when in ovo vaccinated with strain F Mycoplasma gallisepticum,.

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.