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Investigations were performed to determine the systemic immune and small intestine (SI) morphological responses of Ross 708 broilers to the Marek's Disease vaccine (MDV) administered alone or in conjunction with the in ovo and dietary administration of calcifediol (25OHD 3 ). Live embryonated hatching eggs were assigned at random to 3 in ovo treatments at 18 d of incubation. Pre-specified in ovo treatments were: commercial MDV-alone-injected (50 µL) or commercial MDV containing 1.2 (MDV+25OHD 3 -1.2) or 2.4 (MDV+25OHD 3 -2.4) μg of 25OHD 3 . A noninjected control treatment was also included. For the growing phase, broilers received a commercial diet containing 250 IU of vitamin D 3 /kg (control) or a commercial diet supplemented with 2,760 IU of 25OHD 3 /kg (Hy-D diet). For determination of serum IgG, nitric oxide, and α-1-acid glycoprotein (AGP) at 14 and 40 d of age (doa), blood was collected from 1 bird per pen (48 total). In the duodenum, jejunum, and ileum of the same bird, villus length (VL), crypt depth (CD), VL to CD ratio (VCR), and villus surface area were also determined. There were no significant dietary x in ovo treatment interactions for any of the variables examined. However, birds fed Hy-D diets had lower serum AGP levels at 14 doa when compared to those fed un-supplemented commercial diets. Additionally, at 40 doa, birds in the MDV+25OHD 3 -1.2 and MDV+25OHD 3 -2.4 treatments experienced a decrease in serum AGP in comparison to those belonging to the noninjected and MDV-alone treatment groups. A higher jejunal VCR was observed at 14 and 40 doa in birds that belonged to the MDV+25OHD 3 -1.2 treatment when compared to those in the noninjected and MDV-alone treatment groups, and dietary Hy-D increased the VL of the duodenum and jejunum in birds at 14 and 40 doa when compared to those fed the commercial diet. In conclusion, both dietary or in ovo administration of 25OHD 3 lowered inflammatory reactions and improved the SI morphology of broilers that were in ovo-injected with the MDV., Competing Interests: DISCLOSURES The authors declare no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Previous work has shown that dietary treatments affect woody breast (WB) incidence differently, which indicates that gut conditions such as gut barrier function, inflammation, and oxidative stress are likely related to WB. In this study, dietary supplementation with antibiotics (bacitracin) or probiotics (Bacillus subtilis) was investigated for their effects on the expression of transcripts related to gut barrier function, inflammation, and oxidative stress in the mucus lining of the jejunum from broilers with or without WB. A split-plot experimental design was used in this study. The dietary treatments served as the main plot factor and the breast muscle condition was the subplot factor. On d 41, jejunum mucus was collected from 1 bird from each of 3 replicate pens in each 3 dietary treatment groups that exhibited WB and an additional bird that contained a normal breast (3 biological replicates/treatment/phenotype; 3 × 3 × 2, total N = 18). Total RNA was extracted using a commercial RNA extraction kit. The expression levels of CLDN1, MUC6, TLR2A, TLR2B, TLR4, IFN-γ, IL-1β, IL-8L1, IL-10, NOS2, and SOD were determined using 2-step RT-qPCR analysis. The gene expression difference in ΔCt values was determined after normalizing with the chicken 18S rRNA gene. When the significant differences occurred between treatments, the relative fold change was calculated using the ΔΔCt method and the significance level was calculated. The PROC GLM procedure of SAS 9.4 was used, and the level of significance was set at P ≤ 0.05. There were no significant interactive effects between diet and the breast muscle condition on the expression of any of the genes tested. However, birds with WB exhibited higher MUC6 (P < 0.0001) gene expression levels than birds with normal breast muscles. In addition, the expression of SOD decreased in birds that were fed the antibiotic diet when compared to birds that were fed the probiotic diet (P = 0.014). In conclusion, WB identified in broilers tested in the current study is attributed to increased expression of mucin, indicating a correlation between WB incidence and gel-forming mucin secretion and pathogen signaling., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

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., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Effects of the in ovo administration of vitamin D 3 (D 3 ) and 25-hydroxyvitamin D 3 (25OHD 3 ) 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 D 3 (D 3 ), 4) 2.4 μg 25OHD 3 (25OHD 3 ), or 5) 2.4 μg D 3  + 2.4 μg 25OHD 3 (D 3 +25OHD 3 ). 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 25OHD 3 treatment group experienced an increase in BWG between 29 and 41 doa when compared to the D 3 or diluent-injected birds. Furthermore, pectoralis major muscle percentage tended (P = 0.059) to increase in birds belonging to the 25OHD 3 treatment in comparison to birds in the D 3 or diluent-injected treatments. These results indicate that regardless of challenge treatment, 2.4 μg of 25OHD 3 may increase the BWG and breast meat yield of birds relative to those that only received an injection of commercial diluent., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Genetic selection and advances in nutrition have improved broiler growth performance. However, meat quality issues have gained preference over increased growth rate. These meat quality issues may be reduced by lowering dietary amino acid (AA) content. In the present study, 5 common commercial broiler strains were fed either a control or an AA-reduced diet. The control diet was formulated to contain the highest digestible AA (lysine, total sulfur AA, and threonine) levels recommended for the 5 strains. The AA-reduced diet was formulated to contain 20% lower levels of these 3 digestible AA than in the control diet. This resulted in a 5 (strains) × 2 (AA levels) factorial arrangement. A total of 1,280 straight run broilers were randomly allocated to 8 replicate blocks. The AA reduction decreased absolute breast weights of 3 strains on day 42 and 2 strains on day 56, and decreased absolute weights of tender, wing, drumstick, and thigh on both day 42 and 56 for all 5 strains. However, the absolute fat pad weight and relative fat pad and thigh weights to BW were increased in the AA reduction treatments on both day 42 and 56. The AA reduction contributed to the lower breast meat pH on both day 42 and 56, which may have been directly related to decreased severe woody breast myopathy (WBM) incidence on day 42 and moderate WBM incidence on day 56. The severity of WBM was positively related to breast weight in all 10 treatments on both day 42 and 56, with the exception of birds in strain 3 on day 56 that were fed the AA-reduced diet. At the same time, AA reduction was more cost-effective when WBM incidence was considered in a theoretical model. In conclusion, WBM severity was associated with higher breast weight in birds of most strains fed either a control or AA-reduced diet. Dietary AA reduction decreased processing yields but decreased WBM incidence, which may be more economical., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

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., (Copyright © 2020. Published by Elsevier Inc.)

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., (Copyright © 2020. Published by Elsevier Inc.)

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 (R low MG) 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 R low MG. Blood samples were taken immediately before the initial R low MG 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 R low MG-challenged group than the unchallenged group of birds regardless of dietary treatment. The R low MG 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 R low MG 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 R low MG challenge was associated with respiratory acidosis. Nevertheless, feeding XPC did not influence the effects of challenge treatment on these postchallenge physiological blood values., (Copyright © 2020. Published by Elsevier Inc.)

Effects of the in ovo injection of vitamin D 3 (D 3 ) and 25-hydroxycholecalciferol (25OHD 3 ) on broiler embryo serum 25OHD 3 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 D 3 , 0.6 μg 25OHD 3 , 0.6 μg D 3 + 0.6 μg 25OHD 3 , 1.2 μg D 3 , 1.2 μg 25OHD 3 , 1.2 μg D 3 + 1.2 μg 25OHD 3 , 2.4 μg D 3 , 2.4 μg 25OHD 3 , or 2.4 μg D 3 + 2.4 μg 25OHD 3 . At 432 h of incubation (hoi), 50-μL solution volumes were injected. Blood samples were collected at 462 hoi for serum 25OHD 3 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 D 3 source alone or in combination had higher serum 25OHD 3 concentrations than those that were injected with diluent alone or diluent containing 0.6 μg of D 3 . Hatchlings that received 1.2 or 2.4 μg of 25OHD 3 had higher percentage of yolk dry matter or lower percentage of yolk moisture levels than noninjected controls and those that received D 3 alone at any level. These results indicate that the in ovo injection of either vitamin D 3 source at levels equal to or higher than 1.2 μg resulted in serum 25OHD 3 concentrations that were higher than that of noninjected controls. In addition, the in ovo injection of 1.2 μg or higher of either vitamin D 3 source did not negatively affect broiler HI or chick quality., (Copyright © 2020. Published by Elsevier Inc.)

There was evaluation of effects of biotin administration on oviductal abundance of transforming growth factor-β (TGF-β) 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 (T 0 ), or 0.3 (T 1 ), or 0.45 (T 2 ) mg/L of biotin. There was assessment the relative oviductal abundances of TGF-β and CA mRNA transcript abundances. Supplemental biotin and age had no effect on the relative abundance of oviductal TGF-β mRNA transcript in hens of Line D. There, however, was a ten-fold greater abundance of TGF-β in hens of the T 0 group of Line B compared with Line D. Relative abundance of TGF-β mRNA transcript was greater in younger hens of Line B; however, biotin supplementation of older hens of the T 2 group of Line B resulted in a similar TGF-β abundance to that of younger hens. Inconstant with the TGF-β abundance, CA abundance in hens of Line B was not affected by supplemental biotin or bird age. Overall, differences in TGF-β or CA abundances did not affect fertility of broiler hens., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Genetic selection in broilers has resulted in improved growth performance, meat yield, and feed conversion efficiency. However, consumers have become increasingly concerned about modern broiler welfare that is related to their rapid growth rate, which may be alleviated by nutrient dilution. This study was conducted to investigate the effects of dietary amino acid (AA) reduction on the growth performance and internal organ development of different genetic strains of broilers. A randomized completed block design with a factorial arrangement of 10 treatments (5 strains × 2 AA levels) was used. The 5 different strains of broilers were fed either a control diet, with digestible AA (lysine, total sulfur AA, and threonine) at the highest recommended levels for the 5 strains, or an AA-reduced diet, with the digestible AA being 20% lower than the control diet. Feed conversion ratio was increased by AA reduction in all 5 strains during day 0-14, 14-28, and 28-41 but was not affected from day 41-55. Body weight and feed intake responses to AA reduction varied in the different strains and ages of birds. Liver weight relative to BW on day 40, and weights of the duodenum and jejunum relative to BW on day 60 were increased by decreasing the dietary AA concentration. These results indicate that the birds had adjusted their organ growth and metabolism in response to increases in digestion, absorption, and utilization efficiency to accommodate a decrease in dietary AA content. Surprisingly, the cost of feed required to produce the same BW was decreased in 4 of 5 strains on both day 41 and 55, which was largely because of the lower price of the diets containing reduced AA levels and the later compensatory growth experienced by the birds fed AA-reduced diets. In the future, when dietary AA levels need to be adjusted to control growth rate and improve welfare status, the genetic strain, age of the birds, and targeted goals need to be taken into consideration., (Copyright © 2020. Published by Elsevier Inc.)

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 significantly 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., (Copyright © 2020. Published by Elsevier Inc.)

The effects of in ovo injected vitamin D 3 source on eggshell temperature (ET) and performance of broilers through 14 D of age (doa) were investigated. Eggs from a 35-wk-old commercial Ross 708 broiler breeder flock were set in a single-stage incubator with 4 treatments representing each of 12 incubator tray levels (blocks). At 432 h of incubation (hoi), noninjected and diluent-injected (50 μL) groups were control treatment groups. Vitamin treatments in the commercial diluent were as follows: 2.4 μg of vitamin D 3 (D 3 ) or 25-hydroxylcholecalciferol (25OHD 3 ). After injection, ET readings were recorded (435, 441, 453, 459, and 465 hoi) by infrared thermometry. Hatchability, hatchling BW, and percentage of male and female hatchlings were determined at 502 hoi. Equal numbers of male and female chicks were placed in each pen and grown out for 14 doa. On a per-pen basis, BW was recorded after hatching at day 7 and 14 doa, and BW gain, average daily BW gain, feed intake (FI), and feed conversion ratio (FCR) were calculated between 0 to 14 doa. The ET of eggs significantly fluctuated during the postinjection time period; however, the type of vitamin D 3  source injected did not affect ET. Nevertheless, the injection of 25OHD 3 resulted in a lower late embryo mortality than the diluent and D 3 injection treatments. In addition, birds that received 25OHD 3 had a lower FI and FCR than birds in all other treatments. In conclusion, the in ovo injection of 25OHD 3 has the potential to improve early posthatch broiler performance without affecting ET., (Copyright © 2019. Published by Elsevier Inc.)

The aim of this study was to evaluate the effects of supplementary CoQ10 in the diets of aged broiler breeder hens on productive and reproductive variables. A total of 128 hens)44 weeks of age) were randomly assigned to one of 16 groups (eight hens per group). The hen-groups (with equal mean egg production and egg weight) were randomly assigned to one of four diet-groups to provide four pen/groups per treatment. There was no CoQ10 supplementation or supplemental amounts of either 300, 600 or 900 mg CoQ10/kg added to the basal diet. Egg production, weight, and mass were determined weekly. To assess fertility, hatchability, and sperm penetration (SP) rate, the hens were artificially inseminated on a weekly basis (from 47-54 weeks of age). The hens were weighed and killed at the end of the experiment for evaluation of the ovarian morphology, oviduct histology, utero-vaginal junction (UVJ) total antioxidant capacity (TAC), and Pdss2, GDF9, and BMP15 mRNA transcript abundances in the germinal disc regions. The results indicated that there was a linear response curve to increasing amounts of supplemental dietary CoQ10 on fertility, hatchability of eggs, SP rates, TAC of the UVJ, fold height and surface epithelia of the magnum and isthmus, and abundance of GDF9, BMP15 and Pdss2 mRNA transcripts in the germinal disc region. In conclusion, the findings of the present study indicate diet supplementation with CoQ10 had beneficial effects on the productive and reproductive variables of aged hens., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest to disclose for this study., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In numerous studies it has been suggested that targeting mitochondria with specific compounds could efficiently inhibit various conditions associated with oxidative stress. The treatment of aged roosters with compounds such as coenzyme Q10 (CoQ10), may improve their reproductive performance by providing protection from oxidative stress. Therefore, this study was performed to assess the effect of supplemental dietary CoQ10 on the testicular function and fertility of aged broiler breeder roosters. A total of 36 roosters)47 weeks of age) were randomly divided into dietary treatments containing either 0, 300 or 600 mg CoQ10/kg diet. Three birds were allocated to each of four replicate groups in each dietary treatment. Between 47 and 54 weeks of age, ejaculates were obtained weekly from the three roosters in each replicate group. Samples in a replicate were pooled and analyzed as a single sample. Between 51 and 54 weeks of age, seminal plasma total antioxidant capacity (TAC), alanine amino transferase (ALAT) and aspartate amino transferase (ASAT) levels were assessed. Fertility, hatchability, and sperm penetration (SP) rates were likewise evaluated. Seminal volume, sperm concentration, sperm plasma membrane functionality, sperm plasma membrane integrity, seminiferous tubule diameter and seminiferous epithelium thickness exhibited quadratic increases in response to increasing levels of dietary CoQ10. Respectively, the 429.19, 433.33, 464.50, 613.50, 392.78 and 447.99 mg/kg dietary concentrations of CoQ10 provided the best results for each of the aforementioned variables. Also, other seminal traits, as well as testosterone concentration, fertility, and SP rates, displayed linear increases in response to the increasing levels of CoQ10. Dietary supplementation of CoQ10 linearly decreased seminal plasma ALAT and ASAT and linearly increased seminal plasma TAC. In conclusion, CoQ10 supplementation in the diet (a minimum of 300 mg CoQ10/kg diet) has the potential to improve the reproductive performance of aged broiler breeder roosters., (Copyright © 2019 Elsevier Inc. All rights reserved.)

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., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)

In a companion study, the effects of dietary antibiotic alternative and coccidial vaccination on the growth performance of male broilers have been reported. In this paper, the effects of dietary probiotics and coccidial vaccination on diversity and composition of cecal microbiota were investigated using a 3 (diets) × 2 (vaccinated or non-vaccinated) factorial setting of treatments. Three diets, including a corn and soybean-meal control diet, an antibiotic diet (a control diet supplemented with bacitracin and salinomycin), and a probiotic diet (a control diet supplemented with Bacillus subtilis) were provided to broiler chicken from day 0 to 42. To simulate an Eimeria challenge in the field, all chicks were gavaged with a 20× dose of commercial coccidial vaccine containing live Eimeria oocysts on day 14. Cecal contents were collected on day 42. High-throughput sequencing of the 16S rRNA gene was used to determine microbial diversity and composition. Coccidial vaccination to broilers reduced bacterial diversity (Shannon index) of the cecal microbiota. There was a significant interaction between the dietary additive and coccidial vaccination on the observed bacterial species number. Diets supplemented with B. subtilis increased bacterial species of non-vaccinated broilers but decreased bacterial species of vaccinated broilers. In contrast, diets supplemented with antibiotics reduced bacterial species of broilers from both groups. Interactions between dietary additive and coccidial vaccination were also observed on microbial composition. Vaccinated broilers fed the B. subtilis diet exhibited the lowest Firmicutes percentage and highest Bacteroidetes percentage within the microbial community. In addition, vaccinated broilers fed the B. subtilis diet exhibited the highest Rikenella microfusus percentage. From this study, the coccidial vaccination on the day of hatch reduced the microbial diversity of broilers at a later age. The inclusion of B. subtilis-probiotics in the feed of vaccinated broilers may reduce microbial diversity in cecal content by increasing the proportion of a predominant bacterial species, R. microfusus, in the microbial community., (© 2019 Poultry Science Association Inc.)

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., (© 2019 Poultry Science Association Inc.)

Effects of the coccidial vaccination and dietary antimicrobial alternatives on growth performance, internal organ development, and intestinal morphology of male broilers subjected to an Eimeria challenge were determined. A total of 1,120 one d-old Ross × Ross 708 male broilers were randomly distributed to 80 floor pens (10 treatments, 8 replication pens/treatment, and 14 chicks/pen). A 2 × 5 factorial arrangement of treatments was used to determine the main and interaction effects of the coccidial vaccination (vaccinated or non-vaccinated) and the dietary additive [1) corn and soybean-meal basal diet, 2) basal diet + antimicrobials (bacitracin and salinomycin), 3) basal diet + probiotics (3 Bacillus subtilis strains), 4) basal diet + prebiotics (mannan-oligosaccharides and β-glucans), and 5) basal diet + probiotics + prebiotics]. To mimic the Eimeria challenge, all chicks were gavaged with a 20x dose of a different coccidial vaccine (live Eimeria oocysts) at Day 14. The coccidial vaccination decreased Day 0-14 and 29-42 BW gain (BWG) and subsequently decreased Day 0-56 BWG. Broilers fed diets with antimicrobials exhibited the lowest feed conversion ratio (FCR) during the periods of Day 0-14 and 15-28, the shallowest ileal crypt depth on Day 28, and the lowest relative duodenum weight on Day 28 and 42. The Pre+Pro diets helped the broilers to reach a lower overall FCR than did the Pro alone diets and helped the broilers reach a FCR similar to that of the Anti diets. However, broilers fed diets supplemented with prebiotics and probiotics exhibited the deepest intestinal crypt depth on Day 28. There was no interaction between coccidial vaccination and dietary additive on growth performance or any carcass yield. In conclusion, antimicrobial additives might reduce the intestinal size of broilers; whereas prebiotic and B. subtilis-based probiotic additives might promote the growth of several digestive organs. Prebiotics can be safely used with B. subtilis-probiotics in broiler feed without compromising feed conversion ability., (© 2018 Poultry Science Association Inc.)

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.

Effects of antibiotic (bacitracin), anticoccidial (narasin), and alternative (Bacillus subtilis and zinc) feed additives on growth performance, internal organ development, and intestinal morphology of commercial broilers with or without subclinical coccidia challenge were determined. A total of 1,344 1-day-old male Ross × Ross 708 broilers were randomly distributed into 12 treatments (6 diets × 2 challenge treatments, 8 replication pens/treatment) in 96 floor pens. The 6 dietary treatments were as follows: a control diet (corn and soybean-meal basal diet), a probiotic diet (basal diet + Bacillus subtilis), a zinc diet (basal diet + 100 ppm zinc), a probiotic and zinc combined diet, an anticoccidial diet (basal diet + narasin), and a practical diet (basal diet + narasin + bacitracin). On day 21, each chick in the challenge treatment was gavaged with a 10× dose of a commercial vaccine containing live Eimeria oocytes, whereas each chick in the non-challenge treatment was gavaged with equivalent distilled water. The subclinical coccidia challenge increased the relative weights of pancreas and decreased the ileal crypt depth of broilers at 26 d of age, increased feed conversion ratios from day 15 to 28 and 29 to 40, and increased the relative weights of duodenum and bursa on day 54. As compared to other diets, anticoccidial and practical diets increased BW gain and decreased feed conversion ratio from day 15 to 28, and increased the day 40 carcass weights. As compared to control diets, probiotic diets decreased BW gain and increased the mortality from day 15 to 28; however, probiotic diets did not affect the overall growth performance from day 0 to 54 or carcass yield on day 54. Growth measurements during periods of day 29 to 40 and day 41 to 54 were not affected by any feed additive. From this study, a subclinical coccidia challenge enlarged specific internal organs and compromised the feed conversion ability of broilers. Dietary Bacillus subtilis did not affect overall growth rate or carcass yield of broilers under subclinical coccidia challenge.

Inovocox EM1 vaccine (EM1) is hatchery-applied via in ovo injection for the control of coccidiosis in broiler chickens. Effects of 3 in ovo injection treatments (INT) and 2 turn-out times (TOT) on the hatching chick quality variables and 35 d posthatch performance of Ross × Ross 708 broilers were investigated. In a single-stage incubator, 1,440 hatching eggs were randomly distributed among 3 INT groups on each of 8 tray levels. At 19 d of incubation (doi), embryonated eggs were subjected to one of the following INT by in ovo injection: noninjected control; 1 × dose of EM1; 10 × dose of EM1. On 21 doi, hatchability of injected eggs (HI), hatching body weight (HBW), and hatching chick quality variables were determined. Additionally, for the grow-out phase, birds belonging to each INT were randomly subjected to a 7 or 10 d TOT. Twenty chicks were initially placed in each of 48 floor pens (6 INT × TOT combination groups × 8 replications) for growth performance evaluation from 0 to 35 d posthatch. The main effect of INT on hatching chick quality variables, as well as the main and interactive effects of INT and TOT on various grow-out performance variables were determined. Although there was no significant INT effect on HI or HBW, significant INT effects on chick total BW, yolk-free BW, and yolk sac weight were observed. There were significant INT effects on BWG and FCR in the 21- to 28-d posthatch interval, as well as on BWG and FCR in the 0- to 35-d posthatch interval. There was no main effect of TOT or interactive effect of INT and TOT on BW and other performance variables from 0 to 35 d posthatch. There was a significant main effect of INT on relative intestine weight at 28 d posthatch. In conclusion, the injection of EM1 vaccine at a 10 × dose may affect hatching chick quality variables and growth performance up to 35 d posthatch.

The current study was conducted to determine the possible effects of the in ovo administration of different dosages of L-ascorbic acid (AA) to broiler hatching eggs on hatchability and its potential for reducing the adverse effects of delayed placement.A total of 702 broiler hatching eggs was hand-injected at 17 d of incubation (DOI) with 100 μL of sterile saline (0.85%) alone or containing 0.5, 1.5, 4.5, or 13.5 mg AA. Hatchability was recorded every 5 h from 480 h to 505 hours. Results showed that AA injection did not affect embryo BW as percentage of set egg weight or yolk sac weight as percentage of embryo weight at 19.5 DOI. The hatching time of all embryos that received an AA in ovo injection was between 480 and 495 h of incubation, and significantly fewer embryos hatched before 480 h in comparison to non-injected controls. Hatchability (above 92% in all groups) was not significantly affected by injection treatment. However, fertile eggs injected with saline containing 4.5 mg AA had the highest hatchability. At 21 DOI, hatching BW as a percentage of set egg weight and yolk sac weight as a percentage of BW were numerically higher in AA injection groups. An in ovo injection of AA at a 13.5 mg/egg level resulted in a numerically higher BW as a percentage of set egg weight. The in ovo injection of AA did not reduce the adverse effects of a 48-hour posthatch pre-placement holding time on BW or on yolk sac absorption. Overall, in ovo injection of L-ascorbic acid (0.5 to 13.5 mg/egg) into fertile broiler hatching eggs at 17 DOI did not negatively affect hatchability or embryo development, and did not prevent the negative effects of a 48-hour posthatch holding time on BW and yolk sac absorption. The range of tolerance as well as the optimal dosage of in ovo-injected AA warrants future study.

The determination of intestinal villus to crypt ratios (VCR) is a common method utilized to evaluate effects of various diet regimens on gut microanatomy and for the histologic quantification of intestinal responses to disease processes. Two methods for the determination of small intestinal VCR were compared in early age chickens. A standard method for VCR determination based on 10 villus and crypt length measurements in the jejunal region of the small intestine was employed for the calculation of villus to crypt length ratio (VCLR). That method was compared to a new approach based on a single histomorphometric determination of the crypt and total mucosal areas using image analysis software. Subtraction of the crypt area from the total area provided the villus area and allowed for the subsequent calculation of villus to crypt area ratio (VCAR). At 4 and 18 h posthatch, VCLR was higher than that of VCAR, but there was no significant difference between VCLR and VCAR at 0 h (hatch) and at 168 h (d 7) posthatch. Nevertheless, the pattern of age-associated changes for VCLR and VCAR were comparable throughout the early posthatch period. Furthermore, the new method used in determining VCAR is subject to less human error, allows for an appreciable reduction in the number of measurements required, and facilitates a larger intestinal segment evaluation. Standard linear measurements require the selection of variable numbers of villi and crypts, whereas the area method only requires selection of a single region that incorporates numerous villi and crypts of variable sizes in providing a less subjective approach. This is particularly advantageous in studies on intestinal disease conditions resulting in marked multifocal variation in villus stature. This study further documented age-associated changes occurring in the VCR of the small intestine during the early posthatch period. Across the 2 methods used for VCR determination, a major and highly significant reduction in the VCR was observed to occur between 18 h and 168 h posthatch.

In a preliminary experiment, the influence of pigment color variation on the temperature readings of the shells (EST) of live embryonated Ross 708 broiler hatching eggs was tested. Prior to set, eggshell color in L*, a*, and b* coordinates were measured at the equator of each egg. Eggshell pigmentation was found not to influence EST from zero through 18 d of incubation (DOI). In a subsequent experiment, EST, as well as air cell (ACT) and cloaca (CLT) temperature measurements were used for the calculation of absolute (GH2O) and specific (gH20) eggshell conductance values for these same types of eggs. An infrared thermometer was used to determine EST from zero to 19 DOI, ACT was measured using a transponder from 12 to 19 DOI, and CLT was determined using a transponder at 4:00 PM at 19 DOI. In the 12 to 19 DOI interval, the values for GH2O as well as for gH20 that were calculated using either EST or ACT were significantly correlated (r ≥ 0.99; P < 0.0001). A similar correlation level for both GH2O and gH20 was likewise observed in the 10:00 AM to 10:00 PM time period at 19 DOI when either EST, ACT, or CLT was used. However, in the 12 to 19 DOI interval, calculated GH2O and gH20 values based on ACT were significantly different from those based on EST. In addition, a significant difference in calculated GH2O and gH20 values resulted when ACT was used rather than when EST or CLT was used in the 10:00 AM to 10:00 PM time period at 19 DOI. In both time periods, GH2O and gH20 values calculated using ACT were significantly lower than those derived using the other 2 types of measurements. These findings suggest that although EST was not affected by shell coloration, because ACT more closely reflects embryo body temperature, it should be used to more accurately calculate the GH2O and gH20 of Ross 708 broiler hatching eggs., (© 2017 Poultry Science Association Inc.)

Effects of the in ovo (i.o.) or subcutaneous (s.c.) method of administration (moa) of the Marek's disease (MD) vaccine and 4 or 18 h pre-placement holding time (pht) on the processing yield of male broilers through 49 d of age (doa) were investigated. Ross 708 broiler hatching eggs (3,900) were either i.o.-vaccinated at 18 d of incubation or chicks from eggs that were not i.o.-vaccinated were s.c.-vaccinated at hatch. The i.o. injections (50 μL) were delivered by a commercial multi-egg injector and s.c. injections (200 μL) were delivered by an automatic pneumatic s.c. injector. The pht was imposed on chicks after vaccination. Sixteen birds were initially assigned to each of 15 replicate floor pens belonging to each of the moa and pht combination groups and were grown out through 48 doa. At 48 doa, 6 birds were randomly selected from each replicate pen and were weighed and fasted for 16 h before being processed. At 49 doa, whole carcass, fat pad, breast muscle, and tenders muscles weights were recorded. Whole carcass weight as a percentage of live BW, and fat pad, breast muscle, and tenders muscles weights as percentages of both live and whole carcass weights were calculated. Upon subjection of the data to a 2 × 2 factorial analysis, only a main effect due to moa was observed for tenders muscles weight as a percentage of live and whole carcass weights. Tenders muscles weight as a percentage of both live (P ≤ 0.010) and whole carcass (P ≤ 0.004) weight was higher in birds hatched from eggs that received i.o. rather than s.c. vaccinations. In conclusion, in comparison to s.c. vaccination, i.o. vaccination increased relative tenders weight yield, whether or not broilers were held for 4 or 18 h prior to placement. Therefore, with regard to broiler processing yield, i.o. and s.c. vaccinations were safe for the administration of the MD vaccine, with i.o. vaccination displaying a slight potential advantage., (© 2017 Poultry Science Association Inc.)

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., (© 2017 Poultry Science Association Inc.)

Effects of the in ovo injection of a commercial coccidiosis vaccine on various hatching chick quality variables and 14 d post-hatch (dph) oocyst shedding have been previously examined. The current study was designed to examine the performance of Ross 708 broilers during the 14 dph period of oocyst shedding following the application of the coccidiosis vaccine. On each of 7 replicate tray levels of a single-stage incubator, a total of 4 treatment groups was randomly represented, with each treatment group containing 63 eggs. Treatments were administered using a commercial multi-egg injector on d 18.5 of incubation. The treatments included 3 control groups (non-injected, dry-punch, and diluent-injected) and one treatment group (injected with diluent containing Inovocox EM1 vaccine). On d 21 of incubation, 20 chicks from each of the 28 treatment-replicate groups were placed in corresponding wire-floored battery cages. Mortality, feed intake (FI), BW gain (BWG), and feed conversion ratio (FCR) were determined for the zero to 7, 7 to 14, and cumulative zero to 14 dph intervals. There were no significant treatment effects on mortality in any interval or on BW at zero dph. There were significant treatment effects on BW at 7 and 14 dph, on BWG and FI in the zero to 7, 7 to 14, and zero to 14 dph intervals, and on FCR in the 7 to 14 and zero to 14 dph intervals. Although the performance variables of birds belonging to the diluent-injected and vaccine-injected groups were not significantly different, the 14 dph BW, 7 to 14 dph FI, and zero to 14 dph BWG and FI of birds belonging to the vaccine treatment group were significantly higher than those in birds belonging to the non-injected control group. It was concluded that use of the Inovocox EM1 vaccine in commercial diluent has no detrimental effect on the overall post-hatch performance of broilers through 14 dph., (© 2017 Poultry Science Association Inc.)

Effects of 2 types of methods of administration (moa; in ovo or s.c.) of the Marek's disease (MD) vaccine and 4 and 18 h pre-placement holding times (pht) on the performance of male broilers through 48 d of age were investigated. Ross 708 broiler hatching eggs (3,900) were either in ovo-vaccinated at 18 d of incubation or chicks from eggs that were not in ovo-injected were vaccinated s.c. at hatch, and chicks from each moa group were held for one of the 2 pht. In ovo injections (50 μL) were delivered by a commercial multi-egg injector and s.c. injections (0.2 mL) were delivered by an automatic pneumatic s.c. injector. Sixteen birds were assigned to each of 15 replicate floor pens belonging to each of the 4 moa and pht combination groups. Mortality and BW gain were determined at weekly intervals, and feed consumption and conversion were determined in the zero to 14, 14 to 28, 28 to 42, and 42 to 48 d age intervals. No interactive effects between moa and pht were observed for any variable, and mortality was not significantly affected by moa or pht. The 14 to 28 d feed consumption and 14 to 21 d BW gain of s.c.-vaccinated birds were lower than that of in ovo-vaccinated birds, and the increase in pht from 4 to 18 h decreased feed consumption through 28 d post hatch and BW gain through 35 d post hatch. Overall, the performances of male Ross 708 broilers through 48 d of age in response to in ovo and s.c. injections of the MD vaccine were comparable, and delays in hatchling placement should be less that 18 h in duration. Furthermore, despite the decrease in BW gain through 35 d associated with the reduction in feed consumption through 28 d in response to the 14 h increase in pht, in ovo injection did not exacerbate the effect of the increase in pht., (© 2016 Poultry Science Association Inc.)

Effects of the in ovo injection of a commercial coccidiosis vaccine on the hatchability and hatching chick quality variables of Ross × Ross 708 broilers were examined. Four treatment (TRT) groups were represented on each of 7 replicate tray levels of a single-stage incubator (28 TRT-replicate groups). Each TRT-replicate contained 63 eggs (1,764 total eggs). On d 18.5 of incubation, eggs were subjected to one of 4 TRT using a commercial multi-egg injector. Three control groups (non-injected, dry-punch, and diluent-injected) and one TRT group (injected with diluent containing Inovocox EM1 vaccine) were used. On d 18.5 of incubation, the site of injection and stage of embryo development were determined. On d 21.5 of incubation (d zero post hatch), hatchability of injected eggs (HI), chick BW, and yolk sac, intestine, and liver weights were determined. On d zero post hatch, 20 chicks from each of the 28 TRT-replicate groups (560 total birds) were placed in corresponding isolated wire-floored battery cages. On a daily basis, from d zero to 14 post hatch, pooled fecal samples from each individual replicate cage were collected for oocyst output determination. There was no significant difference among TRT for HI or chick BW on d 21.5 of incubation. In the non-injected control and vaccine-treated groups, mean HI was 93.1 and 89.4%, respectively, and chick BW were 43.4 and 43.8 g, respectively. The mean embryonic stage score was 2.09, and 84.8 and 15.3% of in ovo injections were in the amnion and embryo, respectively. Oocyst shedding began 4 d post hatch (d 6 post injection), and reached a peak at d 7 post hatch (d 10 post injection). It was concluded that the in ovo injection of Inovocox EM1 vaccine did not have a significant detrimental effect on broiler embryogenesis or hatching chick quality., (© 2016 Poultry Science Association Inc.)

The relationships of eggshell, air cell, and embryo cloacal temperatures in Ross × Ross 708 broiler hatching eggs were determined. Twenty eggs were weighed and set on each of 3 tray levels of a single incubator. Eggshell temperature (EST) of the eggs were recorded once in the morning (AM) and afternoon (PM) between 0 and 19 d of incubation (DOI) using an infrared thermometer (IRT). All eggs were candled and a transponder was implanted in the air cell of eggs containing live embryos (12 per tray level) at 12 DOI. At 19 DOI, transponders were implanted in the cloaca of live embryos from those same eggs. Air cell temperature (ACT) and EST readings were recorded once in the AM and PM between 12 and 19 DOI, and ACT and cloaca temperature (CLT) readings were recorded every 6 h between 19 and 21 DOI. The EST and ACT readings between 13 and 19 DOI were positively correlated. However, their respective mean temperatures between 13 and 19 DOI differed. The EST and ACT were not significantly influenced by tray level. Nevertheless, a main effect due to location (eggshell vs. air cell), and an interaction between DOI and time of day (AM and PM) in the 13 to 19 DOI interval were observed. Furthermore, an interaction was observed between location (air cell and cloaca) and the 6 h sequential time periods in the 19 to 21 DOI interval. However, across the entire 19 to 21 DOI interval, mean ACT and CLT were not significantly different, and were positively correlated. These data suggest that ACT readings are higher than those of EST during the last half of incubation, and that between 13 and 19 DOI, ACT readings may have the potential for use as a minimally invasive method by which to more accurately estimate the true core body temperature of broiler embryos. The effects of this method on hatchability and post-hatch performance need determination to better establish its practicality., (© 2016 Poultry Science Association Inc.)

Effects of method of administration [moa; in ovo (i.o.) or s.c.] of the Marek's disease vaccine and pre-placement holding time (pht) on early post-hatch male broiler chick quality was investigated. Sixty-five Ross × Ross 708 broiler hatching eggs were randomly set in each of 15 replicate trays (blocks) belonging to each of 4 pre-assigned moa and pht treatment combinations (3,900 total eggs) in a single stage Jamesway incubator. Eggs that were i.o.-vaccinated received injections at 18 d of incubation and male chicks from eggs that were not i.o.-injected were vaccinated by s.c. injection at hatch. The i.o. injections (50 μL) were delivered by a commercial multi-egg injector and the s.c. injections (200 μL) were delivered by an automatic pneumatic s.c. injector. Male chicks from each moa group also were subjected to either a 4 or 18 h pht. At hatch and placement total and yolk-free BW; body length; body mass index; yolk sac weight; yolk-free body and yolk sac weights as percentages of total BW; and yolk-free body and yolk moisture concentrations were determined. Chick BW also was determined at 7 d of age. Hatchability of fertile eggs was not affected by i.o. injection. However, at hatch, body length was increased and body mass index was decreased in response to i.o. injection. No main effect of moa or an interactive effect with pht was observed for the above variables at placement. However, body length was longer and body mass was lower in the 18 h than in the 4 h pht chicks. Placement yolk sac and body weights, and the 7 d BW of 18 h pht chicks was also lower than that of 4 h pht chicks. In conclusion, prolonging pht for 14 h adversely affected early chick quality, whereas i.o. injection did not negatively affect the early post-hatch quality of Ross × Ross 708 broiler chicks whether or not they were held for 4 or 18 h prior to placement., (© 2016 Poultry Science Association Inc.)

Effects of commercial antimicrobials and the individual and combinational use of commercial prebiotics and probiotics in feed from d zero to 41 on the growth performance, small intestine size, jejunal morphology, and ileal resident bacteria population of broiler chickens were determined. A total of 1,040 one-day-old male Ross × Ross 708 broilers were randomly distributed to 80 floor pens (5 treatments, 16 replications per treatment, 13 chicks per pen). Five dietary treatments were employed: 1) a corn soybean-meal basal diet (served as a negative control diet, NC); 2) a basal diet supplemented with a commercial prebiotic product (Pre); 3) a basal diet supplemented with a probiotic product containing Bacillus subtilis spores (Pro); 4) a basal diet supplemented with both prebiotic and probiotic products (Pre + Pro); and 5) a basal diet supplemented with commercial antimicrobials (served as a positive control diet, PC). At d 14, Pre diets improved the relative level of Lactobacillus in ileal mucosa as compared to NC, Pro, or PC diets (P = 0.045) without improving broiler BW. Broilers fed PC diets exhibited the highest BW gain from d 15 to 27, the lowest duodenum, jejunum, and ileum relative weights as percentage of BW at d 27, and the highest breast weight at d 42 (P = 0.026, 0.035, 0.002, 0.025, and 0.035, respectively). Broilers fed Pro or Pre + Pro diets exhibited higher BW gain from d 28 to 41 (P = 0.005) and higher overall BW gain from d zero to 41 (P = 0.039) than those fed other diets. Dietary treatments did not affect jejunal morphology or ileal resident Escherichia coli level at any age. From our results, including spores of Bacillus subtilis in feed may stimulate growth at a later age and may facilitate broilers in reaching their target weight sooner. Therefore, probiotics are recommended as potential alternatives to antimicrobials in chicken diets, especially in grower and finisher feed., (© 2016 Poultry Science Association Inc.)

Mycoplasma gallisepticum (MG) is a major and economically significant pathogen of avian species. When administered before lay, F-strain MG (FMG) can reduce egg production during lay, but the ts-11 strain of MG (ts11MG) does not exert this effect. Two trials were conducted to determine the effects of pre-lay vaccinations of ts11MG, MG-Bacterin (MGBac), or their combination, in conjunction with an FMG vaccination overlay after peak production on the digestive and reproductive organ characteristics of Hy-Line W-36 layers housed in biological isolation units (4 units per treatment, 10 birds per unit). The following vaccination treatments were administered at 10 wk of age (woa): 1) Control (no vaccinations); 2) MGBac; 3) ts11MG; and 4) ts11MG and MGBac combination (ts11MG+MGBac). At 45 woa, half of the birds were vaccinated with a laboratory stock of high passage FMG. In both trials, parameters determined in 4 birds per unit at 55 woa included: BW; fatty liver hemorrhagic syndrome incidence; mean number of mature ovarian follicles; ovarian, oviduct, and small intestine weights; and the weights and lengths of the various portions of the oviduct and small intestine. Treatment effects were observed for the weights of the entire small intestine and the duodenum, jejunum, and ileum, as percentages of BW; and for vagina weight as a percentage of total oviduct weight. In general, the weights of the small intestine and its 3 components were increased in response to the FMG vaccine that was administered at 45 woa. An FMG vaccination at 45 woa may increase relative intestine weight in layers; however, use of a prelay MGBac vaccine alone or in combination with ts11MG, with or without an FMG overlay, does not affect the gross characteristics of their digestive and reproductive organs, and may be used without having an adverse effect on their performance, as was observed in a previous companion study., (© 2015 Poultry Science Association Inc.)

Effects of the in ovo injection of organic Mn, Zn, and Cu in association with post-hatch (POH) feed and water restriction on the performance and physical-chemical bone parameters of male Ross × Ross 708 broilers were examined. On 17 d of incubation, a total of 1,872 eggs were subjected to in ovo injection using a commercial multi-egg injector. Treatments (TRT) includingd non-injected and diluent-injected controls. The respective Zn, Mn, and Cu levels (mg/mL) added to the diluent of the low (LMD) and high mineral (HMD) TRT groups were 0.181, 0.087, and 0.010, and 0.544, 0.260, and 0.030, respectively. The 4 TRT groups were then sub-divided into 2 POH holding time (HT) groups, with 15 birds randomly allocated to each of 6 replicate pens in each of the 8 groups. The first HT group (0HT) had immediate access to water and feed, and the second HT group (24HT) contained birds that were kept in transport baskets for 24 h before being released. Performance was determined and selected birds were subsequently necropsied and their tibiae extracted for analysis. In comparison to birds from 24HT group, those in the 0HT group had a higher BW gain and feed intake, and a lower FCR through 21 d POH. The percentage of bone ash of the birds belonging to the HMD group was higher than all other TRT on d 1 POH and was higher than the non-injection control group on d 21 POH. On d 1, the LMD and HMD groups had higher tibial Mn concentrations than those of the control groups. On d 7, bones from the HMD group had a higher concentration of Mn than did the non-injected control group, and likewise, on d 21 POH, had a higher concentration of Zn than did the control groups. In conclusion, a 24HT negatively affected the performance of the birds during the first 2 wk POH; however, the LMD and HMD TRT had a positive influence on bone mineralization., (© 2015 Poultry Science Association Inc.)

Effects of the in ovo injection of commercial diluent containing supplemental microminerals (Zn, Mn, and Cu) on hatchability and hatching chick quality variables in Ross × Ross 708 broilers were examined. On 17 d of incubation (doi) eggs were subjected to 1 of 4 treatments using a commercial multi-egg injector. Treatments included non-injected (treatment 1) and diluent-injected (treatment 2) control groups. Those in treatment 3 received diluent containing 0.181, 0.087, and 0.010 mg/mL of Zn, Mn, and Cu, respectively, and those in treatment 4 received diluent containing 0.544, 0.260, and 0.030 mg/mL of Zn, Mn, and Cu, respectively. A total of 1,872 eggs were distributed among 4 treatment groups on each of 6 replicate tray levels. Hatchability of fertile eggs set (HF) was determined on 20.5 and 21.5 doi. On 21.5 doi, HF and mean hatching chick weight (MHW) were determined. One bird from each treatment replicate group was randomly selected, weighed, and necropsied for the extraction of their livers and tibiae. The tibiae fresh and dry weight, length, width, bone breaking strength (BBS), and percentage of bone ash (PBA) were determined. The dry livers were weighed and ashed. Injection treatment had no significant effect on HF at 20.5 doi. However, there was a significant injection treatment effect on HF at 21.5 doi. The HF of eggs at 21.5 doi in treatment 4 was significantly lower than that of the non-injected control group, with treatment 3 being intermediate. Furthermore, there were no significant treatment effects noted for MHW fresh and dry tibia weights, tibia length and width, tibia length to weight ratio, BBS, liver ash content, or percentage of minerals (Ca, P, Mg, Mn, and Zn) in the tibia ash. However, embryos from eggs that received treatment 4 had a significantly higher PBA in comparison to all other treatments. In conclusion, although treatment 4 negatively affected HF, the injection of diluent containing the high micromineral concentration has the potential to improve bone mineralization., (© 2015 Poultry Science Association Inc.)

Mycoplasma gallisepticum (MG) is a major and economically significant pathogen of avian species. When administered before lay, F-strain MG (FMG) can reduce egg production during lay, but the ts-11 strain of MG (ts11MG) does not exert this effect. Two trials were conducted to determine the effects of pre-lay vaccinations of ts11MG, MG-Bacterin (MGBac), or their combination, in conjunction with an FMG challenge overlay after peak production on the blood characteristics of commercial layers. In each trial, 160 mycoplasma-free Hy-Line W-36 layers were housed in negative-pressure biological isolation units (4 units per treatment, 10 birds per unit) from 9 through 52 wk of age (woa). The following vaccination treatments were administered at 10 woa: 1) Control (no vaccinations); 2) MGBac; 3) ts11MG; and 4) ts11MG and MGBac combination (ts11MG+MGBac). At 45 woa, half of the birds were challenged with a laboratory stock of high-passage FMG. Parameters measured in both trials were whole-blood hematocrit and serum concentrations of cholesterol (SCHOL), triglycerides, calcium, and total protein (STP). An age×treatment interaction (P=0.04) was observed for STP between 23 and 43 woa. The STP concentration in the ts11MG and ts11MG+MGBac groups was higher at 33 woa, but was lower at 43 woa, in comparison to the Control group. Also, at 38 woa, the STP of the ts11MG+MGBac group was higher than that of the MGBac group. Although use of the ts11MG vaccine alone or in combination with MGBac may influence circulating STP concentrations when administered before lay, it remains effective in protecting layers against the adverse effect of a post-peak challenge of FMG on egg production, as was observed in a previous companion study., (© 2015 Poultry Science Association Inc.)

Live F-strain Mycoplasma gallisepticum (FMG) vaccines are presently being used to help control field-strain MG outbreaks. However, they may exert some adverse effects on egg production. Live strains of MG of lesser virulence as well as killed vaccines have little or no effect on egg production, but afford lower levels of protection. This has led to research investigating their use in combination with a subsequent overlay vaccination of FMG given later in the production cycle. In the present study, 2 trials were conducted to investigate the effects of prelay vaccinations of live and killed MG vaccines or their combination, in conjunction with an FMG vaccine overlay after peak production, on the egg characteristics of commercial layers. The following vaccination treatments were administered at 10 wk of age (woa): 1) unvaccinated (Control), 2) MG-Bacterin (MGBac) vaccine, 3) ts-11 strain MG (ts11MG) vaccine, and 4) MGBac and ts11MG combination (MGBac + ts11MG). At 45 woa, half of the birds were overlaid with an FMG vaccine. In each trial, internal egg and eggshell parameters including egg weight (EW), Haugh unit score (HU), eggshell breaking strength (EBS), percentage yolk weight (PYW), percentage albumen weight (PAW), percentage eggshell weight (PSW), eggshell weight per unit surface area (SWUSA), percentage yolk moisture (PYM), and percent total lipids (PYL) were determined at various time periods between 21 and 52 woa. At 28 woa, SWUSA was lower in the ts11MG and MGBac + ts11MG groups compared to the Control group. Conversely, at 43 woa, SWUSA was higher in the ts11MG than in the MGBac group. Between 23 and 43 woa, PYL was higher in the MGBac and ts11MG groups in comparison to the Control group. In conclusion, vaccination with MGBac alone or in combination with ts11MG at 10 woa with or without an FMG vaccine overlay at 45 woa does not adversely affect the internal egg or eggshell quality of commercial layers throughout lay., (© 2015 Poultry Science Association Inc.)

Serum concentrations of 25-hydroxycholecalciferol [25(OH)D3] in broiler embryos at 19 d of incubation:doi:have been shown to increase 3 times by the in ovo injection of 0.60 μg 25(OH)D3 on 18 doi. In this trial, effects of the injection of 25(OH)D3 at 18 doi on the yolks and sera of male and female Ross×Ross 708 broiler embryos were assessed. On 18 doi, embryonated eggs that were set in a single stage incubator were assigned to 6 replicate trays within each of 2 injection treatment groups. Treatments included those injected with 100 μL commercial diluent (control) and those injected with 0.60 μg 25(OH)D3 in 100 μL commercial diluent. On 19 doi, embryos and their yolk sacs were extracted for determination of sex, yolk weight, BW, serum CA and phosphorous concentrations, and yolk CA, phosphorous, moisture, dry matter, and lipid concentrations. The weight of female embryos with their attached yolk sacs as a percentage of set egg weight was greater than that of males (P=0.03). There were treatment×sex interactions for the weight of embryos with their attached yolk sacs relative to 19 doi egg weight (P=0.05) and for yolk CA concentration (P=0.004). In eggs that received 25(OH)D3, the weight of female embryos with their attached yolk sacs relative to 19 doi egg weight was higher than that of males (P=0.005), and percentage yolk CA was higher in control eggs containing female embryos in comparison to those containing males (P=0.007). An injection of 0.60 μg 25(OH)D3 at 18 doi eliminated yolk CA differences associated with embryo sex, suggesting that 25(OH)D3 may influence sex-related differences in the rate of yolk CA absorption by broiler embryos and may be related to subsequent sex-related differences in posthatch bone strength., (© 2015 Poultry Science Association Inc.)

In a companion study, high amino acid (AA) or apparent metabolizable energy (AME) densities in the diets of broilers from 8 to 21 d of age were found to improve feed conversion. A total of 1,120 male Ross×Ross 708 chicks were randomly allocated to 80 pens (8 treatments, 10 replications per treatment, 14 chicks per pen). A 2×2×2 factorial arrangement of treatments was used to investigate the interaction among the protein source (high distillers dried grains with solubles diet [hDDGS] or high meat and bone meal diet [hMBM]), AA density (moderate or high), and AME density (2,998 or 3,100 kcal/kg) of diets on small intestine morphology. Duodenum, jejunum, and ileum samples from 2 chicks per pen were collected and measured individually at 21 d. Jejunum sections were processed for histological analysis. Chicks fed hDDGS diets exhibited longer small intestines than did chicks fed hMBM diets. Particularly, when chicks were fed high AA density diets, jejuna were longer in groups fed hDDGS diets than groups fed hMBM diets. Dietary treatments did not affect jejunum villus height, width, area, crypt depth, villus to crypt ratio, goblet cell size, or cell density. In birds fed diets containing a moderate AA and a high AME density, jejunum muscle layers of chicks fed hDDGS diets were thicker than those fed hMBM diets. Chicks exhibited a lower feed conversion ratio (FCR) and a higher BW gain when their crypts were shorter. In conclusion, an hDDGS diet may facilitate small intestine longitudinal growth in broilers, which may subsequently improve dietary nutrient absorption. In addition, broiler chicks with shallow intestinal crypts exhibited better growth performance., (© 2014 Poultry Science Association Inc.)

Improved bone development and mineralization in broilers have been attributed to the use of 25-hydroxylcholecalceiferol [25(OH)D3] as a dietary supplement. In this study, effects of the in ovo injection of 25(OH)D3 delivered in commercial diluent on 18 d of incubation (doi) on subsequent bone development and mineralization in male and female Ross × Ross 708 broilers were investigated. The variables investigated included bone mineral density and breaking strength, bone ash concentration, and calcium and phosphorus bone ash concentrations. In a single-stage incubator, with 6 treatments on each of the 10 tray levels, a total of 2,400 experimental broiler hatching eggs were evenly and randomly set. Eggs were treatment-injected and transferred to corresponding hatching baskets on 18 doi. Experimental treatment groups were those that received 0.2, 0.6, 1.8, or 5.4 µg of 25(OH)D3 that were delivered in 100 µL of commercial diluent. Noninjected and diluent-injected controls were also included. On 21 doi, chicks were pulled and placed in corresponding floor pens, and on each of d 0, 14, and 28 posthatch (poh), 2 birds of each sex from each pen were randomly selected for necropsy and extraction of both of their tibia bones. Bones from the right leg were subjected to mineral density analysis and those from the left leg were used to determine breaking strength and residual bone ash concentration. Furthermore, ash calcium and phosphorus concentrations on d 14 and 28 poh were determined. There was a treatment × sex × age interaction for bone breaking strength. Bone breaking strength in male birds on d 28 poh was higher in the 0.20, 0.60, and 1.80 µg of 25(OH)D3-injected treatment groups than in the diluent-injected control group. In conclusion, although the in ovo injection of 25(OH)D3 had no positive effect on the bone development of Ross × Ross 708 broilers through d 28 poh compared with noninjected controls, it may provide a benefit to those subjected to an injection of commercial vaccine diluent., (©2014 Poultry Science Association Inc.)

Avian spermatozoa are characteristically high in polyunsaturated fatty acids which predispose them to lipoperoxidation, thereby diminishing their fertility. As a by-product, well-known for antioxidative properties, dried apple pomace (AP) was fed to aging Ross 308 breeder roosters (n=80) at the dietary inclusion levels of 0 (AP0), 10 (AP10), 20 (AP20), or 25 (AP25) percent for 14 consecutive weeks. Seminal traits were studied every other week. At the end of the trial, sperm fatty acids profile, seminal plasma total antioxidant capacity (TAC), fertility, hatchability, and hatchling quality were evaluated, using 240 artificially-inseminated young hens. Dietary AP increased sperm motility and livability and decreased the seminal content of thiobarbituric acid reactive species. Dietary treatment and age interacted to positively affect sperm concentration and sperm membrane integrity. Feeding AP was associated with an increase in C20:4(n-6), C22:4(n-6), and total unsaturated fatty acids percentages. Birds in the AP25 and AP20 treatment groups respectively showed 6 and 7% increases in fertility rate. Interestingly, a higher hatchability rate was found for AP20 group, associated with a higher number of sperm penetration holes in the perivitelline membrane and a lower rate of early embryonic mortality. However, hatchling quality was not affected by dietary AP. Overall, these data suggest that AP could remarkably improve several sperm characteristics, seminal TAC, fertility, and hatchability rate in aging breeder roosters. These improvements were also associated with a higher content of total unsaturated FA in the sperm plasma membrane. Future studies are needed to disclose the causal mechanisms involved., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The effects of protein source and amino acid (AA) and AME levels in the diets of male broilers from 8 to 21 d of age on subsequent growth and blood and carcass traits were investigated in the current study. Fourteen Ross × Ross 708 male broiler chicks were randomly allocated to each of 80 floor pens arranged in a randomized complete block design. Each diet contained 1 of 2 dietary protein sources (high inclusion of distillers dried grains with solubles or high inclusion of meat and bone meal), 1 of 2 AA densities (moderate or 10% higher), and 1 of 2 AME densities (2,998 or 3,100 kcal/kg). Experimental diets were fed from 8 to 21 d of age, and common diets from 1 to 7 and 21 to 55 d of age. The higher AME density in high inclusion of meat and bone meal diets increased serum triglyceride and cholesterol levels on d 20. The dietary inclusion of high inclusion of distillers dried grains with solubles or lower levels of AA increased high-density lipoprotein cholesterol on d 20. Feeding the high-AA-density diet decreased feed intake without affecting BW gain, which resulted in a lower feed conversion ratio (FCR). A high-AME-density diet lowered feed intake but increased BW gain, which resulted in a lower FCR from 8 to 21 d of age. Feed intake, BW gain, FCR from 21 to 54 d of age, and carcass weight on 42 and 55 d of age were not affected by treatments from 8 to 21 d of age. However, early dietary manipulation from 8 to 21 d of age affected fat and meat yield at 42 and 55 d of age. Moreover, a high-AME diet decreased feed cost per carcass weight gain from 8 to 55 d of age. In conclusion, high AA or AME densities during the grower phase, from d 8 to 21 of age, may improve growth during the grower feeding phase, but may also affect meat yield during the latter grow-out phases. Furthermore, high-AME diets from 8 to 21 d of age may save on feed costs for meat production., (Poultry Science Association Inc.)

Different vaccine strains of Mycoplasma gallisepticum have been used on multiple-age commercial layer farms in an effort to protect birds against virulent field-strain infections. Use of the F-strain of M. gallisepticum (FMG), as an overlay vaccine during lay, may be necessary because of the lower level of protection afforded by M. gallisepticum vaccines of low virulence given before lay. Two replicate trials were conducted to investigate effects of live and killed M. gallisepticum vaccines administered individually and in combination before lay, in conjunction with an FMG vaccine overlay after peak egg production (EP), on the performance characteristics of commercial layers. The following treatments were utilized at 10 wk of age (woa): 1) control (no vaccinations); 2) ts11 strain M. gallisepticum (ts11MG) vaccine; 3) M. gallisepticum-Bacterin vaccine (MG-Bacterin); and 4) ts11MG and MG-Bacterin vaccines combination. At 45 woa, half of the birds were overlaid with an FMG vaccine. Hen mortality, BW, egg weight, percentage hen-day EP, egg blood spots, and egg meat spots were determined at various time periods between 18 and 52 woa. The data from each trial were pooled. Treatment did not affect performance in interval I (23 to 45 woa). However, during interval II (46 to 52 woa), the EP of control and MG-Bacterin-vaccinated birds that later received an FMG vaccine overlay was lower than that in the other treatment groups. Furthermore, treatment application reduced bird BW during interval II. Despite the effects on BW and EP, no differences were observed for egg blood or meat spots among the various treatments. It is suggested that the vaccination of commercial layers before lay with ts11MG, but not MG-Bacterin, may reduce the negative impacts of an FMG overlay vaccination given during lay. These results establish that the vaccination of pullets with ts11MG in combination with the vaccination of hens with an FMG overlay, for continual protection against field-strain M. gallisepticum infections, may be used without suppressing performance., (Poultry Science Association Inc.)

Increases in circulating acute phase protein (APP) levels occur in reaction to systemic infections in animals. However, no previous research has been conducted to monitor possible changes in APP levels of birds in response to prelay vaccinations of various live attenuated Mycoplasma gallisepticum vaccines in conjunction with their subsequent use as an overlay vaccine during the production period. Serum concentrations of the APP, α1-acid glycoprotein (AGP), were determined on d 0, 1, 3, 7, 14, and 28 after subjecting commercial laying hens to one of the following treatments at 10 wk of age (woa): 1) control (no vaccination); 2) ts-11 strain M. gallisepticum (ts11MG) vaccination; 3) M. gallisepticum-bacterin (MGBac) vaccination; and 4) ts11MG and MGBac combination (ts11MG & MGBac) vaccination. Furthermore, at 45 woa, the birds in half of the units assigned to each treatment group were vaccinated with high-passage F-strain M. gallisepticum (HpFMG). Birds in treatment 1 that were (single control) and were not (double control) vaccinated with HpFMG, and birds in treatments 2, 3, and 4 that were vaccinated with HpFMG were further tested during lay on d 0, 1, 3, 7, 14, and 28 after vaccination. On d 7, 14, and 28 postvaccination at 10 woa, the ts11MG & MGBac, ts11MG, and MGBac group AGP concentrations were not different from one another, but all were higher than those in the control group. Similarly, on d 3, 7, and 14 postvaccination, the single control, and the MGBac ts11MG, and ts11MG & MGBac treatment groups that were later vaccinated with HpFMG at 45 woa, were not different, but all were higher than that in the double control group. In conclusion, elevated circulation AGP concentrations may be used to detect and confirm subclinical infections in pullets up to 28 d after having been vaccinated with ts11MG, MGBac, or their combination. Furthermore, in association with depressed performance, elevated serum AGP concentrations in layers may be used to confirm HpFMG infections up to 28 d after its use as a vaccine., (Poultry Science Association Inc.)

Exposure to high levels of polyunsaturated fatty acid predisposes spermatozoa to lipid peroxidation, resulting in their decreased fertility. Ginger powder (GP), which is high in antioxidative compounds, was fed to aged breeder roosters to improve their reproductive performance. Seventy-five 52-wk-old Cobb 500 breeder roosters randomly received either 0 (GP0), 15 (GP15), or 30 (GP30) g of GP/kg of diet for 14 consecutive wk, during which time their seminal characteristics were evaluated every 2 wk. At the end of the trial, semen samples were tested for determination of sperm fatty acid (FA) concentration and seminal plasma total antioxidant capacity. Furthermore, sperm penetration was assayed, and using 225 artificially inseminated hens, fertility and hatchability rates were determined. Dietary GP improved sperm forward motility, live sperm percentage, and sperm plasma membrane integrity. These were associated with a decrease in the percentage of abnormal sperm. The seminal TBA reactive species concentration was lower in birds belonging to the GP30 treatment in comparison with those in the GP15 and GP0 treatments. The feeding of GP resulted in overall decreases and increases in sperm saturated and unsaturated FA, respectively. The n-6:n-3 FA ratio of sperm was decreased in the GP30 group in comparison with controls. The highest levels of sperm C20:4(n-6) and C22:6(n-3) FA were recorded in the GP15 and GP30 treatments, respectively. A higher percentage of sperm C22:4(n-6) FA was found in GP-fed roosters. Seminal plasma total antioxidant capacity was considerably improved by the GP15 and GP30 treatments. Further, a higher number of perivitelline membrane sperm penetration holes was recorded for the GP30 treatment in comparison with the GP15 and GP0 treatments. Interestingly, although hatchability, chick quality, and embryonic mortality were not affected by dietary treatment, fertility rate was improved by the feeding of GP. In conclusion, dietary GP improved most of the seminal characteristics evaluated in aged roosters of this study, suggesting that it has potential for use in attenuating age-related subfertility in senescent male commercial broiler breeders.

The effects of in ovo injection of 25-hydroxycholecalciferol [25(OH)D3] at various dosages on weight, breaking strength, and ash and mineral concentrations of left tibial bones in Ross × Ross 708 broilers on d 0 and 21 posthatch were investigated. Six treatment groups were equally represented on each of 10 tray levels (blocks) of a single-stage incubator. The 6 treatment groups, containing 21 eggs each, were randomly arranged on each tray level with respect to those on other tray levels. A multi-egg injector was used to inject eggs on d 18 of incubation according to their preassigned treatments. The experimental treatments included noninjected and diluent-injected (100 µL of commercial diluent) controls, and those that received 0.15, 0.30, 0.60, or 1.20 µg of 25(OH)D3 in 100 µL of diluent. On d 0 and 21 posthatch, 3 chicks from each treatment replicate group were randomly selected for necropsy and the subsequent extraction of their left tibial bones. Tibia samples were weighed and then subjected to breaking strength and ash concentration analysis. One of the 3 residual bone ash samples in each treatment replicate group was randomly selected, digested, and analyzed for Ca, P, Mg, K, Zn, and Mn concentrations. The relative weight, breaking strength, and percentage ash and mineral concentrations of broiler tibias on d 0 and 21 posthatch were not affected by treatment. However, trend analysis of percentage tibial ash on d 21 revealed a dosage effect (P = 0.068). The results of this study suggest that the in ovo injection of 0.15 to 1.20 µg of 25(OH)D3 on d 18 of incubation did not influence subsequent bone development or mineralization in Ross × Ross 708 broilers on d 0 and 21 posthatch. Nevertheless, further trend analysis suggested that increased dosage levels of 25(OH)D3 above 1.20 µg may have the potential to lead to increases in bone mineralization.

In ovo injection of 25-hydroxycholecalciferol [25(OH)D3] has been shown to improve hatchability of injected broiler eggs. Effects of the in ovo injection of commercial diluent containing various levels of 25(OH)D3 on broiler posthatch performance and carcass characteristics were investigated in 2 trials. On each of 10 tray levels of a single-stage incubator, all treatment groups were randomly represented with each containing 21 and 40 eggs in trials 1 and 2, respectively. Treatments included noninjected and diluent-injected (100 µL commercial diluent-injected) controls, and those that received 0.15, 0.30, 0.60, or 1.20 µg of 25(OH)D3 in trial 1 and 0.20, 0.60, 1.80, or 5.4 µg of 25(OH)D3 in trial 2, in 100 µL of commercial diluent using a commercial multi-egg injector on d 18 of incubation. On d 21 of incubation, chicks from each treatment replicate group were placed in corresponding floor pens. Feed intake, BW gain, and feed conversion were determined for the weekly and cumulative 0 to 21 d age intervals in trial 1 and for the weekly and cumulative 0 to 48 d age intervals in trial 2. In trial 2, 2 birds from each sex were selected from each treatment replicate group for determination of processing carcass characteristics on d 49 posthatch. Feed intake in the 0 to 7, 7 to 14, and 14 to 21 d age intervals and BW gain in the 0 to 7 and 14 to 21 d age intervals were affected by treatment in trial 2. The in ovo injection of up to 1.20 and 0.60 µg of 25(OH)D3 in trials 1 and 2, respectively, did not affect the BW gain of birds during the 0 to 7, 7 to 14, and 14 to 21 d age intervals compared with the noninjected and diluent-injected control groups. It was concluded that the in ovo injection of up to 1.20 µg of 25(OH)D3 into the amnion has no detrimental effect on the overall posthatch performance of broilers.

The effects of the in ovo injection of commercial diluent containing various levels of 25-hydroxycholecalciferol [25(OH)D3] on hatchability and hatching chick quality variables in Ross × Ross 708 broilers were examined in 2 trials. All treatment groups, each containing 21 and 40 eggs in trials 1 and 2, respectively, were randomly represented on each of 10 replicate tray levels of a single-stage incubator. On 18 d of incubation (doi), eggs were subjected to 1 of 6 treatments using a commercial multi-egg injector. Treatments included noninjected and diluent-injected controls, along with those that received diluent containing 0.15, 0.30, 0.60, or 1.20 µg of 25(OH)D3 in trial 1 and 0.20, 0.60, 1.80, or 5.4 µg of 25(OH)D3 in trial 2. Hatchability of injected eggs (HI) was recorded on 20.5, 21.0, and 21.5 doi, and embryonic mortalities through 21.5 doi were determined. On 21.0 doi in each trial, the BW, body length, and weights and moisture concentrations of the livers and yolk sacs of male and female chicks in each replicate group were determined. In a preliminary trial, the in ovo injection of 0.60 µg of 25(OH)D3 on 18 doi significantly elevated its serum level concentrations in embryos on 19.25 doi. In both trials, the HI of noninjected controls through 21.0 doi was higher than that of diluent-injected controls. In trial 1, the HI of eggs on 21.0 doi after being injected with 0.30, 0.60, or 1.20 µg of 25(OH)D3 was higher compared with that of diluent-injected controls, and in trial 2, the HI of eggs on 21.0 and 21.5 doi after being injected with 0.60 µg of 25(OH)D3 was higher compared with that of diluent-injected controls. In conclusion, the in ovo injection of 0.60 µg of 25(OH)D3 may be used to alleviate depressions in HI in Ross × Ross 708 broiler hatching eggs that can occur in response to the in ovo injection of commercial diluent.

Two simultaneous trials were conducted using a commercially available, live, F strain Mycoplasma gallisepticum (FMG) vaccine (trial 1) or 2 inocula of layer complex-derived MG strains (LCD-MG; trial 2). In each of the 2 trials, 4 commercial turkeys were housed in each of 2 adjoining pens immediately adjacent to air inlets. The turkeys (8/trial) were inoculated in the right eye with either a 1× dose of FMG (trial 1) or with 0.02 mL of 1 of 2 actively growing LCD-MG inocula (4 turkeys/inoculum; trial 2). In each of the 2 trials, one pen housing 4 inoculated turkeys was maintained without the addition of other poultry, whereas 16 MG-free broilers and 4 MG-free layers were added to the other pen of 4 inoculated turkeys. Within each of the trials and at increasing intervals, either 4 layers (3 pens) or 4 turkeys (3 pens) were placed down-airstream from the inoculated pens. The distance of the first pen from the inoculated turkeys was separated by the width of one pen that was empty. Succeeding down-airstream pens were situated such that the empty distance (absence of any poultry) between pens that contained poultry doubled from one pen to the next such that the final pen that contained poultry had 4 empty pens between it and the next up-airstream pen that also contained poultry. At 106 d postinoculation, all poultry were bled, swabbed for MG from the choanal cleft, and then euthanized and necropsied. No commingled poultry in trial 1 (FMG), whether inoculated (turkeys) or commingled (layers and broilers), died during the course of the trial, and 5 of the 8 FMG-vaccinated turkeys exhibited serological but not cultural evidence of mycoplasmosis. In trial 2 (LCD-MG), 2 commingled broilers died and no inoculated turkeys exhibited either serological or cultural evidence of mycoplasmosis. In both trials, no poultry housed down-airstream from the inoculated poultry showed evidence of clinical signs of mycocplasmosis and none showed either serological or cultural evidence of mycoplasmosis.