A walk through the broiler breeder life: how do footpad dermatitis and gait scores develop from rearing to slaughter?

The two most common animal-based indicators used to evaluate leg health in broiler chickens are footpad dermatitis (FPD) and gait scoring, but these indicators are less explored in broiler breeders. This study is the first to investigate FPD and gait scoring in broiler breeders during their lifespan from rearing to end of life. In total, eight flocks were monitored (four Ross and four Hubbard) at five different timepoints, in rearing (5 and 15 weeks of age), during the production period (25 and 45 weeks of age) and at the end of the production period (approximately 60 weeks of age). At each visit, 50 hens and 25 roosters were gait scored (six-point scale) and footpads from another 50 hens and 25 roosters were evaluated (five-point scale) (total n = 3000 breeders, 2000 hens and 1000 roosters). Litter quality and air quality were measured at each visit. The results showed that the overall prevalence of FPD in rearing was low and that it increased towards the end of the production, with a mean FPD score of 2 out of a maximum 4 in the hens, indicating moderate lesions and 1.5 in the roosters. In all houses, the litter was dry and loose. FPD was not related to the litter quality, but to air quality, especially the ammonia concentration (P < 0.001). Overall, the gait score were good, and increased with age in both hens (P < 0.001) and roosters of both hybrids (P < 0.001).

Avian Pathogenic Escherichia coli (APEC) in Broiler Breeders: An Overview.

Poultry meat is one of the major animal protein sources necessary to meet the global protein demand. Sustainability in broiler production is the key to achieving its continuous supply, and broiler breeders play a critical role in maintaining this sustainability by providing good quality chicks. Colibacillosis, the disease caused by avian pathogenic Escherichia coli (APEC), causes severe economic losses to the poultry industry globally. Moreover, APEC causes an additional burden among broiler breeders, such as a decrease in egg production and mortality among these birds. There is vertical transmission of APEC to the broiler chicks through eggs, resulting in increased first-week mortality and subsequent horizontal transmission at the hatchery. In this regard, the vertical transmission of antibiotic resistance genes is another concern that needs attention. Controlling several diseases in broiler breeders would possibly reduce the first-week mortality in chicks, thereby maintaining the production level. For that, constant monitoring of the bacterial populations is critical. Moreover, amidst the increased antibiotic resistance pattern, more focus on alternative treatment strategies like vaccines, probiotics, and bacteriophages is necessary. Future research focusing on strategies to mitigate APEC in broiler breeders would be one of the finest solutions for sustainable broiler production.

Development of a multivalent adjuvanted inactivated vaccine against variant arthrotropic avian reoviruses.

Variant avian reoviruses (ARVs) are economically important emerging pathogens of poultry, which mainly affect young broiler chickens and cause significant production losses. Currently, there are no effective commercial vaccines available for control and prevention of emerging variant ARVs. In this study, monovalent inactivated adjuvated (20% Emulsigen D) broiler breeder vaccines containing antigens from ARV genotype cluster (C) group -2, -4, -5, or -6, and a multivalent vaccine containing antigens from all the four indicated genotypic cluster groups were developed and evaluated for their efficacy in protecting broiler progenies against homologous or heterologous ARV challenge. The use of monovalent or multivalent inactivated vaccines in a prime-boost immunization strategy induced the production of ARV specific antibodies in broiler breeders. The maternal antibodies were effectively transferred to broiler progenies. Broiler progenies obtained from immunized breeders demonstrated milder clinical symptoms and reduced gross and histopathological lesions after homologous ARV challenge. More severe gross and histological lesions were observed in challenged progenies from unvaccinated broiler breeders. However, cross protection was not observed when either of the monovalent-vaccine groups were challenged with a heterologous virus. In addition, the progenies from the unvaccinated ARV challenged control or heterologous ARV challenged vaccinated groups had significantly reduced body weight gain (p < 0.01) than the unchallenged-control, challenged-multivalent, or homologous ARV-challenged monovalent vaccine groups. However, homologous ARV challenged progenies in the multivalent or monovalent vaccine groups had similar body weight gain as the control unchallenged group with significantly reduced viral load (p < 0.01) in the gastrocnemius tendon tissue. This study indicates that broad-spectrum protection of broiler progenies from variant ARV infections is feasible through the development of multivalent vaccines after proper characterization, selection and incorporation of multiple antigens based on circulating ARV genotypes in targeted regions.

Physiological and behavioural effects of intermittent fasting vs daily caloric restriction in meat-type poultry.

Intermittent fasting (IF) is the practice of temporal food restriction to promote metabolic switching between a glucose- and a ketone-based metabolism, which has been reported to come with diverse health benefits. IF practices appear to confer many of the advantages of caloric restriction without restricting total energy intake, and studies in both rodents and humans suggest organism-wide improvements in neurological, cardiovascular and metabolic health. IF is also commonly employed in the commercial rearing of breeding meat-type poultry, i.e. broiler breeders, which require strict feed restriction throughout life to maintain physical health. While the scientific poultry literature holds vast amounts of data on such "skip-a-day" feeding schedules, it has been unclear to what extent avian and mammalian literature may be compared as broiler breeders are typically feed-restricted to around 30% of ad libitum intake even in IF schedules. In this study, we set out to disentangle the effects of IF and caloric restriction in meat-type poultry by employing both IF and daily feeding schedules at two different restriction levels. Our results suggest that the physiological response to IF in chickens is only marginally affected by the intensity of feed restriction, while behavioural parameters are more closely related to feeding level and are expected to better mirror animal welfare. Our results suggest that avian and mammalian literature on IF should be comparable. Meat-type chickens do show some peculiarities in response to IF, such as a reduced insulin sensitivity, but it is currently unclear whether this is true for all chickens or is an effect of the intense selection for rapid growth in meat-type chickens.

Erysipelothrix rhusiopathiae Infection Associated with Swollen Head Syndrome in a Broiler Breeder Flock in North Georgia.

An unusual case of swollen head syndrome in a 55-wk-old broiler breeder flock was identified in north Georgia in the summer of 2019. The presenting complaint was elevated mortality and visibly swollen heads. Necropsy of affected birds on the farm primarily revealed signs of bacterial septicemia, with few large scab lesions near the vent area. Bacterial culture analysis identified multiple organisms, but the primary organism of interest was identified as Erysipelothrix rhusiopathiae, cultured from affected liver, lung, sinuses, and one swollen wattle of birds in the affected house. Histopathologic analysis identified gram-positive rod-shaped bacteria in the spleen and liver (consistent with bacterial septicemia) confirmed with special staining (Brown & Hopps Gram stain). These organisms were noted to be consistent with E. rhusiopathiae; E. rhusiopathiae infection in broiler breeder chickens is a rare occurrence and is primarily associated with turkeys and/or swine production systems.

Reporte de caso- Infección por Erysipelothrix rhusiopathiae asociada con el síndrome de cabeza hinchada en un pollo de engorde. En el verano del 2019, se identificó un caso inusual de síndrome de cabeza hinchada en una parvada de reproductoras de pollos de engorde de 55 semanas de edad en el norte de Georgia. Las observaciones iniciales incluyeron mortalidad elevada y cabezas visiblemente inflamadas. La necropsia de las aves afectadas en la granja reveló principalmente signos de septicemia bacteriana, con pocas lesiones costrosas grandes cerca del área de extractores de la ventilación. El análisis de cultivos bacterianos identificó múltiples organismos, pero el principal organismo de interés fue identificado como Erysipelothrix rhusiopathiae, cultivado a partir de hígado, pulmón, senos paranasales y de una barbilla inflamada de aves en la caseta afectada. El análisis histopatológico identificó bacterias grampositivas en forma de bastón en el bazo y el hígado (compatibles con septicemia bacteriana) confirmadas con tinción especial (tinción de Gram de Brown y Hopps). Se observó que estos organismos eran compatibles con E. rhusiopathiae; La infección por E. rhusiopathiae en pollos de engorde se presenta de forma esporádica y se asocia principalmente con sistemas de producción de pavos y/o cerdos.

Differences in gut bacterial community composition between modern and slower-growing broiler breeder lines: Implications of growth selection on microbiome composition.

In the last century broiler chicken lines have undergone an extensive breeding regime aimed primarily at growth and high meat yield. It is not known if breeding has also resulted in a change to the broiler breeder's associated gut microbiota. Here we compared the gut microbiota of 37-week-old commercial Cobb breeding dams with dams from a broiler Legacy line which has not undergone selection since 1986. The dams from both lines were kept together in the same shed under the same management protocol from day of hatch to avoid additional confounders. We chose this age to allow significant bacterial exchange, thus avoiding exposure dependent artifacts and so that we could compare dams at the same developmental state of adulthood and peak laying performance. Significant differences in the composition of the cecum bacterial communities were found. Bacteria of the genus Akkermansia, implicated in mucin degradation and associated with host metabolic health, accounted for 4.98% ± 5.04% of the Cobb cecum community, but were mostly absent from the ceca of the Legacy line dams. Inversely, Legacy dams had higher levels of Clostridiales, Lactobacillales and Aeromonadales. These results show that breeding has resulted in a change in the gut microbiota composition, likely by changing the physiological conditions in the mucosa. It remains unclear if changes in gut microbiota composition are a part of the mechanism affecting growth or are a secondary result of other physiological changes accelerating growth. Therefore, the identification of these changes opens the door to further targeted research.

Prevalence of Potential Pathogenic and Antimicrobial Resistant Escherichia coli in Danish Broilers.

Avian pathogenic Escherichia coli (APEC) are important bacteria in broiler production in terms of economy, welfare, and use of antibiotics. During a previous outbreak of APEC in the Nordic countries, it was suggested that the pathogenic clones of E. coli causing the outbreak originated from grandparent stock and were transmitted to the offspring, causing increased first week mortality. This study investigated whether the pathogenic potential of E. coli at the parent and broiler level differs in relation to pathogenic potential described by the level of virulence-associated genes and pattern of antimicrobial resistance. The hypothesis was that, due to higher biosecurity at the parent level, the E. coli population will show a lower level of antimicrobial resistance and carry fewer virulence-associated genes, as a result of fewer E. coli infections observed. From four parent flocks and eight broiler flocks, 715 E. coli were isolated from cloacal swabs of newly hatched chickens (Ross 308). The isolated E. coli were characterized by eight virulence-associated genes and phenotypic resistance against six antimicrobials. It was found that the prevalence of virulence-associated genes and phenotypic antimicrobial resistance varied significantly between flocks, and the virulence-associated genes papC and irp2 and resistance against ampicillin were significantly more prevalent in breeder flocks compared to broiler flocks.

Keel bone fractures in broiler breeders: is palpation a reliable diagnostic method?

The aim of this study was to estimate the sensitivity and specificity of palpation relative to necropsy for detection of keel bone fractures (KBF) in broiler breeders. In addition, the study investigated observer reliability of palpation. Four commercial breeder flocks (Ross 308 n = 2, Ranger Gold n = 1, Hubbard JA 757, n = 1) were included in the study. A total of 400 hens and 60 roosters were examined after culling or slaughter, at end of lay (63 weeks). Keel bones were first palpated independently by two raters with a varying degree of experience in palpation of keel bones in laying hens. After palpation, a necropsy with investigation of the keel bone was conducted. The prevalence of KBF at end of lay for hens, as diagnosed by necropsy, varied from 14-58%, while only one in 60 assessed roosters had KBF. Palpation had poor sensitivity, with differences between raters ranging from 56% to 36% when hybrid is not considered. The specificity of palpation for all hybrids together was 85% and 88%, for the two raters, respectively. The two raters had moderate agreement, Gwet's agreement coefficient (95% confidence interval): 0.60 (0.52-0.69). In conclusion, palpation has poor diagnostic accuracy for detection of KBF in broiler breeders, and other methods, like necropsy, must be applied for reliable assessments. KBF appears to be a prevalent condition in different hybrids of broiler breeder hens, but not in roosters.RESEARCH HIGHLIGHTS This is the first study to investigate palpation as a diagnostic method for detection of KBF in broiler breeders.Palpation has poor diagnostic accuracy for detection of KBF in broiler breeder hens with differences between raters.KBF can be a prevalent problem in broiler breeder hens of several hybrids, but not in roosters.

Effect of perch access on perching, health and production outcomes in commercial broiler breeder flocks.

There is a need for more knowledge about perch use in broiler breeders and the potential effects of perches on health and production outcomes. The aim of this study was to investigate the use of perches by commercial broiler breeders, effect of perch access on keel bone fractures (KBF), footpad dermatitis (FPD) and number of floor eggs. Two commercial breeder flocks (Ross 308) reared at the same facility were observed during the production period. Half of each flock was provided with 15 cm perch/bird and the other half had no perches. The perch group had two types of perches; a steel plate mounted on the hen feeder lines "feeder perch" (15 cm high) and elevated plastic perches (5 cm high). Perching by hens and roosters was recorded during the dark period by counting birds on each of the two perch types in 10 sections and in the corresponding patches on the control side at 25, 35, and 45 wk of age (WOA). FPD was scored in 100 random hens in each group at 30 WOA and end of lay, KBF was scored by postmortem in 100 random hens in each group at end of lay, and number of floor eggs (n) in each treatment was scored daily. More hens perched on the feeder perch with the steel plate mounted, compared to the feeder line without the steel plate, but this difference decreased with age (P < 0.0001). Within the perch treatment, more hens perched on the feeder lines compared to the plastic perches at all ages (P < 0.0001). When combining number of hens on the plastic and feeder perches, on average 6.7 birds perched per meter perch, which is full capacity given an average shoulder width of 15 cm/bird. Perch use among the roosters was low overall, but more roosters perched in the perch group compared to the control group at 35 WOA (P = 0.007). Between 47 and 53% of the hens had KBF at the end of the lay. At 30 WOA, birds housed with perches were more likely to have lower FPD. Perch treatment did not affect number of floor eggs. In conclusion, broiler breeder hens perch when the perches are sufficiently high and allow all birds to perch simultaneously, and access to perches may have positive effects on FPD.

Effects of twice a day feeding and split feeding during lay on broiler breeder production performance, eggshell quality, incubation traits, and behavior.

Eggshell quality of broiler breeders' eggs decreases at the end of the laying period. Feeding a limited daily allowance of feed in the morning does not supply the necessary nutrients, particularly calcium for eggshell formation, at the right time of the day. Therefore, an experiment was conducted to study the effects of providing a standard diet twice a day or split feeding (special morning and afternoon diet) in broiler breeders on production performance, eggshell quality, incubation traits, and behavior. At 50 wk of age (WOA) 576 females and 48 males were randomly allotted to 24 floor pens and assigned to one of three treatments: 1) Standard breeder diet fed once a day (100% at 0730 h) (CON1x), 2) Standard breeder diet fed twice a day (50% at 0730 h and 50% at 1400 h) (CON2x), and 3) Split feeding fed twice a day, with a special morning (0730 h) and afternoon (1400 h) diet composition (SP2x). The morning diet was energetically comparable with the control diet, but it contained more protein and phosphorus (P) and less calcium (Ca). The afternoon diet had a lower energy, protein and P and a higher Ca content than the control and morning diet. The SP2x birds tended to have a higher egg production between 51 and 55 WOA (27.0 vs. 25.9 eggs; P = 0.088) compared to the CON1x birds, while the CON2x birds (26.6 eggs) did not differ from the other treatments. No differences were found on egg production for the total period (51-60 WOA) and on other production parameters. The different feeding strategies did not affect eggshell quality and incubation traits. However, the feeding strategies affected the behavioral patterns considerably. Twice a day feeding (CON2x and SP2x) resulted in more time spent on eating and sitting, and in less time spent on foraging and object pecking (P ≤ 0.05) compared to feeding once a day (CON1x). In conclusion, twice a day feeding improves behavior and split feeding improves both egg production and behavior in broiler breeders, however, no effects were observed on eggshell quality and incubation traits.

Dietary tributyrin improves reproductive performance, antioxidant capacity, and ovary function of broiler breeders.

The objective of this experiment was to investigate the influence of dietary tributyrin on reproduction performance and ovary function of broiler breeders with different egg laying rate. Two hundred fifty-six AA broiler breeders (48-wk-old) were allocated to 4 treatment in a 2 × 2 factorial arrangement with the main effects of tributyrin supplementation (0 and 1,000 mg/kg tributyrin [TRI]) and 2 egg laying rate levels (average [AR, 81.01 ± 0.79%] and low [LR, 70.98 ± 0.95%]). The results shown that the LR breeders presented higher egg weight, but lower egg laying rate, qualified egg rate and feed efficiency than the AR breeders (P(laying) < 0.05). Also, the superoxidase dismutase (SOD) activity in magnum was lower while malondialdehyde (MDA) was higher in ovary and magnum of LR breeders than that in the AR breeders (P(laying) < 0.05). Dietary supplementation with tributyrin significantly enhanced egg weight (P(TRI) < 0.05), increased albumen height as well as Haugh unit (HU) in AR breeders (P(interaction) < 0.05), and also had higher total antioxidant capacity (T-AOC) and lower MDA in ovary (P(TRI) < 0.05). The cell apoptosis rate and proapoptosis related gene expression (caspase 8, 9 and Bax) in the ovary of LR breeders was higher, while anti-apoptosis related gene (Bcl-2) expression were lower in LR breeders when compared with the AR breeders (P(laying) < 0.05). Dietary supplementation with tributyrin decreased the cell apoptosis rate and downregulated caspase 9 expression in LR breeders (P(Interaction) < 0.05), up-regulated the Bcl-2 expression in both 2 breeders (P(TRI) < 0.05). These findings suggest that the breeders with lower egg laying rate also characterized by deteriorate ovary function indicated by lower antioxidant capacity and higher cell apoptosis rate. Dietary supplementation with tributyrin increased egg albumen quality, decreased ovarian proapoptosis related gene expression to improve reproductive tract function; and the positive effect on egg albumen quality is more pronounced in average reproductive breeders.

Effect of Supplementation of Zinc-Methionine on Egg Production, Semen Quality, Reproductive Hormones, and Hatchability in Broiler Breeders.

A biological study was conducted to explore the effect of zinc-methionine (Zn-Met) supplementation on productive, reproductive, and immunological response in broiler breeders. Adult healthy 45-week breeder males (192) and females (288) were used in a completely randomized design. Birds were randomly divided into four treatments consisting of six replicates and fed basal diet (control, 40 mg/kg), basal diet supplemented with Zn-Met 20 (T1), 40 (T2), and 60 mg/kg (T3). There was no effect (P > 0.05) on body weight and feed consumption among the breeders due to the supplementation of organic Zn. The T3 group had significantly (P < 0.05) higher semen volume, sperm motility, concentration, and live sperm count. The seminal plasma calcium and alkaline phosphatase activity were higher (P < 0.05), and total cholesterol and aspartate transaminase levels were low in the T3 group. Birds fed with additional supplementation of Zn (60 mg/kg) had improved both cellular and humoral immunity. Throughout the experimental period, the hen day egg production was comparable (P > 0.05) among the experimental groups. Organic Zn-supplemented group showed significant difference in both the internal and external egg qualities-albumen, yolk index, and shell thickness. The higher dose of organic Zn-fed groups had a significant difference in estrogen and progesterone concentration, and the highest testosterone concentration was observed in the T2 group. Supplementary organic Zn had a significant effect on the concentration of Zn and Cu in the seminal plasma. Serum Zn and Cu concentration was significantly increased due to the supplementation of organic zinc in both male and female breeders. The fertility and hatchability percentage were higher (P < 0.05) in the T2 group. It could be concluded that the additional supplementation of organic Zn (zinc-methionine) at 40 mg/kg to the basal diet improved the reproductive performance in broiler breeders.

Estimating total lysine requirement for optimised egg production of broiler breeder hens during the early-laying period.

The production performance of broiler breeder hens in response to different levels of total lysine during the early laying period was investigated. A total of 126 Ross 308 parent stock hens were offered one of seven dietary treatments formulating elevated contents of total lysine ranging from 0.55% to 0.79% (0.04 scale; 133 g of feed) from 23 to 29 weeks of age. Each treatment had six replicates with three birds per pen. Body weight was recorded triweekly and eggs were collected and weighted at 9:00 am daily. One hen from each pen was euthanized to collect blood samples and visceral organs were harvested and weighed. Egg production, egg weight and egg mass were lower (p < 0.05) in hens offered a diet containing 0.55% total lysine compared to those fed the diet containing higher total lysine. Hens offered a diet containing 0.71%, 0.75%, and 0.79% total lysine had greater (p = 0.008) egg production rate compared to those offered a diet containing lysine less than 0.71%. The number of total eggs produced tended to be greater (p = 0.083) in hens offered a diet containing 0.71 and 0.75% total lysine compared to the other treatments. The number of settable egg production was higher (p < 0.001) in hens offered a diet contacting 0.79% total lysine compared to those fed the diet containing lower levels of total lysine. The relative weights of oviduct and ovary were lower (p < 0.05) in hens offered a diet containing 0.59% total lysine compared to the other treatments. No difference found in body weight, the number of total eggs, double-yolk eggs and abnormal shell eggs among the treatments. The urea nitrogen, estradiol-17 beta and progesterone in plasma were not affected by treatments. Based on linear- and quadratic-plateau models, total lysine requirements for egg production, settable egg production and egg mass at the early laying period were to be 0.73%, 0.77%, and 0.71%, respectively. Modern broiler breeder hens likely require higher total lysine than NRC recommendation in a diet for enhancing productivity during the early-laying period.

Effects of feeding broiler breeder hens a coextruded full-fat flaxseed and pulses mixture without or with multienzyme supplement.

The effects of coextruded full-fat flaxseed and pulses (FFF; 1:1 wt/wt) mixture on n-3 polyunsaturated fatty acids (PUFA) enrichment in egg yolk, hepatic attributes, apparent retention (AR) of components, and ceca metabolites were evaluated in broiler breeder hens. The diets were as follows: 1) corn-soybean control, 2) control diet plus 18% FFF (FFF-), and 3) FFF plus enzyme supplement (FFF+) containing galactanase, protease, mannanase, glucanase, xylanase, amylase, and cellulase activities. Twenty-six-week-old Cobb 500 broiler breeder hens were allocated to 30 identical cages (2 hens/cage) and given 1-week adaptation period. The 3 diets were assigned to 10 replicate cages based on postadaptation BW and fed based on breeder curve for 30 D. Excreta samples were collected from day 24 to 27 for determination of AR of components, and eggs were collected from day 28 to 30 for yolk polyunsaturated fatty acids analyses. On day 30, birds were weighed, killed via cervical dislocation, liver weighed, and stored for fat analyses. Ceca digesta samples were taken for concentration of short-chain fatty acids. Liver and yolk weights as well as total yolk FA were not influenced by diets (P > 0.05). Control birds had lower yolk concentration of α-linolenic acid than birds fed either FFF- or FFF+ (P < 0.01) corresponding to 7.5, 36.8, and 37.3 mg/g for the control, FFF-, and FFF+, respectively. Control birds also exhibited lower yolk concentration of docosahexaenoic acid (P < 0.01). Control birds had higher hepatic concentration of crude fat and apparent retention of dry matter and crude protein compared with either the FFF- or FFF+ birds (P < 0.05). Birds fed FFF- diet had lower ceca digesta concentration of lactic acid than control and FFF+ (P < 0.05) birds. Results showed broiler breeder hens enriched egg yolk with n-3 polyunsaturated fatty acids without effects on the liver while the supplemental enzyme did not improve the utilization of FFF.

Contribution of the Broiler Breeders' Fecal Microbiota to the Establishment of the Eggshell Microbiota.

In broiler chicken production, microbial populations on the eggshell surface following oviposition are still poorly characterized, though they may significantly impact both poultry and public health. The aim of this study was to describe the microbiota of both broiler breeder hens' feces and the surface of their eggs to assess the contribution of the parental fecal microbiota to the eggshell microbiota. A total of twelve breeder flocks in Quebec, Canada, were sampled at two different times, and a total of 940 feces and 16,400 egg surface samples were recovered. Using 16S rRNA gene sequencing, we showed that even if the microbiota of both feces and eggshells were mainly composed of the phyla Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes, the bacterial community compositions and structures differed between both types of samples. Our results also showed that both the sampling time and the flock identity significantly influenced the alpha- and the beta-diversities of the studied microbiomes. Using a Venn diagram, we showed that 1790 operational taxonomic units (OTUs) were shared between feces and eggshell samples. Sequences associated with genera of potentially pathogenic and spoilage bacteria, Acinetobacter, Campylobacter, Escherichia/Shigella, Helicobacter, Listeria, Proteus, Pseudomonas, Salmonella, and Staphylococcus, were shared between sample types. Some OTUs highly represented in the fecal microbiota and associated with Lactobacillus and Streptococcus genera, were absent from eggshells, suggesting a selection during the microbiota transfer and/or the potential role of environmental contamination. To the best of our knowledge, this is the first study using 16S rRNA sequencing to describe the contribution of the transfer from the fecal microbial ecosystem of laying breeder hens to the establishment of the microbiota on the surface of laid eggs, as well as the bacterial communities at both the broiler breeder feces and the eggshell levels.

Effects of Replacing Inorganic with Respective Complexed Glycinate Minerals on Apparent Mineral Bioavailability and Deposition Rate in Tissues of Broiler Breeders.

The study was conducted to evaluate the effects of replacing inorganic trace minerals (ITMs) with respective low-dose complexed glycinate minerals (CGMs) on their bioavailability and retention during peak laying period of broiler breeders. In this experiment, 648 ZhenNing broiler breeders (23 weeks old) were randomly allocated to four treatments with six replicates (27 birds/replicate) and fed for 14 weeks including 2 weeks adaptation period. The treatments were T1-ITM, commercially recommended levels of ITMs (Cu, Zn, Fe, and Mn sulphates); T2-MIX, half of the minerals were supplemented with ITMs and half with CGMs; T3-L-CGMs, minerals were supplemented with CGMs (50% level of T1); and T4-M-CGMs, minerals were supplemented with CGMs (70% level of T1). The results showed that birds fed on ITM had lower bioavailability of Fe, Mn, and Zn (P < 0.05) than those fed on L-CGMs, but the highest (P < 0.01) bioavailability of Cu was found in those fed on MIX. Mineral retention (in serum, muscle, bone, and tissues) was not affected by reducing supplementation levels of trace minerals up to 50% of ITMs, but Zn (in serum, liver, kidney, heart, and albumen) and Fe (in serum and the yolk) retention was negatively affected (P < 0.05). In conclusion, replacing dietary ITMs with low-dose complexed glycinate minerals increases the apparent bioavailability of Fe, Mn, and Zn without compromising the mineral retention rates in most of the tissues tested.

Variações fisiológicas, influência da idade e sexo no perfil bioquímico sanguíneo de aves da linhagem pesada de frango de corte na fase de recria / Physiological variations and influence of age and gender on poultry of heavy lineage of chicken´s biochemical profile during the rearing stage

Este estudo teve o objetivo de comparar o perfil bioquímico sérico de machos e fêmeas da linhagem pesada de frango de corte, nas idades de quatro, 12 e 20 semanas, em uma unidade de produção industrial, no município de Uberlândia-MG. Após a pesagem das aves, foram coletadas amostras de sangue de 15 aves de cada sexo de cada faixa etária. Os soros obtidos foram avaliados em analisador automático para os seguintes parâmetros bioquímicos: proteína total, albumina, globulinas, ácido úrico, colesterol, triglicérides, gamaglutamiltransferase, aspartato aminotransferase, alanina aminotransferase, creatina quinase, fosfatase alcalina, cálcio e fósforo. Imediatamente após a coleta de cada amostra, avaliou-se a glicemia no sangue total, utilizando-se um glicosímetro. As alterações fisiológicas e metabólicas que as aves apresentaram na fase de recria refletiram na variação dos níveis bioquímicos séricos na maioria dos constituintes avaliados, os quais exibiram diferenças significativas (P<0,05), comparando-se sexo e idade.(AU)

This study aimed to compare the levels of glucose in the blood and serum´s metabolites enzymes and minerals of poultry of heavy lineage of chicken at the age of four, twelve and twenty weeks in an industrial production unit in the city of Uberlândia-MG. After weighing the birds, blood samples were collected from 15 birds of each gender in the three ages. The serum obtained was evaluated in an automatic biochemical analyzer for the following parameters: total protein, albumin, globulin, uric acid, cholesterol, triglycerides, alkaline phosphatase, gamma-glutamyl transferase, aspartate aminotransferase, alanine aminotransferase, creatine kinase, calcium and phosphorus. Immediately after the collection of each sample, we evaluated glucose levels by means of a glycosimeter. The physiological and metabolic changes that birds present in the rearing age reflected in the variation of serum biochemical levels in most constituents evaluated, showing significant differences (P< 0.05) comparing age and gender.(AU)

Detection of multidrug resistant Escherichia coli in the ovaries of healthy broiler breeders with emphasis on extended-spectrum ß-lactamases producers.

In the last few years, antimicrobial resistant (AMR) Escherichia coli have been detected in newborn chickens suggesting their vertical transmission from breeding birds to their offspring. However, little is known about the presence of AMR E. coli in the reproductive organs of broiler breeders. The aim of this study was to investigate the presence of E. coli in the ovaries of healthy broiler breeders and to study their antimicrobial resistance. Samples from broiler breeders (n = 80) collected from 80 different broiler breeder flocks were included in this study. Antibiotic susceptibility testing was performed using disk diffusion method according to Clinical and Laboratory Standards Institute guidelines. Minimal inhibitory concentrations (MICs) of five antimicrobial agents were determined by Etest. PCR and sequencing were used to detect the blaESBL genes. E. coli were detected in the ovaries of thirty seven out of 80 (46.25%) sampled flocks. High levels of resistance to various first-line antimicrobial agents were recorded in E. coli isolates. This study showed that 89.18% of E. coli isolates were multidrug resistant (MDR). Furthermore, MDR extended-spectrum ß-lactamases (ESBL)-producing E. coli were detected in the ovaries of four different broiler breeder flocks. Molecular characterization revealed that three isolates harboured blaCTX-M-1 gene and one isolate expressed blaSHV-12 gene. In addition, one blaCTX-M-1 -producing E. coli co-harboured the blaTEM-1 gene. These findings would contribute to a better epidemiological understanding of MDR E. coli for improve existing preventive strategies in order to reduce the dissemination of antimicrobial resistance in the broiler production system.

Two Single Incursions of H7N7 and H5N1 Low Pathogenicity Avian Influenza in U.K. Broiler Breeders During 2015 and 2016.

Low pathogenicity (LP) avian influenza viruses (AIVs) have a natural reservoir in wild birds. These cause few (if any) overt clinical signs, but include H5 and H7 LPAIVs, which are notifiable in poultry. In the European Union, notifiable avian disease (NAD) demands laboratory confirmation with prompt statutory interventions to prevent dissemination of infection to multiple farms. Crucially, for H5 and H7 LPAIVs, movement restrictions and culling limit the further risk of mutation to the corresponding highly pathogenic (HP) H5 and H7 AIVs in gallinaceous poultry. An H7N7 LPAIV outbreak occurred during February 2015 at a broiler breeder chicken premise in England. Full genome sequencing suggested an avian origin closely related to contemporary European H7 LPAIV wild bird strains with no correlates for human adaptation. However, a high similarity of PB2, PB1, and NA genes with H10N7 viruses from European seals during 2014 was observed. An H5N1 LPAIV outbreak during January 2016 affecting broiler breeder chickens in Scotland resulted in rapid within-farm spread. An interesting feature from this case was that although viral tropism occurred in heart and kidney endothelial cells, suggesting HPAIV infection, the H5N1 virus had the molecular cleavage site signature of an LPAIV belonging to an indigenous European H5 lineage. There was no genetic evidence for human adaptation or antiviral drug resistance. The source of the infection was also likely to be via indirect contact with wild birds mediated via fomite spread from the nearby environment. Both LPAIV outbreaks were preceded by local flooding events that attracted wild waterfowl to the premises. Prompt detection of both outbreaks highlighted the value of the "testing to exclude" scheme launched in the United Kingdom for commercial gallinaceous poultry in 2014 as an early warning surveillance mechanism for NAD.

Dos incursiones únicas de influenza aviar de baja patogenicidad H7N7 y H5N1 en criadores de pollos de engorde en el Reino Unido durante 2015 y 2016. Los virus de influenza aviar de baja patogenicidad tienen un reservorio natural en aves silvestres. Estos causan pocos (si es que se presentan) signos clínicos evidentes, pero se incluyen los virus de influenza de baja patogenicidad H5 y H7, que son notificables en avicultura. En la Unión Europea, las enfermedades aviares notificables (NAD, por sus siglas en inglés) requieren de confirmación de laboratorio con intervenciones reglamentarias rápidas para prevenir la diseminación de la infección a múltiples granjas. De manera crucial, para las los virus de baja patogenicidad H5 y H7, las restricciones de movimiento y el sacrificio limitan el riesgo adicional de mutación hacia los correspondientes virus H5 y H7 altamente patógenos en aves comerciales. Un brote de influenza aviar de baja patogenicidad H7N7 ocurrió en febrero del 2015 en una granja de pollos reproductores de pollos de engorde en Inglaterra. La secuenciación completa del genoma sugirió un origen aviar estrechamente relacionado con las cepas de aves silvestres contemporáneas europeas de baja patogenicidad H7 sin indicios para la adaptación humana. Sin embargo, se observó una alta similitud de los genes PB2, PB1 y NA con los virus H10N7 de focas europeas durante el 2014. Un brote de influenza aviar de baja patogenicidad por H5N1 en enero del 2016 que afectó a los pollos reproductores de pollos de engorde en Escocia resultó en una rápida propagación dentro de la granja. Una característica interesante de este caso fue que, aunque el tropismo viral ocurrió en las células endoteliales del corazón y el riñón, lo que sugería una infección por un virus de alta patogenicidad, el virus H5N1 tenía el sitio de disociación molecular característico de un virus de baja patogenicidad perteneciente a un linaje indígena H5 europeo. No se observó evidencia genética para la adaptación humana o la resistencia a los medicamentos antivirales. También es probable que la fuente de la infección fue a través del contacto indirecto con las aves silvestres mediadas a través de la propagación de fómites desde el entorno cercano. Ambos brotes de influenza aviar de baja patogenicidad fueron precedidos por inundaciones locales que atrajeron aves acuáticas silvestres a las instalaciones. La rápida detección de ambos brotes resaltó el valor del esquema de "Diagnóstico para Excluir" establecido en el Reino Unido para la avicultura comercial en el 2014 como un mecanismo de vigilancia de alerta temprana para las enfermedades aviares notificables.

Mortality and Egg Production Patterns in the United States Prior to HP/LPAI H7N9 Detection.

In March 2017, two commercial broiler breeder operations were confirmed with H7N9 highly pathogenic avian influenza (HPAI), and an additional six commercial broiler breeder operations were found positive with an H7N9 low pathogenicity avian influenza virus (LPAIV) or an H7 LPAIV (N type not identified). To better understand conditions leading up to testing positive for AI, egg production and mortality data for the 6 mo before the outbreak were obtained from five case farms (two HPAIV-infected farms and three LPAIV-infected farms) and two control farms. Both HPAI farms experienced a sudden spike in mortality immediately before testing positive. Two LPAI farms experienced drops in egg production along with slight increases in mortality that occurred after a negative serologic test and before a positive PCR test. The third LPAI farm also had a notable drop in egg production with a coinciding increase in mortality before testing positive for AIV (last negative test date not available). Additionally, both HPAI farms and two LPAI farms reported mild respiratory illnesses in the weeks prior to testing positive for AI. Control farms did not experience similar drops in production or increase in mortality. Clinical signs on LPAI farms were mild and easily confused with background health patterns, suggesting the need for improved sensitivity to identify LPAI quickly. Applying a trigger of a 2% drop in egg production along with a mortality of 8 per 10 000 hens in individual barns showed that all case farms would be identified and uninfected farms would be falsely triggered on 1% of days monitored.

Mortalidad y patrones de producción de huevos en los Estados Unidos antes de la detección del virus de la influenza aviar H7N9 de baja y alta patogenicidad. En marzo del 2017, se confirmaron dos operaciones de reproductores pesados comerciales con influenza aviar altamente patógena H7N9 (HPAI) y adicionalmente se encontraron seis operaciones de reproductores pesados comerciales con un virus de influenza aviar de baja patogenicidad H7N9 (LPAIV) o con un virus de baja patogenicidad H7 con un subtipo de neuraminidasa no identificado. Para comprender mejor las condiciones que condujeron a un resultado positivo de influenza aviar, se recolectaron los datos de producción de huevo y mortalidad de cinco granjas que presentaron casos (dos granjas infectadas con el virus de alta patogenicidad y tres granjas infectadas con el virus de baja patogenicidad) y dos granjas control durante los seis meses anteriores al brote. Las dos grajas infectadas con el virus de alta patogenicidad experimentaron un aumento repentino en la mortalidad inmediatamente antes de que se determinaran como positivas. Dos granjas con el virus de baja patogenicidad experimentaron caídas en la producción de huevo junto con un ligero aumento en la mortalidad que se produjo después de que mostraran respuesta negativa a las pruebas serológicas y antes de resultar positivas mediante pruebas de RT-PCR. La tercera granja infectada con el virus de baja patogenicidad también tuvo una caída importante en la producción de huevo con un aumento coincidente en la mortalidad antes de que mostraran un resultado positivo para influenza aviar (la fecha de la última prueba negativa no se encontró disponible). Además, tanto las dos granjas con influenza aviar de alta patogenicidad como dos granjas con influenza aviar de baja patogenicidad reportaron enfermedades respiratorias leves en las semanas previas a la fecha cuando mostraron resultados positivos para la influenza aviar. Las granjas control no experimentaron caídas similares en la producción de huevo o aumento en la mortalidad. Los signos clínicos en las granjas de baja patogenicidad fueron leves y se confundieron fácilmente con los patrones de salud normales de la parvada, lo que sugiere la necesidad de mejorar la sensibilidad para identificar rápidamente la a la influenza aviar de baja patogenicidad. Con la aplicación de una alarma que se desencadene con una caída del 2% en la producción de huevo junto con una mortalidad de ocho por cada 10 mil gallinas en casetas individuales mostró que todas las granjas problema serían identificadas y que las granjas no infectadas podrían ser activadas falsamente en el 1% de los días monitoreados.