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Domesticated chickens (Gallus gallus domesticus) are a dominant part of the global human diet. Although the early domestication history of this species remains disputed, Mainland Southeast Asia (MSEA) is assumed to have been the initial domestication center. The eastward spread of chickens into Island Southeast Asia (ISEA) and the Pacific is typically attributed to human‐mediated dispersals. Chicken remains are relatively common at Pacific Neolithic sites but are extremely rare in the archaeological records of MSEA and ISEA. Therefore, the exact routes and timing of the human‐mediated spread of chickens from their native range in MSEA into the Pacific remain questions of interest. Here, we present the earliest evidence of Gallus on the Indonesian island of Flores at Liang Bua. This site has yielded an extensive stratigraphic sequence that spans from ~190,000 calendar years (ka) ago until the present and includes dense accumulations of faunal remains. Twelve bones from the cave's Holocene deposits have been identified as Gallus. The oldest remains, a right and left coracoid, were each directly dated to ~2,250 calibrated radiocarbon years before present (ka cal. BP), whereas the youngest Gallus elements are ~0.3 ka old. Although wild Green Junglefowl (Gallus varius) and Red Junglefowl (Gallus gallus) are found on Flores today, the absence of either of these species in deposits at Liang Bua older than ~2.5 ka as well as the size and shape of the oldest coracoids suggests that these remains likely represent domesticated G. gallus. This is the first evidence for domesticated chickens in the Neolithic of Flores and the first directly dated Gallus remains in Wallacea. The absence of chickens in the fossil record of ISEA suggests that Red Junglefowl (and perhaps Green Junglefowl also) reached Wallacea via human‐mediated dispersal(s) at least ~2.25 ka cal. BP. [ABSTRACT FROM AUTHOR]

Although fancy caudae are important traits for chicken breeds, factors associated with their morphological diversity are not fully understood. We analyzed the caudal skeleton of the Tosa-jidori, Chabo, and Minohikichabo breeds with wild-type, erect, and rich caudae, respectively. Five of six Tosa-jidori chickens had four caudal vertebrae, whereas all six Chabo and five of six Minohikichabo chickens had five. The angle of the apex pygostyli with respect to the margo cranialis was significantly larger and smaller in Chabo and Minohikichabo than Tosa-jidori chickens, respectively. These findings indicated that the caudal skeleton is one of important factors for forming the characteristic traits of chicken breeds. [ABSTRACT FROM AUTHOR]

Individual differences in inhibitory control, an aspect of cognition, are found in many species. How this variation links to affective states is not much explored, and could be relevant for welfare. As less fearful, more optimistic, individuals may act more impulsively, inhibitory control could link to less negative, more positive, affective states. Alternatively, poorer inhibitory control could associate with more negative, less positive, affective states, as poorer inhibitory control can result in individuals being less able to adapt to changing environments and more likely to show stereotypies. We here explored in three cohorts (N = 209) of captive red junglefowl, the ancestor of domestic chickens, how inhibitory control associated with affective states. Specifically, we measured inhibitory control with a detour task, and negative and positive affective states with a tonic immobility test and a cognitive judgement bias test, respectively. Cognition and behaviour can differ between ages and sexes. Therefore, we investigated how inhibitory control related to affective states in younger chicks (≈2.5 weeks old), older chicks (≈5 weeks old) and sexually mature adults (≈28 weeks old) of both sexes. In younger chicks, poorer inhibitory control associated with less negative, more positive, affective states. We found no relationship between inhibitory control and affective states in older chicks or adults, nor sex differences regarding how inhibitory control related to affective states. Overall, our results suggest that inhibitory control can link to affective states and that the nature of these links can change over ontogeny.

The study was conducted in order to compare the effects of light-emitting diode (LED) light with a different color on performance parameters, histomorphometric features of the small intestine and some blood parameters in growing partridges. For this purpose, a total of 450 Chukar partridges (Alectoris chukar) were perdivided into three experimental groups including green light (GL), daylight (DL) and blue light (BL), and 250-lumen lighting. Each group contained 150 partridges with 5 repetitions per group. Experimental groups balanced according to initial live weight and raised under the same feeding and environmental conditions within the scope of the needs of partridges during 35 days. GL group showed higher live weight (P0.05). Higher villus height (VH), villus width, villus surface area were obtained in GL group, followed by DL and BL (P0.05). Serum glucose (P

Microvascularization of domestic fowl kidneys was studied using scanning electron microscopy (SEM) of vascular corrosion casts (VCCs). Two types of nephrons, mammalian‐type (MT) and reptilian‐type (RT) nephrons and their glomerular structure were analysed quantitatively by 3D morphometry. A significant difference in shape and size between the MT and RT glomeruli was found. The mean diameter of the RT glomeruli was about 56 µm, while that of MT glomeruli was significantly larger, namely about 80 µm. The afferent arterioles in mammalian‐type glomeruli usually bifurcated into two lobular branches and formed a complex glomerular capillary network with numerous loops. Reptilian‐type glomeruli consisted of a single capillary forming few loops and leaving the glomerulus as efferent arteriole. Diameters of afferent and efferent arteriolar replicas were similar in all three kidney divisions of MT and RT nephrons. The absence of the interconnecting branches between the MT nephron capillaries at the gross inspection suggests that the mammalian‐type nephron glomeruli, although more complex than the reptilian type, are not equivalent to those in mammalian kidneys. [ABSTRACT FROM AUTHOR]

Fancy breeds of Japanese indigenous chicken display extensive morphological diversity, particularly in tail feathers. Although marked differences in tail and bone traits have been reported between Tosa-jidori (wild type) and Minohikichabo (rich type) breeds, little is known about the pattern of genetic inheritance in cross experiments. Therefore, this study aimed to investigate the strain and sex effects, and inheritance patterns, in the morphometric variation of pygostyle bones among Tosa-jidori, Minohikichabo, and their F 1 hybrids. Five morphological traits, angle of the apex of the pygostyle, pygostyle length, margo cranialis length, tail feather number, and body weight, were evaluated at the adult stage. A significant strain difference was detected in all traits, whereas significant sex differences were observed in only three traits, but not in the angle of the apex of the pygostyle and tail feather number. In F 1 hybrids, the angle of the apex of the pygostyle was significantly different to that of Tosa-jidori but not that of Minohikichabo, whereas the pygostyle length and tail number of F 1 hybrids were significantly different from those of Minohikichabo but not those of Tosa-jidori. A significant heterosis effect was found in the margo cranialis length and body weight. All five traits showed nonadditive inheritance patterns but varied in each trait between partial dominance (angle of the apex of pygostyle), full dominance (pygostyle length and tail feather number), and over-dominance (margo cranialis length and body weight). Interestingly, different patterns of genetic inheritance in the F 1 hybrid were observed at different locations, even within the same pygostyle bone. Using the Japanese indigenous chicken model, these results provide a substantial step toward understanding the genetic architecture of morphology in chickens., (© 2024 Wiley Periodicals LLC.)

The effect of taurine on the turkey spermatozoa motility and viability during the in vitro incubation was assessed. Experimental samples were prepared by diluting the raw semen in nine different concentrations of taurine - from 10 mg/ml to 0.078125 mg/ml. The motility parameters were evaluated by the CASA system (Computer Assisted Semen Analyser) using the program Sperm Vision® and for spermatozoa viability assessment the eosin-nigrosin staining was performed. Selected parameters were evaluated at six time periods: 0, 1, 2, 3, 4, and 5 h at 5°C and 41°C. At 5°C, a significantly lower percentage of motility and progressive motility was detected only in the samples with the highest concentration of taurine (10 mg/ml) at time 0 and 1. After 2 h of incubation a significant preventive effect of taurine on spermatozoa parameters was observed. The tendency of the taurine effect on motility parameters was different during the in vitro incubation at 41°C. Significantly lower values of motility parameters were detected in all experimental samples in comparison to the control after 5 h. The analysed concentrations of taurine did not significantly affect viability of turkey spermatozoa during all time periods. A higher percentage of dead spermatozoa were observed at 41°C (4.87-9.90%) if compared to 5°C (2.12-4.88%). The results indicated that the addition of taurine (from 2.5 to 7.5 mg/ml) to turkey spermatozoa positively affected the monitored spermatozoa parameters incubated at 5°C.

The present study was conducted on blood cells of thirty healthy domestic fowl, guinea fowl and pigeon, ten birds of each group. Lymphocyte showed strongly positive reaction in fowl while moderate in guinea fowl and weak in pigeon in the form of black-brown patches when blood smears were stained for acid phosphatase. Eosinophil of guinea fowl as well as pigeon showed moderate positive reaction however, reaction was weak in fowl for alkaline phosphatase in the form of brown coloured granules. Eosinophil of guinea fowl as well as pigeon showed strongly positive reaction, while reaction was moderately positive in fowl for peroxidase. All cells were negative in all the three species for non-specific esterase. [ABSTRACT FROM AUTHOR]

Occurrence of Newcastle disease (ND) and characterization of the Avian Paramyxovirus-1 (APMV-1) amongst backyard fowls (Gallus gallus domesticus) and pigeon (Columba livia domestica) was studied. ND was suspected in two fowl flocks (100% morbidity, 86% mortality) and six pigeon flocks (21.68% morbidity, 14.16% mortality) with respiratory and/or enteric clinical signs in fowls and predominantly neurological signs in pigeons was observed. Cloacal swabs, tissue lysates or infected allantoic fluid could haemagglutinate (HA) chicken erythrocytes and pigeon convalescent serum inhibited haemagglutination (antibody titres >1/16). A 534 bp product was amplified from clinical samples and infected allantoic fluids by Reverse Transcriptase PCR (RT-PCR) targeting a partial Fusion protein gene including its cleavage site. The fowl and pigeon isolate was found to be velogenic and lentogenic respectively by virulence characterization. Fowl isolate grown in chicken embryonated eggs (CEE) showed 10-8.68 Embryo Infectious Dose (EID50) with a Mean Death Time (MDT) of 51.43 h and the Intra-Cerebral Pathogenicity Index (ICPI) in day-old chicks was 1.51. Pigeon isolate had corresponding values of 10-7.20 EID50, MDT of 92.00 h and ICPI of 0.43. Deduced amino acid sequence at Fusion protein cleavage site showed 112R-R-R-K-R*F117 velogenic motif for the fowl isolate and 112G-R-Q-G-R*L117 lentogenic motif for the pigeon isolate. Both isolates were found to be 84.1% related phylogenetically, while fowl isolate clustered with genotype XIII, the pigeon isolate clustered with genotype II and vaccine strains of APMV-1. This is the first instance of APMV-1 characterization in the region with the possibility of a vaccine spill over in pigeons. [ABSTRACT FROM AUTHOR]

The study was conducted in order to compare the effects of light-emitting diode (LED) light with a different color on performance parameters, histomorphometric features of the small intestine and some blood parameters in growing partridges. For this purpose, a total of 450 Chukar partridges (Alectoris chukar) were perdivided into three experimental groups including green light (GL), daylight (DL) and blue light (BL), and 250-lumen lighting. Each group contained 150 partridges with 5 repetitions per group. Experimental groups balanced according to initial live weight and raised under the same feeding and environmental conditions within the scope of the needs of partridges during 35 days. GL group showed higher live weight (P<0.05), live weight gain (P<0.01) and feed intake (P<0.05). Feed conversion and viability rates were similar among the groups (P>0.05). Higher villus height (VH), villus width, villus surface area were obtained in GL group, followed by DL and BL (P<0.001). The differences in crypt depth (CD) and VH/CD were not significant (P>0.05). Serum glucose (P<0.01) and lactate dehydrogenase levels (LDH) (P<0.05) were increased in GL groups. Serum high-density lipoprotein level (HDL) was found to be higher in DL group (P<0.01). Consequently, GL group had better results in growing partridges. GL could be utilized under intensive farming conditions for partridges. [ABSTRACT FROM AUTHOR]

In vitro and in vivo experiments were conducted to study the effects of synbiotic supplementation on Salmonella enterica ser. Enteritidis (SE) proliferation, cecal content load, and broiler carcass contamination. Lactobacillus reuteri, Enterococcus faecium, Bifidobacterium animalis, and Pediococcus acidilactici culture supernatants decreased (P < 0.05) the in vitro proliferation of SE at 1:1 supernatant: pathogen dilution. A total of 240 Cobb-500 broiler chicks were randomly allotted to three treatment groups (8 replicates/group with 10 birds/replicate): control (basal diet), antibiotic (Virginiamycin at 20 mg/kg feed), synbiotic (PoultryStar® ME at 0.5 g/kg feed containing L. reuteri, E. faecium, B. animalis, P. acidilactici and a Fructooligosaccharide) from day of hatch. At 21 d of age, all birds in experimental groups were orally inoculated with 250 μl of 1 X 109 CFU SE. Antibiotic supplementation increased (P < 0.05) body weight and feed consumption, compared to the control group. Birds in the synbiotic supplementation had intermediate body weight and feed consumption that were not significantly different from both the control and antibiotic group at 42 d of age in SE infected birds. No significant effects were observed in feed efficiency at 42 d of age among the groups. Antibiotic and synbiotic supplementation decreased (P < 0.05) SE load in cecal contents by 0.90 and 0.85 log units/ g and carcass SE load by 1.4 and 1.5 log units/mL of rinsate compared to the control group at 42 d of age (21 dpi). The relative abundance of IL-10, IL-1, TLR-4, and IFNγ mRNA was decreased (P < 0.05) in the antibiotic and synbiotic supplementation groups compared to the control birds at 42 d of age (21 dpi). It can be concluded that synbiotic supplementation decreased SE proliferation in vitro and decreased SE load in the cecal contents and broiler carcass. [ABSTRACT FROM AUTHOR]

Background: Intestinal parasitic infection affects 3.5 billion people in the world and mostly affecting the low socio-economic groups. The objectives of this research works were to estimate the prevalence and determinants of intestinal parasitic infection among family members of known intestinal parasite infected patients. Methods and materials: A comparative cross-sectional study design was implemented in the urban and rural settings of Mecha district. The data were collected from August 2017toMarch 2019 from intestinal parasite infected patient household members. Epi-info software was used to calculate the sample size, 4531 household members were estimated to be included. Data were collected using interview technique, and collecting stool samples from each household contact of intestinal parasite patients. Descriptive statistics were used to estimate the prevalence of intestinal parasites among known contacts of intestinal parasite patients/family members. Binary logistic regression was used to identify the determinant factors of intestinal parasitic infection among family members. Results: The prevalence of intestinal parasite among household contacts of intestinal parasite-infected family members was 86.14% [95% CI: 86.14% - 87.15%]. Hookworm infection was the predominant type of infection (18.8%). Intestinal parasitic infection was associated with sex, environmental sanitation, overcrowding, personal hygiene, residence, substandard house, role in the household, source of light for the house, trimmed fingernails, family size, regular handwashing practice. Protozoa infection was associated with habit of ingesting raw vegetable, playing with domestic animals, water source and the presence of household water filtering materials. Conclusion: High prevalence of intestinal parasitic infection was observed among household contacts of primary cases. [ABSTRACT FROM AUTHOR]

Over the last 20 years, a new group of systemic insecticides–the neonicotinoids—has gained prominence in arable systems, and their application globally has risen year on year. Previous modelling studies using long-term data have suggested that neonicotinoid application has had a detrimental impact on bird populations, but these studies were either limited to a single species or neglected to analyse specific exposure pathways in conjunction with observed population trends. Using bird abundance data, neonicotinoid usage records and cropping data for England at a 5x5 km resolution, generalised linear mixed models were used to test for spatio-temporal associations between neonicotinoid use and changes in the populations of 22 farmland bird species between 1994 and 2014, and to determine whether any associations were explained by dietary preferences. We assigned farmland bird species to three categories of dietary exposure to neonicotinoids based on literature data for species diets and neonicotinoid residues present in dietary items. Significant estimates of neonicotinoid-related population change were obtained for 13 of the 22 species (9 positive effects, 4 negative effects). Model estimates for individual species were not collectively explained by dietary risk categories, so dietary exposure to neonicotinoids via ingestion of treated seeds and seedlings could not be confirmed as a causal factor in farmland bird declines. Although it is not possible to infer any generic effect of dietary exposure to neonicotinoids on farmland bird populations, our analysis identifies three species with significant negative estimates that may warrant further research (house sparrow Passer domesticus, skylark Alauda arvensis and red-legged partridge Alectoris rufa). We conclude that there was either no consistent effect of dietary exposure to neonicotinoids on farmland bird populations in England, or that any over-arching effect was not detectable using our study design. The potential for indirect effects of insecticide use on bird populations via reduced food availability was not considered here and should be a focus for future research. [ABSTRACT FROM AUTHOR]

The development of an organism involves the formation of patterns from initially homogeneous surfaces in a reproducible manner. Simulations of various theoretical models recapitulate final states of natural patterns, yet drawing testable hypotheses from those often remains difficult. Consequently, little is known about pattern-forming events. Here, we surveyed plumage patterns and their emergence in Galliformes, ratites, passerines, and penguins, together representing the three major taxa of the avian phylogeny, and built a unified model that not only reproduces final patterns but also intrinsically generates shared and varying directionality, sequence, and duration of patterning. We used in vivo and ex vivo experiments to test its parameter-based predictions. We showed that directional and sequential pattern progression depends on a species-specific prepattern: an initial break in surface symmetry launches a travelling front of sharply defined, oriented domains with self-organising capacity. This front propagates through the timely transfer of increased cell density mediated by cell proliferation, which controls overall patterning duration. These results show that universal mechanisms combining prepatterning and self-organisation govern the timely emergence of the plumage pattern in birds. [ABSTRACT FROM AUTHOR]

The use of antibiotics in livestock production is considered a major driver of antibiotic resistance on a global scale. In Vietnam, small- and medium-scale livestock producers dominate the domestic market and regulatory pushes have done little to decrease antibiotic use. In order to inform future policy directions, this study aims to explore knowledge, attitudes, and practices amongst livestock producers to identify their perspectives on antibiotic use and resistance. A total of 392 small- and medium-scale producers specialized in pig, poultry and aquaculture production participated in the study. The results showed that the primary reason for antibiotic use reported by producers was for the treatment of infections (69%). However, prophylactic use was also evident, with farmers reporting other reasons for antibiotic use such as “animals display abnormal symptoms or behaviour” (55%), the “weather is about to change” (25%), or “animals on neighboring farms fall ill” (27%). Only one-fifth of producers demonstrated favorable attitudes towards antibiotic use and preventing antibiotic resistance. Moreover, administering antibiotics remained the preferred countermeasure directly applied by farmers at the first indication of disease (17%), compared to enacting hygiene (10%) or quarantine (5%) measures. The results showed divergent trends amongst producers, with pig producers demonstrating higher levels of knowledge, more favorable attitudes, and higher self-reported utilization of good practice. Better knowledge, attitudes, and practices were also associated with producers who engaged in efforts to explore information on antibiotic use and resistance, which improved incrementally with the number of sources consulted and hours invested. However, there were some areas where increased knowledge or more favorable attitude scores did not translate into better practices. For instance, producers with higher levels of formal education performed significantly better than those with lower education in terms of knowledge and attitude, though both groups reported similar practices. The findings of this study may support future interventions to prevent both antibiotic misuse and the development of antimicrobial resistance. [ABSTRACT FROM AUTHOR]

The cellular DNA sensor cGMP-AMP synthase (cGAS) detects cytosolic viral DNA via the stimulator of interferon genes (STING) to initiate innate antiviral response. Herpesviruses are known to target key immune signaling pathways to persist in an immune-competent host. Marek’s disease virus (MDV), a highly pathogenic and oncogenic herpesvirus of chickens, can antagonize host innate immune responses to achieve persistent infection. With a functional screen, we identified five MDV proteins that blocked beta interferon (IFN-β) induction downstream of the cGAS-STING pathway. Specifically, the MDV major oncoprotein Meq impeded the recruitment of TANK-binding kinase 1 and IFN regulatory factor 7 (IRF7) to the STING complex, thereby inhibiting IRF7 activation and IFN-β induction. Meq overexpression markedly reduced antiviral responses stimulated by cytosolic DNA, whereas knockdown of Meq heightened MDV-triggered induction of IFN-β and downstream antiviral genes. Moreover, Meq-deficient MDV induced more IFN-β production than wild-type MDV. Meq-deficient MDV also triggered a more robust CD8+ T cell response than wild-type MDV. As such, the Meq-deficient MDV was highly attenuated in replication and lymphoma induction compared to wild-type MDV. Taken together, these results revealed that MDV evades the cGAS-STING DNA sensing pathway, which underpins the efficient replication and oncogenesis. These findings improve our understanding of the virus-host interaction in MDV-induced lymphoma and may contribute to the development of novel vaccines against MDV infection. [ABSTRACT FROM AUTHOR]

At higher latitudes, vertebrates exhibit a seasonal cycle of reproduction in response to changes in day-length, referred to as photoperiodism. Extended day-length induces thyroid-stimulating hormone in the pars tuberalis of the pituitary gland. This hormone triggers the local activation of thyroid hormone in the mediobasal hypothalamus and eventually induces gonadal development. In avian species, light information associated with day-length is detected through photoreceptors located in deep-brain regions. Within these regions, the expressions of multiple photoreceptive molecules, opsins, have been observed. However, even though the Japanese quail is an excellent model for photoperiodism because of its robust and significant seasonal responses in reproduction, a comprehensive understanding of photoreceptors in the quail brain remains undeveloped. In this study, we initially analyzed an action spectrum using photoperiodically induced expression of the beta subunit genes of thyroid-stimulating hormone in quail. Among seven wavelengths examined, we detected maximum sensitivity of the action spectrum at 500 nm. The low value for goodness of fit in the alignment with a template of retinal1-based photopigment, assuming a spectrum associated with a single opsin, proposed the possible involvement of multiple opsins rather than a single opsin. Analysis of gene expression in the septal region and hypothalamus, regions hypothesized to be photosensitive in quail, revealed mRNA expression of a mammal-like melanopsin in the infundibular nucleus within the mediobasal hypothalamus. However, no significant diurnal changes were observed for genes in the infundibular nucleus. Xenopus-like melanopsin, a further isoform of melanopsin in birds, was detected in neither the septal region nor the infundibular nucleus. These results suggest that the mammal-like melanopsin expressed in the infundibular nucleus within the mediobasal hypothalamus could be candidate deep-brain photoreceptive molecule in Japanese quail. Investigation of the functional involvement of mammal-like melanopsin-expressing cells in photoperiodism will be required for further conclusions. [ABSTRACT FROM AUTHOR]

Unlearned tendencies to approach animate creatures are of great adaptive value, especially for nidifugous social birds that need to react to the presence of potential social companions shortly after hatching. Domestic chicks’ preferences for taxidermized hens provided the first evidence of social predispositions. However, the nature of the stimuli eliciting this predisposition is not completely understood. Here we explore the unlearned preferences of visually naïve domestic chicks for taxidermized animals. Visually naive chicks were tested for their approach preferences between a target stimulus (an intact stuffed animal whose head region was clearly visible) and a control stimulus. After confirming the predisposition for the intact stuffed fowl hen (Exp. 1), we found an analogous preference for a taxidermized, young domestic chick over a severely scrambled version of the same stimulus, whose body structure was completely disrupted, extending to same-age individuals the results that had been obtained with taxidermized hens (Exp. 2). We also directly tested preferences for specimens whose head region is visible compared to ones whose head region was occluded. To clarify whether chicks are sensitive to species-specific information, we employed specimens of female mallard ducks and of a mammalian predator, the polecat. Chicks showed a preference for the duck stimulus whose wings have been covered over a similar stimulus whose head region has been covered, providing direct evidence that the visibility of the head region of taxidermized models drive chicks’ behaviour in this test, and that the attraction for the head region indeed extends to females of other bird species (Exp. 3). However, no similar preference was obtained with the polecat stimuli (Exp. 4). We thus confirmed the presence of unlearned visual preferences for the head region in newly-hatched chicks, though other factors can limit the species-generality of the phenomenon. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance in Campylobacter, common in poultry, is a global public health issue. The emergence and spread of antimicrobial resistant Campylobacter has been linked to the use of antimicrobials in food animals. Small poultry flocks are becoming increasingly popular not only as a source of food but also as pets, yet not all small flock owners are aware of proper antimicrobial use practices and safe food handling protocols. This trend could contribute to antimicrobial resistance. In order to determine the prevalence of antimicrobial resistance in Campylobacter in small poultry flocks, we analyzed data from birds that had been submitted to a diagnostic laboratory in Ontario between October 2015 and September 2017. A pooled cecal sample was obtained from each submission and cultured for Campylobacter jejuni and Campylobacter coli. Three isolates were recovered from each positive sample and tested for susceptibility to nine antimicrobials using a broth microdilution method. Overall, 176 isolates were recovered (141 chicken, 21 turkey, 6 duck, and 8 game bird). A high frequency of resistance to tetracycline was observed in the C. jejuni isolates from chickens (77%) and turkeys (100%), and in the C. coli isolates from turkeys (50%) and game birds (40%). Campylobacter jejuni isolates had higher odds of resistance to tetracycline (OR = 3.54, P ≤ 0.01) compared to C. coli isolates. Overall, there was a low frequency of resistance to quinolones and a very low frequency of resistance to macrolides. Multidrug resistance was uncommon. The high prevalence of tetracycline resistance emphasizes the importance of prudent antimicrobial use in small flocks. Although low, the presence of resistance to macrolides and quinolones, which are used to treat campylobacteriosis in humans, highlights the need for proper food safety and infection control practices by small flock owners to prevent exposure to antimicrobial resistant Campylobacter. [ABSTRACT FROM AUTHOR]

Sexual selection promotes the evolution of conspicuous animal ornaments. To evolve as signals, these traits must reliably express the “quality” of the bearer, an indicator of individual fitness. Direct estimates of individual fitness may include the contribution of longevity and fecundity. However, evidence of a correlation between the level of signal expression and these two fitness components are scarce, at least among vertebrates. Relative fitness is difficult to assess in the wild as age at death and extra-pair paternity rates are often unknown. Here, in captive male red-legged partridges, we show that carotenoid-based ornament expression, i.e., redness of the bill and eye rings, at the beginning of reproductive life predicts both longevity (1–7 years) and lifetime breeding output (offspring number and hatching success). The recently proposed link between the individual capacity to produce red (keto) carotenoid pigments and the efficiency of cell respiration could, ultimately, explain the correlation with lifespan and, indirectly, fecundity. Nonetheless, in males of avian species, carotenoid-based coloration in bare parts is also partially controlled by testosterone. We also manipulated androgen levels throughout life by treating males with testosterone or antiandrogen compounds. Treatments caused correlations between signal levels and both fitness components to disappear, thus making the signals unreliable. This suggests that the evolution of carotenoid-based sexual signals requires a tightly-controlled steroid metabolism. [ABSTRACT FROM AUTHOR]