Guinea fowl eggshell structural analysis at different scales reveals how organic matrix induces microstructural shifts that enhance its mechanical properties.

Guinea fowl eggshells have an unusual structural arrangement that is different from that of most birds, consisting of two distinct layers with different microstructures. This bilayered organization, and distinct microstructural characteristics, provides it with exceptional mechanical properties. The inner layer, constituting about one third of the eggshell thickness, contains columnar calcite crystal units arranged vertically as in most bird shells. However, the thicker outer layer has a more complex microstructural arrangement formed by a switch to smaller calcite domains with diffuse/interlocking boundaries, partly resembling the interfaces seen in mollusk shell nacre. The switching process that leads to this remarkable second-layer microstructure is unknown. Our results indicate that the microstructural switching is triggered by changes in the inter- and intracrystalline organic matrix. During production of the outer microcrystalline layer in the later stages of eggshell formation, the interactions of organic matter with mineral induce an accumulation of defects that increase crystal mosaicity, instill anisotropic lattice distortions in the calcite structure, interrupt epitaxial growth, reduce crystallite size, and induce nucleation events which increase crystal misorientation. These structural changes, together with the transition between the layers and each layer having different microstructures, enhance the overall mechanical strength of the Guinea fowl eggshell. Additionally, our findings provide new insights into how biogenic calcite growth may be regulated to impart unique functional properties. STATEMENT OF SIGNIFICANCE: Avian eggshells are mineralized to protect the embryo and to provide calcium for embryonic chick skeletal development. Their thickness, structure and mechanical properties have evolved to resist external forces throughout brooding, yet ultimately allow them to crack open during chick hatching. One particular eggshell, that of the Guinea fowl, has structural features very different from other galliform birds - it is bilayered, with an inner columnar mineral structure (like in most birds), but it also has an outer layer with a complex microstructure which contributes to its superior mechanical properties. This work provides novel and new fundamental information about the processes and mechanisms that control and change crystal growth during the switch to microcrystalline domains when the second outer layer forms.

Influence of photoperiod and exogenous melatonin on testis morpho-physiology of sexually mature guinea fowl (Numida meleagris).

The biological effects of simulated photoperiod and melatonin on the control of reproduction of guinea fowls (Numida meleagris) are not well understood. Herein, thirty (30) sexually mature guinea fowl cocks were randomly assigned to 1-6 groups (n = 5) and subjected to different photoperiodic regimes in the presence or absence of exogenous melatonin (Mel; 1 mg/kgBW/day, i/m) for eight weeks. Testes of the euthanized cocks were processed for gross morphology, histological, histochemical, and oxidative stress markers. Testosterone concentration was determined in serum samples using the enzyme-linked immunosorbent assay (ELISA) technique. We observed an increase in testicular size in the Mel and Non-Mel groups under long-day (LD) photoperiods, and in the Non-Mel group under short-day (SD) photoperiod. Conversely, the testicular size was drastically reduced in the Mel group for SD. Seminiferous tubules in the Mel and Non-Mel groups of the SD showed cytomorphological changes, including degenerated cells, focal vacuolations, and depletion of germinal epithelium. However, the germinal epithelium appeared to be complete and active in both the Mel and Non-Mel groups for the LD. In all groups, the testes showed positive staining for PAS with varying intensities. There was a significant difference in PAS-staining intensity between different photoperiodic regimes and exogenous melatonin. The study observed the interaction between photoperiods and exogenous melatonin on glutathione reductase (GSH), malondialdehyde (MDA), and serum testosterone. Overall, the results indicated that a long-day (LD) photoperiod, combined with exogenous melatonin, enhanced reproductive activity in male guinea fowl by increasing testicular size and serum testosterone concentration.

The fatty acid profile and the quality of breast and leg muscles in female and male pearl gray guinea fowl (Numida meleagris).

The aim of this study was to evaluate the fatty acid (FA) profile and the quality of breast and leg muscles in male and female guinea fowl. In comparison with leg muscles, breast muscles had a higher content of dry matter and total protein, and contained less fat and total collagen (P ≤ 0.05). Sex had no effect on the chemical composition of the studied muscles or the FA profile of intramuscular fat (IMF) (P > 0.05). The IMF of breast muscles was characterized by higher proportions of total saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs), and lower proportions of total unsaturated fatty acids (UFAs) and monounsaturated fatty acids (MUFAs) (P ≤ 0.05) than the IMF of leg muscles. The physicochemical properties of guinea fowl meat were significantly influenced by muscle type (P ≤ 0.05), but not by sex (P > 0.05). Leg muscles were characterized by a higher pH, higher cooking loss, lower lightness (L*), lower drip loss, a higher contribution of redness (a*), and a lower contribution of yellowness (b*) than breast muscles (P ≤ 0.05). The experimental factors had no effect on the sensory attributes or the shear force values of the analyzed muscles (P > 0.05). The unique sensory attributes, high protein content, and low fat content of the analyzed muscles indicate that guinea fowl meat can be a dietary supplement and an addition to other types of meat consumed, especially that most guinea fowl are reared in extensive farming systems that contribute to sustainable food production.

Release the hens: a study on the complexities of guinea fowl as tick control.

Established tick control strategies often involve methods that can be damaging to existing environmental conditions or natural host ecology. To find more environmentally friendly methods, biological controls, like predators of ticks, have been suggested. There are natural predators of ticks, but most are generalists and not expected to control tick populations. Helmeted guinea fowl (Numida meleagris (L.) (Galliformes: Numididae)) have been suggested to be biological controls of ticks, and therefore, tick-borne pathogens, but their potential role as hosts for ticks complicates the relationship. A study was conducted to assess whether guinea fowl reduces the abundance of lone star ticks, Amblyomma americanum (L.) (Acari: Ixodidae), or whether they are hosts of ticks. Using mark-recapture techniques, painted lone star ticks were placed into 3 different treatments: penned, excluded, and free range. The recapture rates of painted ticks were compared. There was a significant difference between excluded and free-range treatments, but not between excluded and penned or between free range and penned. To investigate the role of guinea fowl as hosts of ticks, coop floors were examined for engorged ticks. Engorged lone star nymphs that had fed on guinea fowl were found. Lastly, ticks collected were tested to identify the potential reduction in risk of tick-borne pathogens. This study found no evidence that guinea fowl are an effective biological control of lone star ticks or tick-borne pathogens, but they are hosts of lone star nymphs. Future studies are needed to assess the complex ecology of a biological control of ticks that is also a host.

Dietary protein levels during 12 to 26 wk improve the growth performance, bone quality, and testosterone in Pearl Gray male guinea fowl (Numida meleagris).

Guinea fowl (Numida meleagris), although native to Africa and despite its many potentials, does not represent the dominant species on the continent because of its seasonal reproductive nature and high keets mortality. This study was conducted to assess the effect of crude protein levels on growth performance, bone characteristics and reproductive activity of Pearl Gray male breeder guinea fowl from 12 to 26 wk of age. A total of 120 twelve-wk-old guinea fowls were randomly allotted to 3 dietary treatments with 8 replicates each and 5 birds per replicate using a completely randomized design. The dietary treatments comprised low level (LL), normal level (NL), and high level (HL) with diets respectively containing 15, 17, and 19% crude protein (CP). The results showed that guinea fowl in the HL treatment had a significantly lower feed conversion ratio (P = 0.008) than those in the other treatments. The birds fed the HL diet had significantly higher concentrations of testosterone (P < 0.05) than in the other treatments. High levels of calcium and phosphorus were observed in the femur of the HL group relative to the LL group. The birds in the LL treatment had a significantly higher (P = 0.007) femur robusticity index than those in the HL treatment. In conclusion, feeding 19% crude protein to Pearl Gray male guinea fowl from 12 to 26 wk of age improves growth performance, the density and strength of the femur and tibia and the reproductive tract. The CP level for the best performance of male guinea fowl from 12 to 26 wk of age is 19%.

Understanding muscle function during perturbed in vivo locomotion using a muscle avatar approach.

The work loop technique has provided key insights into in vivo muscle work and power during steady locomotion. However, for many animals and muscles, ex vivo experiments are not feasible. In addition, purely sinusoidal strain trajectories lack variations in strain rate that result from variable loading during locomotion. Therefore, it is useful to develop an 'avatar' approach in which in vivo strain and activation patterns from one muscle are replicated in ex vivo experiments on a readily available muscle from an established animal model. In the present study, we used mouse extensor digitorum longus (EDL) muscles in ex vivo experiments to investigate in vivo mechanics of the guinea fowl lateral gastrocnemius (LG) muscle during unsteady running on a treadmill with obstacle perturbations. In vivo strain trajectories from strides down from obstacle to treadmill, up from treadmill to obstacle, strides with no obstacle and sinusoidal strain trajectories at the same amplitude and frequency were used as inputs in work loop experiments. As expected, EDL forces produced with in vivo strain trajectories were more similar to in vivo LG forces (R2=0.58-0.94) than were forces produced with the sinusoidal trajectory (average R2=0.045). Given the same stimulation, in vivo strain trajectories produced work loops that showed a shift in function from more positive work during strides up from treadmill to obstacle to less positive work in strides down from obstacle to treadmill. Stimulation, strain trajectory and their interaction had significant effects on all work loop variables, with the interaction having the largest effect on peak force and work per cycle. These results support the theory that muscle is an active material whose viscoelastic properties are tuned by activation, and which produces forces in response to deformations of length associated with time-varying loads.

Effect of pearl guinea fowl eggshell ultrastructure and microstructure on keets hatchability.

Variability in shell structure is an evolutionary mechanism in birds that enables them to adapt to specific environmental conditions. This variability may also occur within the same species under the influence of individual indicators, such as the age or health status of females. While interspecies variation is quite obvious and easy to interpret, the reasons for intraspecies variation remain unclear. In this study, we examined the ultra- and microstructure of guinea fowl eggshells to identify the association between variations in shell structure and hatchability outcomes. We analyzed the visual differences between shells with low (L), intermediate (I), and high (H) external porosity using scale invariant feature transform analysis with NaturePatternMatch software. We found that the external pore image was closely related to the overall porosity of the shell before incubation. The total pore area, total porosity, and diffusion index (GH2O) were highest in group H shells (P < 0.001). Posthatching shells were characterized by an increased diameter and total surface area, decreased pore number (P < 0.001), as well as shortened mammillary layer (P < 0.001) and decreased total consumption of mammillary knobs (P < 0.001). The porosity indices of posthatching H shells had intermediate values between L and I. Although the effect of shell structure parameters on hatching was not confirmed, we assumed that all categories (L, I, and H) of shells were ideal for incubation. This suggests that the shell structure adapts to the metabolic rate of developing embryos; however, differences in shell structure affect the duration of incubation and synchronization of hatching. Both L and H shells showed delayed and prolonged hatching. Therefore, we recommended that guinea fowl eggs with different external porosity parameters should be incubated separately for better hatching synchronization. Differences in GH2O between L, I, and H eggs suggest that the shell porosity characteristics of guinea fowl eggs may be a key determinant of the rate of water loss during storage before incubation.

Photoperiodic-dependent histomorphological changes in the excurrent duct system of helmeted guinea fowl subjected to short day (8L:16D), long-day (16L:8D) light/dark cycles and exogenous melatonin.

In the present study, the influence of varying photoperiods [short day light 8L:16D, long day light 16L;8D] and exogeneous melatonin on the excurrent duct system of male helmeted guinea fowl was investigated using histo-morphological and histometric approaches. A total of twenty-eight (28) guinea fowl birds were randomly divided into Group I: Short daylight (SD; 8 HL), Group II: (SD +1mg/kg melatonin; 8 HL+ Mel), Group III: Long daylight (LD; 16 HL) and Group IV: (LD +1mg/kg; 16 HL + Mel)] and comprises of seven birds (n=7) per group. At the end of the 8 weeks of experimentation, the excurrent ducts were excised and processed for routine histological examination and the variations in histo-morphometrical parameters were determined using the GIMP2 software. Histologically, apart from the moderate cellular degeneration observed in efferent duct epithelia of the SD subgroups: (8 HL and 8 HL + Mel), there was remarkable spermatozoa presence in the lumens of the epididymal duct and ductus deferens of both 16 HL and 16 HL + Mel groups. The histo-morphometric data (luminal, ductal diameters and epithelial heights) were significantly increased (p <0.05) in the excurrent ducts of guinea fowl exposed to 16 HL and 16 HL + Mel, as compared to other groups. There was significant decrease (p <0.05) in stereocilia height (SH) in 16 HL compared to 8 HL sub-groups of lower segments. Although, a non-significant (p >0.05) increase in SH was observed in melatonin-treated groups, regardless of photoperiod. Taken together, these sets of data from this study indicate the importance of artificial light and exogenous melatonin in the control of seasonality of reproduction and which could be used to influence the reproductive cycle of the guinea fowl.

Effect of Variety and Sex on the Carcass and Meat Quality Traits of Guinea Fowl (Numida meleagris L.).

The aim of this study was to evaluate selected parameters of carcass and meat quality in 16-week-old pearl gray and lavender guinea fowl. The birds were raised in summer and fall, in an extensive system. Until 4 weeks of age, the birds were kept indoors, and from week 5 until slaughter they could use outdoor space enclosed by a fence, adjacent to the building. Guinea fowl were fed complete chicken diets: starter (weeks 0−6), grower (weeks 7−12), and finisher (weeks >13). In comparison with lavender guinea fowl, pearl gray birds had higher live weight at slaughter (p = 0.001) and higher carcass weight (p = 0.001). Females, compared with males, had a higher carcass dressing percentage (p ˂ 0.001), lower liver weight (p = 0.008), lower heart weight (p ˂ 0.001), and lower total weight of giblets (p = 0.004). The leg muscles of pearl gray guinea fowl, compared with those of lavender birds, had a higher content of dry matter (p ≤ 0.029). The breast muscles (p ˂ 0.001) and leg muscles (p = 0.017) of lavender guinea fowl contained less fat than the muscles of pearl gray birds. The breast muscles of females had a higher content of dry matter (p = 0.044) and ash (p = 0.016), and lower total collagen content (p = 0.028) than the breast muscles of males. The leg muscles of females were characterized by a higher pH (p ˂ 0.001), and lower cooking loss (p = 0.004) and drip loss (p = 0.005) than the breast muscles of males. The breast muscles of lavender guinea fowl, compared with those of pearl gray birds, were characterized by a higher chroma value (p ˂ 0.001), and a higher contribution of redness (p ˂ 0.001) and yellowness (p = 0.002), and their leg muscles were lighter in color (p ˂ 0.001), with a higher contribution of yellowness (p = 0.041) and a higher hue angle (p = 0.037). The value of chroma (p = 0.004) and the contribution of yellowness (p = 0.002) were higher in the breast muscles of females, compared with males. Neither variety nor sex affected (p > 0.05) the evaluated sensory properties of guinea fowl meat or the proportions of total SFAs, total UFAs, total MUFAs, and total PUFAs in the intramuscular fat (IMF) of breast and leg muscles. Meat from guinea fowl of both analyzed varieties can be an excellent alternative to more popular types of poultry meat due to its high nutritional value and eating quality.

Sensory characteristics and consumer preference for meat from guinea fowl fed hevea seed meal or cashew nut meal supplemented diets.

This study is part of a series of studies on the possibility of substituting alternative protein source supplements to the diet of guinea fowl in order to improve food security in the fight against poverty on the African Continent. This study assesses the identified sensory characteristics of guinea fowl meat and consumer preferences to determine if the possible alternative supplements identified result in a product acceptable to consumers and if consumer preference was evident. Indigenous guinea fowl or selected breed (Galor animals) were fed a control diet C, a commercial diet I (diet used for guinea fowl in Côte d'Ivoire), or one of 2 experimental diets N (diet C supplemented with 15% cashew nut meal) or diet H (diet C supplemented with 15% detoxified hevea seed meal). Meat samples were assessed by 120-trained people using 18 sensory attributes. Principal component analysis (PCA) showed that meats from guinea fowl fed diet C or diet I were clearly distinguished from guinea fowl fed N or H diets and that meat of indigenous guinea fowl or Galor animals were also clearly distinguished. The results of the hierarchical group analysis showed that meat from guinea fowl fed diet H was the preferred guinea fowl meat. A first partial least squares regression PLSR1 identified the relationships between guinea fowl meat samples, their sensory attributes and consumer preference and showed that 82.6% of the sensory data of the first 2 principal components accounted for 95.5% of the preference. The PLSR2 identified the relationships between guinea fowl samples, their sensory attributes, and their biochemical characteristics and showed that the fat content of the meat determined the intensity of flavor, odor, juiciness, and tenderness of the meat. Our results showed that meat from birds fed diet H was preferred, and thus emphasized the existence of a place for the use of hevea seed meal in guinea fowl diet in Côte d'Ivoire.

Sclerocarya birrea caffra nut meal as a substitute to soyabean meal: Effects on growth performance, feed intake and utilisation and viscera macromorphometry of blue-helmeted guinea fowl.

Imported soyabean meal (SBM) is the major dietary protein (DP) source for the sub-Saharan African poultry industry making poultry production costly. Therefore, alternative locally available DP sources are required. We evaluated the potential of locally available Marula nut meal (MNM) to substitute SBM in Guinea fowl (GF) diets by determining its effects on growth, feed intake (FI) and utilisation and viscera macromorphometry. Five grower diets wherein, on a CP basis, MNM substituted SBM at 0, 25, 50, 75 and 100% were formulated. Thirty-eight 4-week-old keets (n = 7 - 8), each individually housed in a cage, were randomly assigned to grower diets, and fed for 5 weeks and then transferred to corresponding finisher diets and fed for 3 weeks. Induction and weekly body mass, daily FI, and terminal body mass (TBM), body mass gain (BMG), average daily gain (ADG) and feed conversion ratio (FCR) were determined. On slaughter, viscera masses, small and large intestines lengths, tibiae and femora indices were determined. In week 2 of the grower phase GF fed diet 3 (50% MNM CP) had the highest weekly BMG and ADG (P < 0.05) and in week 5 GF fed diet 5 (100% MNM CP) had the highest FI (P < 0.05). Dietary MNM did not affect the GF's BMG, ADG, FI and FCR during weeks 1, 3 and 4 of the grower phase. In week 3 of the finisher phase GF fed diet 3 (50% MNM CP) had the highest (P < 0.05) FCR. Dietary MNM had no effect (P > 0.05) on the trial BMG, ADG and FI of the GF but GF reared on grower and finisher diets 3 (50% substitution of SBM CP) had the highest (P < 0.05) FCR. MNM had no effect on tibiae and femora masses, lengths, and mass: length ratios and viscera macromorphometry of the GF. We conclude that MNM can, on a CP basis, substitute SBM, in GF grower and finisher diets at 25%, 75% and 100% without compromising growth, FI and utilization and viscera of GF.

Axial skeletal morphological studies on the helmeted Guinea fowl (Numida meleagridis).

This study on the morphological features of bones of the helmeted guinea fowl (Numidia meleagridis) specifically the axial skeleton was conducted for documentation and valuable information on differences when compared with other species of the same order. Ten (10) Helmeted guinea fowls (5 females and 5 males) with an average weight of 3.0 kg were euthanized via jugular vein severance with bone preparation achieved via the use of insect larvae. The skull presented an elongated structure made up of paired and unpaired flat, short and long bones with distinctive features. The frontal bone projected caudodorsally to form a horn like structure, the frontal process at its middle while the vomer was absent. The cervical vertebrae were 14 in number starting from the first (Atlas) to the last vertebra without a rib. Specific distinguishing features were evident in the Atlas, Axis, 3rd to 5th, 6th to 11th and 12th to 14th cervical vertebrae. The thoracic vertebrae presented 7 bones comprising the 1st single free vertebra; notarium (fused 2nd to 5th), 6th single free vertebra and the last 7th vertebrae that fused with the synsacrum which was an ankylosis of the lumbar and sacral vertebrae. The caudal vertebrae were 7 with the last; the pygostyle being distinct in appearance. The ribs were 7 pairs, of which the first two were asternal while the remaining five were sternal and consisted of proximal vertebral and distal sternal portions. The curved uncinate process articulated to the caudal border of the 2nd and vertebral portions of the 3rd to 5th ribs. The guinea fowl proved to be a carinate by presenting a single sternum with dorsolateral processes and a ventral carina. In conclusion, this study revealed that except for the skull, the axial skeleton of the Helmeted Guinea fowl presented similarities to that of the domestic fowl (Gallus domesticus).

Socioeconomic correlates, typology and characterization of indigenous guinea fowl (Numida meleagris, Linnaeus) farming in Benin, West Africa.

The role of agriculture in Benin, Western Africa cannot be overemphasized, where livestock production is a major occupation among the rural population as it serves as a means of livelihood and sustenance. This study was carried out to examine the socio-economic correlates of guinea fowl production status in Benin and to characterize their management practices. 165 farmers across 10 regions in Benin were selected using the non-probabilistic snowball sampling method. Information on farmers' socio-economics, management practices and constraints to optimum production were elicited with the aid of a structured questionnaire and subjected to analysis. The results showed that across all the 10 regions surveyed, guinea fowl farming was the dominant occupation, particularly among men (81.0%) irrespective of sociolinguistic groups, religion and level of education. About one-third (34.5%) of the farmers had no formal education. In terms of characterization, four clusters of guinea fowl farmers were identified based on geographical location, educational level, management technique and farming experience. The constraints to guinea fowl production were slow growth and high mortalities as a result of diseases (40.7%) and predators (29.1%). Improvement in feeding (30%) and veterinary care (33.9%) were part of suggestions made by farmers to increase the productivity of the birds. The study concluded that adequate technical support and scientific research are inevitable in this sector as this will considerably improve the rural populations living conditions through enhanced income and therefore constitute a real lever for rural development.

Genetic diversity of indigenous guinea fowl (Numida meleagris) using microsatellite markers in northern Togo.

Indigenous guinea fowl is an important animal resource for improving rural household income. In order to provide molecular data for a sustainable management of this poultry resource, an assessment of the genetic diversity and phylogenic relationships was undertaken on seven guinea fowl phenotypes from two agroecological zones (Dry Savannah and Atakora) of Togo. Genotyping was carried out using 18 microsatellite markers on 94 individuals from Dry Savannah (59) and Atakora (35) zones. The results obtained showed a high genetic diversity, with six as an average alleles per locus and an observed heterozygosity of 0.512. However, the FIS values varied from 0.047 (Lavender) to 0.257 (Albino), reflecting a deficit of heterozygotes, which suggests low to moderate inbreeding levels. The genetic distances between phenotypes are low, ranging from 0.0068 (Bonaparte-Pearl grey) to 0.1559 (Lavender-Albino), unlike the strong genetic identities that reflect a strong genetic similarity between the seven phenotypes of indigenous guinea fowl studied. These results indicate the existence of a single indigenous guinea fowl population, derived from three probable parental populations, with a high within population genetic diversity (phenotypic or agroecological zone). These results could be of use to conservation and improvement programs aiming at the maintenance and sustainable exploitation of this important socio-cultural and economic resource in Togo.

Bioremediation of Cu and Zn by guinea fowl feather wastes and biodegradation of Cu- and Zn-polluted feathers by free and immobilized heavy-metal-tolerant bacterium Pseudochrobactrum sp. IY-BUK1.

One of the major pollutants generated from guinea fowl farms and slaughterhouses is guinea fowl feather (GFF) wastes. Chicken feathers are an important substrate for removing aqueous pollutants due to their structural characteristics, but the application of GFFs for such purposes has not been elucidated. This study was carried out to determine the potential of raw as well as chemically and physically pretreated GFFs in the bioremediation of copper (Cu) and zinc (Zn) from aqueous solutions and the subsequent biodegradation of Cu- and Zn-laden GFFs using free and immobilized heavy-metal-tolerant bacteria. Using atomic adsorption spectrometry, the ability of treated and untreated GFFs to adsorb Cu and Zn was determined, and the generated heavy-metal-laden GFFs were degraded using Pseudochrobactrum sp. IY-BUK1. The results revealed that under optimized conditions, acetone and autoclave pretreatment enhanced Cu and Zn removal by 40% within 6 h when compared with raw GFFs. Similarly, complete biodegradation of Cu- and Zn-laden GFFs was achieved at pH 8, with 2% inoculum size, and at 25°C using IY-BUK1 in 7 days. Upon optimization of physical and nutritional conditions, using one factor at a time and response surface methodology, the maximum keratinase activity was achieved at 30°C, with 3% inoculum size and 3.5% polluted GFF concentration in 3 h. The degradation and keratinase activity were further enhanced by 50% by the immobilization of Pseudochrobactrum sp. IY-BUK1 cells compared with free cells. Thus, GFFs can act as good biosorbents, and together with IY-BUK1, the use of GFFs can be an alternative approach to dispose of GFFs, thus preventing environmental pollution via bioremediation.

Positive Influence of a Probiotic Mixture on the Intestinal Morphology and Microbiota of Farmed Guinea Fowls (Numida meleagris).

To understand the effectiveness of a probiotic mixture on intestinal morphology, mucus layer composition, and cecal microbiota diversity, 40 10-day-old Guinea fowls (Numida meleagris) were assigned to two groups: the control group (C), receiving drinking water, and the treated group (P), receiving water plus a commercial multi-strain probiotic (Slab51®, 2 × 1011 CFU/L). Birds were slaughtered after 4 months, and the intestines were collected. Samples from the duodenum, ileum, and cecum were processed for morphological and morphometric studies, and conventional glycohistochemistry. Cecal samples were also used to assess the microbiota by 16S metataxonomic approach. Group P showed significant increase in the villus height (p < 0.001 in the duodenum and p < 0.05 in the ileum and cecum), villus width (p < 0.05 in all investigated tracts), depth of crypts (p < 0.001 in the duodenum and cecum; p < 0.05 in the ileum), and goblet cells per villus (p < 0.001 in all investigated tracts) compared with group C. Cecal microbiota of the birds varied considerably and comparing the relative abundance of the main observational taxonomic units (OTUs), a positive enrichment of several beneficial taxa, such as Oscillospira, Eubacterium, Prevotella, and members of the Ruminococcaceae, was observed. The enrichment of those taxa can improve microbiota stability and resilience facing environmental stresses, enhancing its resistance against invading pathogens. Ruminococcaceae, which represent the most important taxon in both groups, and Prevotella have a key role in the gut physiology due to the production of short-chain fatty acids (SCFAs), which are a vital energy source for enterocytes, improve glucose metabolism, and exert an overall anti-inflammatory effect. Probiotic administration enriches the presence of Coprococcus, Oscillospira, and Eubacterium taxa that produce butyrate, which exerts a beneficial effect on growth performance, structure of villi, and pathogen control and has anti-inflammatory properties too. This study indicates that Slab51® supplementation positively affects the morphology and microbiota diversity of the guinea fowl intestine.

Detection and Typing of a Fowl Adenovirus Type 1 Agent of Pancreatitis in Guinea Fowl.

Adenoviral pancreatitis has been amply described for decades in guinea fowl. Although its pathologic picture has been characterized fairly well, its etiology still remains only partially clarified. Based on several outbreaks diagnosed on commercial guinea flocks raised in France since 2017, we performed direct whole-genome sequencing from pancreatic lesional tissue by using the Oxford Nanopore Technologies (ONT) sequencing method. We generated 4781 viral reads and assembled a whole genome of 43,509 bp, clustering within fowl adenovirus type 1 (FAdV-1). A phylogenetic analysis based on a partial sequence of the hexon and short fiber genes on viruses collected in France showed 98.7% and 99.8% nucleotide identity, respectively. Altogether, these results confirm that an FAdV-1 closely related to chicken and other avian strains is the agent of pancreatitis in guinea fowl. This study illustrates the potential of ONT sequencing method to achieve rapid whole-genome sequencing directly from pathologic material.

Detección y tipificación de un adenovirus aviar tipo 1 (FAdV-1), agente de pancreatitis en gallinas de Guinea. La pancreatitis adenoviral se ha descrito ampliamente durante décadas en gallinas de Guinea. Aunque su cuadro patológico se ha caracterizado bastante bien, su etiología todavía permanece sólo parcialmente aclarada. Sobre la base de varios brotes diagnosticados en parvadas comerciales de guineas criadas en Francia desde el año 2017, se realizó una secuenciación directa del genoma completo a partir del tejido de la lesión pancreática mediante el método de secuenciación desarrollado por Oxford Nanopore Technologies. Se generaron 4781 lecturas virales y se ensambló un genoma completo de 43,509 pb, que se agrupó dentro del adenovirus aviar tipo 1 (FAdV-1). Un análisis filogenético basado en una secuencia parcial de los genes hexón y de fibra corta de virus recolectados en Francia mostró identidades de nucleótidos de 98.7% y 99.8%, respectivamente. En conjunto, estos resultados confirman que un adenovirus aviar tipo 1 estrechamente relacionado con el pollo y otras cepas aviares es el agente de la pancreatitis en la gallina de Guinea. Este estudio ilustra el potencial de las tecnologías desarrolladas por Oxford Nanopore Thechnologies para lograr una secuenciación rápida de todo el genoma directamente a partir de material patológico.

Effects of egg storage duration on egg quality, metabolic rate, hematological parameters during embryonic and post-hatch development of guinea fowl broilers.

Considering the value of guinea fowl keets, successful incubation of eggs is particularly desirable in this poultry species. This study evaluated the effect of egg storage duration on egg quality, heat production, hematological parameters during embryonic development and post hatch performance of guinea fowl broilers. A total of 800 hatching eggs of guinea fowl were used for this study. Before incubation, 12 eggs per treatment were used to analyse egg quality. Then, eggs were numbered, weighed, and assigned to 2 treatment groups of 400 eggs each according to storage duration of 5, and 10 d at a temperature of 18°C. The eggs were set for incubation at 37.7°C and 55% relative humidity for 28 d in a forced-draft incubator. To determine heat production as a measure of metabolism, 60 eggs in each replicate were transferred to respiratory cages post hatch two 12 wk old guinea fowl were also used to determine heat production. CO2 and O2 were recorded to calculate heat production at internal pipping, hatch and at 12 wk of age. The hatched keets were reared for 12 wk and data were collected on feed intake, body weight and feed conversion ratio. Blood samples were collected at hatch and at 12 wk of age from 24 guinea fowls per treatment to analyze haematological parameters. The results showed that embryos and guinea fowls at 12 wks of age from eggs stored for 5 d had higher (P ˂ 0.05) heat production and body weights. However, a significant higher (P ˂ 0.05) level of basophile, eosinophils, and lymphocytes was observed in guinea fowls from 10 d storage egg. It was concluded that extended duration of egg storage negatively influenced the metabolic rate of embryos. It also impacted hematological parameters which may suggest influence on immune response during embryonic and post-hatch growth.

Plasticity of the gastrocnemius elastic system in response to decreased work and power demand during growth.

Elastic energy storage and release can enhance performance that would otherwise be limited by the force-velocity constraints of muscle. Although functional influence of a biological spring depends on tuning between components of an elastic system (the muscle, spring-driven mass and lever system), we do not know whether elastic systems systematically adapt to functional demand. To test whether altering work and power generation during maturation alters the morphology of an elastic system, we prevented growing guinea fowl (Numida meleagris) from jumping. We compared the jump performance of our treatment group at maturity with that of controls and measured the morphology of the gastrocnemius elastic system. We found that restricted birds jumped with lower jump power and work, yet there were no significant between-group differences in the components of the elastic system. Further, subject-specific models revealed no difference in energy storage capacity between groups, though energy storage was most sensitive to variations in muscle properties (most significantly operating length and least dependent on tendon stiffness). We conclude that the gastrocnemius elastic system in the guinea fowl displays little to no plastic response to decreased demand during growth and hypothesize that neural plasticity may explain performance variation.

Description of the first isolates of guinea fowl corona and picornaviruses obtained from a case of guinea fowl fulminating enteritis.

Guinea fowl fulminating enteritis has been reported in France since the 1970s. In 2014, a coronavirus was identified and appeared as a possible viral pathogen involved in the disease. In the present study, intestinal content from a guinea fowl involved in a new case of the disease in 2017 was analysed by deep sequencing, revealing the presence of a guinea fowl coronavirus (GfCoV) and a picornavirus (GfPic). Serial passage assays into the intra-amniotic cavity of 13-day-old specific pathogen-free chicken eggs and 20-day-old conventional guinea fowl eggs were attempted. In chicken eggs, isolation assays failed, but in guinea fowl eggs, both viruses were successfully obtained. Furthermore, two GfCoV and two GfPic isolates were obtained from the same bird but from different sections of its intestines. This shows that using eggs of the same species, in which the virus has been detected, can be the key for successful isolation. The consensus sequence of the full-length genomes of both GfCoV isolates was highly similar, and correlated to those previously described in terms of genome organization, ORF length and phylogenetic clustering. According to full-length genome analysis and the structure of the Internal Ribosome Entry Site, both GfPic isolates belong to the Anativirus genus and specifically the species Anativirus B. The availability of the first isolates of GfCoV and GfPic will now provide a means of assessing their pathogenicity in guinea fowl in controlled experimental conditions and to assess whether they are primary viral pathogens of the disease "guinea fowl fulminating enteritis".RESEARCH HIGHLIGHTSFirst isolation of guinea fowl coronaviruses and picornaviruses.Eggs homologous to the infected species are key for isolation.Isolates available to precisely evaluate the virus roles in fulminating enteritis.First full-length genome sequences of guinea fowl picornaviruses.