Comparative morphological study of skeletal muscle weight among the red jungle fowl (Gallus gallus) and various fowl breeds (Gallus domesticus).

We examined the weight distribution of skeletal muscles of the red jungle fowl, then compared these values with those of domesticated populations to determine how muscle distribution has changed by selecting breeding. Sonia, Fayoumi, and Rhode Island Red were selected for comparison from livestock breeds, while Japanese Shamo and Thai fighting cocks were selected from cockfighting groups. Principal component analysis was applied using body size-free data. The mass distribution of muscles clearly differed between the wild, livestock, and cockfighting groups, demonstrating that muscle distribution has changed after selecting breeding, coupled with functional demands of each group. The red jungle fowl, which has the ability to fly, could be clearly distinguished from the flightless domesticated populations due to differences in flight pectoral muscle size. The cervical muscles in the wild population were smaller than in the domesticated groups; these do not contribute to flight. The gluteal muscles were larger in the fighting cock group, functionally coupled to their traditionally preferred upright posture. Wild bird populations typically exhibit reduced weight of their hind limbs, associated with flight, but as the red jungle fowl displays largely terrestrial behavior, these muscles are similar in arrangement and relative size to those of the livestock groups. We showed that the mass distribution pattern of skeletal muscles expresses selecting breeding strategy and clearly reflects the specific traits for each group.

Screening of in vitro nutrient digestibility coefficients of selected insect meals in broiler chickens, black-meat chickens and quails.

The objective of this study is to identify potential insect species comparing with commonly used protein sources based on efficiency of the in vitro digestibility on dry matter (DMd), organic matter (OMd) and crude protein (CPd) in broiler chickens, black-meat chickens (Native breed) and quails. Each of gastric mucosa, pancreas and duodenal mucosa were obtained from proventriculus, pancreas and duodenum, respectively. Crude digestive enzyme extracts (CTE) were extracted from these organs to perform in vitro digestibility. Eighteen insect samples and six commonly used protein sources were served as substrates which were evaluated on DMd, OMd and CPd in triplicate for each substrate. The CTE from gastric mucosa was used to simulate proventriculus, whereas small intestine was simulation by adding the CTE from pancreas and duodenum. The large variation of chemical composition between insect meals was presented. For commonly used protein sources, animal proteins were higher on digestibility than plant proteins (p < .001). Quails represented a great potential to digest insect meals comparing other animals. Based on CPd results, there were potential insect species for broiler chickens (Achroia grisella: AG, Tenebrio molitor: TM and Musca domestica), black-meat chickens (Patanga succincta, TM and AG) and quails (Hermetia illucens, Acheta domesticus and Locusta migratoria; p < .001). The evidences from this study suggest that these insect species contain a great potential to use as alternative protein sources promoting an animal production with sustainability. However, the in vivo experimentation must be performed to confirm in further study.

Effects of dietary supplementation with different levels and molecular weights of fungal ß-glucan on performances, health and meat quality in broilers

Objective: To investigate the effects of dietary supplementation with different levels and molecular weights of fungal ß-glucan on productive performances, health, carcass traits and meat quality in broilers. Methods: Two hundred and ten of one-day-old chicks with equal sex were assigned to seven experimental groups in 2×4 factorial arrangement. These groups were supplemented with (0, 10, 30 and 60 ppm) of molecular weight 1-3, 1-6 ß-glucan (low or high). High molecular weight ß-glucan (H: 943 kDa) was obtained from Ophiocordyceps dipterigena BCC 2073, whereas H with -Irradiation treatment was performed to achieve low molecular weight ß-glucan (L: 8 kDa). Results: There was no statistical significance in productive performances, apparent digestibility and interaction between fixed factors along 42 days of experiment (P>0.05). A higher caecal amylase activity was present in the group that received L, while there was a dramatic decrease in H and the control groups, respectively (P<0.05). The increase of supplemental dose increased caecal amylase activity (P<0.05). Immunomodulatory effects from L was revealed by the marked increase of phagocytic activity, relative weight of thymus and bursa of fabricius (P<0.05). Similarly, the additive dose at 30 ppm provided the same results, whereas the only significant difference with supplementation at 60 ppm was an increase in phagocytic activity (P<0.05). Interestingly, villi height of broilers fed L was higher than other groups (P<0.05). The treatments did not influence haematology, blood chemistry, antibody production level against vaccination, carcass traits and meat quality (P>0.05). Conclusion: The supplementation of L at 30 ppm was suggested to achieve benefits of immune modulation without adverse effects on other parameters.

Potential of Insect Meals as Protein Sources for Meat-Type Ducks Based on In Vitro Digestibility.

There has been a dramatic increase in duck meat consumption. As a result, ducks are an interesting alternative type of livestock. Animal-based proteins such as fishmeal and animal by-products are valuable nutrients with high digestibility, but they are associated with cost fluctuations, pathogen contamination, and environmental impacts. Therefore, plant-based proteins are used, but they have the disadvantages of inappropriate amino acid profiles, anti-nutritional factors, and mycotoxin contamination. Insect meal contains favorable nutrients and low production costs and is environmentally friendly; however, there is a large number of insect species. Therefore, the purpose of this investigation is to screen insects for their potential use as a protein source in the duck diet. Insect meal with a high proportion of low-digestible components was shown to have low digestibility. Yellow mealworm larvae, giant mealworm larvae, lesser wax moth larvae, house fly larvae, mulberry silkworm pupae, and American cockroach nymph have the potential to be alternative protein sources for ducks. Insect meal has been widely studied and is used in animal nutrition to replace common protein sources that have several disadvantages and to promote sustainability in animal production. Two-step in vitro digestibility using crude enzyme extracts from digestive tracts of meat-type ducks (Cherry Valley) was performed on general protein sources and insect meals to compare the in vitro digestibility of organic matter (OMd) and crude protein (CPd). Variation in chemical components between different types of insect meal was found. A positive correlation was found between OMd and the ether extract composition in insect meal, whereas a negative correlation was shown between crude fiber and acid detergent fiber. Contrasting relationships were found between CPd and crude fiber and acid detergent fiber in insect meal. In conclusion, the yellow mealworm larvae (Tenebrio molitor), giant mealworm larvae (Zophobas morio), lesser wax moth larvae (Achroia grisella), house fly larvae (Musca domestica), mulberry silkworm pupae (Bombyx mori), and American cockroach nymph (Periplaneta americana) are potential protein sources for ducks based on OMd and CPd digestibility after screening with an in vitro digestibility technique.

Promoting the use of locally produced crops in making cereal-legume-based composite flours: An assessment of nutrient, antinutrient, mineral molar ratios, and aflatoxin content.

Cassava, rice, and banana flours were used individually to replace wheat flour in cereal-legume-based composite flours. The proximate composition, mineral content, antinutritional effect, mineral molar ratios, and aflatoxin level were investigated. Replacing wheat flour with rice flour significantly (P < 0.05) improved protein, fat, potassium, and phosphorus content in samples. The molar ratios of phytate or oxalate to minerals (calcium and zinc) in all composite flours were lower than the reported critical values, except phytate to iron. However, all samples, except full replacement by rice flour, might not provide adequate zinc bioavailability when the effect of calcium and phytate on zinc absorption was collectively considered. Although all composite flours were contaminated with aflatoxins, only the control composed of wheat flour did not meet the EU regulatory threshold (4.0 µg/kg) for total aflatoxins. The findings showed that nutritional properties and aflatoxin content of composite flours can be improved by replacement with local crops.

Genetic diversity analysis of Thai indigenous chickens based on complete sequences of mitochondrial DNA D-loop region.

OBJECTIVE: Complete mtDNA D-loop sequences of four Thai indigenous chicken varieties, including Pra-dhu-hang-dam (PD), Leung-hang-khao (LK), Chee (CH), and Dang (DA) were explored for genetic diversity and relationships with their potential ancestor and possible associates to address chicken domestication in Thailand. METHODS: A total of 220 complete mtDNA D-loop sequences of the four Thai indigenous chicken varieties were obtained by Sanger direct sequencing of polymerase chain reaction amplicons of 1,231 to 1,232 base pair in size. A neighbor-joining dendrogram was constructed with reference complete mtDNA D-loop sequences of Red Junglefowl (RJF) and those different chicken breeds available on National Center for Biotechnology Information database. Genetic diversity indices and neutrality test by Tajima's D test were performed. Genetic differences both within and among populations were estimated using analysis of molecular variance (AMOVA). Pairwise fixation index (FST) was conducted to evaluated genetic relationships between these varieties. RESULTS: Twenty-three identified haplotypes were classified in six haplogroups (A-E and H) with the majority clustered in haplogroup A and B. Each variety was in multiple haplogroups with haplogroups A, B, D, and E being shared by all studied varieties. The averaged haplotype and nucleotide diversities were, respectively 0.8607 and 0.00579 with non-significant Tajima's D values being observed in all populations. Haplogroup distribution was closely related to that of RJF particularly Gallus gallus gallus (G. g. gallus) and G. g. spadiceus. As denoted by AMOVA, the mean diversity was mostly due to within-population variation (90.53%) while between-population variation (9.47%) accounted for much less. By pairwise FST, LK was most closely related to DA (FST = 0.00879) while DA was farthest from CH (FST = 0.24882). CONCLUSION: All 4 Thai indigenous chickens are in close relationship with their potential ancestor, the RJF. A contribution of shared, multiple maternal lineages was in the nature of these varieties, which have been domesticated under neutral selection.

Morphological variation in brain through domestication of fowl.

Great variations in the size, shape, color, feather structure and behavior are observed among fowl breeds. Because many types of domestic fowls have been bred for various purposes, they are ideal to assess the relationship between brain morphology and avian biology. However, little is known about changes in brain shape that may have occurred during fowl domestication. We analyzed the brains of red jungle fowl and domestic fowl to clarify differences in the brain shape between these breeds, as well as the shape changes associated with size enlargement using three-dimensional geometric morphometrics. Principal component and multivariate regression analyses showed that ventrodorsal bending, anteroposterior elongation and width reduction were significantly correlated with brain size. According to the size-dependent analysis, the red jungle fowl brain has an intermediate shape between the brain of young broilers and that of large domestic fowl and adult broilers. After the size effect is removed, geometric morphometric analyses show that the brain of red jungle fowl is different from that of domestic fowl, with large round cerebral hemispheres. Significant correlations exist between the skull length and brain volume among fowl, while the brain volume relative to the skull length is distinctly larger in red jungle fowl compared with domestic fowl. The distinct brain shape and increased relative brain size of red jungle fowl may be driven by the presence of large, rounded cerebral hemispheres.

Chicken primordial germ cell motility in response to stem cell factor sensing.

Avian primordial germ cells (PGCs) are destined to migrate a long distance from their extra embryonic region via the vascular system to the gonadal ridges where they form the germ cells. Although PGC migration is crucial for a genetic continuation to the next generation, the factors and mechanisms that control their migration remain largely unknown. In the present study the chemotactic effect of stem cell factor (SCF) was examined on chicken blood circulating PGCs (cPGC), employing 3D chemotaxis slides and time-lapsed imaging analyses as an in vitro study model. Upon in vitro exposure to an SCF gradient, 77.1% (54 out of 70) of cPGCs showed a clear response, of which 48.1% (26 out of 54) polarized with the consecutive formation of a persistent membrane protrusion and significant directional migration towards the gradient and the others showed transient membrane protrusions. In contrast, the controls and apparently SCF unresponsive cPGCs and c-kit-negative red blood cells (RBCs) showed only cytoplasmic cycling with random formations of membrane blebbing and no directional migration. Significant (p < 0.05) differences between the SCF-treated and control cPGCs and RBCs were found in the migration parameters of eccentricity, accumulated and Euclidean distances, and migration velocity. The SCF-treated PGCs also revealed a chemotactic response, as judged by their significant displacement of center of mass and Rayleigh test. Complete inhibition of all the SCF-induced responses in PGCs was found following pretreatment of the cPGCs with 10 µM of the c-kit inhibitor, STI57l, prior to SCF exposure. In addition, cPGCs were found to be positive for c-kit expression using a polyclonal goat anti-mouse c-kit primary antibody, suggesting that the cPGCs were capable of SCF sensing and the potential involvement of SCF/c-kit in the chemotactic migration. Therefore, SCF is suggested to function as a chemoattractant in the migration of chicken cPGC.