The Tosa-no-Onagadori (briefly Onagadori) is one of the native Japanese chickens that is characterized by extremely long tail feathers in males, and thus designated as a “Special National Natural Treasure” of Japan. We investigated the timing of sexual maturity of the Onagadori and White Leghorn hens and the quality of the first 10 eggs laid by these young hens to obtain basic information for reproducing the Onagadori efficiently and also to assess their usefulness as research material for quantitative trait loci (QTL) analysis of egg-related traits. Onagadori and White Leghorn hens reached sexual maturity at around 237 and 192 days of age, respectively. The repeatability, a genetic parameter, of 22 egg quality traits including weight, size, and color of the eggshell, albumen, and yolk was estimated to be 0.14-0.61 and 0.15-0.83 for the Onagadori and White Leghorn, respectively, which indicated the stability of Onagadori eggs as well as the White Leghorn and further suggested that young Onagadori hens lay eggs with suitable quality to produce more offspring from their earliest egg laying stage. Principal component analysis with the 22 egg quality traits revealed five principal components explaining 79.70% of the total phenotypic variance. One-way ANOVA revealed differences between the two breeds in PC2 (heights of the albumen and yolk, size of the whole egg, and weights of the whole egg and albumen), PC3 (eggshell color), and PC4 (weight, thickness, and strength of the eggshell), which means that besides cultural assets the Onagadori is also valuable for QTL analysis of egg-related traits, for which phenotypic differences are quite useful for detecting corresponding loci.
The Kurokashiwa breed of native Japanese chickens is primarily reared in Shimane and Yamaguchi Prefectures, Japan. To reveal the genetic diversity and differentiation among the Kurokashiwa populations in both prefectures, 29 microsatellites were analyzed. To prepare the microsatellites, 54, 55, and 24 blood samples were collected from the Kurokashiwa populations of five fancy breeders in Shimane Prefecture, three fancy breeders in Yamaguchi Prefecture, and the Livestock Technology Research Department, Yamaguchi Prefectural Agriculture and Forestry General Technology Center (LTRDY), respectively. The corrected number of alleles (allelic richness: AR) was considerably low (1.63-2.48) through all Shimane and Yamaguchi populations. However, inbreeding coefficient (FIS) values were not significant in the entire Shimane and Yamaguchi ornamental populations as well as the LTRDY population. In addition, there was no statistically significant difference in expected heterozygosity (HE) through all populations in Shimane and Yamaguchi Prefectures, although the HE varied from 0.237 to 0.445 depending on populations. The topology of the phylogenetic tree, pairwise FST values, and STRUCTURE analysis indicated that Kurokashiwa populations were genetically separated between Shimane and Yamaguchi Prefectures. On the other hand, there was no genetic differentiation among ornamental populations within each prefecture, which seemed to have resulted from adequate random matings by exchanging individuals among fancy breeders within each conservation community, along with a proper random mating within LTRDY. The present study proposes a conservation strategy suggesting that the Kurokashiwa populations of Shimane and Yamaguchi Prefectures should be maintained separately with continuous exchange of birds within each conservation community to preserve genetic diversity. Also, the LTRDY population should be independently kept by avoiding matings with ornamental bird populations because it is a well established closed colony with a uniform genetic constitution.
Genetic variation and phylogenetic relationships among 76 birds belonging to Indian Red Jungle Fowl (RJF) and three domestic chicken breeds viz. one Indian native sport breed, Aseel (AS) and two global high yielding breeds of egg type, White Leghorn (WL) and meat type, Red Cornish (RC) were evaluated using Amplified Fragment Length Polymorphism (AFLP) markers. A total of 318 scorable dominant AFLP bands in the range of 50-500 bp using 20 EcoRI/TaqI primer combinations were detected across populations. The mean number of polymorphic bands across all four populations was 15.5 per primer combination. Species-specific bands were also found in all populations except WL. Nei’s gene diversity was measured between RJF and domestic chickens and it was significantly higher in RJF population (0.309) as compared to the domestic chicken populations of AS (0.129), WL (0.067) and RC (0.066). RJF showed maximum genetic distance with RC (0.221) and minimum with AS (0.177) population. The divergence between RJF and domestic chicken was observed by constructing an UPGMA dendrogram. RJF was present in one cluster and whereas the three domestic chickens were tightly clustered in another group. This clustering pattern was also confirmed by principal component analysis (PCA). The estimate of genetic identities (GI) and genetic distances (GD) using Nei (1972) also suggest comparatively more closeness of RJF with AS (an Indian native chicken breed) than those of commercial breeds WL and RC. These results support the earlier understanding that chicken was first domesticated for game purpose rather than as food.
The present study investigated the effects of dietary arginine (Arg) supplementation on immune functions of broiler chickens inoculated with infectious bursal disease vaccine (IBDV). A total of 500 one-day-old female Ross (308) broilers were randomly assigned into 10 treatments (5 replicates per treatment, 10 birds per replicate). On day 14, birds were inoculated intramuscularly with IBDV or saline. Birds were fed diets containing one of five dietary Arg concentrations: 9.9, 13.9, 17.6, 21.3, or 25.3 g/kg respectively. The IBDV inoculation significantly reduced (P<0.05) serum lysozyme and IgA concentration, mitogen-stimulated peripheral blood mononuclear cell (PBMC) proliferation (Con A), PBMC in vitro NO and H2O2 yield, and serum anti-Newcastle disease virus (NDV) body titers. Increasing Arg concentration linearly increased (P<0.05) serum lysozyme concentration, quadratically increased (P<0.05) in vitro PBMC NO yield, linearly and quadratically increased (P<0.05) PBMC proliferation (LPS). Serum anti-IBDV antibody titers tended to be increased quadratically (P＝0.06) by increasing Arg concentration. The Arg requirement of IBDV inoculated chickens (18.9±0.5) for minimum FCR was higher (P<0.05) than that of un-inoculated chickens (16.0±1.3). The Arg requirements of IBDV inoculated chickens for the highest IgA concentration (17.5±0.6 g/kg) and PBMC proliferation (LPS) (19.8±2.1 g/kg) tended to be higher (P<0.10) than those for un-inoculated chickens (IgA: 16.1±0.6 g/kg; PBMC proliferation (LPS): 16.3±0.8 g/kg). These results indicate that dietary Arg supplementation may have a potential effect in alleviating IBDV-inoculation induced immunosuppression via enhancing the immune function of chickens.
We have previously shown that, under thermoneutral conditions, the growth performance of chicks fed a rice-based diet containing 6% soybean oil [metabolizable energy (ME): 2,800 kcal/kg] for 28 days was comparable to that obtained with a corn-based diet containing 6% soybean oil (ME: 3,100 kcal/kg). However, there is no information available concerning how such diets compare with respect to growth performance under heat stress conditions. The present study was therefore conducted to clarify differences in dietary effectiveness between corn-based and whole-grain paddy rice-based diets [formulated to be equivalent in terms of fat (6%), but not iso-caloric] under the two conditions of acute and chronic heat stress (Experiment 1 and Experiment 2, respectively). In Experiment 1, the body weight gain of a corn- and rice-fed group of chickens exposed to acute heat (33°C-12 h) were significantly decreased compared with that of a corn-fed control group (24°C), with similar results obtained for the two heat-treated groups. Malondialdehyde (MDA) levels in the M. pectoralis superficialis were significantly increased in corn-fed birds exposed to acute heat stress, but not in the rice-fed group (33°C-12 h). In Experiment 2, body weight gains in the corn- and rice-fed groups exposed to chronic heat (33°C-6 d) were significantly decreased, and to a similar extent, compared with the corn-fed control group (24°C). Muscle MDA levels in the corn- and rice-fed groups were similarly increased by the chronic heat exposure compared with the control group. These results suggest that, in response to acute heat stress (but not chronic heat stress) conditions, the feeding of whole-grain paddy rice diet to chickens may attenuate skeletal muscle oxidative damage compared with that in corn-fed chickens. The possible involvement of intestinal morphology (such as the villus height: crypt depth ratio observed here) on growth performance is also discussed.
In the present study, the effect of dietary supplementation of mixed fermented medicinal plants (FMP) on growth performance in broilers and whether FMP have potential to serve as antibiotic growth promoter (AGP) alternatives was investigated. A total of 765 1-d-old male broiler chicks (ROSS strain) were used in a 5 wk feeding experiment and randomly divided into 5 groups with 9 replicates of 17 birds each. The treatments were NC (negative control, basal diet), PC (positive control, basal diet with 5 ppm enramycin), FMP 0.05 (basal diet with FMP 0.05%), FMP 0.1 (basal diet with FMP 0.1%), and FMP 0.2 (basal diet with FMP 0.2%). Both body weight gain and feed conversion ratios were improved, as compared with NC or in response to FMP supplementation, respectively. Additionally, dry matter and nitrogen retention, metabolizable energy, and excreta noxious gas emission of ammonia, hydrogen sulfide, and total mercaptans were improved as compared with NC or in response to FMP supplementation, demonstrating a positive correlation. The amount of intestinal microflora was improved (increased Lactobacillus spp counts and reduced E.coli counts) as compared with NC, PC, and a dose response increase of FMP supplementation, in both the small and large intestines. Taken all together, our results suggest and support the viable possibility that FMPs supplementation can be used as an effective alternative to AGPs for improving the performance of broilers.
This study was conducted to evaluate the effects of supplementing methionine (Met) and lysine (Lys) in low protein (Low-CP) diet during 1-21 days of age, and subsequent re-feeding with conventional diet during 22-42 days of age on growth performance, serum lipid profile, chemical body composition and carcass quality of broiler chickens. During 1-21 days of age (starter period), 480 male broiler chicks (Ross 308) were divided into three treatments and given the following diets: 1) conventional diet group (all nutrients met the requirements of the strain), 2) Low-CP diet without Met and Lys supplementation and 3) the Low-CP diet supplemented with Met and Lys (Low-CP+Met+Lys). During the finisher period (22-42 days of age), all groups were fed a diet containing the same nutrients in accordance with the recommendations of the strain. At 21 days of age, Low-CP+Met+Lys diet showed significantly better growth performance and breast meat yields than those of the Low-CP diet group. Feed and protein intake of the chicks fed conventional diet was significantly higher than both of the other groups (P<0.01), whereas Low-CP+Met+Lys diet clearly improved protein efficiency (P<0.01). Feeding Low-CP diet increased abdominal fat content and body energy content (P<0.05), while the supplementing synthetic amino acids slightly decreased the fat content. Triglyceride, very low density lipoprotein (VLDL) and T3 hormone in blood were significantly increased in Low-CP+Met+Lys diet group compared to the conventional diet (P<0.05). After the re-feeding phase, feeding Low-CP diet groups were unable to compensate body weight equal to the conventional diet, although a compensation of FCR was observed. Feeding Low-CP+Met+Lys diet showed the same breast meat yield compared to the conventional diet, but abdominal fat, triglyceride and VLDL in blood were significantly increased (p<0.05). In conclusion, supplementing Met+Lys in Low-CP diet improved performance production, but was still inferior to the conventional diet.
This study was conducted to investigate the effect of hatching weight (HW) on the growth, immunity and oxidative status of broilers for 21 d. Male chicks (Arbor Acres) were divided into 2 groups according to HW (51.30±0.21 and 42.97±0.11 g, respectively), each of which consisted of 8 replicates of 10 birds. Chicks with high HW exhibited heavier body weight in the first two weeks (P<0.05). Concentrations of total protein (TP), globulin (GLB) and albumin (ALB) were higher in broilers with heavier HW at d 14, 14 and 7, respectively (P<0.05). At d 7, heavier chick exhibited a higher liver glutathione (GSH)/oxidized glutathione (GSSG) ratio (P<0.05), which may result from simultaneously decreased GSSG content (P＝0.092). Meanwhile, a trend for decreased serum malondialdehyde (MDA) (P＝0.055) and total corticosterone (CORT) content (P＝0.086) was observed in heavier chicks. In addition, heavier chicks tended to have a higher serum GSH content at d 21 (P＝0.063). A higher HW would exert a significant effect on the body weight and oxidative status of broilers but not on nutrient digestibility and immune function at immediate posthatch, which then gradually disappeared as birds grew older.
Infectious bursal disease (IBD) is a viral disease of young chickens that produce severe lesions in the bursa of Fabricius and other organs inducing immunosuppression and mortality in birds. This study indicates that oral administration of IFN-α and IL-2 during 16 days produced a significant reduction in animals’ morbidity and mortality to IBD virus (IBDV) infection accompanied with a decrease in symptoms and bursal tissue damage. The treatment also increased body weight, not only in birds challenged with IBDV, but also in uninfected controls. Infected birds treated with cytokines presented the same bursal index and organs’ weight that controls; since untreated animals showed a significant decrease in these parameters. Finally, cytokine administration represents a new alternative to IBDV vaccination.
This study was conducted to characterize avian encephalomyelitis (AE) viruses obtained from various flocks of breeder and commercial chickens in South Korea. Young chicken less than 4 weeks old showed neurological sign were diagnosed as typical AE infection between 2006 and 2011. In 2013, idiopathic AE occurred on the unvaccinated 79 day-old chickens that had clinical signs of ataxia and paralysis. Phylogenetic analysis of viral protein 2 genes of AE viruses showed that all AE field viruses tested were genetically similar to vaccine strain [Calnek 1143]. In the embryo-inoculation test via the yolk sac, only one field strain and one commercial vaccine were embryo-adapted. The results indicated that the AE outbreaks in South Korea were caused by strains genetically similar to vaccine strain indicating possibility of vaccine breakdown or persistence in the chicken population.
The aim of this study was to compare the bioactive and taste-related compounds in defatted freeze-dried chicken soup (DFDS) made from Korean native chickens (WoorimatdagTM, KNC) and commercial broilers (CB) available at retail. The betaine, carnitine, histidine dipeptide, creatine, nucleotide, free amino acid content, and fatty acid composition were analyzed in six DFDS samples from each breed. Histidine dipeptides were not detected in any DFDS samples. DFDS made with KNC had significantly higher betaine, carnitine, inosine-5′-monophosphate, inosine, and cysteine content compared to that prepared from CB. Furthermore, lipid layer separated from soup made with KNC showed a significantly higher linoleic, α-linolenic, arachidonic, and docosahexaenoic acid content, and lower saturated fatty acid content. In addition, DFDS from CB possessed a higher valine, isoleucine, leucine, phenyalanine, methionine, creatine, and hypoxanthine content than that from KNC. Our findings suggest that DFDS from KNC was qualitatively superior due to enhanced nutritional and taste-related factors compared to that made with CB.