The present study aims to investigate the maternal origin and genetic diversity of laying-type Japanese quail lines based on partial sequences (453 base pairs) of a mitochondrial DNA (mtDNA) control region. A total of 478 individuals from 12 lines were sequenced and six different haplotypes with eight variable sites were identified. All haplotypes, two of which were identical to previously reported sequences, were typical for the Japanese quail (Coturnix japonica) and were distinct from those of the common quail (Coturnix coturnix) in a phylogenetic analysis including other published haplotypes. One haplotype was distributed in the majority of individuals (84.9%, 406/478) across all lines. Within each line, 72.5–100% of individuals had this predominant haplotype. The second most common haplotype was detected in 12.8% (61/478) individuals. These two haplotypes accounted for 97.7% of all individuals. The remaining four haplotypes were distributed with a low frequency; these were observed in five, three, two, and one individuals across all lines, respectively. All lines showed a low degree of haplotype diversity ranging from 0.0000 to 0.4321. Genetic differentiation indexes (FST) were not significant in approximately 80% pairwise comparisons of lines. The results suggest limited maternal origin and low mtDNA diversity of laying-type quail lines and may reflect their breeding history where the present gene pool was rooted in a small number of founders.
This study evaluated the antioxidant capacity of Ricinus communis L. (RC) leaves and powder when used as a feed additive for laying hens. Results showed that the total phenolic content of the aqueous leaf extract of Ricinus communis L. (RCE) was 48.39 mg gallic acid equivalent (GAE) per gram dry weight (DW). The flavonoid content was 9.76 mg quercetin dihydrate equivalent (QE)/g DW. Ferrous chelating activity was approximately 56.2% with an RCE concentration of 1 mg/mL; the highest chelating activity was 91.2% with 4 mg/mL extract. The reducing power of 1 mg/mL RC was 1.17 times better than 1 mg/mL butylated hydroxytoluene (BHT). The Trolox equivalent antioxidant capacity (TEAC) value of 12.5 mg/mL RCE was equivalent to 3.09 mg/mL Trolox. RCE (10 mg/mL) had a lipid oxidative inhibition capacity of 35.3%. A total of 80 ISA brown laying hens at twenty-nine weeks of age were randomly allocated into the control or 1 of 3 treatment groups; the latter received 0.5%, 1% or 2% of RC, respectively, for 12 weeks. Results showed that the RC supplementation improved the feed conversion rate and 0.5% RC generated the best results. Additionally, the egg yolk score was significantly increased in all RC-supplemented groups. Moreover, there was no significant difference in serum characteristics between the treatment groups. Serum antioxidant enzyme activity showed that superoxide dismutase (SOD) activity increased in the RC-supplemented groups relative to the control but was not significantly different. mRNA expression levels of the antioxidant regulatory genes GCLC, GST, HO-1, SOD1, and SOD2 were significantly increased with 2% RC supplementation. In summary, RC is a suitable feed additive for laying hens and the addition of 0.5% RC leaf powder resulted in the greatest benefits.
In this study, we aimed to investigate the influence of maternal folate deficiency on the production performance and serum parameters of broiler offspring. The 120 healthy female broilers (30-week-old) were randomly allotted into two groups. The groups were either fed a basal diet supplemented with 2.0 mg/kg folate (NF) or basal diet (FD). The experiment lasted 12 weeks, and 120 fertilized eggs were collected from each group for hatching. In total, 80 chicks were selected from each group and fed under the same conditions. No significant difference was observed in the average daily feed intake, average daily gain, and feed to gain ratio of 21- and 42-day-old broilers between NF and FD groups (P>0.05). Moreover, slaughter performance of 21- and 42-day-old broiler offspring were not affected by the maternal FD. The subcutaneous fat thickness at the age of 21 days increased significantly by maternal FD (P<0.01); however, there was no significant difference between the two groups at 42 days of age (P>0.05). Similarly, no significant differences were detected in the intermuscular fat width, lipid percentage in the liver, breast muscle, and thigh muscle between the NF and FD groups at 21- and 42-days of age (P>0.05). Serum concentrations of MTHFR, DHFR, LEP, IGF2, LPL and HCY in the 21-day-old broilers were not affected by maternal FD (P>0.05), but those of HSL at 21 days of age was enhanced by maternal FD (P<0.05). These findings indicated that maternal folate deficiency had no influence on production performance, slaughter performance, most fat traits of 21- and 42-day-old broiler offspring, and serum parameters of 21-day-old broiler offspring except HSL.
The goal of this study was to evaluate the influences of mannan oligosaccharides (MOSs) and/or Bifidobacterium on the growth and immunity of pigeons over a 56-day period. One hundred paired adult pigeons were randomly divided into four groups of five paired pigeons. Paired pigeons with two young squabs were housed in a man-made aviary. Parent pigeons in the control group received a basal diet (C), while the other three groups were fed with the basal diet supplemented with 20 g of MOSs/kg of feed (M), 10 g Bifidobacterium (1×1010 CFU/g)/kg of feed (B), or a combination of M and B (MB). We found higher body weights (BW) in pigeons of the B group than in the C, M, and MB groups. None of the treatments exerted significant effects involving spleen and thymus indices, whereas M birds tended to improve the bursa of Fabricius index. Pigeons fed with the M-supplemented diet exhibited improved serum immunoglobulin M (IgM) concentrations compared with those fed with C and the B- and MB-supplemented diets. In addition, M treatment increased immunoglobulin A (IgA) levels compared with MB treatment. MB treatment improved serum immunoglobulin G (IgG) concentrations compared to that by the C treatment. The concentration of secretory immunoglobulin A (sIgA) was significantly reduced in the duodenum and increased in the ileum in pigeons fed with the MB-supplemented diet. This study indicated that dietary supplementation with Bifidobacterium increased the growth performance. Dietary supplementation with MOSs or in combination with Bifidobacterium was able to improve immune function in pigeons but exerted no apparent effect on weight gain. Accordingly, in terms of economic benefits, the findings suggested that supplementation with Bifidobacterium alone may improve production performance, and that supplementation with MOSs alone may improve immune function in pigeons.
A study using pair-feeding technique was conducted to determine whether heat exposure directly or indirectly (via reduced feed intake) increases intestinal mucosal damage and permeability to endotoxin in broiler chickens. Male broiler chickens (Ross 308), 27-d-old, were subjected to one of the three treatments (n=8): 1) thermo-neutral conditions (24°C) with ad libitum feed intake, 2) heat stress conditions (33°C) with ad libitum feed intake, or 3) pair-feeding under thermo-neutral conditions, with the feed intake identical to that of heat-stressed chickens. Using these groups, two experiments were performed to evaluate temporal changes in the intestinal morphology in response to each treatment. In experiment 1, chickens were sacrificed after 24 h of exposure to the treatment conditions, while in experiment 2, chickens were sacrificed after 12 or 72 h of exposure to the treatment conditions. In experiment 1, exposure to heat stress conditions for 24 h significantly decreased both the villus height to crypt depth ratio and number of proliferating cell nuclear antigen (PCNA)-positive cells in the duodenum and increased the plasma endotoxin concentration. These findings were not observed in pair-fed chickens. In experiment 2, intestinal integrity and function were unaffected by 12 h of heat stress. On the other hand, chickens exposed to heat stress for 72 h exhibited significantly damaged intestinal morphology in the duodenum as well as increased plasma endotoxin concentration; these negative effects were not observed in pair-fed chickens. These findings suggest that the intestinal morphology and permeability changes observed in chickens that are heat-stressed for 24–72 h are due to the heat stress conditions and not due to reduced feed intake.
Experiments were conducted to evaluate the effect of crude glycerin inclusion in the diets of Betong chicken on the characteristics of their carcasses, internal organs, meat quality, lipid oxidation, and fatty acid profiles. One hundred 1-day-old chicks were raised for 8 weeks. Subsequently, the birds were sexed based on their morphological features, and weighed. Forty-eight male chickens, with comparable body weights, were randomly allotted to receive any of the three experimental diets, containing 0, 50 or 100 g crude glycerin/kg feed, on an as fed basis until they were 20 weeks old. A total of 24 chickens were slaughtered and their carcass characteristics and meat quality were studied. Results showed that carcass characteristics and internal organ parameters were not affected by crude glycerin supplementation (P>0.05). After chilling for 24 h, pH of the meat decreased in all groups (P>0.05), while shear force and cooking loss were not affected (P>0.05). Furthermore, crude glycerin did not affect the parameters such as crude protein, ether extract, ash, moisture and proportions of different fatty acid contents of meat of the Betong chicken (P>0.05). However, breast meat color and lipid oxidation were influenced by crude glycerin in diet (P<0.05). These results suggest that crude glycerin can be used at concentrations up to 10% in Betong chicken diet from 8 to 20 weeks of age. Nevertheless, its effect on breast meat color and lipid oxidation need to be considered.
Neurotensin is secreted from intestinal N cells in response to the food ingestion. Influences of different dietary protein levels on neurotensin-immunoreactive cells in the chicken ileum were examined by using immunohistochemical and morphometrical techniques. The results showed that dietary protein had an obvious influence on neurotensin-immunoreactive cells in the chicken ileum. Four experimental groups were used, with dietary crude protein (CP) levels of 18% (control), 9%, 4.5% and 0%. Enteroendocrine cells showing neurotensin-immunoreactivity were located in crypts and villous epithelium in all groups. Most of the neurotensin-immunoreactive cells in the villous epithelium showed pyramidal or spindle-like shape with a long cytoplasmic process reaching the intestinal lumen, but cells with round or oval shape were found in the CP4.5% and 0% groups. Frequencies of occurrence of neurotensin-immunoreactive cells in the CP18%, 9%, 4.5% and 0% groups were 42.4±3.3, 36.6±2.2, 30.8±2.6 and 25.4±3.8 (cell count per mucosal area: cells/mm2, mean±SD), respectively. There were significant differences in neurotensin-immunoreactive cell frequency between the control and lower CP level, 4.5% and 0%, groups. A significant correlation was found between frequency of occurrence of neurotensin-immunoreactive cells and daily protein intake. These results indicate that ingested protein is likely to be a potential signal for neurotensin production and secretion of N cells in the chicken ileum.
The nasal mucosa plays an important role in the immune system, with nasal mucous cells secreting mucin that, along with pili, exclude foreign substances from intervening. Nasal mucosal-associated lymphoid tissue (NALT), present in the nasal lamina propria, acts as a local immune system. In birds, the Harderian gland in the orbit also plays an important role in the local immune system. In this study, we analyzed the pathway from the nasolacrimal duct to the nasal cavity in chickens and the distribution of the nasal mucous cells responsible for defense mechanisms against pathogens. To determine the three-dimensional structure of the pathway from the nasolacrimal duct to the nasal cavity, we made casts of the anatomy by injecting an acrylic resin into the area. We then prepared paraffin sections to determine the distribution of the NALT and mucous cells. The mucous gland was clearly seen in the mucosal epithelium of the nasal cavity, suggesting that the pathway along the nasal cavity develops a nonspecific immune system to deal with large foreign substances, such as bacteria, using mucins that are secreted from the mucous glands. Hence, there is not only a physical barrier but also an antibacterial activity. Unlike in other animals, morphologically, the nasolacrimal duct in chicken becomes the ventral nasal meatus and opens into the choanae in the caudal portion of the nasal cavity. NALT was prominently present in the lamina propria of the ventral nasal meatus, suggesting the presence of a specific immune system protecting against avian viruses. Thus, responses to vaccine stimulation could be developed from tissues along the pathway of the ventral nasal meatus via the nasolacrimal duct running from the punctum. These morphological studies suggest that the instillation of eye drops could be used as an efficient vaccination method for avoiding respiratory diseases.
The aim of this study was to determine the effects of live probiotics Lactobacillus reuteri (LR) and Clostridium butyricum (CB) on the expression of genes of innate immune system in broiler chick ileum and cecum. Chicks were administered 500 µl water with or without LR or CB, daily from day 1 to 6 after hatching. The ileum and cecum were collected on day 7 for analysis of gene expression of Toll-like receptors (TLRs), pro- and anti-inflammatory cytokines, and antimicrobial peptides (AMPs) using real-time PCR. The expression of TLR2-1 was upregulated by CB in the ileum and that of TLR5 was upregulated by both LR and CB. Expression of IL-1β and TGFβ2 in the ileum and of TGFβ3 and TGFβ4 in the cecum was upregulated by both LR and CB. The gene expressions of avian β-defensin (AvBD) 1 and cathelicidin (CATH) 3 were upregulated by CB and that of AvBD4 was upregulated by LR in the cecum. However, the expression of CATH2 in the ileum was downregulated by LR. These results suggest that probiotic LR and CB treatments affect a part of the innate defense system in the ileum and cecum by modulating the expression of innate immune molecules including TLRs, pro- and anti-inflammatory cytokines, and AMPs.
The skeletal muscle growth rate is a major feature differentiating meat- and laying-type chickens. A large amount of ATP is required during skeletal muscle synthesis, in which mitochondrial energy production capacities play a significant role. Additionally, mitochondria may participate in muscle protein degradation via reactive oxygen species generation. To investigate the differences in mitochondrial energetic characteristics between chickens exhibiting different growth rates, this study evaluated respiratory capacities in response to different types of respiratory substrate, protein abundances, assembly of individual respiratory complexes (I–V) and supercomplexes, and reactive oxygen species generation rates. These characteristics were compared between mitochondria from the breast muscle (M. pectoralis superficialis) of seven-week-old meat- and laying-type male chickens. Blue native polyacrylamide gel electrophoresis analysis revealed that meat-type chickens exhibited a significantly lower protein abundance of complex III (cytochrome bc1 complex), complex V (F0F1 ATP synthase), and total amount of supercomplexes than did laying-type chickens. There were no differences between chicken types in the respiration rate of mitochondria incubated with either pyruvate/malate or succinate, each of which drives complex I- and complex II-linked respiration. Carnitine palmitoyltransferase-1-dependent and -independent respiration during ATP synthesis and carnitine palmitoyltransferase-2 enzymatic activity were significantly lower in meat-type chickens than in layingtype chickens. For mitochondria receiving pyruvate/malate plus succinate, the reactive oxygen species generation rate and its ratio to the oxygen consumed (the percentage of free radical leak) were also significantly lower in meat-type chickens than in laying-type chickens. These results suggested that the mitochondrial energetic capacities of the breast muscle of meat-type chickens could be lower than those of laying-type chickens at seven weeks of age. Furthermore, the lower reactive oxygen species generation rate in meat-type chickens might have implications for rapid muscle development, which is possibly related to their lower muscle protein degradation rates.