The aim of the current pathomorphological study was to find out the prevalence of various pathological conditions of the axial skeleton associated with posterior paralysis in commercial broiler chickens at a farm over a prolonged period. Cases of clinical posterior paralysis at a commercial broiler chicken farm were registered over a one-year period of research. Of the examined 36 broiler flocks, signs of posterior paralysis were found in a total of 1480 (0.21%) chickens from 23 flocks. In 22 of these flocks, the chickens with posterior paralysis were recorded, marked, and put in an isolation premise where they were kept with access to food and water until the respective flocks were to be processed. In one of the flocks, posterior paralysis was found in 71 chickens at the age of 34 days in association with an outbreak of femoral head necrosis (FHN), arthritis, and osteomyelitis, which were also isolated. During the period of isolation, 13 of these chickens died, and the surviving 58 were processing at a processing plant. A total of 151 vertebral columns were randomly collected from 6 isolated chicken carcasses from each of the 23 flocks at the processing plant, which had exhibited posterior paralysis, as well as following autopsy of the 13 chickens that had died from the isolation premise of the flock where simultaneous occurrence of FHN, arthritis, and osteomyelitis was observed. The samples were submitted to gross, histological, radiography, and microbiological examinations. Spondylolisthesis (64; 42.3%), followed by cases of spondylosis with ankylosis, osteosclerosis and fractures (54; 35.8%), vertebral osteomyelitis (19; 12.6%), and osteochondrosis with scoliosis and fractures (14; 9.3%) were the most prevalent conditions.
Taiwan commercial native chickens have played a vital role in the domestic market due to Taiwanese traditional cooking style and culture. This study investigated the genetic characterization and population structure of 10 Taiwan commercial native chicken populations, together with two exotic breeds and one population of red jungle fowl, using 22 microsatellites. The results showed that Taiwan commercial native chickens generally harbored high genetic diversity but lower than that of red jungle fowl population in terms of number of alleles and gene diversity. The neighbor-joining tree revealed a poor resolution with only two branches showing bootstrap values above 70%. Based on Bayesian clustering approach, thirteen populations were inferred into eight distinct clusters namely Game bird, B strain, L2 strain, White Broiler and White Leghorn with an average proportion of membership higher than 0.90 and the values higher than 0.85 for red jungle fowl, Hakka chicken and Hakka strain while four remaining breeds were closely related together. The population structure showed Taiwan commercial native chickens are more admixed, in contrast to occidental highly productive breeds. The high genetic variation within breed as shown in the results of the analysis of molecular variance, facilitated by gene exchanges, did not allow discriminating in an efficient way. This suggests that the genetic pool of Taiwan commercial native chickens is well distributed among breeds and therefore there is a good potential for adaptation to new environmental conditions or markets. Some populations, namely L2 strain and B strain showed very high inbreeding coefficient and thus could be considered at risks. Therefore, management needs to be taken into account for the populations, to prevent inbreeding depression and maintain genetic diversity.
Fatty acid-binding proteins (FABPs) are members of lipid-binding proteins that participate in lipid uptake and intracellular transport. This study was designed to investigate the effects of the liver bile acid-binding protein (L-BABP) and the liver fatty acid binding protein (L-FABP) genes on chicken growth and body composition traits. Three SNPs (SNP1, SNP2 and SNP3) of the L-BABP and six SNPs (SNP7-SNP9, SNP11-SNP13) of the L-FABP were detected firstly by DNA sequencing. Seven SNPs (SNP6 and SNP15-SNP20) of the L-FABP were detected by DNA sequencing and were found in the chicken genomic databases at the same time. Sequenom MassARRAY was developed to genotype 966 birds from the Northeast Agricultural University F2 (NEAUF2) resource population and the Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF) population. Linkage disequilibrium analysis showed that the L-BABP SNPs appeared to be strongly linked with each other and were located within a haplotype block in both populations. SNP7 and SNP8, SNP12 and SNP13, SNP19 and SNP20 of the L-FABP were in strong linkage disequilibrium, respectively. The L-BABP polymorphisms were significantly associated with body weight (BW) (P<0.05) in the NEAUF2 and the NEAUHLF populations and abdominal fat weight (AFW) and abdominal fat percentage (AFP) (P<0.05) in the NEAUHLF population. The L-BABP diplotypes were significantly associated with BW (P<0.05) in the NEAUF2 and the NEAUHLF populations. There was no consistent association between the thirteen SNPs of the L-FABP and the growth and body composition traits in either the NEAUF2 or the NEAUHLF populations. The research suggests that the L-BABP could be a candidate locus to affect growth traits in chickens.
Hybrid sterility is a postzygotic reproductive isolation mechanism that prevents successful interbreeding between different species. The mule duck, an intergeneric F1 hybrid between the domestic duck (Anas platyrhynchos) and Muscovy duck (Cairina moschata), displays sterility with gametogenesis failure in both sexes. Although the F1 hybrid male is known to exhibit large-sized testes that produce no sperm, the spermatogenic phenotype has not been well described. In this study, we revealed the abnormal meiotic phenotype of the F1 hybrid spermatocytes and dissimilarity in the karyotypes between the two parental species. Histological examination of the F1 hybrid testis showed the accumulation of primary spermatocytes with irregular highly condensed chromosomes in the seminiferous epithelium, whereas secondary spermatocytes and postmeiotic cells were absent and many testicular cells undergoing apoptosis were present. Cytogenetic analyses of spermatogenic cells from the F1 hybrid male revealed that meiosis succeeded in entering pachytene, but failed to progress beyond diakinesis-metaphase I in primary spermatocytes, and that a number of degenerated spermatocytes were present at pachytene. Karyological observations showed morphological differences in chromosome 1 and the Z chromosome between the parental species. These results collectively suggest that the main cause of abnormal spermatogenesis in the F1 hybrid is pachytene and/or metaphase I arrest, which possibly resulted from the failure of homologous chromosome pairing, recombination, and subsequent chromosome segregation due to chromosomal incompatibility between the parental species.
The objective of the present study was to evaluate the temperament of a native Japanese chicken breed (Tosa-Jidori) using the tonic immobility test for the detection of fearfulness. Each chick (2, 5, 10 or 15-day old) was placed on its back on a table and restrained by hand. Thereafter, if the chick lay still, it was then released and observed. The number of inductions and tonic immobility duration was recorded. The duration in the male was shorter than that in the female at 2-day old, whereas higher than that in the female at 15-day old. The duration of tonic immobility was affected by age in the male (P<0.05). There was a positive correlation between them in the male, and a negative correlation in the female. As for the number of induction, no significant differences and tendencies were found between sex and age. These findings demonstrate that Tosa-Jidori chicks show sexual differences in the fear response and further suggest that the temperamental differences may correspond to genetic characteristics of breeds.
Myogenesis is a complex developmental progress in which a variety of transcription factors play essential roles in regulating myogenesis. However, the genetics programs that control myogenesis molecular mechanism are poorly understood. Therefore, meat-breeding and egg-breeding chicken were selected as male parent, Korean quails were used as female parent for hybridizing. To identify differentially expressed genes between the different hybrids, suppression subtractive hybridization (SSH) have been undertaken for generating cDNA collections of representative mRNAs specific to muscle tissue with meat-hybrid versus egg-hybrid. Following SSH, 54 clones were sequenced and analysed through BLASTX. The results showed that 26 Expressed Sequence Tags (ESTs) found no homology while the other 22 ESTs found the homology in GenBank and 4 ESTs might have correlation with myogenesis.
This study was conducted to investigate the effects of combination of linseed oil (rich in omega 3 polyunsaturated fatty acid, ω3 PUFA) and palm oil (rich in saturated fatty acid, SFAs) on the growth performance, meat quality, and fatty acid composition of birds under high environmental temperature. Experiment was conducted in summer (average high temperature 31°C). Birds in the positive temperature control group (PTC) and negative temperature control group (NTC) were fed with maize-soybean meal-maize gluten basal diet, the other 4 experimental groups were fed with basal diets containing linseed oil (LO), palm oil (PO), or their combination at the ratio of 3:2 (linseed oil/palm oil, w/w, group LPI) or 2:3 (group LPII), respectively. Results showed that the NTC deleteriously affect the growth performance, carcass quality and fatty acid composition of chickens than PTC group. The growth performance of birds under high environmental temperature was improved by oil supplementation. Furthermore, the combination of both oils achieved a better growth performance than the single oil during 22 to 42 d. Compared with NTC group, the yields of breast, leg and carcass were significantly improved in group LPI. Fatty acid composition of meat was significantly modified by dietary oil, and PUFA, especially ω3 PUFA in meat was increased by linseed oil (P<0.05). However, the MUFA and SFA contents in meat were not positively correlated with their contents in diet. Birds fed with combined oil at the ratio of 2:3 (w/w) achieved better economic results. It was concluded that the combination of linseed and palm oils at 2:3 (w/w) in chicken diets had more positive effect on growth performance, enhanced the n-3 PUFA content in meat, and economically better than single dietary oil.
The aim of this study was to examine the influence of three kinds of grain proteins digested by trypsin on plasma glucose and amino acid concentrations in young chickens. At first, we examined the time course change in the absorption of glucose and amino acids from small intestine after oral administration of glucose and amino acid solution. At 0, 20, 40, 60, 80, 100 and 120 min after administration, blood samples were taken from the mesenteric vein, and plasma concentrations of glucose and amino acids were measured. Plasma glucose concentration reached to the highest value at 20 min after oral administration, and this value was remained until 120 min. Most of amino acids were showed the highest concentration at 20 min after oral administration. Secondly, the influence of trypsin-digested grain proteins on the absorption of glucose and amino acids from small intestine was examined. Wheat gluten, corn zein and soybean protein were digested by trypsin, and each digested protein was mixed with glucose and amino acid solution. At 20 min after oral administration of mixture solution, blood samples were taken from mesenteric vein. Plasma glucose level was not affected by any protein digesta. The digesta of soybean protein elevated plasma level of histidine compared to that of corn zein. The digesta of wheat gluten increased plasma concentrations of both phenylalanine and proline compared to the control. Thirdly, the interactive effect of glucose and wheat gluten digesta on the absorption of amino acids from small intestine was examined. The increase in the absorption of amino acids by wheat gluten digesta was not influenced by oral administration of glucose. These results suggest that the digesta of grain proteins has the potency to modify the absorption of amino acids from small intestine of chickens.
A six-week trial was conducted to estimate the dose limit of sodium bicarbonate (SB) in the diet of broiler chickens exposed to high ambient temperature. The estimation of SB dose limit was based on the growth performance, blood biochemical parameters and histological observation of the renal tissues of chickens. A total of 450 day-old male broilers were randomly distributed to five groups with SB supplemented at levels of 0 (control), 0.5%, 1.0%, 2.0% and 4.0%. The minimum and maximum average ambient temperatures were 26.4°C and 32.5°C, respectively, with relative humidity ranging from 57.2% to 83.8%. Results showed that (1) A linear effect of increasing dietary SB level was observed on body weight gain (BWG) (P<0.05), feed intake (FI) (P<0.05) and feed to gain ratio (F:G) (P<0.05) from day 1 to 21 and day 1 to 42. Supplementation of 4.0% SB decreased BWG (P<0.001) and FI (P<0.001), but increased F: G (P<0.001) from day 1 to 21, and decreased FI (P<0.001) from day 1 to 42. (2) Compared with the control treatment, an SB of 4.0% gave higher incidences of diarrhea (P<0.001), mortality (P<0.001) and ascites related mortality (P<0.001). (3) Rectal temperatures were linearly decreased (P<0.05) with rising SB levels. (4) Blood biochemical analysis indicated that SB higher than 1.0% decreased blood hemoglobin (HGB) (P<0.001), and increased hematocrit (HCT) (P<0.001) and serum malondialdehyde (MDA) concentration (P<0.001) on day 21. (5) Microscopic examination revealed that significant renal haemorrhage appeared when SB exceeded 1.0% and tubular dilation was observed in 4.0% SB treatment. In summary, dietary supplementation of 4.0% SB resulted in poor growth performance and higher mortality. In addition, SB higher than 1.0% affected blood biochemical parameters and caused renal lesions. The current results suggest that the dose limit of dietary SB is less than 1.0% for broilers under high ambient temperatures.
An experiment with 495 one-day-old male broiler chicks was conducted to investigate the effects of different dietary levels of canola meal (0, 10, 20%) and copper (0, 125, 250 mg/kg) on performance, carcass characteristics and some blood parameters. A completely randomized design with 3×3 factorial arrangement was used with 5 replicates from 1 to 42 of age. Feed intake was not significantly affected by treatments during 1 to 21 d, 21 to 42 d and throughout the study (P>0.05). The body weight gain and feed conversion ratio was significantly impaired (P<0.05) when 20% canola meal was added in the diets between 1 to 21 d. Addition of copper significantly improved body weight gain (P<0.01) and feed conversion ratio (P<0.05) of the birds during the 21 to 42 d and throughout the study. Carcass yield significantly (P<0.05) increased due to addition of 250 mg/kg of copper. Proportion of thyroid glands (P<0.0001), breast, liver, gizzard, pancreas and cecal significantly (P<0.05) were affected by 20% canola meal. Plasma alkaline phosphatase and blood glutathione peroxidase activities were unaffected (P>0.05) by dietary treatments. An added level of 20% canola meal was significantly reduced plasma zinc concentration. Levels of copper supplementation increased (P<0.001) plasma copper and decreased (P<0.05) plasma zinc levels. Plasma lipids altered by supplementation of copper, so that decreased plasma triglycerides (P<0.01) and cholesterol (P<0.05) concentrations and also increased high density lipoprotein (P<0.05). In conclusion, the results of this study indicate that no effects of added canola meal up to 20% of the diet on the growth performance. In addition from this study it can conclude that supplementation with dietary copper had beneficial effects on growth performance and plasma biochemical characteristics of broiler chickens.
Lines of evidence suggest that hypothalamic neuropeptides have a physiological role in the regulation of food intake in mammals. However, little is known about the age-dependent change of hypothalamic neuropeptides in chicks. In this study, we investigated the age-dependent changes in hypothalamic mRNA levels of neuropeptide Y (NPY, an orexigenic neuropeptide), proopiomelanocortin (POMC, the precursor of anorexigenic neuropeptides), and corticotropin-releasing factor (CRF, a possible mediator in the POMC-induced anorexigenic pathway) in growing broiler chicks. The weights of body and abdominal adipose tissue of chicks were measured at 7, 14, 21, and 28 days of age, and the hypothalamic mRNA levels of NPY, POMC, and CRF were analyzed by real-time PCR. Hypothalamic NPY mRNA levels at 14 and 28 days of age were significantly (P<0.05) lower than that at 7 days of age. Hypothalamic POMC mRNA level at 28 days of age was significantly lower than that at 7 days of age. Hypothalamic CRF mRNA level was not affected throughout the experimental period. Abdominal adipose tissue weight was significantly increased after 14 days of age in chicks. Our findings demonstrated that the expressions of NPY and POMC are dependent on age in boiler chicken hypothalamus.
This study was conducted to examine the effect of feeding concentrated rice-washing water (CRWW) on growth performance and lipid peroxidation levels in broiler chickens. CRWW (89.8% moisture) was dried at either a high (130°C) or low temperature (60°C). Three experimental diets were formulated as follows: 1) control diet; 2) diet containing 20% high-temperature dried CRWW (HT-CRWW); and 3) diet containing 20% low-temperature dried CRWW (LT-CRWW). Twenty-one chicks were divided into a control group and two treatment groups (seven chicks per group) at 15 days of age. The control group was fed the control diet, and the treatment groups were fed either an HT-CRWW or LT-CRWW-containing diet for 12 days. The growth performance (body weight, weight gain, feed intake, and feed efficiency) and the weight of the pectoral muscles were not different between treatment groups. Both HT-CRWW and LT-CRWW had a higher total polyphenol content and free radical scavenging activity than corn meal. Malondialdehyde (MDA) content, a marker of lipid peroxidation, was significantly lower in the skeletal muscle of chicks fed the HT-CRWW-containing diet compared with chicks fed the control diet; however, MDA content in chicks fed the LT-CRWW-containing diet did not differ from that of controls. CRWW has promise as a high-energy feed resource, and CRWW dried at high temperatures might affect lipid peroxidation in broiler chickens through higher antioxidant activity.
Relationships between physiological variables of middle and late post-hatch broilers with their corresponding egg and embryo variables were examined. Sixty Ross×Ross 708 broiler hatching eggs were randomly set on each of 8 replicate tray levels of an incubator. On 10.5 d of incubation, transponders were implanted in the air cells of 4 embryonated eggs per replicate for determination of internal egg temperature (Temb) through d 18.5. On d 18.5, the implanted embryonated eggs were transferred to a hatcher unit where they were monitored for hatch every 12 h. Incubation length, eggshell water vapor conductance (GH2O), specific GH2O (gH2O; GH2O adjusted to a 100 g set egg weight basis), and GH2O constants (KH2O) of the embryonated eggs were determined. Chicks were placed in corresponding replicate floor pens and were grown out from 0 (21.5 d of incubation) to 48 d of age. On 28 and 48 d post-hatch, approximately 2 birds per pen were necropsied for determination of BW, and the relative weights and moisture concentrations of their liver, breast muscle, and left gastrocnemius muscle. Breast muscle moisture concentration on d 28 was negatively correlated with GH2O, gH2O, and KH2O, and breast muscle moisture concentration on d 48 was negatively correlated with incubation length. However, relative body and breast muscle weights on d 48 were positively correlated with gH2O and KH2O, and relative BW on d 48 was positively correlated with incubation length. More importantly, relative breast muscle weight on d 48 post-hatch was negatively correlated with Temb. The variables Temb, GH2O, gH2O, and KH2O may differentially influence the physiological variables in birds during the middle and late post-hatch grow out periods, and bird metabolic and hydration statuses may be adjusted later during the post-hatch period, so that bird BW will eventually reach its genetically predetermined level.
To elucidate biochemical mechanisms underlining high plasma glucose in chicken embryo, gene expression profile of gluconeogenic key enzymes were characterized. The liver and skeletal muscle were collected from 13- to 21-day embryos (E) (n＝8) of layer chicken and the mRNA of pyruvate carboxylase (PC), cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C), mitochondrial phosphoenolpyruvate carboxykinase (PEPCK-M), muscle-type fructose-1,6-bisphosphatase (mFBPase), liver-type fructose-1,6-bisphosphatase (lFBPase) and glucose-6-phosphatase (G6Pase) were measured by real-time PCR. All the enzymes were expressed in the liver, whereas in the skeletal muscle, only mFBPase and G6Pase were detected. In the liver, all the enzymes except for G6Pase peaked either on E13 or E15. G6Pase expression was the highest between E15 and E19. In the skeletal muscle, mFBPase peaked on E19 and G6Pase peaked on E15. These results suggest that gluconeogenesis is active in chicken embryos but regulations of mRNA expressions of the gluconeogenic key enzymes are different between liver and muscle. The results also suggest that the skeletal muscle, which is generally not regarded as a tissue conducting an active gluconeogenesis, may contribute to the regulation of embryonic plasma glucose to some extent, and warrant further investigations of the presence of enzyme activities.
Pattern recognition receptors play an important role in distinguishing foreign organisms and triggering host defense responses. In this study, we present evidence for differential immune responses in chicken monocytes exposed to the mannose receptor (MR) ligands mannan and horseradish peroxidase (HRP). In our study, mannan significantly up-regulated the expression of the MR gene at a high concentration of 200 μg/ml, but HRP did not. In stimulation experiments, neither mannan nor HRP induced nitric oxide (NO) production or stimulated cytokine (IL-1β, IL-6, and IL-10) gene expression. A concentration of 200 μg/ml mannan induced a significant increase in Toll-like receptor 2 (TLR2) gene expression. The gene expression of TLR1 and 3 was significantly up-regulated by different HRP concentrations. In contrast to TLR1 and 3, TLR4 exhibited a significant decrease in gene expression in a dose-dependent manner. These results may suggest that MR ligands affect the innate immune response of TLRs in chicken monocytes.
A study was conducted in order to investigate quality traits and sensory properties of frozen broiler breast meat pretreated with increasing concentration (from 0 to 2%) of sodium chloride (salt). Meat samples were obtained in a single major commercial processing plant from a homogenous flock of chicken broilers (Cobb strain, 44 days-old, mixed sex, average live weight of 2.55 kg). Whole breasts were collected at random immediately after chilling and fillets (P. major muscles) were deboned by hand. A total of 12 groups of fillets were subsequently salted by hand with 0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0% of sodium chloride, packaged in bags, quickly frozen in the processing plant and stored at －24°C for 3 months. Prior to analysis, fillets were thawed at 2-4°C for 72 h and 12 fillets per group were used to determine chemical-physical characteristics (pH, colour, and sodium chloride content), functional properties (drip loss, cooking loss on raw and minced meat, AK-shear force, TBARS analysis) and sensory traits (level of tenderness, level of juiciness and overall liking). The addition of salt determined significant modifications of overall chemico-physical traits of the meat with special regards to pH, colour, water holding capacity and texture. Increased levels of salt determined a higher pH, darker colour, superior water holding capacity (assessed by drip and cooking losses), and higher tenderness (lower AK-shear values). The maximum improvement of water holding capacity was observed for salt level higher than 1.2%. Inclusion of salt up to 2% did not exert a negative effect on lipid peroxidation. Sensory test evidenced higher scores of overall preference of meat starting from 0.8% salt concentration; highest scores of tenderness, juiciness and overall preference in meat samples with high salt content (1.6 and 2.0% groups) were observed.