A single nucleotide polymorphism (SNP) site, alleles A and C, within promoter region of insulin-like growth factor 1 gene (IGF1) showed significant association with chicken growth, body composition and skeletal traits. In the present study, we performed genotyping of this SNP in Asian native chicken populations, layer and broiler populations using PCR-RFLP and comparison of gene expression level and growth traits among the SNP genotypes. By the PCR-RFLP, allele C frequency was estimated to be within the range of 0.64-1.00 in 12 Asian native chicken populations, 0.48-1.00 in eight layer stocks and 0.00-0.14 in two broiler stocks examined in this study. In all chicken populations, the observed number of each SNP genotype was in good agreement with the Hardy-Weinberg expectations. Body weight (BW), average daily gain (ADG), growth rate and IGF1 gene expression level in three-week liver were compared among three SNP genotypes obtained by AC×AC crossing. The rankings of each genotype with respect to BW, ADG and growth rate were AA>AC>CC, and statistical significance (P<0.05) was found within AA and CC in BW and ADG. The rankings of each genotype with respect to the IGF1 gene expression level was AC>AA>CC. Although we could not find statistically significant difference among the genotypes in the growth rate and the gene expression level, the mean values of CC were lower than those of AA in all traits.
To investigate the mechanism regulating transcription of the prolactin (PRL) gene in avian species, the PRL promoter region in Ceylon junglefowl, Japanese quail, ring-necked pheasant, turkey, Indian peafowl and helmeted guineafowl were cloned and sequenced. In each species, approximately 4,800-5,900bp were sequenced. The PRL promoters of 7 galliformes including red junglefowl were found to have, on average, 91.2% sequence identity over the entire region and 97% sequence identity was observed in the proximal promoter (from the initiation codon (+55) to -130). Moreover, average of sequence identities was 91.6% among 11 avian species (7 galliformes, duck, Java sparrow, budgerigar and ostrich). In the PRL proximal promoter, putative Pit-1 binding site and vasoactive intestinal peptide response element were conserved among avian species. These results suggest that that the mechanisms involved in gene expression of PRL may be conserved in Galliformes.
Experiments were conducted to determine the effect of vitamin A deficiency in chicks on tissue ascorbic acid, plasma oxidant status and antioxidant capacity, and renal L-gulonolactone oxidase activity (GULO) in broiler chickens. Chicks were reared in battery cages and fed a practical diet with vitamin A (control) or the same diet without supplemental vitamin A from day-old to 23 or 30 days of age. The treatments were arranged in a randomized complete block design with 6-8 replications. At termination body weight, feed intake, and tissue weights were recorded and tissues analysed for ascorbic acid, GULO activity, antioxidant activty, and oxidant status. Growth, feed intake, relative weights of bursa of Fabricius, liver, spleen and testis were significantly reduced in vitamin A-deficient chicks. Vitamin A deficiency depressed renal GULO activity by 20% (P<0.08) and 33% (P<0.007) in Experiment 1 and 2 respectively. Bursal, hepatic, splenic, testicular, and plasma ascorbic acid concentrations, plasma total antioxidant activity, and plasma oxidant status were not altered by the decrease in GULO activity. However, plasma advanced oxidation protein products were lower (P<0.02) in vitamin A-deficient chickens. The lack of effect on tissue ascorbic acid and antioxidant capacity suggest that metabolic changes associated with vitamin A deficiency may reduce ascorbic acid excretion. The reduction in plasma advanced oxidation protein products may be ascribed to lower metabolic activity because of hypothyroidism in vitamin A-deficient chicks. In conclusion, short-term vitamin A deficiency in broiler chicks reduced GULO activity without concomittant changes in tissue ascorbic acid.
The experiment was conducted to determine influence of caecectomy on digestibility quantities of amino acids for soybean (SBM), canola (CM), sunflower (SFM) meals in adult Rhode Island Red (RIR) cockerels with using conventional addition method (CAM) for 7 d: a 4-d adaptation and a 3-d experiment period on the basis of a completely randomized design with 4 replicates. In assayed meals, caecectomy decreased (P<0.05) apparent digestibility quantities of amino acids, except for tyrosine, methionine and leucine for CM and arginine and valine for SFM in adult cockerels. The most decrement of apparent digestibility quantity was for phenylalanine (8.9% decrement) in SBM and for cysteine (14.5% and 22.7% decrement, respectively) in CM and SFM. Differences between intact and caecectomised cockerels were (P<0.05) significant for true digestibility quantities of amino acids, except for threonine in SBM, serine and valine in CM and histidine, arginine, threonine and valine in SFM. The most difference in true digestibility quantity was for phenylalanine (11.8%) in SBM and for cysteine (12.8 and 18%, respectively) in CM and SFM. However, caecectomy decreased mean apparent and true digestibility of total amino acid in SBM (3.8 and 3.1%, respectively), CM (3.1 and 3.0%, respectively) and SFM (5.3 and 5.1%, respectively) which this effect was greater for SFM. Therefore, the caecectomy is an effective method for increasing precision in measurements of the digestibility of amino acids for these meals in bioassays based on excreta collection in adult cockerels.
To evaluate the effect of malic acid (MA) on performance and some digestive tract (gut) traits of Japanese quails, 320 quails were divided into 4 treatment groups each with 4 replicates containing 20 birds. While one of groups was fed a mash form basal diet with no additives (0MA), other groups were fed the diets with malic acid at 0.4 (0.4MA), 0.8 (0.8MA) or 1.2 (1.2MA) g/kg from 7 to 42d of age. The weight gains of 0.8MA and 1.2MA birds and the feed consumption of 1.2MA were higher than those of 0MA. Addition of the malic acid to the diets did not affect the feed efficiency. The 0.8MA birds had a higher carcass weight compared to other groups. The 1.2MA birds had a higher gut length compared to the 0MA. The results indicated that feeding diets with malic acid at 0.8 and 1.2g/kg might increase weight gain and feed consumption without affecting feed efficiency and a significant benefit of feeding diet with malic acid at 0.8g/kg compared to the control diet was obtained in terms of carcass weight in the Japanese quails.
A 4×2 factorial experiment of four dietary energy levels (2,776, 2,820, 2,864 and 2,908kcal/kg) and two strains (Bovans White and Dekalb White) was conducted to determine the influence of dietary energy on performance, egg composition, egg solids, and egg quality of two strains of commercial Leghorns during Phase 2 (from 40 to 51 week of age). This experiment lasted 12 weeks. Bovans White hens (n=768) and Dekalb White hens (n=768) at 40 week of age were randomly divided into 16 treatments (8 replicates of 12 birds per treatment). Bovans hens had significantly higher egg production, percent egg yolk, Yolk/Albumen ratio, whole egg solid, and crack eggs than Dekalb hens while Bovans hens had significantly lower egg weight, feed conversion, egg specific gravity, percent shell, Haugh unit, shell thickness, and yolk color than Dekalb hens. With increasing dietary energy hens linearly adjusted feed intake from 105.0 to 101.7g/hen/day to achieve a constant energy intake so that the same amount of dietary energy (5.2kcal) was used to produce 1g of egg. Increasing dietary energy had significant effects on feed conversion, percent yolk, percent albumen, Yolk/Albumen ratio, and dirty eggs. Based on feed conversion, increasing dietary energy to 2,864kcal ME/kg by the addition of poultry oil might be sufficient for optimal performance of laying hens during Phase 2 (wk 40 to 51).
Portomicron remnant and very low density lipoprotein (VLDL) remnant in chickens were prepared by the method using ultracentrifugation (d<1.019) following an in vitro incubation of portomicron or VLDL prepared from chicken plasma with chicken lipoprotein lipase (LPL) for 2h at 37°C. The portomicron remnants and VLDL remnants yielded the almost single peak in the elution pattern on Bio-Gel A50m column (1.6×50cm) and the particle sizes were smaller than portomicron and VLDL since the elution of remnants by Bio-Gel A50m was similar to LDL rather than portomicron and VLDL. Chicken remnants had low triacylglycerol contents with high cholesterol and lower apolipoprotein C contents compared to portomicron or VLDL. These findings present the possible procedure to prepare in vitro chicken LPL-generated portomicron- and VLDL-remnants and suggested that the chicken remnants are characterized by a peculiar apolipoprotein composition while resemble to mammalian remnants in the lipid composition and particle size.
Chicken primordial germ cells (PGCs) circulate in the bloodstream and migrate to germinal ridges. In order to assess the migration frequencies of PGCs to left or right germinal ridges, PGCs were transferred into the bloodstream of recipient embryos and analysed the presence of the donor PGC-derived mitochondrial DNA in the left or right gonad of embryos. First, minimum number of donor PGCs needed to detect donor-derived DNA in the gonads of recipient embryos incubated for 16.5 days were assessed, and found that a single PGC-derived DNA can be detected in the gonads. Then, a single PGC was transferred into the recipient bloodstream and analysed the presence of donor PGC-derived DNA in the left or right gonad of recipient embryos. When male PGCs were transferred into male or female recipient embryos, the donor-derived DNA was detected in the left gonad at the frequency of 61.5% (8/13) or 82.6% (19/23), respectively. On the other hand, when female PGCs were transferred into male or female recipient embryos, the donor-derived DNA was detected in the left gonads at the frequency of 72.2% (27/36) or 91.5% (43/47), respectively. The frequency of male or female PGCs migrating to the left germinal ridge of recipient embryos were 75.0% (27/36) or 83.1% (69/83), respectively, whereas the frequency of male or female recipient embryos attracting PGCs to their left germinal ridge were 69.4% (34/49) or 88.6% (62/70), respectively. These results suggest that female PGCs tended to migrate to the left germinal ridge more frequently than male PGCs, and female recipient embryos tended to attract PGCs in the left germinal ridge more frequently than male recipient embryos. This preferential migration of PGCs to left germinal ridge would be very important for female PGCs to differentiate normally and give rise to functional gametes efficiently.
A novel strategy has been developed to generate muscular dystrophy chickens by means of germline chimeras. Donor embryos were obtained from the New Hampshire chicken; NH-413 strain which have genes responsible for Fukuyama type muscular dystrophy (Saito et al., 2005). Donor cells were isolated from the center of area pellucida of the blastoderms. Recipient embryos were obtained from White Leghorn chicken; Line-M. The generated chimeric chickens had the donor derived brown plumage in the down in some extent, suggesting that the cells containing muscular dystrophy were introduced into the chimeras. These chimeric chickens have been raised until sexual maturity. The chimeric chickens were back-crossed to donor strain; the NH-413 strain. The phenotype of some of the offspring was very similar to that of the donor strain. The offspring showed some characters typical to the muscular dystrophy. It was suggested that the donor derived NH-413 strain offspring was generated. The established system should be one of the powerful strategies for breeding and regeneration of the muscular dystrophy chickens.
Glutathione peroxidase 1 (cellular glutathione peroxidase, EC 220.127.116.11 (GPX1)) is an antioxidant enzyme that plays an important role in scavenging reactive oxygen species to protect cells from oxidative damage. To clone the quail GPX1, total RNA was extracted from mature female quail liver. Degenerated primers were designed based on conserved sequences among five species (human, monkey, cattle, rat, and mouse) to amplify the quail fragment GPX1 with reverse transcription polymerase chain reaction. The cDNA sequence of partial Japanese quail GPX1 is 212 nucleotides in length. The rapid amplification of cDNA ends system (5′ and 3′ RACE) was used to obtain the full-length Japanese quail GPX1 cDNA. The 843-nucleotide quail GPX1 cDNA contains a 153 amino acid open reading frame, a 7bp 5′-untranslated region, and a 377bp 3′-untranslated region containing the poly A tail. It contains putative selenocysteine residue which is encoded by an unusual stop codon TGA. Comparison of amino acid sequences showed that Japanese quail GPX1 shares 65-74% identity with GPX1 of other animals, suggesting that our clone is an authentic member of GPX1. GPX1 mRNA was expressed in all tissues examined including kidney, adrenal gland, liver, small follicle, small intestine, heart, and breast muscle; the highest level was detected in liver. This quail GPX1 cDNA will provide a tool for further studies of GPX1 expression in the quail.
Non-coliform gram-negative bacteria like Salmonella, pseudomonas and proteus are the causes of yolk sac infection. In this study, we evaluated the effect of formaldehyde on the reduction rate of egg shell, yolk and yolk sac contamination. Two hundred and forty hatching eggs from a broiler breeder farm and hatchery as well as sixty newly-hatched chicks (5 stages) were selected for bacteriological examinations. Stages include: Stage 1: Before cleaning and first disinfection, Stage 2: After first disinfection, Stage 3: Before setting inside the setter, Stage 4: Time of transferring from setter to hatcher, Stage 5: Newly-hatched chicks. Alcaligenes faecalis was isolated from 18.3%, 11.7%, 8.3% and 10.0% of egg shells from stages 1 to 4 respectively and it was also isolated from 11.7% of yolk sacs. Non-coliform gram-negative bacteria were not isolated from yolks in any stages. Based on this research the existence of non-coliform gram-negative bacteria on the hatching egg shells is normal. Immediately egg collection after laying and proper disinfection with formaldehyde can lead to a significant reduction of non-coliform gram-negative bacteria with which the risk of bacteria penetration in to the yolk will decrease dramatically. Formaldehyde is usually effective in reducing non-coliform gram-negative contamination, however, in this study it could not affect significantly (p=0.323) on these contaminations, which maybe due to the fact that the bacteria were in the form of spores. The reduction of contamination rate was significant (p=0.049) only between stages 1and 3 which can be attributed to secondary fumigation by formaldehyde.
Aluminum sulfate (alum, [Al2 (SO4)3. 14H2O]) additions to poultry litter can be used effectively as litter amendments, which can lead to greatly reduce ammonia emissions and phosphorus solubility in the poultry industry. However, there are little studies which compare the effects of alum and liquid alum with respect to the enivornmental effects of poultry litter. The goal of this study was to evaluate the effects of alum and liquid alum on pH, EC, moisture, ammonium and soluble phosphorus contents from poultry litter during 3 weeks. The treatments were mixed in the upper 1cm of litter, which included 3.5g alum, 5.5g alum, 7.5g alum, 8g liquid alum, 13g liquid alum, and 17g liquid alum/100g litter. The litter pH was much lower (P<0.05) for alum and liquid alum-treated litter than those of untreated litter. Moisture contents for all treatments at 0 and 2 weeks affect (P<0.05), but there were no significantly differences among all treatments at 1 and 3 weeks. Application of alum and liquid alum with the different rates increased EC, ammonium, and decreased soluble reactive phosphorus (ranging from 30% to 85.4%) when compared to the controls. These results indicate that using one of the several techniques, acidification, litter amendments would be an alternative option for holding litter NH4 and reducing soluble reactive P by lowering litter pH.