In mammals, a normal offspring can be obtained even from infertile male by intracytoplasmic sperm injection (ICSI). Although ICSI technique has permitted significant progress in clinical practice in humans and mouse to date, it has been established recently in birds. In addition, efficiency of fertility and developmental rates has been low and no chick has been produced by in vitro fertilization and culture. Furthermore, polyspermic fertilization and subsequent normal developmental processes remains unknown. The enhancement of fertility and developmental rates is the first step in the avian ICSI system to be applied for protection of endangered species and production of transgenic and clone birds. This review paper describes (1) the establishment of ICSI technique in Japanese quail, (2) molecular mechanisms whereby polyspermy activates development of quail oocyte, (3) improvement of ICSI efficiency by phospholipase Cζ cRNA. Also, possible application of ICSI for avian sex manipulation and transgenic birds was summarized.
The identification of the sex of chickens or chicken cells has biological and industrial significance. In the laboratory, molecular techniques have utilized W chromosome-specific repetitive DNA sequence fragments, such as Xho I or EcoR I family, for gender identification in chickens. The present study examined a rapid and reliable fluorescence in situ hybridization (FISH) procedure for chick sex identification using an easily obtainable sample: uncultured feather pulp cells. A chicken W chromosome-specific 416-bp partial DNA fragment of Xho I family was digoxigenin-labeled by polymerase chain reaction and used as an FISH probe for chick sex identification. In 60 newly hatched chicks, 28 of the chicks that were subsequently identified as females by the visual identification of ovaries exhibited a positive W-specific probe signal in their feather follicle cells; the others were negative for the W-specific probe signal and were identified as males by the presence of testes. Therefore, the FISH results were in perfect agreement with the anatomical analysis. We suggest that this FISH technique using feather follicle cells and the W-specific DNA probe will be useful for a fast, convenient and accurate sex diagnosis of newly hatched chicks.
The complete mitochondrial D-loop region was sequenced for a total of 18 individuals of Bangladeshi native chickens (BNC); full feathered (nana) (n＝7), naked neck (Nana) (n＝8) and Red junglefowl (RJF) (n＝3). The alignment of mitochondrial D-loop sequence of these chicken populations with 39 reference sequences from DNA databank; White Leghorn, G. g. murghi, G. g. bankiva, G. g. spadiceus, G. g. gallus and other Asiatic chickens was done to identify the phylogenetic position of BNC for the conservation and improvement of chicken genetic resource. The nucleotide variation of sequence among haplotypes for within and between populations of BNC supported the phenotypic variation of individual of the populations. Phylogenetic analysis showed that 57 individuals were grouped into 6 clades. Of the BNC populations, 6 nana, 7 Nana and 2 RJF individuals (83.3%) were closely related with each other and only 1 nana and 1 Nana (11%), and 1 RJF (5.5%) individuals were divergent from them. Therefore, the phylogenetic tree showed low genetic distance and close relationship within and between the chicken populations of Bangladesh, which were closely related with G. g. murghi of Indian origin, and also related with G. g. bankiva, G. g. gallus implying the origin of gene flow to Bangladesh. The genetic information from this study may serve as an initial step to make future plans to assess more molecular information on genetic diversity for the characterization, conservation and improvement of valuable chicken genetic resource of Bangladesh.
Genetic variations were detected in duck growth hormone (GH) gene promoters at 8 positions in the genome of ducks from 3 regions (Mandalay, Khayan, and Sittwe) in Myanmar. Different frequencies were detected in the 3 regions. Higher frequencies were detected at positions, 244, 294, 586, and 665 of the GH promoter from both Mandalay and Khayan than in the ducks from Sittwe. The duck populations of Mandalay and Khayan have been partially selected for egg production by introducing a layer strain of Thailand native ducks, whereas that of Sittwe has been maintained without introduction of any other strain. The differences in the frequency of variations reflect that the breeding method in each region is unique. Since most of the variations were located in sequences similar to the promoters found in chickens and turkeys, variations in the promoter may affect laying performance by changing the expression of GH mRNA levels in the anterior pituitary gland.
In order to investigate the polymorphisms of two candidate genes, WISP1 (Wnt-1-induced secreted protein) and NMI (N-myc (and STAT) interactor), and their effects on embryonic mortality, 187 dead and 71 normal embryos of AiJiaoHuang (AJH) and 154 dead and 70 normal embryos of ZhuSi (ZS) chicken were collected. Two single nucleotide polymorphisms (SNPs), rs14261761 (T/C) at exon5 of WISP1 and rs14630452 (A/T) at exon5 of NMI, were genotyped by PCR-RFLP (polymerase chain reaction-restriction fragment-length polymorphism). Our results showed that the mortality rates of different genotypes of rs14261761 were significantly different in ZS chicken, and the death risk of TT genotype tended to be higher than that of TC; rs14630452 significantly influenced the embryonic mortality of AJH chicken, and the death risk of TT genotype was 4 and 2 times higher than that of AA and AT genotypes, respectively (TT>AT>AA). These results indicated that these two SNPs both affected the chick embryonic mortality.
The protein kinase adenosine monophosphate-activated γ3-subunit (PRKAG3) gene encodes the muscle specific isoform of the regulatory γ3 subunit of adenosine monophosphate activated protein kinase (AMPK), which participates in regulation of energy metabolism and food intake in animals. In the present study, we investigated the genetic polymorphisms of the PRKAG3 gene and the association with carcass performance in 470 Daheng meat-type chickens. One nucleotide substitution (c. 3207 A>G) was detected in the eleventh exon, which caused an amino acid change (p. 1069 T>A). The frequencies of the three genotypes were 44.22% (AA), 36.98% (AB), and 18.80% (BB), respectively. The association of genotypes with chicken carcass traits showed that the genotypes were significantly associated with live weight (LW), carcass weight (CW), breast muscle weight (BMW), leg muscle weight (LMW), abdominal fat weight (AW) and subcutaneous fat thickness (SFT) traits. The BB genotype has higher performance than which of genotypes AB and AA in traits LW, CW, BMW, LMW and AW (P≤0.01 or P≤0.05), which would be genetically advantageous to improve carcass traits in Daheng meat-type chickens. To our knowledge, this is the first report to study the genetic polymorphism of the PRKAG3 gene and its association with carcass traits in chicken.
This study was conducted to compare the effects of DL-2-hydroxy-4-[methylthio] butanoic acid (HMB) and DL-methionine (DLM) on egg production performance and egg quality of laying hens. Two hundred and eighty-eight commercial laying hens were assigned to 3 dietary treatment groups and fed the experimental diets from 34 to 46 weeks of age. The bioefficacy of HMB relative to DL-methionine (DLM) was set at 88% (weight/weight), therefore 0.115% of HMB and 0.101% of DLM were added to a basal diet. DLM and HMB supplementation increased body weight, feed intake, hen-day egg production, egg weight, FCR and egg mass (P<0.01). These supplementations also increased yolk and albumen weight (g/egg) (P<0.01), while DLM slightly decreased albumen weight (% of egg). Consequently, Haugh unit was poor by DLM supplementation but did not by HMB supplementation (P<0.05). DLM supplementation significantly increased fat content in egg (g/egg and % of egg), though level of estradiol in blood was elevated by HMB supplementation. In conclusion, HMB supplementation (as 88% bioefficacy of DLM) can be used as an effective methionine source. However, mechanism of protein and fat synthesis and/or degradation of laying hens may be differed when different form of methionine is supplied.
A small-scale feeding trial was conducted with 30 BUT Big 6 male turkeys (15 in each group) fed diets containing 0% or 15% distillers dried grain with soluble (DDGS) to investigate the effects of DDGS on meat quality, including fatty acid composition, and lipid peroxide and glutathione status of blood and liver. Quality parameters of breast meat did not differ between the treatments groups, except significantly higher shear force in the group fed diet-containing DDGS. DDGS inclusion did not cause significant changes in the chemical composition of breast muscle but revealed significantly lower proportion of myristic, palmitoleic and total saturated fatty acids, and higher proportion of linoleic and total polyunsaturated fatty acids. The higher proportion of polyunsaturated fatty acids of the diet containing 15% DDGS caused higher malondialdehyde content in blood plasma and red blood cell haemolysate, but not in liver or muscle homogenates. Consequently reduced glutathione content was significantly lower in blood plasma but higher in liver homogenate as effect of DDGS added to the diet, but did not differ in red blood cell haemolysate. Glutathione peroxidase activity showed similar changes as reduced glutathione. These results suggest that higher proportion of polyunsaturated fatty acids of the diet containing 15% DDGS resulted in higher malondialdehyde formation in blood, but not in liver and breast muscle because of the activation of the glutathione redox system in liver.
Lactobacillus fermentum 1.2029 strain with high adhesion was selected for studying the mucin expression of the small intestine epithelium of broilers after the strain was orally administrated. The strain was allowed to adhere to Caco-2 and to a hydrophobic solvent to evaluate its adhesive properties. Adhesion to intestinal mucin of chickens was also tested to further characterize the in vivo adhesion of the strain. Afterward, the acid and bile salt tolerance of the strain was also evaluated. L fermentum 1.2029 showed good adhesive ability and was able to survive in low pH conditions and in the presence of bile salts. The in vivo study showed that the strain significantly increased goblet cell density in the jejunum and the level of MUC2 mRNA in both the jejunum and ileum (P<0.05). L. fermentum 1.2029 treatment didn’t affect the thickness of the mucous layer. These results demonstrate that L. fermentum 1.2029 has protective functions, thereby regulating the goblet cell density and the expression of mucin in the small intestine of broilers. This work also suggests that L. fermentum 1.2029 is a potential probiotic feed additive for the improvement of the intestinal function of chickens.
In this study, we investigated the effects of dietary soybean-germ protein (SGP) on abdominal fat accumulation in growing broiler chickens. A total of 24 seven day-old male broiler chicks were allocated to two cages and fed a control diet or a SGP diet for 21 days. Dietary SGP significantly decreased the weight of abdominal adipose tissue. Hepatic triglyceride content and plasma levels of triglyceride and very low density lipoprotein-triglyceride were significantly decreased by dietary SGP. The enzymatic activity and mRNA level of fatty acid synthase in the liver were significantly decreased by dietary SGP. These results suggest that dietary SGP might reduce abdominal fat accumulation by downregulation of fatty acid synthesis in the liver of growing broiler chickens. The weights of breast muscles and thighs were significantly increased by dietary SGP. The ribosomal capacity of the breast muscles was significantly increased by dietary SGP. These results suggest that dietary SGP might increase skeletal muscle weight by upregulation of protein synthesis in the muscle of growing broiler chicken. All our findings suggest that SGP can be used as a new feed ingredient for broiler chickens.
Experiments were conducted to determine the effects of different types of paddy rice (dehulled, crushed and untreated whole-grain forms) on growth performance in broiler chickens. In Experiment 1, a control diet containing 41.6% corn (control), and three experimental diets containing 40.7% dehulled, 43% crushed or 43% whole-grain paddy rice, were formulated to be iso-caloric (3,100 kcal/kg ME) and iso-nitrogenous (20% crude protein), but to contain different levels of fat (6%, 5.6%, 10.7%, 10.7%, respectively). Groups of 0-day-old chickens were the fed experimental diets ad libitum for 28 d. The average final body weight of groups fed the crushed and untreated whole-grain paddy rice was significantly lower (P<0.05) than that of the control group, but that of dehulled rice-fed group was slightly higher than the control group. This finding implies that the growth retardation seen with crushed or untreated whole rice could be caused by the feed intake-reduction due to the fat addition to the experimental diets. In Experiment 2, the control diet containing corn and the experimental diets containing dehulled and untreated whole-grain paddy rice were formulated to contain similar levels of fat (5.6-6%) and to be iso-nitrogenous (20%), but not to be iso-caloric. As a result, the average body weight gain of the whole-grain rice-fed chickens showed a considerable increase compared with the control diet-fed chickens even though the energy content of the former diet was only about 90% that of the control diet. It is concluded that whole-grain paddy rice could serve as a valuable constituent of broiler chicken feed, but that excess fat in the diet to maintain the ME content (3,100 kcal/g) could have a negative effect on growth performance.
Glycation is non-enzymatic reaction causing dehydrating condensation between carbonyl group of reducing sugars and amino group of proteins. In the case of glucose and tryptophan, this reaction forms Schiff base followed by two different reactions of Amadori rearrangement generating Amadori product and Pictet-Spengler reaction generating (1R,3S)-1-(D-gluco-1,2,3,4,5-pentahydroxypentyl)-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (PHP-THβC). Amadori product undergoes further complex reaction to form advanced glycation end products (AGEs). PHP-THβC is one of β-carbolines consisting of an indole skeleton and various side chains. As chickens are known to be one of hyperglycemic animals, it seems to be accelerated glycation and easily produced PHP-THβC when chickens are given excess dietary tryptophan. However, there are little investigations of physiological role of glycated tryptophan. In this study, therefore, various concentrations of PHP-THβC added into culture medium for chicken embryo myoblasts and protein synthesis was measured to clarify the relation of PHP-THβC to muscle protein synthesis. Protein synthesis of chicken embryo myoblasts was decreased by addition of PHP-THβC in range of physiological concentrations in the culture medium. In conclusion, it was supposed that the elevation of PHP-THβC levels in the serum of hyperglycemic animals would decrease muscle protein synthesis.
In order to estimate arginine (Arg) requirements of male broilers (Ross 308) during the 21-to 42-day period and exposed to hypobaric condition, six diets (200 g/kg CP and 13.4 MJ ME/kg) with graded levels of Arg (8.8 to 14.3 g/kg) were allocated to four pens of twelve birds each. Body weight gain, feed:gain, breast meat yield, plasma nitric oxide (NO) concentration, and right to total ventricular weight ratio (RV/TV) were determined as response criteria. Responses to Arg supply were nonlinear and attained plateau values (ymax) within the studied range of Arg supply. The estimated Arg requirements for maximal body weight gain and optimal feed:gain during the 21 days under study were 12.4, and 12.2 g/kg of diet, respectively. The estimated Arg requirement for maximizing breast meat yield was 12.6 g/kg of diet. Based on the response in plasma NO and RV/TV, the estimated requirements were 13.0, and 13.2 g/kg of diet, respectively. Data obtained for the individual factors clearly indicate that the NRC recommendations for Arg are not sufficient for maximizing body weight gain, optimizing feed:gain and preventing the onset of pulmonary hypertension in broiler chickens exposed to hypobaric condition. Data may be used for future modeling of broilers’ Arg requirements.
Carnosine and its methylated derivative anserine are dipeptides present in high levels in chicken muscles. They are antioxidants and putative neurotransmitters. If administration of β-alanine, one of the constituents of carnosine, could increase levels of these dipeptides in the brain and muscles, it may improve brain function and increase commercial values of the chicken meat. In the present study, we investigated whether orally administered β-alanine could increase these dipeptide levels in the brain, Musculus pectoralis superficialis, and plasma in broiler chicks. Broilers (2 days old) were given oral doses of β-alanine (0.176, 0.88, 4.4 and 22 mmol/kg) twice a day for 5 days. Carnosine levels were dose-dependently increased in the brain, Musculus pectoralis superficialis, and plasma while no influence of anserine was detected. These results suggest that supplemental β-alanine could be effective in increasing carnosine levels in the brain and muscle of broiler chicks.
A 52-day pen trial on 10.2 cm built-up litter topped with pine shavings used a randomized complete block design (Tukey’s HSD p≤0.05). A total of 2,160 Cobb male chicks were randomly assigned to 48 pens (12 blocks) at 45 chicks/pen providing 0.0771 m2 per chick. Four phase feeds were used (0-17, 17-31, 31-42, and 42-52 days). Salinomycin (66.14 mg/kg) and 3-Nitro® 20 (50.0 mg/kg) were added from 0-31 days. Dietary treatments were: 1) negative control (nCON); 2) BMD® at 55.12 mg/kg 0-31 days, Stafac® at 22.05 mg/kg 31-52 days (AGP); 3) Actigen® (ACT) at 400 mg/kg; and 4) BMD® at 55.12 mg/kg 0-31 days, Stafac® at 22.05 mg/kg 31-52 days plus Actigen® (ACT) at 400 mg/kg (AGP＋ACT). From 0-17 days, feed conversion ratio (FCR; p＝0.026) and mortality-adjusted FCR (MAFCR; p＝0.027) were lower for AGP and AGP＋ACT than nCON, with ACT intermediate and statistically separate from other groups. At 31 days, body weight (BW; p＝0.043) was greater for AGP＋ACT than nCON, with AGP and ACT intermediate. From 0-31 days, FCR (p<0.001) and MAFCR (p<0.001) were lower for AGP, ACT, and AGP＋ACT than nCON. At 42 days, BW was greater (p＝0.006) for AGP and AGP＋ACT than nCON, with ACT intermediate. The 0-42 day FCR (p＝0.002) and MAFCR (p＝0.006) were lower for AGP and AGP＋ACT than nCON, with ACT intermediate. At 52 days, BW were greater (p<0.001) for AGP, ACT, and AGP＋ACT than nCON. From 0-52 days, FCR (p<0.001) and MAFCR (p<0.001) were lower for AGP＋ACT than nCON, with AGP and ACT intermediate, and mortality percent was lower (p＝0.096) for AGP＋ACT than nCON, with AGP and ACT in between. Based on performance, Actigen® at 400 mg/kg was statistically equivalent to BMD®/Stafac® from 0-52 days and BMD®/ Stafac® plus Actigen® was the most effective treatment.