An experiment was conducted to evaluate the effect of naked neck (Na) gene, sex and their interaction on immunocompetence of chickens. Three genotypes (NaNa, Nana and nana) were the offspring of heterozygous naked neck (Nana) Fayoumi (Egyptian breed) males and females. They were reared under similar environmental, managerial and hygienic conditions. The present results showed that the NaNa birds had lower mortality rate as compared to Nana and nana counterparts. The NaNa genotype had significantly heavier 8wk-body weight and higher relative weights of bursa, spleen, heart and liver compared to nana sibs. With respect to cutaneous basophilic hypersensitivity (CBH) response, the presence of Na gene in a double state significantly increased dermal swelling response to phytohemagglutinin-P (PHA-P) injection compared to nana counterparts. The Nana genotype was intermediated in the most cases. Dermal swelling response to PHA-P, relative bursa weight and relative spleen weight were significantly affected by interaction between Na gene and sex. Concerning correlations between productive traits and immunocompetence, it could be speculated that the body weight was negatively correlated with relative lymphoid organs weight in all genetic groups. However, the body weight was significantly positive correlated with toe-web swelling measured at all times in NaNa and Nana genotypes. In conclusion, the difference among genetic groups in response to PHA-P and in some physiological response suggest that the NaNa genotype had higher cell-mediated immune response followed by Nana compared to nana genotype. Accordingly, introducing Na gene in susceptible strains may be benefit to increase immunocompetence of chicken.
Two experiments were conducted to determine threonine requirement for maximum performance and breast and drumstick major muscle relative weights of turkey toms raised from 8-10wk and 11-13wk of age. Also plasma free amino acid concentration in response to feeding a diet with graded levels of threonine was measured. A corn-peanut meal diet was formulated to contain 0.59, 0.72, 0.85, 0.98 and 1.11% threonine and fed to Large White turkey males (British United Turkeys, BUT) in both trials. Each treatment was replicated among 5 and 8 individual cages in experiments 1 and 2, respectively. Two days prior to the end of each trial, blood was removed from the brachial vein of five toms per treatment and analyzed for plasma amino acid concentration. At the end of each experiment, final body weight and feed consumption were recorded and feed efficiency was computed. Birds were then sacrificed and pectoralis major and gastrocnemius muscles were weighed. The 0.85% dietary threonine resulted in the highest weight gain and feed efficiency ratio in the first trial. In the second experiment an increase (P<0.05) in weight gain was also obtained by the 0.85% dietary threonine with no further significant improvement beyond that level. Therefore the current results indicate that the threonine requirement for maximum weight gain of turkey toms raised from 8 to 10 and 11 to 13wk of age is 0.85%. The changes in blood threonine concentration further supported the estimated requirement of threonine obtained from the performance data. Increasing dietary threonine from 0.59 to 1.11% during both growing periods, however, had no effect on pectoralis major or gastrocnemius muscles yield. In conclusion threonine requirement for maximum performance of the grower turkey tom raised from 8 to 13wk of age was 0.85% diet, a value slightly higher than that reported in the literature.
This study investigated the suitable metabolizable energy (ME) level of molt diet for hens that cease producing eggs without being subjected to great stress. During the preliminary period, White Leghorn hens were fed a corn-soybean meal-based layer ration ad libitum. After a 4-wk preliminary period, the hens were randomly divided into 3 treatment groups and 1 control group; the control group was persistently fed the layer ration. The 3 treatment groups were fed the following diets ad libitum for 4wk: (1) 100% molt diet based on corn, wheat bran, and corn gluten feed (ME 2.3Mcal/kg M100:); (2) 85% molt diet with 15% rice hull (ME 1.9Mcal/kg M85:); and (3) 70% molt diet with 30% rice hull (ME 1.6Mcal/kg M70:). During the post-molt period, the hens were returned to the layer ration. During the molting period, the heterophil: lymphocyte (H:L) ratio, ovary and oviduct weights, and MEn intake were measured. Egg production, egg weight, egg quality, body weight, and feed intake were measured throughout the experiment. During the molting period, the feed intake, body weight, and ovary and oviduct weights in the molted groups were significantly (P<0.01) lower than those in the control group. In the M70 group, egg production ceased completely within 9 d; and decreased to 4.2% by day 10 and 9 in the M100 and M85 groups, respectively. The H:L ratio was the highest, intermediate, and least in the M70, M100 and M85, and control groups, respectively. At 1, 2 and 4wk, the MEn intake in the M70 group was lower than the requirement level. Throughout the post-molt period, the egg production and quality in the molted groups improved compared to that in the control. We assume that ad libitum access to low energy molt diet (ME 1.6Mcal/kg) effectively induces molting and increases post-molt production.
The effect of dietary enzyme (Optizyme) on the performance of Japanese quail hens fed isocaloric and isonitrogenous diets containing 0, 10, 20 and 30% of Nigella seed meal (NSM) as a protein source was studied. A corn-soybean meal diet was used as a control diet. Eight groups of birds having 8 replicates consisting of 2 females and 1 male were used, and productive and reproductive traits and egg quality were measured. Hens fed 10% NSM produced significantly more eggs than those fed 0, 20 and 30% NSM diets. Shell thickness was also significantly higher in the 10% NSM group. Supplementation of enzyme significantly improved egg production and tended to improve shell thickness when a 20% NSM diet was fed, but not when 30% NSM was given. Furthermore, the enzyme significantly improved the fertility rate when fed a 20% NSM diet, but not in the groups fed a 30% NSM diet. From these observations, Japanese quail hens can be fed diet containing 10% NSM. Moreover, this level can be increased to 20% when supplemented with enzyme.
The present study was conducted to investigate (1) the effective day of treatment with Fadrozole, nonsteroidal aromatase inhibitor (AI), during incubation for sex reversal, (2) the mRNA expression of aromatase (P450arom), anti-Müllerian hormone (AMH) and estrogen receptor α (ERα) in quail gonad and gonadal structures after the AI treatment before hatching and (3) the effects of AI on gonad growth, left-right asymmetry of the gonad and body weight gain between 1 to 7 weeks posthatch. (1) Females AI-treated at 0, 2 and 4 days of incubation had symmetrical gonads at hatch similar to normal males, whereas those treated at 6 and 8 days of incubation had asymmetrical gonads. (2) In females AI-treated at day 0 of incubation, the left gonad became an ovotestis at day 15 of incubation, displaying seminiferous tubules with testicular-like cords and ovarian follicle with ovum. In the control group, P450arom mRNA expression was significantly higher in females than males. However, AI-treated females showed 2 response-patterns of either higher or lower expression. The latter was similar to that of control males. No significant differences in levels of AMH and ERα mRNA between sexes either in control or AI-treated groups was observed. (3) A gradual increase in body weight of the control males and females without sex difference was observed up to 5 weeks of age. However, at 6-7 weeks the average weight of females was heavier than males each in control and treated group. These results indicate that shortly before day 6 of incubation P450arom mRNA expression, at least in a part, is important for asymmetrical formation of gonads in female quail. In AI-treated females, the high responder show similar level of P450arom mRNA in control males and the low responder do not respond to the AI. Body weight is controlled non-gonadally in quail.
The aims of this study was to find out the histological differences of the mucosa and comparative analysis of Ig-containing plasma cells among the different segments of the gastrointestinal tract of broiler and native chickens of Bangladesh. The conventional histological study revealed that the lining epithelium of the proximal segments (esophagus, crop, and proventriculus) were thicker in the broiler. The esophageal glands were more in the broiler than the native chickens. The villi of the duodenum, jejunum and ileum were slender and longer in the broiler in comparison to the native chickens. The number of goblet cells in the duodenum, jejunum, and ileum was more in the native chickens than the broiler. The indirect immunohistochemistry revealed that very few immunoglobulin (Ig)-containing plasma cells were present in the epithelium and lamina propria of esophagus, crop, and proventriculus of the broiler and native chickens. The frequency of the population of these cells were abundantly located in the lamina propria, around the intestinal gland and in the core of the villi from duodenum to ileum of broiler and native chickens. The intraepithelial IgA-containing epithelium was observed only in the epithelium of the native chickens. Segmental variation of Ig-containing plasma cells was noticed in these two strains of chickens. The IgA-, IgG-, and IgM-containing plasma cells were significantly more in the most of the segments of the small intestine of the native chickens. This suggested that besides the existence of histological variation in the gastrointestinal tract of broiler and native chickens, the Ig-containing plasma cells were significantly more in the different segments of the digestive tract of native chickens possible due to their scavenging.
The present study was conducted to show a profile of mRNA expression of sex-differentiation related genes in the duck gonad. Fertile duck eggs (Cherry-valley) were incubated (hatching at day 28 of incubation) and the gonads were collected at days 7, 8, 10, 12 and 15 of incubation after taking photos of the gonads. Left gonad was used for identification of genetic sex and for total RNA extraction. Reverse transcription-polymerase chain reaction (PCR) was performed using appropriate forward and reverse primers for each of FOXL2, P450arom, DMRT1, AMH, P450c17, SF1, ER α and AR genes of the chicken and the corresponding cDNA fragments were sequenced for duck. Subsequently, real-time PCR was performed to detect mRNA expression of those genes in the duck embryo. Male bilateral gonads assumed symmetry in appearance throughout the examined period, whereas the female gonads were noticeably asymmetric at 10 days of incubation with a smaller size of the right. Female asymmetry was distinct by day 15 of incubation. In females, FOXL2 and P450arom mRNA expression began at day 8 of incubation and remained high thereafter, but in males only negligible expression was detected. In males, mRNA expression of DMRT1 and AMH was detected at day 7 of incubation and tended to increase gradually thereafter, whereas in females the expression remained low throughout the examined period. Though the slight expression of P450c17 mRNA started at day 7 only in males, the expression was low throughout the examined period, whereas in female the expression was distinct at day 8 of incubation and remained high thereafter. Expressions of the other genes were variable with no differences in each expression between the sexes. The results indicate that FOXL2 and P450arom play an important role for the ovarian formation.
β-Endorphin is an endogenous ligand for both mu- and delta-opioid receptors (MOR and DOR), and has an important role in feeding behavior in the central nervous system in mammals. The present study was done to elucidate whether central injection of β-endorphin enhances feeding behavior in neonatal chicks and to investigate the interaction with the MOR and DOR. We found that the intracerebroventricular (ICV) injection of β-endorphin (50pmol) significantly stimulated food intake in neonatal chicks during the 60-min period postinjection. In addition, the orexigenic effect of β-endorphin was significantly attenuated by the MOR, but not by the DOR antagonist. These results indicate that the administration of β-endorphin into the chick brain produces the orexigenic effect through the MOR.
Interspecies or even inter-genus somatic nuclear transfer is considered to be an effective means for conserving a wide variety of avian genetic resources. However, somatic nuclear transfer offspring production is currently limited to mammals. Therefore, the present experiment was designed in an attempt to produce inter-genus somatic nuclear transferred gonadal germ cells (snt-GGCs) between chicken and quail. Electrofusion was carried out between embryonic blood cells (EBCs) collected from 4-day-old embryos (donor cells) and gonadal germ cells (GGCs) from 7-day-old chick embryos or 6-day-old quail embryos (recipient cells). GGCs were labeled with PKH26 fluorescent dye as a marker. Electrofusion was carried out according to previously described methods. The combinations of donor-recipient cells were designed to contain all four possible combinations: E(c)-G(c), E(q)-G(q), E(q)-G(c) and E(c)-G(q), where E, G, c and q are abbreviations for EBCs, GGCs, chick and quail, respectively. Following electrofusion, the fusion solution containing cells were stained with 1μg/mL Hoechst 33342. PKH26-labeled cells with two or more nuclei of different sizes were determined to be snt-GGCs. The experiment was replicated ten times and snt-GGCs were observed in five (50%), three (30%), four (40%) and five (50%) replicates. The average number of snt-GGCs produced per replicate were 0.6 (1.2%), 0.3 (0.6%), 0.5 (1.0%) and 0.5 (1.0%) for E(c)-G(c), E(q)-G(q), E(q)-G(c) and E(c)-G(q), respectively. The present results demonstrate that inter-genus snt-GGCs can be produced by electrofusion using EBCs and GGCs in avian species.
Safflower (Carthamus tinctorius) has been used as a traditional medicinal plant to enhance natural immunity and treat cancers. However, limited information exists on the mechanisms responsible for its immune enhancing properties. In this study, the immunostimulatory effects of a methanol extract of safflower leaf were assessed by in vitro lymphocyte proliferation, tumor cell cytotoxicity, and nitric oxide production by cultured chicken macrophages. A crude methanol extract of safflower leaf stimulated spleen lymphocyte proliferation and nitric oxide production, and inhibited the viability of tumor cells significantly greater than medium controls. Sequential gel filtration chromatographic separation of the methanol extract on Sephadex G-25 and Sephacryl S-200 columns resulted in a partially purified preparation that retained the ability to induce lymphoproliferation, tumor killing, and NO production. These results demonstrate for the first time that safflower leaf contains immunostimulatory and anti-tumor component(s) that may be potentially useful as a dietary immunomodulator for poultry.
The present study was conducted to improve the rate and stage of blastoderm and embryo development of quail oocytes by intracytoplasmic sperm injection (ICSI) with quail phospholipase Cζ (PLCζ) cRNA. Blastoderm development of quail oocytes cultured for 24 or 72h were staged under a stereomicroscope. The blastoderms were stained with 4,6-diamidino-2-phenylindole (DAPI) for cell division progress. A quail PLCζ cDNA clone was isolated from sperm by RT-PCR. The 1978bp nucleotide sequence contained an ORF encoding 637 amino acids of protein. The deduced quail PLCζ protein consists of EF-hand domain, X and Y catalytic domain and C2 domain, but lacked a plextrin-homology (PH) domain at the N-terminus. RT-PCR analysis revealed that PLCζ mRNA is expressed only in the testis. ICSI into a quail oocyte without PLCζ cRNA induced blastodermal development in 16% (4/25) of the oocytes which reached stages III-VI 24h after culture. In contrast, ICSI together with PLCζ cRNA (in 3nl at 60μg/ml) into a quail oocyte induced blastoderm development more than 2 fold (36.8%, 7/19) with embryos reaching stages VI-VII. Furthermore, 72h after culture ICSI into a quail oocyte without PLCζ cRNA induced embryo development in 15.4% (2/13) of the oocytes and reached stages V-VII. In contrast, ICSI together with PLCζ cRNA (in 3nl at 60μg/ml) into a quail oocyte induced 3 fold more embryo development (50%, 9/18) with embryos between stages VI and over X. The microinjection of PLCζ cRNA significantly improved the conventional ICSI method by enhancing the proportion and the stages of embryo development. Accordingly, the present PLCζ cRNA microinjection method in birds may contribute to assist in the production of transgenic birds and protection of endangered species of birds.