Maturation and ovulation of Japanese quail oocytes under in vitro conditions

1. An in vitro system for ovulation and maturation of Japanese quail oocytes is described.

2. Ovarian follicles removed from the ovary at 2, 4 or 6 h before the estimated time of ovulation may ovulate under in vitro conditions.

3. The presence of progesterone in the medium had a stimulatory effect on the process of maturation, as has been shown for Xenopus oocytes.     

Onset of oestrus and periovulatory events in sheep exposed to 5 and 14 days of CIDR treatment with and without eCG

The present study supports that 5‐day short‐term CIDR treatments without administration of eCG are equally effective for inducing oestrus behaviour, preovulatory LH discharge and ovulation in sheep than classical protocols based on 14‐day treatments plus eCG at CIDR withdrawal. However, the implementation of a 5‐day protocol without eCG for fixed‐time artificial insemination would be adapted to a later timing of ovulation (p < .05).     

In vitro formation of holes on the inner perivitelline layer of quail ovum by chicken spermatozoa

The aim of the present study was to examine whether chicken semen can be substituted for quail semen to conduct in vitro experiments on fertilization. Chicken spermatozoa was incubated with the inner perivitelline layer (IPL) isolated from the largest follicle in the quail ovary under in vitro conditions. The perforation of chicken and quail spermatozoa were assessed by counting the number of all visible holes in the pieces of IPL. No difference was found in the number of holes formed by the chicken sperm and quail IPL interaction compared with that between intraspecies. In addition, the number of holes in the IPL was significantly increased with the increase in sperm concentration from 1 × 10⁶ to 8 × 10⁶ sperm/mL (P < 0.05). Interestingly, after treatment of chicken spermatozoa with 2.5 mg/mL of the solubilized quail IPL followed by incubation with the intact chicken IPL, the number of holes in the intact chicken IPL was significantly decreased as compared with that of spermatozoa treated without the solubilized IPL (P < 0.05). This indicates that sperm receptors in the solubilized quail IPL and binding ligands on the chicken spermatozoa would find each other and bind, forming complexes and these complexes blocked the interaction between chicken spermatozoa and intact chicken IPL. These results show that: (i) chicken spermatozoa possess the penetrability into quail IPL; and (ii) a high degree of affinity via the receptor interactions exists between chicken spermatozoa and quail IPL. Therefore, it appears that the substitution of chicken semen for quail semen is possible to use as an in vitro technique to examine the sperm‐IPL interaction during fertilization in quail.     

Primary analysis of DNA polymorphisms in the TRIM region (MHC subregion) of the Japanese quail,Coturnix japonica

Based on sequences of two cosmid clones from Japanese quail (Coturnix japonica, Coja), we confirmed that the syntenic cluster, GNB2L1～BTN1～BTN2, is located in the quail TRIM subregion of the quail major histocompatibility complex (MHC Coja) region. These cosmids also included four CjBG loci and one CjLEC locus; therefore, the quail TRIM subregion was thought to be adjacent to the BG/LEC subregion. We then identified three polymorphic markers – CjHEP21, CjTRIM39.2 and CjBTN2 – in the TRIM subregion that may be useful for the functional analysis of the MHC‐Coja region. We examined MHC‐Coja sequences from 321 individual quails sampled from 11 inbred strains, and we found eight alleles for each of the three genes – CjHEP21, CjTRIM39.2 and CjBTN2. These polymorphisms represent the first avian DNA markers in the TRIM subregion. Additionally, we discovered a quail‐specific VNTR (variable number of long tandem repeats, 133–137 bp) in intron 7 of CjBTN2. We identified 25 haplotypes in the sample of 321 quail; these haplotypes comprised combinations of all 24 alleles of the three polymorphic genes. We suggest that there are two recombination hotspots, one between each pair of adjacent loci. All strains, except AMRP, contained multiple haplotypes; the AMRP strain contained a single, apparently fixed haplotype.     

Developmental stages of the blue‐breasted quail (Coturnix chinensis)

Chickens and Japanese quail (Coturnix japonica) have traditionally been the primary avian models in developmental biology research. Recently, the blue‐breasted quail (Coturnix chinesis), the smallest species in the order Galliformes, has been proposed as an excellent candidate model in avian developmental studies owing to its precocious and prolific properties. However, data on the embryonic development of blue‐breasted quail are scarce. Here, we developed a normal developmental series for the blue‐breasted quail based on developmental features. The blue‐breasted quail embryos take 17 days to reach the hatching period at 37.7°C. We documented specific periods of incubation in which significant development occurred, and created a 39‐stage developmental series. The developmental series for the blue‐breasted quail was almost identical to that for chickens and Japanese quail in the earlier stages of development (stages 1–16). Our staging series is especially useful at later stages of development (stages 34–39) of blue‐breasted quail embryos as a major criterion of staging in this phase of development was the weight of embryos and the length of third toes.     

Premature luteal regression in a pregnant mare and subsequent pregnancy maintenance with the use of oral altrenogest

Premature luteal demise or luteal insufficiency is not well characterised as a cause of pregnancy loss in domestic species, including horses. In this report, a mare inseminated with cooled‐transported semen at our facility returned for a routine pregnancy diagnosis at 15 days post ovulation. Ultrasonography per rectum revealed endometrial oedema and the absence of visual indication of a corpus luteum on either ovary. Nonetheless, an embryonic vesicle small for the gestational age was identified. Daily oral altrenogest treatment was implemented immediately. Serum progesterone concentration was 0.67 ng/ml, which is below the threshold considered adequate for pregnancy maintenance in the mare. Examinations were repeated at 17, 25, 30, 39, 49, 72 and 120 days post ovulation. At 25 days post ovulation the embryonic vesicle presented normal development for the gestational age. In addition, sequential blood samples were collected to measure progesterone, equine chorionic gonadotrophin and oestrone sulphate concentrations. Although progesterone concentration did not exceed 2 ng/ml until 72 days post ovulation, all other results were unremarkable and a healthy filly was born uneventfully at 344 days post ovulation.     

Pharmacokinetics of florfenicol in the plasma of Japanese quail

Abstract

AIM: To determine the pharmacokinetics and bioavailability of florfenicol in the plasma of healthy Japanese quail (Coturnix japonica).

METHODS: Sixty-five quail were given an I/V and I/M dose of florfenicol at 30 mg/kg bodyweight (BW). A two-period sequential design was used, with a wash-out period of 2 weeks between the different routes of administration. Concentrations of florfenicol in plasma were determined using high-performance liquid chromatography (HPLC).

RESULTS: A naíve pooled data analysis approach for the plasma concentration-time profile of florfenicol was found to fit a non-compartmental open model. After I/V administration, the mean residence time (MRT), mean volume of distribution at steady state (V_ss), and total body clearance of florfenicol were 12.0 (SD 0.37) h, 8.7 (SD 0.22) L/kg, and 1.3 (SD 0.08) L/h/kg, respectively. After I/M injection, the MRT, mean absorption time (MAT), and bioavailability were 12.3 (SD 0.37) h, 0.2 (SD 0.02) h, and 79.1 (SD 1.79)%, respectively.

CONCLUSIONS: The time for the concentration of florfenicol to fall below the probable effective concentration of 1 µg/ml of approximately 10 h is sufficient for the minimum inhibitory concentration needed for many bacterial isolates. Further pharm acodynamic studies in quail are needed to evaluate a suitable dosage regimen.     

Effect of ovsynch versus prostaglandin F2α protocol on estrus response,ovulation rate,timing of ovulation and pregnancy per artificial insemination in Sahiwal cows

Sahiwal cow is Bos indicus which is an important dairy breed of tropical and sub‐tropical region. Research on reproduction is rare in this breed. The objectives of the present study were to determine the effect of Ovsynch (OVS) versus prostaglandin F_2α (PG) protocol on estrus response and its intensity, ovulation rate, timing of ovulation and pregnancy per artificial insemination (AI) in Sahiwal cows. Experimental cows (n = 80) were of mixed parity, lactating, suckled, ≥120 days postpartum with body condition score 3.08 ± 0.34 and 375‐475 kg of body weight which were randomly assigned to receive either OVS (n = 46) or PG (n =34) protocol. Cows were inseminated twice at 12 and 24 h after second gonadotropin releasing hormone in the OVS group, and 72 and 84 h after administration of prostaglandin F_2α in PG group, respectively. The results revealed that estrus response did not differ (P > 0.05) and was 87% in OVS and 78% in PG cows. Ovulation rate did not differ (P > 0.05) and was 50% in both, OVS and PG cows. The pregnancy per AI did not differ (P > 0.05) and was 43% in OVS compared to 31% in PG cows. It is concluded that estrus response, ovulation rate and pregnancy per AI of OVS protocol is the same as PG in Sahiwal cows.     

Effect of Modified Eros Centre on Some Reproductive Parameters of the Sow

The effect of a modified eros centre on weaning to oestrus interval, follicle size, ovulation and farrowing rate and total born litter size was investigated. In modified eros centre 94.4% and in group housing 79.1% of the sows (p < 0.01) expressed oestrus within 10 days post‐weaning. Weaning to oestrus interval was shorter (p < 0.001) for sows kept in modified eros centre. The interval from onset of oestrus to the time of ovulation was longer for sows in group housing (p=0.05). The time of ovulation was negatively correlated (r=?0.50) with the interval from weaning to oestrus (p=0.005). The time of ovulation after onset of oestrus was significantly (p < 0.05) shorter for sows expressing oestrus within 2–4 days of weaning, compared with the animals that expressed oestrus between days 5 and 6 post‐weaning and was shortest for sows expressing oestrus after day 6 post‐weaning. Farrowing rate was not affected by a modified eros centre. Litter size tended to be smaller in group‐housed weaned sows (p=0.10). The timing of last artificial insemination relative to time of ovulation did not affect litter size (p > 0.10). The implication of these results is that a modified eros centre may improve some of the post‐weaning oestrous parameters of the sow.     

Isolation of DNA from embryo and chorio-allantoic membranes and sexing by PCR in Japanese quail

1. The aim of this study was to evaluate the amount and quality of genomic DNA isolated from embryos and their chorioallantoic membranes (CAM) and to investigate the utility of different PCR methods for identifying the sex of Japanese quail embryos.

2. Fertilised eggs were incubated at 37°C for 120?h and DNA was isolated from samples of embryos and CAM. Target regions of the CHD-W gene or XhoI repeat sequence were amplified by PCR and examined on agarose gels or by using a capillary electrophoresis system.

3. DNA samples from embryos had significantly higher OD260 values than those from CAM, while OD260/280 values were not significantly different between embryos and CAM.

4. Gender identification was not possible by PCR amplification of the CHD gene region or XhoI repeat sequences examined on agarose gels, whereas males and females of Japanese quail were distinguishable when PCR products of the CHD gene were separated by capillary electrophoresis.

5. The results showed that high molecular weight DNA could be isolated from both embryo and CAM of Japanese quail. DNA isolated from CAM could be used for molecular genetic studies where embryos would be used for other purposes, such as in situ hybridisation. A capillary electrophoresis system could be used for identifying the gender of Japanese quail embryos.     

Effect of environmental factors and changes in the body condition score on the onset of the breeding season in mares

Several methods have been proposed to advance the onset of the breeding season in horses. Most of them are based on the exposure to an artificial lighting period combined with hormonal treatments. Mares exposed to an artificial photoperiod are most often housed indoors where the ambient temperature is often higher than the outside temperature. Mares held in barns are also exposed to different daylight intensities than horses kept outside, depending on the architecture. In the current study, we evaluated the impact of ambient temperature, daylight intensity and changes in body condition score (BCS) on the timing of first ovulation after winter anestrus in mares exposed to an artificial photoperiod. Mares (n = 211) were housed in barns with different ambient temperature and daylight exposure but with the same artificial photoperiod exposure (except for a natural photoperiod control group). Artificial photoperiod as well as an increase in BCS over the winter significantly advanced the first spring ovulation. The BCS at the start and end of the anestrus period did not have an effect on the interval to first ovulation and neither did the modest increase in ambient temperature in the barn. However, a higher light intensity during the daytime significantly advanced the first spring ovulation. The results of this study suggest that exposure to more sunlight advances the onset of the breeding season. This effect is likely mediated through the biological effect of short wavelength blue light and its impact on melatonin suppression and biological rhythms. We suggest that greater/direct exposure to the blue light component of daylight improves the response to the artificial photoperiod. The results of the present study can further assist to optimize the conditions that lead to an efficient spring transition of breeding mares.     

Immunohistochemical and ultrastructural characterization of the ovarian surface epithelium of Japanese quail (Coturnix japonica)

Contrary to humans, most ovarian tumors in other species do not arise from the ovarian surface epithelium but are of follicular‐, stromal‐ or germ‐cell origin. One of the few species where ovarian cancer arises from the ovarian surface epithelium (OSE) is chicken (Gallus domesticus). Little is known about the morphology of the OSE in other avian species. In our study we analyzed the OSE morphology of Japanese quail (Coturnix japonica) using ultrastructural and histochemical techniques. Carbohydrate residues have been studied by using a panel of fluorescein isothiocyanate labeled lectins. Japanese quails are commonly used animal models in biomedical research as their housing is comparatively inexpensive and they show a short generation interval. Our ultrastructural and histochemical results demonstrate that the quail ovarian surface epithelium shows characteristic features which resemble the epithelia of both chicken and human. Additionally, the ovarian surface epithelium of the Japanese quail contains cytokeratin as well as vimentin intermediate filaments in their cytoplasm. Therewith and among other parts the quail OSE shows many characteristic features also seen in those of humans, which may qualify quail's ovary as a potential animal model for human ovarian carcinomas.     

Characterization of the cathelicidin cluster in the Japanese quail (Coturnix japonica)

The Japanese quail has several advantages as a low‐fat meat bird with high immunity against diseases. Cathelicidins (CATHs) are antimicrobial peptides that play an important role in innate immunity. The aim of this study was to characterize the CATH cluster in the Japanese quail (Coturnix japonica). The Japanese quail CATH (CjCATH) cluster, contains four CATH genes, as in the chicken. The coding sequences of CjCATHs exhibited >85.3% identity to chicken CATHs. The predicted amino acid sequences of the four CjCATH genes contained the cathelin‐like domain characteristic of CATH proteins. Polymorphisms were detected in the open reading frames (ORFs) of all CjCATH sequences. Two amino acid substitutions were observed in the antimicrobial region of the mature peptide of CjCATH2, and predicted to influence peptide function. CjCATH1 is expressed in lung, heart, bone marrow and bursa of Fabricius (BF). CjCATH2 is expressed in bone marrow. CjCATH3 is expressed in lung, heart, bone marrow, BF, tongue and duodenum. CjCATHB1 is expressed in bone marrow and BF. This study is the first to characterize CATH genes in the Japanese quail, and identifies novel antimicrobial peptide sequences belonging to the cathelicidin family, which may play a role in immunity in this species.     

Skeletal development in blue‐breasted quail embryos

The blue‐breasted quail (Coturnix chinensis), the smallest species of quail with short generation interval and excellent reproductive performance, is a potential avian research model. A normal series of skeletal development of avian embryos could be served as a reference standard in the fields of developmental biology and teratological testing as well as in the investigation of mutation with skeletal abnormalities and in the study of the molecular mechanisms of skeletal development through genome manipulation. Furthermore, ossification sequence shows a species‐specific pattern and has potential utility in phylogeny. However, data on the skeletal development of blue‐breasted quail embryos are scarce. Here, we established a series of normal stages for the skeletal development of blue‐breasted quail embryos. Cartilage and ossified bones of blue‐breasted quail embryos were stained blue and red with Alcian blue 8GX and Alizarin red S, respectively. The time and order of chondrification and calcification of their skeletons were documented every 24 hr from 3 to 17 days of incubation, and a 15‐stage series of skeletal development was created. Moreover, a comparative study with the Japanese quail (Coturnix japonica) demonstrated that ossification sequence differed significantly between these two species.     

Intestinal mucosa develops in a sex-dependent manner in Japanese quail (Coturnix japonica) fed Saccharomyces cerevisiae

ABSTRACT

1. The aim of study was to investigate whether the impact of the yeast Saccharomyces cerevisiae on the histological structure of the intestine, innervation of the small intestine wall, and basal biochemical serum parameters in Japanese quail was sex dependent.

2. One-day-old healthy male and female Japanese quail were fed either a basal diet containing no yeast (control group) or the basal diet plus 1.5% (15 g/kg of diet) of yeast (S. cerevisiae inactivated by drying). Samples from the duodenum and jejunum were taken from each bird at the age of 42 days. Blood samples were collected at this age and the concentrations of glucose, total protein, creatinine, uric acid, lipid profile (total cholesterol, low density lipoproteins (LDL), high density lipoproteins (HDL) and triacylglycerols (TG)), alanine aminotransferase (ALAT), aspartate aminotransferase (AspAT), lactate dehydrogenase (LDH), amylase (AMY), calcium, phosphorus and iron were determined.

3. Female quail fed diets supplemented with yeast had significantly lower total cholesterol and amylase activity than the control females. The concentration of HDL was higher in the male quail than in the females, irrespective of the treatment. An opposite effect was observed in LDL. The diet treatments influenced the activity of AspAT, which was significantly less in the male quail fed diets with 1.5% yeast.

4. Supplementation with S. cerevisiae increased the myenteron, submucosa and mucosa thickness, villus length and thickness and size of absorptive surface, while the number of villi and enterocytes were decreased in the duodenum in males. Female quail showed an increased absorptive surface in the jejunum. The Meissner (submucosal) plexuses were influenced by the feeding and sex to a greater extent than the Auerbach plexus (in the muscularis propria).

5. The results demonstrated that S. cerevisiae (1.5%) in the diet caused significant positive effects in Japanese quail, exerting an effect on the morphology of the small intestine in a sex-dependent manner.     

Characterization and expression of non‐polymorphic liver expressed antimicrobial peptide 2: LEAP‐2 in the Japanese quail,Coturnix japonica

Liver‐expressed antimicrobial peptide 2 (LEAP‐2) is a cationic peptide that plays an important role in innate immunity for host defense. The aim of this study was to characterize the LEAP‐2 gene in the Japanese quail (Coturnix japonica). Japanese quail LEAP‐2 (CjLEAP‐2) was identified from the Japanese quail draft genome database by a local BLAST analysis using chicken LEAP‐2 (GgLEAP‐2). The exon‐intron structure of CjLEAP‐2, analyzed from three quails, is composed of three exons, as is the chicken LEAP‐2 homolog (GgLEAP‐2). An analysis of the coding sequence revealed that CjLEAP‐2 is 231 bp long, like GgLEAP‐2, and 93% identical to GgLEAP‐2 at the nucleic acid level. The predicted amino acid sequence of CjLEAP‐2 contained the liver‐expressed antimicrobial peptide 2‐precursor domain and four cysteine residues characteristic of the LEAP‐2 protein. The amino acid sequence of the mature peptide of CjLEAP‐2 was 100% identical to that of GgLEAP‐2. We confirmed that CjLEAP‐2 was transcribed in at least seven tissues, including the digestive system. Additionally, the mature peptide region of CjLEAP‐2 exhibited no polymorphisms in 99 quails from six strains. Taken together, these findings indicate that CjLEAP‐2 is non‐polymorphic and therefore, it likely plays an important role in the innate immunity of quail as it does in chicken.     

Timing of follicular phase events and the postovulatory progesterone rise following synchronisation of oestrus in cows

In cows the timing of both ovulation and the subsequent postovulatory progesterone rise are critical to successful fertilisation and early embryo development. The aim of this study was to determine the degree of variability in the timing of ovulation relative to other follicular phase events and to determine how variations in the timing of follicular phase events contribute to the timing of the postovulatory progesterone rise. Plasma concentrations of progesterone, oestradiol and luteinising hormone (LH) and the timing of oestrus and ovulation were determined following induction of luteolysis were determined in 18 mature, non-lactating Holstein-Friesian cows. Four cows were excluded on the basis of abnormal reproductive function. In the remaining 14 cows oestrus occurred at 57.4+/-4.3h and the LH surge at 54.6+/-4.0h following luteolysis (progesterone <1ngmL(-1)) followed by a fall in circulating oestradiol concentration at 64.6+/-4.4h. Cows ovulated at 88.0+/-4.7h with the postovulatory progesterone rise (to >1ngmL(-1)) occurring 159+/-7.2h after luteolysis. There was considerable variation in the timing of ovulation following luteolysis (range 64-136h) onset of oestrus (range 24-40h) and onset of the LH surge (range 24-44h). Cows were then split on the basis of interval from progesterone fall to progesterone rise giving groups (n=7 per group) with intervals of 180.6+/-6.7 and 138.3+/-5.7h (P<0.001). Between groups, both the intervals from luteolysis to ovulation (98.3+/-6.9 vs 77.7+/-3.4h; P<0.05) and ovulation to progesterone rise (82.3+/-4.2 vs. 60.6+/-5.5h; P<0.01) were longer in late rise cows. There was no difference between groups in the interval from oestrus or LH surge to ovulation. In conclusion the results of this study further highlight the high variability that exists in the timing and interrelationships of follicular phase events in the modern dairy cow, reemphasising the challenges that exist in optimising mating strategies. However, the data do suggest that in cows with poor post ovulatory progesterone secretion, the key problem appears to be poor post ovulatory development rather than a delay in ovulation.     

Timing of induction of ovulation in mares treated with Ovuplant or Chorulon

Reliable induction of timed ovulation is an important managerial tool in any horse-breeding operation. Not only does breeding close to ovulation increase pregnancy rates when using cooled, frozen, or poor-quality semen, but it also reduces the number of inseminations needed per cycle, resulting in a more efficient breeding program. To better predict ovulation time in the long estrus period of the mare, one could increase the frequency of transrectal palpations and ultrasounds and/or implement hormonal therapies to induce ovulations. However, previous studies have been unclear on the exact timing of ovulation of mares treated with human chorionic gonadotropin (Chorulon, Intervet Inc, Millsboro, DE) or deslorelin acetate (Ovuplant, Pharmacia and UpJohn Co, Kalamazoo, MI). This study was designed to determine the timing of ovulation after Ovuplant or Chorulon treatment in normal cycling mares presented to the veterinary clinic. In addition, the pregnancy rates were determined for mares bred when a single insemination, using frozen or chilled semen, was performed at a fixed time (36 hours) after Ovuplant or Chorulon treatment. Thirty-two mares were given a subcutaneous injection of 7.5 mg of prostaglandin F2α (Lutlyse, Ft Dodge Animal Health, Ft Dodge, IA) 5 days after the last ovulation and were examined every 48 hours until estrus was detected based on a dominant follicle and the presence of endometrial edema as determined by ultrasonographic examination. Group 1 (N = 12) was treated intravenously with 2,500 units of Chorulon, and group 2 (N = 20) was treated subcutaneously with Ovuplant as soon as mares were determined to be in estrus. Once treated all mares were examined by rectal palpation and ultrasound at 0, 12, 24, 28, 30, 32, 34, 36, 38, 40, 42, 44, 48, 60, 72, 84, 96, hours or until ovulation was detected. Ovulation rate in response to Chorulon was 83.3% at 48 hours, 91.6% at 72 hours, and 100% at 96 hours. All of the mares in the Ovuplant-treated group had ovulated by 48 hours. Chi-square analysis of the data showed a significant (P < .01) variation in the distribution of ovulation times between mares treated with Chorulon and mares treated with Ovuplant. This study provides enough evidence to support the hypothesis that timing of ovulation is a more reliable event in mares treated with Ovuplant compared with those treated with Chorulon.