This experiment was conducted to evaluate the permissible concentration (P.C.) of gizzerosine (GIZZ) in the broiler diet. Four diets (DL-GIZZ: 0, 0.4, 0.5 and 0.6ppm) were prepared. Eighty broiler chicks were allocated to each diet and fed for 28 days. The numbers of chicks displaying the growth retardation and the total number of the days of growth retardation were as follows: the basal diet; 4 chicks, 4 days. 0.4ppm diet; 10 chicks, 10 days. 0.5ppm diet; 12 chicks, 22 days. 0.6ppm diet; 15 chicks, 19 days. The chicks fed on 0.4ppm diet showed the same trend as those on the basal diet until the 27th day of the experiment, however, 5 chicks showed growth retardation on the last day.
It was impossible to estimate the P.C. of dietary GIZZ from the results of this experiment except that P.C. was less than 0.4ppm (DL). This is because it is possible that more chicks might have had a depressed performance on the 0.4ppm (DL) GIZZ diet, if the feeding was continued for more than 4 weeks, according to the duration of commercial broiler feeding. In order to determine the P.C. of GIZZ, more experiments, in which the concentration of GIZZ extending to a lower range than 0.2ppm (L) should be performed. The duration of such an experiment should correspond to practical feeding periods. It is very important to consider carefully the relationship between the dietary concentration of GIZZ and the duration of the experiment in analyzing the results.
There was no statistically significant difference in the weight gains and feed intakes between the diets. However, the weight gains of the 0.4 and 0.5ppm diets were 40.3g and 26.1g respectively more than that of the basal diet, in spite of greater numbers of growth retarded chicks on both the former diets. The feed efficiencies among the diets were the same. These observations seem likely to show that there was a possibility that a small amount of GIZZ promoted the growth and the feed intake of the chicks.

View full abstract

A dual-chambered incubation system has been developed in which the vectorial secretion of progesterone of the quail granulosa layer in response to ovine luteinizing hormone (LH), can be measured. In the presence of LH in the chamber originally faced on the yolk, there was an equal increase in progesterone secretion in both of chambers after 3 h of incubation at 39°C. When LH was added in the chamber originally faced on the theca layer, progesterrone secretion was significantly higher in this chamber than in the chamber originally faced on the yolk. These results indicate that the LH stimulation on the granulosa cells is from the side of theca layer and progesterone output is preferentially to the theca layer, and that this incubation system of the granulosa layer is quite effectual for the study on the vectorial secretion of steroid hormones from cells.

View full abstract

The W chromosomal DNA fragments of the domestic chicken, Gallus gallus domesticus, and Japanese quail, Coturnix coturnix japonica, were separated as bands by pulsed field gel electrophoresis after digestion with restriction endonucleases. These fragments were detected with 14 kinds of restriction endonucleases out of the 20 kinds in the chicken and only 1 kind of restriction endonucleases out of 16 kinds in the quail. In the chicken, many of these fragments were molecules greater than 2 megabasepairs (Mb) in size and hybridized with the W chromosome-specific 0.7Kb XhoI repetitive DNA sequences of the chicken. However, the W chromosomal DNA fragments which did not show hybridization with the 0.7Kb XhoI repeating unit were detected as 3 bands with DraI digestion and as 4 bands with EcoRI digestion up to a size less than 2Mb in the chicken. The results may suggest that there could be some other repeating units than has been reported before.

View full abstract

The present study was designed to localize androgen receptor in the cloacal gland of the male Japanese quail by immunohistochemical method. Frozen sections of the cloacal tissue were immunostained using a polyclonal antibody to human androgen receptor. In 15 days old male quail embryos, 20 and 80 days old birds, the positive immunoreaction for androgen receptor was observed in the nuclei of glandular cells and dorsal proctodeal epithelial cells. The intensity of immunoreactive staining in the glandular cells was higher in 80 days old birds than the others. The structure of the cloacal gland was much well developed in testosterone-treated 6-day-old males than in vehicle treated ones. In both testosterone-treated and vehicle treated immature quails, positive immunoreaction was observed in the glandular cells and dorsal proctodeal epithelium. These results suggest that androgens induce the development of cloacal gland and doral proctodeal epithelium and also enhance the secretory activity of cloacal gland in an androgen receptor mediated manner.

View full abstract

Hatching results of eggs shipped were reported here. The broiler eggs were delivered from a farm at Miyazaki to a hatchery at Okinawa. The delivery was done 60km by a van, 610km by a freighter and 10km by another van. The total delivery distance and time were 680km and 35 hours, respectively. Approximately 5.4 million broiler eggs were used in 340 hatchery operations from 1987 to 1990. The vans were not air-conditioned. Insulated containers were used to keep at 20°Cwhen shipping only from June to October. The eggs were set in a setter within 7 days after eggs were laid.
Hatchability of the eggs set in each year was ranged from 80.0 to 88.1%. Healthy chicks were obtained from 97.1 to 98.8% of newly hatched chicks. Seasonal effect was observed on hatchability of the eggs. Hatchability in spring and winter was higher than that in summer, respectively. Hatchability was also under the influence of hen age laid the eggs. Hatchability was 87.7% from 28 to 30 and 88.8% from 36 to 40 weeks of age of the hen. Decreasing tendency of hatchability was observed after 46 weeks of age of hen. Hatchability from 51 to 58 weeks of hen age decreased less than 80%.
The hatchability of the eggs shipped in the current study, it would seem similar to those of conventional unshipped eggs. It is considered that no obvious interference was observed in hatching results of eggs delivered under conditions mentioned above.

View full abstract

Alkaline phosphatase (ALP)-positive osteogenic cells following the administration of estrogen to mature male quail were isolated and the action of estrogen on the proliferation of these cells was examined. Following the treatment with estrogen, 60% of the cells isolated from the femoral endosteal surface and the bone marrow were ALP-positive osteogenic cells. These cells cultured for 144 hours in media containing 10^-9, 10^-8 and 10^-7 M estrogen. These cultured cells caused an estrogen dose-dependent increase in ALP-positive cell content. The autoradiographic results also indicated an estrogen dose-dependent acceleration of 3H-thymidine uptake by osteogenic cells, which was inhibited by an anti-estrogenic tamoxifen. These results suggest that estrogen stimulates the proliferation of oteogenic cells.

View full abstract

Granulosa cells of avian follicles proliferate during follicular growth, and differentiate to secrete progesterone in response to luteinizing hormone (LH), when the follicle becomes the largest. In order to study the mechanism of growth and differentiation, quail granulosa cells were cultured with various gonadotrophins or epidermal growth factor (EGF).
The culture medium was a mixture of McCoy's 5 a and Ham's F 12 (1:1) supplemented with glutamine, HEPES and antibiotics. The concentration of fetal calf serum was 10% during the initial 6 hr, and then was reduced to 1%. In order to evaluate the LH response of the cells after the culture, the cells were incubated with or without LH for 3 hr in Krebs-Ringer solution, and progesterone production was measured.
When the granulosa cells were cultured with follicle stimulating hormone (FSH) for 72 hr, the response to LH was increased while the cell numbers were not increased. When the granulosa cells were cultured with EGF for 72 hr, the cell numbers increased, but the LH response of the cells was diminished.
These results suggested that the growth and differentiation of the granulosa cells during follicular maturation was controlled by both FSH and EGF.

View full abstract

Crude cell membrane fractions of cephalic and caudal lobes of the anterior pituitary of chickens were obtained, and binding to ¹²⁵I•arginine vasotocin (AVT) were examined. In both lobes, the binding to ¹²⁵I•AVT was specific and saturable. Equilibrium dissociation constant (Kd) and maximum number of binding sites (NBS_max) estimated by the Scatchard analysis were the order of 10^-10M and the value of 10^-13moles per mg protein, respectively. Although the value of the Kd was not different, the NBS_max value in laying hens was higher than that in cocks and also was higher in caudal lobes than in cephalic lobes. The results suggest that AVT receptors are present in the anterior pituitary of chickens.

View full abstract

This study was conducted to elucidate the effects of Aigamo ducks on growth and production of rice plant in paddy rice farming. Three paddy fields were used: (1) control plot, no ducks and no agrochemicals; (2) agrochemicals plot, agrochemicals were used according to the standard established by Kagoshima prefecture and (3) Aigamo plot, no agrochemicals but keeping ducks. Thirty five Aigamo ducks in four weeks of age were introduced to the plot (10a) initially and the number was adjusted to seventeen later. Aigamo ducks were kept in the plot for two months, at which the head of rice plants have formed.
The following result was obtained.
1. The height of rice plant in the agrochemicals plot was significantly (P<0.01) higher than those of other two plots during the first half period, but their differences in height disappeared during the latter half period.
2. The number of culms of rice plant increased in the order of Aigamo, control and agrochemicals plots.
3. Total leaf area of rice plant in the agrochemicals plot was significantly (P<0.01) higher than those of other two plots. Where the height of rice plant was 60-70cm, the relative illuminance did not differ among three plots, but where the height of rice plant was 50cm or below, agrochemicals plot tended to have lower relative illuminance than those of other two plots.
4. The number of rice plants badly damaged by Aigamo ducks was 446, which is equivalent to 4.5%.
5. The number of heads, ripening grains and yield crops per stump of rice plant increased in the order of Aigamo, control and agrochemicals plot. But the yield crops of rice plant per 10a did not differ between Aigamo and agrochemicals plots.

View full abstract