Estrone sulfate (E₁S) is predominantly present in the maternal circulation of pregnant animals and is excreted into the feces and urine. Hence, it is estimated that E₁S is partly present in the environment, which may be discharged from farms. The present study was undertaken to examine whether E₁S affected the endocrine function in animals. Male Japanese quails were intramuscularly treated 1mg of E₁S everyday for 4 days. Blood samples were obtained just before the treatment and at the 4 days after the onset of treatment to measure the concentrations of testosterone, E₁S and triacylglyceride. Apoptotic cell death was detected in the paraffin sections of testis. The weight of testis was significantly reduced in the E₁S treated groups compared with that of untreated group. Treatment of E₁S to the quail significantly increased plasma E₁S and triacylglyceride concentrations and significantly reduced plasma testosterone concentration. Some Sertoli cells in the E₁S treated group showed apoptotic cell death, whereas there is few apoptotic cells in the untreated group. These results indicate that E₁S has ability to induce apoptosis in the testicular cells and reduction of testicular weight and testosterone concentration, possibly due to the unconjugation of E₁S. It is also suggested that E₁S may be one of risk factors for endocrine disrupter in wild life.

View full abstract

To establish the basic histological data on intestinal villi in chickens fed a semi-purified pellet diet, birds were divided into the following groups : intact control (IC), 3-d fasting (F), ad libitum refeeding of a formula mash diet (AFM), or force-feeding of a formula pellet diet (FFP) or a semi-purified pellet diet (FSP) for one day after 3-d fasting. The intestinal histological recovery in these groups was compared with light (LM) and scanning electron microscopy (SEM).
The body weight recovery was similar in AFM and FFP, but they tended to be faster than that of FSP. In LM observations, the decreased values of villus height, cell area, cell mitosis, and villus area in F tended to recover to the IC level in AFM and FFP and but did not recover in FSP. All parameters of AFM and FFP were almost the same. In SEM observations, the dome-shaped cells, cell outlines, and cell protuberances seen in IC became faint in F, and the luminal surface area of the cells became small (P<0.05). After refeeding, the dome-shaped cells and the clear cell outline reappeared in AFM and FFP, and such a morphological recovery was clearer in FFP than AFM. The luminal surface area of the cells tended to increase in AFM and increased in FFP (P<0.05). In addition, cell clusters were frequently observed in FSP. The present histological observations after refeeding suggest that the formula diet can induce hypertrophic intestinal histological alterations at the villus and cell levels. However, although the semi-purified diet does not bring about the histological activation of the villi, it is quicker than the formula diet to activate the cell function. Therefore, it seems that the formula diet produces intestinal histological alterations related to intestinal function at LM and SEM levels, but such a relationship is limited to the SEM level in the semi-purified diet.
This demonstrates that nutritional and physiological data from the semi-purified diet cannot always be applied to feeding with a formula diet.

View full abstract

Type I collagen is one of the major components contained in the eggshell membrane. The aim of this study was to determine whether the expression of type I collagen mRNA is changed during the passage of the egg through the oviduct in Japanese quail. Immunofluorescent cytochemistry to localize type I collagen in the oviduct and semi-quantitative RT-PCR to examine the changes in its mRNA expression were carried out. Immunoreactive type I collagens were localized in the tubular gland cells of the isthmus as well as in the interglandular connective tissue of all the oviductal regions. The expression of type I collagen (α2) mRNA was significantly greater when the egg was in the isthmus, compared when the eggs were in the other regions. We suggest that the synthesis of type I collagen by the glandular cells of the isthmus is enhanced in association with the egg passage through that region.

View full abstract

The effects of supplementation of cellulase, xylanase, pectinase, hemicellulase, glucanase, phytase and protease of microbial origins on digestibilities of crude protein (CP) and dry matter (DM) of maize in vitro were examined in the present study. Changes in the viscosity during in vitro digestion were also examined as an index of carbohydrate digestibility. Cellulase significantly improved CP digestibility. Protease, phytase, pectinase, xylanase, glucanase, and hemicellulase had no effect on the CP digestibility. Crude protein digestibility was the highest when all the enzymes except protease were added. No enzymes used had significant effect on DM digestibility of maize. Supplementing maize with protease, cellulase, pectinase, xylansase, phytase, glucanase, or hemicellulase had no effect on the viscosity at both peptic and pancreatic phases. On the other hands, viscosity of maize was the highest when all the enzymes were added simultaneously. These results suggest that the viscosity is not always a good index of carbohydrate digestibility. In conclusion, the present results strongly suggest that cellulase and the combination of carbohydrases improves CP digestibility of maize while protease inhibits the actions of these enzymes.

View full abstract

Domestic chickens, which are precocial, have relatively well developed mechanisms of food intake regulation at hatch. Although their body weight is similar at hatch, broiler- and layer-type chickens have different growth rates and food intake following hatch. The purpose of the present study was to compare the hypothalamic content of the monoamines norepinephrine (NE), epinephrine (E), dopamine (DA) and serotonin (5-HT), and their metabolites dihydroxyphenylacetic acid (DOPAC), 4-hydroxy-3-methoxyphenylacetic acid (HVA) and 5-dihydroxyindolacetic acid (5-HIAA) between these strains on day 18 of incubation, and at 0 day-of-age. In both strains, 5-HT and 5-HIAA levels increased with age. On day 18 of incubation, the amounts of NE and E were almost the same between the two strains. Thereafter, the content of both monoamines rapidly increased at hatch in both strains, and layer-type chicken embryos had significantly higher E levels compared to broiler-type chicken embryos. The levels of DOPAC and HVA on day 18 of incubation were higher in broiler-type chicken embryos than in layer-type chicken embryos, but these differences were reduced at hatch. These changes at hatch may partly explain the difference in the performance between the two strains.

View full abstract

A total of 192 d-old Arbor Acres broiler chicks were fed ad libitum up to 42 d of 16 isonitrogeneous and isocaloric diets of different combination levels of phytase (0, 750, 1000 and 1250FYT/kg) (FYT=Feed Grade Yield Treatment Unit) and carbohydrase (0, 80, 100 and 120ppm/kg) for a better utilization of parboiled rice polish (PRP) in broiler diet. The growth rate, feed conversion efficiency, survivability, meat yield and profitability increased almost linearly by using increased levels of mixed enzymes in PRP based diets. Therefore, it was concluded that it is feasible to reduce grain by using abundant PRP in ration with the supplementation of phytase and carbohydrase, and this treatment may be an efficient and economic way to improve performance of broiler as well as profitability.

View full abstract

The effects of storage of eggs for 0, 2, 8, 14, or 18 days prior to incubation, as measured by growth and developmental homeostasis of bilateral traits, were studied in broiler embryos. Data were obtained on hatchability, and for 10 embryos from eggs selected at random at 10, 14, and 18 days of incubation and at hatch from each storage period. Skeletal traits included lengths of left and right face, wing, tibia, femur, and shank as well as weights of the heart and left and right lungs. Eggs stored for 14 and 18 days had poorer hatchability than those stored for 0 and 2 days, with the 8-day storage group intermediate. There was a trend (P=0.08) for reduced lung weights of embryos from eggs stored for 18 days before incubation, whereas length of storage had no effect on heart weights. Femur and tibia lengths were affected by length of preincubation storage. Lengths of femur, tibia and shank differed among embryonic ages demonstrating that these bones grow at different rates during incubation. Polynomial equations are provided for size of traits. Developmental asymmetry of bilateral traits was influenced by length of preincubation storage and embryonic age. Relative asymmetry declined steadily from 10 days of incubation towards time of hatch.

View full abstract

This study was conducted to elucidate relationship between testicular protamine mRNA expression and spermatogenic activity in the quail as the following experiments. (1) Quail were raised under continuous light condition after hatching and body weights, testis weights, spermatogenic activity and protamine mRNA levels were determined weekly between 3 and 8 weeks. (2) The other group of quail raised under continuous light condition up to 6 weeks after hatching were kept in either continuous light or reduced light-length (8-hour light, 16-hour darkness) conditions for 3 weeks. At 6 and 9 weeks old, the same parameters were measured as in the foregoing experiment. Spermatogenic activity was evaluated by Bartholomew’s classification after histological examination of the testis and mRNA expression of testis protamine was analyzed by Northern blot. Between 3 and 5 weeks old, body weights, testis weights, and cloacal gland protrusion areas significantly increased and thereafter they stayed at plateau levels. Spermatogenic activity markedly increased from stage II to VI between 3 and 5 weeks old and stayed at stage VI up to 8 weeks old. Spermatids and immature sperm were firstly observed at 4 weeks old. Protamine mRNA levels were also first detected at 4 weeks old and increased at 5 weeks old. A marked expression were maintained after 6 weeks old. In contrast, short daylengths treatment after 6 weeks old significantly reduced testis weights, cloacal gland protrusion areas, spermatogenic activity, and protamine mRNA levels at 9 weeks old (P<0.05) when compared to those raised under continuous light condition. Spermatogenic activity dropped from the full activity of stage VI to elongated spermatid (IV) or spermatocyte (II-III) stage after the treatment. Protamine mRNA levels also significantly decreased in response to short daylengths. These results suggest that protamine mRNA expression is highly related to spermatogenic activity in the quail.

View full abstract

In order to improve transfection efficiency of the stage X blastoderm of chickens by in vivo electroporation, the effect of the size of the upper and lower electrodes was examined. The plasmid DNA (pbAEGFP) was injected into the stage X blastoderm followed by applying electric pulses vertically to the blastoderm layer. The manipulated embryos were incubated using an embryo culture system, and the GFP gene expression was then examined. By decreasing the size of the upper electrode or by increasing the size of the lower electrode, the effect of the electric pulses was clearly enhanced. Although the introduced GFP gene was efficiently expressed in the embryonic and extra-embryonic tissues, the expression in the embryos was transient. No integration of the GFP gene into the chromosomes of germline cells of chickens was detected.

View full abstract