Oogenesis in the common Japanese conger Conger myriaster   总被引：1，自引：0，他引：1  

TOMOKO  UTOH  NORIYUKI  HORIE  AKIHIRO  OKAMURA  YOSHIAKI  YAMADA  SATORU  TANAKA  NAOMI  MIKAWA  ATSUSHI  AKAZAWA  HIDEO P  OKA 《Fisheries Science》2003,69(1):181-188

ABSTRACT:    We investigated the process and characteristics of oogenesis in the common Japanese conger Conger myriaster . Young fish caught in November 1996 were reared for use in this experiment. Fish were sampled monthly from December 1997 to August 1998. Some were injected with human chorionic gonadotropin to stimulate ovarian maturation from May to August 1998. Oocytes from the chromatin nucleolus stage to the secondary yolk globule stage were obtained from non-hormone-treated fish; those of more advanced stages were obtained from hormone-treated ones. We divided oocyte development into eight stages from the chromatin nucleolus stage to the maturation stage. The yolk vesicle stage was not separated because yolk vesicles began to appear just after appearance of yolk globules. Oocyte, oil droplet, yolk globule and nucleus diameters all increased concomitant with oocyte development. Oil droplet and yolk globule diameters increased remarkably at the maturation stage. However, zona radiata thickness peaked at the secondary yolk globule stage, decreasing gradually thereafter. Increased gonadosomatic index was related to oocyte development as found in European and Japanese eels receiving hormone treatment to mature. The present study is the first report describing oogenesis characteristics in congrid eels. It indicates that oogenesis is almost identical to that of other anguillid eels.  相似文献   

Dietary vitamin A requirements of juvenile Japanese flounder Paralichthys olivaceus   总被引：1，自引：0，他引：1  

L.H.H. HERNANDEZ  S.-I. TESHIMA  M. ISHIKAWA  S. ALAM  S. KOSHIO  & Y. TANAKA 《Aquaculture Nutrition》2005,11(1):3-9

A 70‐day feeding experiment was conducted to assess the dietary vitamin A (VA) requirements of juvenile Japanese flounder (Paralichthys olivaceus). Six semi‐purified diets with VA supplementations of 0, 5000, 10 000, 15 000, 20 000 and 25 000 IU kg^?1 were fed twice a day to triplicate groups of 20 juveniles per tank with an initial weight of 1.59 ± 0.01 g (mean ± SE). Weight gain (WG) and specific growth rate (SGR) increased as dietary VA increased up to 10 000 IU kg^?1. Significantly lower WG and SGR were observed for the 0 IU kg^?1 treatment than for treatments of 5000, 10 000 and 15 000 IU kg^?1. Highest WG and SGR were observed in fish fed 10 000 IU kg^?1; slightly lower values were recorded in fish fed 15 000, 20 000 or 25 000 IU kg¹. No significant difference was observed in survival rate among treatments. Whole body total lipid was significantly higher in fish fed 0 and 5000 IU kg^?1 than for other levels. Reduced growth and small livers were observed as signs of VA deficiency in fish fed 0 IU kg^?1. Slightly reduced growth and pale fragile livers were observed as effects of VA excess in fish fed 25 000 IU kg^?1. Total retinol contents in liver and eyes increased with increasing levels of dietary VA. No retinol was detected in livers, and significantly lower total retinol content was observed in eyes, of fish fed 0 IU kg^?1. WG analysed by the broken line method indicated that an optimum dietary VA requirement of 9000 IU kg^?1.  相似文献   

Effect of citrus pulp silage feeding on concentration of beta‐cryptoxanthin in plasma and milk of dairy cows     

Masahito TANAKA  Yuko KAMIYA  Tomoyuki SUZUKI  Yutaka NAKAI 《Animal Science Journal》2010,81(5):569-573

Citrus pulp is known to contain a functional molecule of beta‐cryptoxanthin which is one of the carotenoids showing anti‐oxidative capacity. Influences of citrus pulp silage feeding to dairy cows on beta‐cryptoxanthin concentration in plasma, other blood properties and milking performances were investigated. Four Holstein cows were fed total mixed ration (TMR) containing citrus pulp silage 20% dry matter (DM) for 2 weeks with free access to the TMR. Dry mater intake, milk production and milk components 2 weeks later were not altered compared with those of the control group without citrus pulp silage. Activities of aspartate aminotransferase, alanin aminotransferase and gamma‐glutamyltranspeptidase in plasma were not affected by feeding of citrus pulp silage. Concentrations of protein, albumin, sulfhydryl residue, ascorbic acid, thio‐barbituric acid reactive substance and urea nitrogen in plasma were also not altered by citrus pulp silage feeding. Concentration of beta‐cryptoxanthin in plasma was increased approximately 20‐fold compared with the control group (P < 0.05). Content of beta‐cryptxanthin in pooled milk fat fraction was also increased approximately three times compared with that of the control group. Feeding of TMR containing citrus pulp silage 15% DM for 30 days to eight dairy cows also increased plasma beta‐cryptoxanthin concentration 30‐fold compared with that before feeding.  相似文献   

Radiotherapy-induced tumor lysis syndrome in a dog with thymoma     

Yusuke WADA  Hiroki YAMAZAKI  Miyuu TANAKA  Ayumi KANEGUCHI  Toshiyuki TANAKA  Hideo AKIYOSHI  Shunsuke NOGUCHI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(8):1290

A 13-year-old, female, mixed-breed dog with a huge cranial mediastinal mass underwent radiotherapy (RT). On the following day, the dog presented with lethargy and anorexia. Hematological examination revealed elevated levels of blood urea nitrogen, creatinine, inorganic phosphorus, potassium, lactate dehydrogenase, creatine phosphokinase and aspartate aminotransferase, decreased calcium level, and metabolic acidosis. Urine output markedly decreased. The patient recovered with fluid therapy and diuretic therapy; however, died suddenly from an unknown cause 11 days after RT completion. Histopathological examination after necropsy showed thymoma in the cranial mediastinum and extensive tubular necrosis of both kidneys which may be due to RT-induced tumor lysis syndrome (TLS). This report suggests that the risk of TLS should be evaluated in dogs with thymoma who undergo RT.  相似文献   

Calming effect of orally administered γ‐aminobutyric acid in Shih Tzu dogs     

Katsuji UETAKE  Ayano OKUMOTO  Noriko TANI  Akihiro GOTO  Toshio TANAKA 《Animal Science Journal》2012,83(12):796-798

The calming effects of γ‐aminobutyric acid (GABA) by oral administration were investigated in four adult Shih Tzu dogs. Three dosage levels (1, 2 and 4 mg/kg body weight) and non‐administration were tested by an increase and decrease method. Changes in activity (for 1.5 h) and urinary cortisol levels (pre‐administration, 3 and 7 h later) of dogs were monitored after administration. Without reference to dosage level, the mean times spent standing (P = 0.06), sitting (P < 0.05) and walking (P < 0.05) tended to decrease compared to non‐administration. A significant depression in the urinary cortisol level was observed at 7 h after administration (P < 0.05). These results indicate that orally administrated GABA exerts calming effects on dogs as well as humans.  相似文献   

Ocular medulloepithelioma in a Thoroughbred     

Y. UEDA  H. SENBA  T. NISHIMURA  T. USUI  K. TANAKA  S. INAGAKI 《Equine veterinary journal》1993,25(6):558-561

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The humoral response in natural Dirofilaria immitis infections in dogs     

K. TANAKA  RB ATWELL 《Australian veterinary journal》1991,68(12):396-399

Plasma samples from dogs with infections of Dirofilaria immitis were assessed using ELISA and Western blotting techniques. These results were then assessed in relation to age and sex of the host, and to the numbers of microfilariae and adult filariae. Dogs with microfilariae tended to have lower levels of infection. In infected dogs, mean ELISA titres increased directly with the degree of infection. Dogs that were either young or mildly infected, showed a preferential antibody reactivity to antigens in the high molecular weight regions of the immunoblots. With increasing age and/or the extent of infection, an antibody response to antigens in the low molecular weight regions was apparent.  相似文献   

Ruminal distribution of the cellulolytic bacterium Fibrobacter succinogenes in relation to its phylogenetic grouping     

Satoshi KOIKE  Jun PAN  Tomoyuki SUZUKI  Toru TAKANO  Chihiro OSHIMA  Yasuo KOBAYASHI  Keiichi TANAKA 《Animal Science Journal》2004,75(5):417-422

To investigate the ecological importance of the cellulolytic bacterium Fibrobacter succinogenes in fiber digestion, ruminal distribution of F. succinogenes was determined in relation to its phylogenetic grouping. Rumen digesta from wethers and steers fed orchardgrass hay, rice straw or fresh orchardgrass were employed as the materials for the analyses. Orchardgrass hay stem incubated in the rumen was also used. By using total DNA extracted from these materials, population sizes of total F. succinogenes and of four different phylogenetic groups of this species were quantitated through competitive polymerase chain reaction (PCR), and restriction fragment length polymorphism analysis of PCR products targeted the bacterial 16S rDNA. Rumen digesta and ruminally incubated hay stems had a reasonably high population size of F. succinogenes (×10^7?8/g) that was composed of strains belonging to the phylogenetic groups 1 and 3. The relative abundance of each group was different among the samples; group 1 dominated on the ruminally incubated hay stem and in the rumen of wethers fed fresh orchardgrass, while group 3 was major in the rumen of wethers and steers on hay diet. These results suggest that there could be phenotypic differences among the phylogenetic groups of F. succinogenes, and group 1 dominating on hay stem might contribute to rumen fiber digestion more than the other groups.  相似文献   

Temperament assessments of lactating cows in three contexts and their applicability as management traits     

Katsuji UETAKE  Robert J. KILGOUR  Toshie ISHIWATA  Toshio TANAKA 《Animal Science Journal》2004,75(6):571-576

The applicability of three behavioral assessments of lactating cows as management traits was verified. Flight responses to an approaching human (flight starting and walking distances, and flight walking speed) at pasture, entrance order into the milking parlour and step‐kick behavior to cup attachment were observed for 713 subject cows in six Australasian dairy farms. On all farms, cows were kept at pasture without any barn housing. Flight responses were measured once, and other assessments were recorded repeatedly for each subject cow. A principal component analysis was performed to verify whether these assessments appear to measure the same trait. A two‐way anova and correlation analyses were then used to test whether obtained principal components were affected by farm, age and milking stage of cows. Australian and some Japanese herd management systems were compared for flight distance using a one‐way anova and a multiple comparison test. Three behavioral assessments clustered in different principal components, indicating that these assessments did not appear to measure the same trait. Factor scores of four principal components were affected by farm (all, P < 0.01), and the scores of principal component 1, interpreted as fear of humans (r = ?0.16, P < 0.01), and component 2, interpreted as aversion to cup attachment (r = ?0.28, P < 0.01), were moderately correlated with age. These results emphasize the necessity of data standardization to reduce the non‐genetic variation resulting from these two affectors. The flight distance at pasture of herds in Australia (6.06 ± 2.85 m) was significantly (P < 0.05) different from the flight distances measured in paddocks (1.50 ± 0.82 m) and free‐stall barns (1.22 ± 1.09 m) in Japan. However, mean distances were not different between the Australian herds at pasture and the Japanese herds at pasture in tie‐stall barns (3.96 ± 2.16 m) or in a free‐stall barn (4.03 ± 1.79 m). This difference could be a result of the fact that only a single measurement was made, so that repeated measurement might improve the usefulness of flight distance as a management trait. In conclusion, it was verified that step‐kick behavior to cup attachment and flight responses to human approach were, although they have some affectors, applicable as objective management traits in lactating cows.  相似文献   

Effects of high ambient temperature and restricted feed intake on nitrogen utilization for milk production in lactating Holstein cows     

Mitsuru KAMIYA  Yuko IWAMA  Masahito TANAKA  Shigeru SHIOYA 《Animal Science Journal》2005,76(3):217-223

Three experiments were performed to examine the effects of high ambient temperature and feed restriction on nitrogen (N) utilization in lactating cows. Experiment 1 investigated N utilization in four cows fed ad libitum in a 2 × 2 crossover design under constant moderate (18°C) or high (28°C) ambient temperatures. The milk N secretion (P < 0.01) and protein concentration (P < 0.05) decreased under high ambient temperature. Experiment 2 investigated N utilization in four cows under constant moderate ambient temperature in a 2 × 2 crossover design with ad libitum or 70% ad libitum feed intake. The milk N secretion and protein concentration both decreased with feed restriction (P < 0.05). Experiment 3 investigated N utilization in four cows fed 70% ad libitum in a 2 × 2 crossover design under constant moderate or high ambient temperatures. The milk protein concentration decreased under high ambient temperature (P < 0.01). The milk N secretion tended to decrease under high ambient temperature (P < 0.10). Therefore, decreased N utilization for milk production at high ambient temperature is mainly caused by a reduced feed intake and the high ambient temperature itself.  相似文献