Journal of Veterinary Medical Science
Online ISSN : 1347-7439
Print ISSN : 0916-7250
ISSN-L : 0916-7250
71 巻 , 3 号
March
選択された号の論文の25件中1~25を表示しています
Anatomy
  • Kozue UCHIO, Kyoko SAWADA, Noboru MANABE
    原稿種別: FULL PAPER
    2009 年 71 巻 3 号 p. 305-312
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    The Institute for Cancer Research (ICR)-derived glomerulonephritis (ICGN) mouse is a good model for renal fibrosis. In the glomeruli and tubulointerstitium of ICGN mouse kidneys, the components of the extracellular matrix (ECM) accumulated, and matrix metalloproteinases (MMPs) participated in this process. To clarify the mechanism of renal fibrosis, we investigated the expression and localization of macrophage metalloelastase (MMP-12), whose functions in kidney diseases are not fully understood, and its regulatory molecules, monocyte chemoattractive protein-1 (MCP-1) and CC chemokine receptor 2 (CCR2), in the kidneys of ICGN mice by RT-PCR, Western blotting and immunohistochemical staining, respectively. Extensive expression of MMP-12 mRNA and its protein was noted in ICGN mice with progressed nephrotic syndrome. The increase in MMP-12 expression occurred predominantly in podocytes. Furthermore, MCP-1 and CCR2 were also increased in podocytes of the ICGN strain. These results suggest that the expression of MMP-12 is involved in the progression of nephrotic syndrome in ICGN mice.
  • Hiroshi MURABAYASHI, Kiyoshi MIYAKAWA, Kunio TANAKA, Mitsuo SEKIKAWA, ...
    原稿種別: FULL PAPER
    2009 年 71 巻 3 号 p. 325-331
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    Substance P (SP)-immunoreactive nerve fibers in the adrenal medulla was very few during postnatal day 0-5, indicating that its synthesis in the neurons and the transport to nerve endings was incomplete by the end of this period. Since the number of SP-immunoreactive nerve fibers gradually increased during postnatal week 1-2, it was hypothesized that SP was not fully transported to nerve endings until postnatal week 1-2. At postnatal week 3, numerous SP-immunoreactive nerve fibers contacted some noradrenaline (NA) cells but not adrenaline (A) cells in the medulla. From postnatal week 3 onward, the abundance and expression patterns of SP-immunoreactive nerve fibers in the medulla were similar to those in adults. At postnatal week 3, the innervation with SP-immunoreactive nerve fibers was completed indicating the possibility that SP affected on the secretory activity of NA cells but not of A cells in the medulla. The medullary SP-immunoreactive nerve fibers contacting the chromaffin cells possessed a few dense-cored vesicles in their endings at postnatal week 8. Very few SP-immunoreactive chromaffin cells were found in the medulla from postnatal day 0 onward, and SP immunoreactivity was primarily observed in granular cores of the cells suggesting that SP and catecholamine synthesized in the chromaffin cells were released from the granules by adequate stimuli. Very few or a few SP-immunoreactive nerve fibers, acting as a vasomotor effect were found around blood vessels in the superficial cortex from postnatal day 0 onward.
  • Saki IMAI, Yasuo MORITOMO
    原稿種別: NOTE
    2009 年 71 巻 3 号 p. 337-340
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    Segmental hypoplasia not associated with vertebral abnormalities was found in a Japanese Black calf that was unable to stand. Constriction occurred between the third and 5th segments of the lumbar spinal cord, and was most severe in the 4th segment. Myelodysplasia, such as hydromyelia and syringomyelia, absence or interruption of the central canal, dysplasia of the gray matter, and absence or divergence of the septal connective tissue at the dorsal median septum or the ventral median fissure, were confirmed histologically. These changes indicate hypoplasia of the segments affected following neural tube closure. Therefore, this case was suspected to be a closed neural tube defect.
  • Masako YAMAMOTO, Shinya KOHARA, Tetsuo KOBAYASHI, Mitsuyuki SHIRAI, Os ...
    原稿種別: NOTE
    2009 年 71 巻 3 号 p. 375-378
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    In our previous study, prenatal diethylstilbestrol (DES) exposure (days 7-21 of gestation) suppressed plasma testosterone levels and histological development in the epididymis of rat offspring. In this study, we measured cell proliferation in epididymal ductules and the expression of steroid hormone receptors and 5α-reductase 1 in the epididymis to assess the effect of DES on epididymal development in the offspring. Prenatal DES exposure did not alter the cell division index, but suppressed the expression of androgen receptor mRNA at 15 weeks after birth, and stimulated estrogen receptor α mRNA at 6 weeks. These results suggest that prenatal DES exposure results in the retardation of epididymal tissue maturation by disruption of the postnatal expression of steroid hormone receptors.
Avian Pathology
Bacteriology
Immunology
  • Boniface NAMANGALA, Patrick DE BAETSELIER, Alain BESCHIN
    原稿種別: FULL PAPER
    2009 年 71 巻 3 号 p. 313-318
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    The host immune system has been documented to influence the course and outcome of infection with the phospholipase-C-deficient (PLC-/-) Trypanosoma brucei brucei. We addressed the resistant mechanisms during trypanosomosis by comparing the immune response to variant-specific surface glycoprotein (VSG) in relatively susceptible C3H mice and trypanotolerant (C57BL/6 × BALB/c)-F1 (B6B-F1) mice infected with PLC-/- parasites. During the early stage of infection, lymphoid cells from both PLC-/--susceptible C3H and -tolerant B6B-F1 mice mainly secreted VSG-specific IFN-γ. Although C3H mice remained locked in a type-I cytokine environment (IFN-γ, TNF-α) during late stage of infection, B6B-F1 mice switched to production of type-II cytokines (IL-4, IL-10) from late stage of infection onwards. It seems that VSG-specific cytokine responses associated with resistance to murine African trypanosomosis are infection-stage dependent, with type-I cytokine responses being critical during the early stage of infection while type-II cytokine responses appear to be more important during the late and chronic phases of the disease. Because of the striking similarities in the course of the PLC-/-infection in B6B-F1 mice with that of the trypanotolerant N'dama cattle naturally-infected with T. congolense, the PLC-/--infected B6B-F1 mice represents a suitable model to study the course of infection and immune responses during bovine trypanosomosis.
Internal Medicine
  • Mamoru ONUMA, Hirotaka KONDO, Sadaharu ONO, Mariko UEKI, Hisashi SHIBU ...
    原稿種別: NOTE
    2009 年 71 巻 3 号 p. 355-358
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    As ferrets can suffer from a wide variety of cardiac disorders, indicators for detecting cardiac abnormalities on plain chest radiography are necessary. A total of 64 ferrets without heart disease underwent radiography in the right lateral (RL) and ventrodorsal positions (VD), and the lengths of the RL-sixth dorsal vertebra (6th DV), RL- and VD-long axis (LA) and RL- and VD-short axis (SA), RL- and VD- vertebral heart size, VD-length of the eighth costa (LEC) and VD-thoracic width at the eighth thoracic vertebra (8th TV) were measured to establish standard values of normal cardiac appearance. We evaluated statistical differences between genders and ferrets weighing < 1 kg and ≥ 1 kg for a total of 38 items. As a result, significant differences (P<0.05) were observed in all items, including some differences that have been reported previously. In particular, the present study established highly accurate standard values for weight differences. Standard values calculated based on the 6th DV and a relational expression obtained by the regression coefficient of the ratio of VD-SA to VD-8th TV, VD-8th TV=2.887 + (0.769 × VD-SA), were considered useful for evaluating normal cardiac morphology in ferrets.
  • Aya MATSUU, Takuya HASHIZUME, Teppei KANDA, Masashi NAGANO, Akihiko SU ...
    原稿種別: NOTE
    2009 年 71 巻 3 号 p. 379-381
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    A 10-year-old Miniature Schnauzer with bilateral cryptorchidism and male external genitalia was referred with a history of abdominal enlargement. Upon exploratory laparotomy, two tumors and a connecting structure similar to fluid-filled uterus were recognized. After cytological and bacterial examinations of the fluid and histological examination, this dog was diagnosed with bilateral Sertoli cell tumor with hydrometra. The karyotype of this dog was 78, XY and the sry gene was detected positive by PCR. We diagnosed this dog as a case of persistent Müllerian duct syndrome (PMDS), which is male pseudohermaphroditism. This is the first report regarding the incidence of PMDS in Miniature Schnauzers in Japan, and it suggests the involvement of a gene carrier.
Laboratory Animal Science
  • In Koo HWANG, Il Yong KIM, Yo Na KIM, Sun Shin YI, Yu Hee LEE, Eun Jeo ...
    原稿種別: FULL PAPER
    2009 年 71 巻 3 号 p. 275-280
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    We investigated the effects of methimazole, an anti-thyroid drug, on the onset of type 2 diabetes in Zucker diabetic fatty (ZDF) rats. For this, 0.03% methimazole was administered to 7-week-old, pre-diabetic ZDF rats in drinking water for 5 weeks and the animals were sacrificed at 12 weeks of age. Methimazole treatment to ZDF rats significantly reduced blood glucose levels, food intake, body weight, and serum T3 levels. Hepatocytes in ZDF-methi rats were more densely stained with eosin than those in ZDF rats because of low fat accumulation in ZDF-methi hepatocytes. The pancreatic islet in ZDF-methi rats was normal compared to that in ZDF rats. Glucagon, not insulin, immunoreactivity in ZDF-methi rats was significantly higher than that in ZDF-methi rats. These suggest that methimazole treatment may delay the onset of type 2 diabetes in leptin receptor-deficient rats and also suggests that thyroid hormones may be necessary for the onset of diabetes.
Pathology
  • Daisuke KOJIMA, Chun-Ho PARK, Yusuke SATOH, Satoshi INOUE, Akira NOGUC ...
    原稿種別: FULL PAPER
    2009 年 71 巻 3 号 p. 319-324
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    Fixed rabies viruses (CVS-11 strain) were inoculated intramuscularly to C57BL/6J mice, and the pathomorphological changes of the spinal cord including dorsal root spinal ganglion cells were investigated. At 4 days postinoculation (PI), viral antigens were first detected in the spinal neurons and dorsal root spinal ganglion cells without producing morphological changes. At 5 days PI, mild infiltration of lymphocytes was observed around the central canal, small blood vessels and leptomeninges. Cells positive to anti-Iba1 and anti-GFAP antibodies increased significantly from 3 to 5 days PI, respectively. Microglia changed their morphological forms to be ramified or amoeboid, and astroglia extended their cytoplasm from the leptomeninges to the parenchyma. At 7 days PI, apoptotic cells were found in the spinal cord and dorsal root spinal ganglion using TUNEL. We confirmed that most of T lymphocytes and a minority of microglial cells underwent apoptosis, using a combination of TUNEL and immunostaining with antibodies to viral phosphoprotein, CD3, Iba1 and GFAP. On the other hand, astroglial cells and virus-infected nerve cells were negative against TUNEL and cleaved caspase-3 antibody. These findings indicate that T lymphocytes and microglial cells died by apoptosis, whereas virus-infected nerve cells died by necrosis. This was accompanied by increased numbers and morphological changes of glial cells associated with the pathogenesis of CVS-11 in the C57BL/6J mouse.
  • Kyohei AGO, Makoto SHIBUTANI, Yukie SAEGUSA, Tomomi SHIMA, Eriko TANIA ...
    原稿種別: NOTE
    2009 年 71 巻 3 号 p. 345-347
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    We report a case of cerebellar neuroblastoma in a 19-week-old p53 null mutation mouse. A white and soft mass was observed at the cerebellar vermis. Histologically, the tumor consisted of solid growth of round to oval pleomorphic cells with frequent mitotic figures. While there were no typical cellular arrangements of embryonic neurogenic tumors, such as Homer-Wright rosette, perivascular pseudorosette, or streaming of neoplastic neurocytes, small populations of the neoplastic cells were immunohistochemically positive for synaptophysin, microtubule-associated protein 2, S-100 and nestin. Both glial fibrillary acidic protein and vimentin were entirely negative in the neoplastic cells. Based on the biological characteristics of neoplastic cells, this tumor was diagnosed as neuroblastoma of the cerebellar origin.
  • Franco MUTINELLI, Antonio CARMINATO, Elisa BOZZATO, Wendy MARCHIORO, L ...
    原稿種別: NOTE
    2009 年 71 巻 3 号 p. 367-370
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    Teratomas are histologically complex tumors arising from germ cells of two or three embryonic layers either in the gonads or occasionally from germ cells that mistakenly migrated to ectopic sites. A case of retroperitoneal teratoma in a regularly slaughtered 4-month-old, male domestic rabbit is reported. A pale reddish, 3 × 4 cm, fibrous mass was detected, loosely connected to the parietal wall in the retroperitoneal region cranial to the kidney. Histologically, the neoplasm contained tissues from ectodermal, endodermal and mesodermal germ layers: nerves and neurons simulating ganglia, cysts lined by squamous epithelium containing keratin and hair, skin adnexa; respiratory glandular epithelium, serous and salivary glands; collagenous connective tissue, muscle fibers, mature cartilage and bone, bone marrow, teeth and fat. To the authors' knowledge this is the first report of a retroperitoneal teratoma in the rabbit.
  • Junichi KAMIIE, Keisuke FUEKI, Harumi AMAGAI, Youichiro ICHIKAWA, Kinj ...
    原稿種別: NOTE
    2009 年 71 巻 3 号 p. 371-373
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    We report herein a case of multicentric myelolipoma in an 11-year-old beagle dog that presented with vomiting. Laparotomy demonstrated the presence of a large mass adherent to the greater omentum and multiple small white maculae in the spleen. Cytological and histological examinations revealed that the mass and maculae comprised mature adipocytes and hematopoietic elements including granulocytic, erythrocytic and megakaryocytic series in several phases of maturation and macrophages containing hemosiderin deposits, resembling bone marrow. Multicentric myelolipoma was diagnosed. This is first report of multicentric myelolipoma in a dog.
Physiology
  • Masato AOYAMA, Yuko MAEJIMA, Toshio SUZUKI, Masayuki IIGO, Shoei SUGIT ...
    原稿種別: FULL PAPER
    2009 年 71 巻 3 号 p. 281-285
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    Previously we reported that androgen treatment reduced the extent of the increase in plasma cortisol (Cor) levels induced by adrenocorticotropic hormone (ACTH) administration in goats. In this study, we investigated the effect of androgen on the plasma levels of androstenedione and aldosterone. Four castrated male goats, which were treated with either 5α-dihydrotestosterone (DHT) or cholesterol (cho), were injected intravenously with 0.005, 0.02 or 0.1 mg of ACTH(1-24). Plasma Cor levels were increased significantly by all doses of ACTH injection, and these extents were lower in DHT-treated goats. Plasma androstenedione levels were also increased by ACTH injection, but DHT treatment seemed to little affect. Plasma aldosterone levels were also increased by ACTH injection, and there were no differences between cho- and DHT treated goats at 15 and 30 min after the ACTH injection. However, when goats were given the lower doses of ACTH (0.02 and 0.005 mg), plasma aldosterone levels were restored rapidly only in cho-treated goats, whereas those in DHT-treated goats were maintained throughout the 60 min experimental period. Consequently, plasma aldosterone levels in DHT-treated goats were higher than those in cho-treated goats at 45 and 60 min. One possible mechanism of the effect of DHT on the ACTH-induced increase in aldosterone synthesis may be the reduction of the activity of P450-17α, that is the enzyme to convert pregnenolone to 17α-OH-pregnenolone, and this mechanism may also be responsible to the suppressive effect of DHT on the ACTH-induced Cor synthesis.
  • Kentaro Q SAKAMOTO, Katsufumi SATO, Yasuhiko NAITO, Yoshiaki HABARA, M ...
    原稿種別: NOTE
    2009 年 71 巻 3 号 p. 341-344
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    We investigated the blood status of 9 Weddell seal mothers and 9 pups during the breeding season in a field study conducted from November to December 2004 at a breeding colony in Antarctica. The blood glucose and total cholesterol concentrations were higher in the pups than in the mothers. On the other hand, the blood urea nitrogen concentration was lower in the pups than in the mothers. Growth-associated depletion of blood triglyceride was observed in the pups and may have been due to the post-weaning fast. The results characterize the blood status of Weddell seals in relation to physiological adaptations for breeding.
  • Seiji MIYAZAWA, Takahiko SHIINA, Tadashi TAKEWAKI, Yasutake SHIMIZU
    原稿種別: NOTE
    2009 年 71 巻 3 号 p. 383-385
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    The aim of the present study was to examine whether entry of peripherally injected drugs into the central nervous system is reduced during hibernation. When a lethal dose of pentobarbital was injected intraperitoneally, the time until cardiac arrest was significantly longer in hibernating hamsters than in active controls. The time difference was not a consequence of low body temperature or diminished circulation, because mimicking these parameters in artificial hypothermia did not prolong the time. In contrast, there was no difference in the time until cardiac arrest after intracerebroventricular injection of the anesthetic. These results indicate that entry of peripherally injected anesthetics into the central nervous system may be suppressed during hibernation.
Public Health
  • Hodaka SUZUKI, Shigeki YAMAMOTO
    原稿種別: REVIEW
    2009 年 71 巻 3 号 p. 255-261
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    Campylobacter species are common bacterial pathogens associated with human gastroenteritis worldwide. In North America, Europe and Japan, campylobacteriosis is one of the leading food-borne bacterial illnesses and the consumption of poultry meats and/or by-products is suspected a major cause of the illness. In this survey, we summarized the research papers describing Campylobacter contamination of retail poultry meats and by-products in various countries of the world. In most of the countries, a majority of retail poultry meats and by-products were contaminated with Campylobacter spp. C. jejuni was usually the dominant Campylobacter species isolated from retail poultry and C. coli was less frequently isolated, although the ratio of C. coli to C. jejuni was considerably different among the countries. However, in Thailand and South Africa, C. coli was the dominant Campylobacter species isolated from retail poultry. A large portion of retail poultry was contaminated with Campylobacter spp. in the world; therefore, further trials are required for finding proper countermeasures and attention should be paid for the sanitary handling of poultry products.
  • Satoru AKASE, Yumi UCHITANI, Yoshiko SOHMURA, Keikichi TATSUTA, Kenji ...
    原稿種別: NOTE
    2009 年 71 巻 3 号 p. 359-362
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    Evaluation of a genetic diagnostic technique using real time PCR of Swine Dysentery (SD) was performed using nox primers. Culture, ordinary PCR and real time PCR were compared in this experiment. Sixty-seven specimens from pigs with clinical signs of SD brought to a slaughterhouse in Shibaura, Tokyo, were used. B. hyodysenteriae was isolated from 49 of the pigs, was detected by ordinary PCR in 49 of the pigs and was detected by real time PCR in 54 of the pigs. Furthermore, we were able to determine the numbers of B. hyodysenteriae cells in all positive specimens by real time PCR. The rapid diagnostic technique established in this experiment was useful for detection of B. hyodysenteriae because it was more effective than ordinary PCR and culture.
Theriogenology
  • Yuzo KOKETSU, Yosuke SASAKI
    原稿種別: FULL PAPER
    2009 年 71 巻 3 号 p. 263-267
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    The objectives of this study were to determine by-parity nonproductive female days (NPD or NPDs) and mating and culling measurements, to determine correlations between by-parity NPDs, mating and culling measurements and herd productivity measurements, and to compare by-parity NPDs between three herd groups (105 herds) with differing reproductive productivities. NPD was defined as the number of days when mated females were neither gestating nor lactating. Correlation analysis and mixed-effects models were performed. On the basis of the 25th and 75th percentiles of pigs weaned per mated female per year, three herd groups were formed: high-, intermediate-, and low-performing herds. The mean NPD of 105 breeding herds (mean ± SEM) was 52.7 ± 1.6 days. The NPDs in parities 1, 6 and ≥ 7 were higher than those in parities 0, 2, 3 and 4 (P<0.05). High-performing herds had a higher farrowing percentage and lower percentage of reserviced females than low-performing herds (P<0.05). Lower by-parity NPDs were correlated with lower percentages of reserviced females, higher farrowing percentages and lower culling rates from parities 1 to 5 (P<0.05). High-performing herds had NPDs that were > 25 days lower in parities 0 to 3 than low-performing herds (P<0.05). High-performing herds had lower culling rates in parities 2 to 5 and higher culling rates in parities 6 and ≥ 7 than low-performing herds (P<0.05). The present study indicates that monitoring the by-parity NPD and mating and culling measurements is a good tool for improvement of herd productivity.
  • Yasunori SHINOZUKA, Harumi HIRATA, Ichiro ISHIBASHI, Yuzo OKAWA, Asako ...
    原稿種別: FULL PAPER
    2009 年 71 巻 3 号 p. 269-273
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    The objective of this field study was to determine the therapeutic efficacy of mammary irrigation for the treatment of dairy cattle diagnosed with acute coliform mastitis caused by gram-negative bacteria. Additionally, the effects of different mammary irrigation regimen fluids such as ozone water and normal saline were compared. Dairy cattle clinically diagnosed with acute coliform mastitis (n=57) were enrolled in the study, randomly assigned to 1 of 3 groups, and received the following treatments: systemic antibiotic administration (SAA group; n=40), mammary irrigation regimen (MIR group; n=10), and both treatments (MIX group; n=7). Significant antipyretic effects, as assessed by rectal temperature measurement, were observed in the MIX and MIR groups. Although 2 irrigating fluids were used, namely, ozone water and normal saline, no significant difference was observed between the 2 groups. Fourteen days after the onset of the treatments, the milk yield recovery rate in MIR group tended to be higher (p=0.06) than that in the SAA group. Additionally, after 30 days of treatment, the MIR group cows demonstrated significantly higher successful recovery rates (p<0.05) than the SAA group cows. These results indicate that mammary irrigation with normal saline is an effective treatment for acute coliform mastitis in dairy cattle.
  • Mitsuo ISHII, Syuichi KOBAYASHI, Tomas J. ACOSTA, Wataru MIKI, Motozum ...
    原稿種別: FULL PAPER
    2009 年 71 巻 3 号 p. 293-297
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    The aim of this study was to establish the effectiveness of administration of oxytocin (OT) on placental expulsion after foaling. Four foaling mares with the placentas retained for up 1 hr after foaling received OT (50 IU) administration at 1 hr intervals before expulsion of the placenta. The changes in the plasma concentrations of OT and the PGF2alpha metabolite (PGFM) were investigated, and the influence of OT administration was considered. The results were as follows. The placenta was expelled after one to three OT administrations in all four mares that received OT. In two mares, which expelled the placenta within 30 min after OT administration, the OT concentration increased and remained high. Expulsion of the placenta was delayed in two mares, and one of these mares, which received three doses of OT beginning 1 hr after foaling, showed only a small increase in the OT concentration after the first administration; the other mare did not receive OT until 3 hr after foaling. The OT concentration was increased before placental expulsion in all the mares, and the PGFM concentration also increased in the two mares with retained placentas. In conclusion, we suggest that intramuscular administration of 50 IU of OT at 1-hr intervals beginning 1 hr after foaling is effective for inducing placental expulsion.
  • Yuko HOSHINO, Yuzo KOKETSU
    原稿種別: FULL PAPER
    2009 年 71 巻 3 号 p. 299-303
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    The objective of this study was to evaluate the impact of increased lactation length (LL) on the reproductive efficiency of sows in herds that were performing differently. The present study used 69,314 parity records for 38,532 sows in 114 herds. Two herd groups, high-performing herds and other herds, were formed on the basis of the upper 25th percentile of pigs weaned per mated female per year. Reproductive efficiency was measured as the estimated number of pigs born alive per farrowed sow per year (PBASY) and was calculated as actual subsequent pigs born alive (PBA) multiplied by estimated litters per farrowed sow per year (LSY) for each farrowed sow. The estimated LSY was calculated as 365 days divided by the actual farrowing interval. Multilevel linear mixed-effects models were used. In our evaluation, an interaction between LL and the herd groups was found for the estimated PBASY (P<0.05). The estimated PBASY of high-performing herds did not decrease as LL increased (P>0.10), although the estimated PBASY of the other herds decreased by 0.04 pigs as LL increased by 1 day (P<0.05). As LL increased from 14 to 28 days, the estimated LSY decreased by 0.19 in the two herd groups (P<0.05). Furthermore, as LL increased by 1 day, subsequent PBA increased by 0.08 pigs in high-performing herds and increased by 0.04 pigs in the other herds (P<0.05). Increased LL may not decrease the performance of sows in high-performing herds, but it may decrease the performance in other herds.
Toxicology
  • Keehae PARK, Gang-Joon HEO
    原稿種別: NOTE
    2009 年 71 巻 3 号 p. 333-336
    発行日: 2009年
    公開日: 2009/04/04
    ジャーナル フリー
    Chemicals are used for treatment of aquatic diseases, but there is little data available about copper sulfate in small ornamental fish. The aim of the present study was to determine the TLm24h and evaluate the toxicity of copper sulfate in the guppy (Poecilia reticulata). The fish were subjected to an acute toxicity test for 24 hr, and the results showed a TLm24h value of 1.17 ppm. Severe hyperplasia and exfoliation of the epithelial cells of gill lamellae and obstruction of the internal cavities of renal tubules with necrotized renal epithelial cells sloughed from the basement membrane were observed. However, no significant changes, except for mild curling of gill lamellae, were found in a subacute toxicity test in which fish were exposed to 1/10 of the TLm24h value for 1 week. Therefore, use of less than 0.12 ppm of copper sulfate may be recommended as a therapeutic level.
Virology
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