巻号一覧
72 巻, 4 号
選択された号の論文の9件中1～9を表示しています
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Kenji OYAMA, Fumio MUKAI2001 年 72 巻 4 号 p. 279-284
発行日: 2001/07/25
公開日: 2008/03/10
ジャーナル フリーA simple genetic algorithm (GA) was used to find a mating design which would produce a higher genetic gain with a lower inbreeding level. Stochastic simulation was conducted to compare the genetic and inbreeding levels between GA mating and random mating. Selection for both mating schemes was based on the predicted breeding values of best linear unbiased prediction (BLUP). When sires had similar relationships with dams, GA failed to find mating design that satisfied the constraints because GA searched for the mating design with a lower inbreeding level than random mating among selected animals. The percentage of successful replicates ranged from 70.5% to 100.0% for a combination of 3 heritabilities and 4 penalty coefficients. The GA reduced 7.8% to 11.4% of inbreeding level (P<0.001) compared to random mating after 9 generations of selection and mating when both males and females had phenotypes. When the trait was measured only on females, GA reduced 8.1% to 14.8% of inbreeding level (P<0.001). Although the increase in genetic level was small, the ability of GA to reduce inbreeding and maintain genetic level was demonstrated.抄録全体を表示PDF形式でダウンロード (505K) -
Masaya YAMANAKA, Tomoko AMANO, Toshiyuki KUDO2001 年 72 巻 4 号 p. 285-290
発行日: 2001/07/25
公開日: 2008/03/10
ジャーナル フリーThe effects of the presence of bovine leukemia inhibitory factor (bLIF) in culture medium on the hatching rate and cell number of inner cell mass (ICM) and trophectoderm (TE) of bovine embryos were examined. Bovine presumptive zygotes were divided into four groups which were in the presence or absence of 10ng/ml of bLIF, and the culture period of the groups in the presence of bLIF was throughout from day 0 to 5 and/or day 5 to 10 (the day of in vitro fertilization was decided as day 0). The cleavage rate at day 2 was not significantly different among the four groups. Hatching rates of zygotes cultured in the presence of bLIF throughout from day 5 to 10 were significantly higher than those of zygotes cultured in the absence of bLIF throughout from day 5 to 10. The cell numbers of TE of hatched blastocysts obtained from zygotes cultured in the presence of bLIF throughout from day 5 to 10 were significantly higher than those of hatched blastocysts obtained from zygotes cultured in the absence of bLIF throughout from day 5 to 10. However, the cell numbers of ICM were not significantly different in the four groups. There were no effect of the presence of bLIF throughout from day 0 to 5 on hatching rate and cell number of ICM and TE. These results indicate that (1) the effect of bLIF depends on the period of its presence, (2) bLIF increases the number of cells in the TE and (3) bLIF acts on the hatching process.抄録全体を表示PDF形式でダウンロード (474K) -
Effects of Exposure to Bovine Follicular Fluid before Freezing on Cryoresistance of Boar SpermatozoaWen-Xian ZENG, Naoki ISOBE, Takato TERADA2001 年 72 巻 4 号 p. 291-298
発行日: 2001/07/25
公開日: 2008/03/10
ジャーナル フリーThe effects of exposure of boar spermatozoa to bovine follicular fluid (bFF) on freezability were examined. It was found that exposure to 75% bFF at 25°C for 1h before freezing yielded high post-thaw motility, progressive motility and velocity at 3h after thawing. But longer periods of bFF exposure did not further increase the aforementioned parameters. The post-thaw progressive motility was significantly higher in spermatozoa exposed to various concentrations of bFF than that of the control group immediately after thawing. All the parameters at different concentrations of bFF treatments were significantly higher than those of the control group at 3h of incubation after thawing. These observations suggest that exposure to bFF before freezing may increase the resistance of boar spermatozoa to cryopreservation stress. It is of great interest to elucidate the mechanism by which bFF protects spermatozoa from cryoinjury.抄録全体を表示PDF形式でダウンロード (710K) -
Chun-cheng XU, Hiroyuki SUZUKI, Koji TOYOKAWA2001 年 72 巻 4 号 p. 299-305
発行日: 2001/07/25
公開日: 2008/03/10
ジャーナル フリーTofu cake added with three levels of ethanol was made into silages and fed to four wethers to investigate characteristics of ruminal fermentation. The animals received a basal diet consisting of the second cut Orchardgrass hay and beet pulp (4:1) and either fresh tofu cake (control) or one of silages made of tofu cake added with ethanol at 2%, 4% and 6% levels was also fed so that it account for 20% of the whole ration. Feeding levels were determined based on metabolic body size and were restricted to 85% of voluntary intake levels. 1) The animals fed with tofu cake silages had different ruminal fermentation compared to those in the control. There were positive or negative linear effects of amount of ethanol added to tofu cake silage on ruminal pH, volatile fatty acid (VFA) and other parameters. 2) The higher the levels of ethanol added to tofu cake silage the higher the total VFA, acetic, valeric and caproic acid levels and adversely the lower the propionic acid levels. 3) The animals fed with tofu cake silages had significantly (P<0.01) higher ratios of propionic acid to acetic acid in the rumen fluid. 4) Rumen fluid taken from the animals fed with tofu cake silages had lower pH and lactic acid than that from the control. 5) Although there were no apparent increase in pH, total VFA level or any particular VFA levels in the rumen for the amount of tofu cake fed to the animals in this study, further investigations for optimum feeding levels of tofu cake are needed.抄録全体を表示PDF形式でダウンロード (514K) -
Koichiro UEDA, Toshiyoshi ICHINOHE, Masahiko OKUBO, Yasushi ASAHIDA2001 年 72 巻 4 号 p. 306-314
発行日: 2001/07/25
公開日: 2008/03/10
ジャーナル フリーThis study attempted to develop a method for quantifying dynamics of particulate matter in the rumen of sheep fed on alfalfa hay at hourly intervals. The four compartments model for four size particulate fractions (large particle (LP):>5, 600, medium particle (MP): 5, 600-1, 180, small particle(SP): 1, 180-300, fine particle (FP): 300-47μm) in the rumen that has multiple pathways of size reduction, fermentation and passage was assumed. The respective rate constants were estimated by applying the in situ method and rare earth markers technique to each ruminal particulate fractions. The fermentation rate of each particulate fraction could be estimated from in situ disappearance curves. The rate of disappearance and the rate of size reduction of multiple pathways were able to be estimated by non-linear regression fitting to the theoretical equations from the dynamics model. The extent of fitting of the changes of markers in particulate fractions to the functions was enough to estimate the rate of disappearance and size reduction of ruminal particulate fractions. The rates of size reduction were 1.55 (LP→MP), 1.06 (LP→SP), 1.94 (LP→FF), 1.76 (MP→SP), 0.46 (MP→FP) and O.84%/h (SP→FP). The rates of fermentation were 1.47 (LP), 0.90 (MP), 0.08 (SP) and 1.19%/h (FP). The rates of passage were 1.82 (SP) and 3.94%/h (FP).抄録全体を表示PDF形式でダウンロード (774K) -
Long Thang PHUNG, Nobuyoshi MATSUNAGA, Satoshi HIDAKA, Hideto KUWAYAMA ...2001 年 72 巻 4 号 p. 315-321
発行日: 2001/07/25
公開日: 2008/03/10
ジャーナル フリーThe aim of the present study was to examine the growth hormone (GH) response to the combined and repeated administrations of growth hormone-releasing peptide-2 (GHRP-2) plus growth hormone releasing hormone (GHRH) in swine. Six cross-bred castrated male swine, 130-135 days of age were used in this study. Animals were given a single intravenous (i.v.) injection of either GHRP-2 (30μg/kg BW), GHRH (1μg/kg BW) and GHRP-2 (30μg/kg BW) plus GHRH (1μg/kg BW) or 5ml saline (served as control) in random order with two days apart. GHRP-2 or GHRH alone and in combination with together stimulated the release of GH in swine. The peak concentrations of GH and areas under the GH response curve (GH AUC) for 120min after these treatments were significantly higher (P<0.01) than those in controls. The combined administration of these two peptides [GHRP-2 (30μg/kg BW) and GHRH (1μg/kg BW)] resulted in a GH AUC significantly greater than the arithmetic sum of those following their separate administrations (P<0.05), demonstrating the synergistic effect for GH release. GH responses to two successive i.v. injections of GHRP-2 (30μg/kg BW) plus GHRH (1μg/kg BW) at 2h interval in swine were increased after each injection; however, peak concentration of GH and GH AUC for 120min after the second injection were significantly lower (P<0.01) than those after the first injection. These results of the present study indicated that the combined administration of GHRP-2 and GHRH synergistically stimulates the release of GH in swine, and the GH responses to the co-administration of these two peptides decrease after the repeated injection. These findings suggest that GHRP-2 and GHRH act through different receptors and intracellular signal transduction and can be used together for stimulating further release of GH in swine.抄録全体を表示PDF形式でダウンロード (659K) -
Yoshihiro NOMURA, Shinzi TOKI, Yasuhiro ISHII, Kunio SHIRAI2001 年 72 巻 4 号 p. 322-328
発行日: 2001/07/25
公開日: 2008/03/10
ジャーナル フリーThe effect of microbial transglutaminase (MTGase, EC 2.3.2.13) on type I collagen self-assembly and the physicochemical property of MTGase-crosslinked pig collagen gel was investigated. The rate of collagen self-assembly, especially the formation of nucleus for collagen fibril was accelerated with the addition of MTGase. MTGase-crosslinked collagen gel was characterized by non-destruction test of dynamic light scattering. Since diffusion coefficient was found to decrease, it was suggested that the spacing of MTGase crosslinked collagen gel became wide. MTGase-crosslinked collagen gel showed lower mechanical strength and about 2°C higher denaturation temperature than that of control. And MTGase-crosslinked collagen gei was not melt at 52°C instantly. The introduction of crosslinkage into collagen with MTGase resulted in the acceleration of collagen self-assembly and the improvement of thermostability of collagen gel.抄録全体を表示PDF形式でダウンロード (1127K) -
Seiichi KOIZUMI, Raymond A. JUSSAUME, Shinichi KOBAYASHI, In-Jen PAN, ...2001 年 72 巻 4 号 p. 329-343
発行日: 2001/07/25
公開日: 2008/03/10
ジャーナル フリーThis study investigated consumer behavior on meats, specifically consumer attitudes regarding future meat consumption in the U.S. The study was based on mail surveys undertaken in October and November of 1994. The sample for the survey was drawn randomly from the population of residents listed in telephone directories in Seattle and Kansas City. The data was obtained from 1, 217 households and was mainly analyzed using multivariate analysis. A five point scale (1=decrease considerably, 5=increase considerably, 3=no change) was used to rate consumers on their plans for the future consumption of different meats. The average consumer attitude index was 3.25 for turkey, 3.18 for chicken, 2.87 for pork, 2.84 for lamb, and 2.77 for beef. These measures were lower than those for vegetables (3.63) and fruits (3.62). Among meat and fish, respondents preferred chicken most, followed by beef, fish, and pork. Preference for chicken was strong in younger households, while preference for fish and lamb was strong among elder households. Households felt that lamb and fish prices were relatively expensive, while chicken was thought to be cheap. However, there were no significant relationships between consciousness for price and actual consumption volume or the consumer attitude index for meats. The extent of uneasiness for eating meat was relatively weak. And the meat consumption volume of respondents who felt uneasy about meat was rather low. There were some differences on the explanation on factors relevant to attitudes about future consumption between beef/pork and chicken.抄録全体を表示PDF形式でダウンロード (1097K) -
Yasuo KOBAYASHI, Masaki YAMADA, Mayu YAMAMOTO2001 年 72 巻 4 号 p. 344-346
発行日: 2001/07/25
公開日: 2008/03/10
ジャーナル フリーSurvival of the recombinant rumen bacterium Butyrivibrio fibrisolvens NO4, expressing an exogenous xylanase and erythromycin resistance, was assessed in vitro and in vivo. Selective enumeration of the recombinant strain from indigenous rumen bacteria was performed using an erythromycin-supplemented anaerobic medium. When incubated in vitro with mixed rumen bacteria and protozoa obtained from sheep, the numbers of the recombinant strain stabilised at 103/ml (48h). When incubated with mixed microbes from the goat rumen, strain NO4 disappeared 48h after inoculation. The presence of protozoa in the culture tended to decrease the numbers of strain NO4 ten-fold compared to bacteria alone. In vivo, numbers declined rapidly after inoculation, and the recombinant strain was no longer detectable in the sheep rumen after 144h.抄録全体を表示PDF形式でダウンロード (253K)
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