巻号一覧
72 巻, 5 号
選択された号の論文の11件中1～11を表示しています
- |<
- <
- 1
- >
- >|
-
Tamao ONO2001 年 72 巻 5 号 p. 361-371
発行日: 2001/09/25
公開日: 2008/03/10
ジャーナル フリーPDF形式でダウンロード (3155K) -
Juan Antonio C. PEREIRA, Mitsuyoshi SUZUKI, Kouichi HAGIYA, Tsutomu YO ...2001 年 72 巻 5 号 p. 372-377
発行日: 2001/09/25
公開日: 2008/03/10
ジャーナル フリーHeritabilities and repeatabilities for milk production traits were estimated by Method R. Data consisted of records of Holstein cows that were used for the national genetic evaluation of 1999 in Japan. The whole data and 10 subsets of the same data were used for heritability (h2) estimation. Heritabilities estimated from the 10 subsets were on average 0.34, 0.32 and 0.30 for milk, fat and protein yields, respectively. These heritabilities were higher by 0.01 than those estimated from the whole data. Repeatability estimates were 0.53, 0.52 and 0.51 for milk, fat and protein yields, respectively. When the analyses were performed by parity, the results were different among parities. Estimates of h2 in the first lactation were 0.40, 0.37 and 0.32 for milk, fat and protein, respectively and decreased in the following lactations. A considerable difference between the first and the remaining lactations might cause a loss of accuracy in the estimation of h2 when a repeatability model is used. Under these circumstances a better approach would be to treat the lactations as different traits. But, actually Method R does not support multiple trait estimation. Therefore, if the differences in h2 among lactations are going to be taken into account in national genetic evaluations, further research is necessary to develop an appropriate procedure in order to estimate heritabilities using all the data available for national genetic evaluations.抄録全体を表示PDF形式でダウンロード (515K) -
Takeshi HONDA, Tetsuro NOMURA, Moriyuki FUKUSHIMA, Fumio MUKAI2001 年 72 巻 5 号 p. 378-385
発行日: 2001/09/25
公開日: 2008/03/10
ジャーナル フリーThe Japanese Black in Hyogo prefecture has been almost closed population. In this paper, genetic diversity of the population was estimated. The materials used were 68, 781 animals born in 1955 to 1998 and their pedigree records traced back to the population in 1937 or before. To assess the diversity, three types of parameters were estimated. Founder genome equivalents (Nge) is the most comprehensive parameter, in which all the causes of the reduction of diversity are accounted for. Effective number of founders (Nef) explains the cause of reduced diversity due to unequal contributions of founders. Effective number of non-founders (Nenf) accounts for the diversity reduced by genetic drift accumulated over non-founders generations. Index of genetic diversity (GD) was estimated by GD=1-1/(2Nge). Nge decreased gradually from 26.9 in 1955 and reached 2.2 in 1998. Before 1970, Nenf showed larger values than Nef, but the order was reversed in the later years. Nenf in the recent years was close to Nge. The index GD showed a sharp decline after 1980 and reached 0.78 in 1998. The major cause of the reduced genetic diversity was considered to be the bottleneck effect due to the concentrated use of breeding animals originated from a few founders.抄録全体を表示PDF形式でダウンロード (596K) -
Tetsuro NOMURA, Fumio MUKAI, Aya YAMAMOTO2001 年 72 巻 5 号 p. 386-394
発行日: 2001/09/25
公開日: 2008/03/10
ジャーナル フリーAntagonistic genetic correlations between growth and reproductive traits exist in broilers, making it difficult to improve these traits simultaneously. In the present study, two selection schemes for achieving desired genetic gains in antagonistically correlated traits were compared in simulation. The population structure and genetic parameters were determined on the basis of an existing broiler line. The first selection scheme (DIS scheme) was based on selection index for achieving desired genetic gains. In the second (FI+LP scheme), a combination of the family index and linear programming technique was applied. The simulated traits were body weight at 6 weeks (BW) and age at sexual maturity of hen (SM). Based on the estimate from the analysis of an actual data set, a positive genetic correlation between the two traits was assumed. This is a typical case of antagonistic selection because a positive gain in BW and a negative gain in SM were required for achieving the breeding goal. The results obtained are summarized as follows: (1) Both DIS and HI+LP schemes produced similar genetic gain averaged over replicates; (2) FI+LP scheme reduced the variance of genetic gain among replicates to 5-70% of DIS scheme; and (3) FI+LP scheme showed a strong robustness against error in the estimate of genetic correlation. In light of these results, it was concluded that FI+LP scheme should be preferable to DIS scheme in developing closed lines of broilers.抄録全体を表示PDF形式でダウンロード (694K) -
Hirokazu MATSUDA, Hiroaki IWAISAKI2001 年 72 巻 5 号 p. 395-403
発行日: 2001/09/25
公開日: 2008/03/10
ジャーナル フリーIn this paper, the conditional expectations in a closed form of the identity-by-descent proportions (IBDPs) that are the elements of the gametic relationship matrix required in the markerassisted prediction of the effects of a cluster of quantitative trait loci (QTLs) and in the segment mapping are examined, considering the half-sib family on which marker information is used in granddaughter design for QTL analyses in outbred populations. It is allowed here that upstream markers in addition to two flanking markers are available. For the possible patterns of haplotype transmission for the two informative markers, analytical solutions of some form to the expectations of the IBDPs between the half-sib sires and between one of the gametes for the grandsire and the sire are derived. Some numerical results calculated using the solutions obtained are presented as an illustration, assuming one situation where the half-sib sires receive the same non-recombinant marker haplotype from the grandsire. Use of the current solutions can make it easier to calculate the gametic relationship matrix required in the prediction of the effects of concern and in the segment mapping under the considered design.抄録全体を表示PDF形式でダウンロード (630K) -
Kentaro T. HARA, Senkiti SAKAI, Masao NAGATA, Fugaku AOKI2001 年 72 巻 5 号 p. 404-409
発行日: 2001/09/25
公開日: 2008/03/10
ジャーナル フリーThe expression of protein tyrosine phosphatases (PTPs) was examined in preimplantation mouse embryos. PTPs expressed in the various developmental stages, including unfertilized oocytes, 2-cell, 4-cell, morula and blastocyst stages, were identified by reverse transcription of mRNA followed by a polymerase chain reaction (RT-PCR) with degenerate oligonucleotide primers corresponding to the conserved catalytic domain of PTP. Sequencing of cDNA clones obtained by RT-PCR revealed the expression of mRPTPB, SHP-1, PTPT9, SHP-2 and LAR. The changes in the expression levels of these PTPs during preimplantation development were examined by RT-PCR using each gene specific primers. The results showed that their expression levels dynamically changed in different manners among PTPs, suggesting that PTPs play roles in the regulation of growth and differentiation during preimplantation development.抄録全体を表示PDF形式でダウンロード (1353K) -
Shuichi OSHIO2001 年 72 巻 5 号 p. 410-415
発行日: 2001/09/25
公開日: 2008/03/10
ジャーナル フリーThis experiment was designed to elucidate the relationships among intake, chewing behavior, digestibility, and the digesta passage through the rumen. Four Holstein heifers (average body weight, 455kg), each with a large ruminal cannula, were given Italian ryegrass hay at one of four intakes (2.44, 4.88, 7.33 and 9.49kg DM/day) in 4×4 Latin square design (12 days per period). Measurements were made for diet digestibility, chewing behavior, rumen volume, outflow rate of rumen fluid and fecal particle size distribution. The apparent digestibilities of the chemical components except crude fat and crude protein decreased with increasing intake. The apparent retention time of dry matter in the rumen was longest (P<0.05) at the intake of 2.44kg/day. However, the values had no significant differences among the higher intakes since rumen volume increased proportionally to the increase of intake. The percentage of fecal particles retained on sieves of 1 and 2mm opening size was significantly (P<0.05) higher in lower intakes (2.44 and 4.88kg/day). While eating time (min/kg DM intake) increased as intake increased, rumination time decreased slightly with the increase in intake. Thus, the total chewing time per unit of intake did not differ significantly among the intakes. The chewing rate during rumination and the total number of chews were higher for higher intake levels. From these results, it was considered that the depression of the digestibility at the higher intakes was influenced not only by the passage rate through the rumen but also partly by lower digestion rate in the post-ruminal digestive tracts. Moreover, under the maintenance level of intakes, the particle size that escapes from the rumen might be longer on account of the lower total chews for unitary intake and the longer particle size of feces.抄録全体を表示PDF形式でダウンロード (505K) -
Hiro-omi YOKOTA, Jae-Hwang KIM, Kazumi KITA2001 年 72 巻 5 号 p. 416-420
発行日: 2001/09/25
公開日: 2008/03/10
ジャーナル フリーAerobic deterioration after opening the silo was studied for direct-cut and wilted napiergrass (Pennisetum purpureum Schum.) ensiled with molasses from sugarcane. The grass was ensiled in a polyethylene bag silo, that was 35cm in diameter and 30cm in height. Moisture contents of the direct-cut and the wilted grass were 86.5% and 78.2%, respectively. Thermistor was placed in the centre of the silage to determine changes of temperature in the silage after exposure to air. After 5months, silages were exposed to air by removing the top of the bag silo. After exposure, temperature in silages increased, reached a highest peak and then decreased. Maximum temperature and time to the highest peak were 34.0°C on day 10, and 39.5°C on day 9 after exposure to air for the direct-cut and the wilted silage, respectively. Silage samples from top layer (5cm below the top surface), middle layer (15cm below the top) and bottom layer (25cm below the top) were taken on 0, 2, 6, 10 and 14 days after exposure to air. The mean pH and lactic acid content (g/100g DM) of the silages of 3 1ayers at day 0 were 3.79 and 10.61, and 4.07 and 6.95 for the direct-cut and the wilted silage, respectively. After exposure to air, pH gradually increased and lactic acid content decreased with time. Top layer silage was enough to keep the pH low against aerobic deterioration for 5 and 2 days in the direct-cut and the wilted silages, respectively.抄録全体を表示PDF形式でダウンロード (360K) -
Hiroki MATSUI, Koretsugu OGATA, Kiyoshi TAJIMA, Takafumi NAGAMINE, Mut ...2001 年 72 巻 5 号 p. 421-426
発行日: 2001/09/25
公開日: 2008/03/10
ジャーナル フリーA cellulase gene from Prevotella ruminicola JCM8958T was cloned and expressed in Escherichia coli, and its enzymatic properties were characterized. A genomic library was screened for 4-methylumbelliferyl-β-D-cellobioside degrading acttivity. A clone designated pPRC4 was selected from 12 positive clones. An insert DNA fragment (5, 794 base pairs) in pPRC4 was sequenced and analyzed, and four open reading frames (ORF) were found. ORF3 consisted of 967 nucleotides, and deduced polypeptide (322 amino acid, about 37, 000 dalton) showed homology with endaglucanases of unidentified anaerobic bacterium, Clostridium sp. strain F1, and C. thermocellum, and cellodextrinases from Fibrobacter succinogenes and Ruminococcus flavefaciens. Predicted isoelectoric focusing point was 6.09. Amino acid sequence of putative catalytic domain of the celiulase showed homology with motif of glycosyl hydrolase family 5, however, the fifth amino acid residue was substituted with phenylalanine. The gene product expressed in Escherichia coli had activity toward AvicelR, carboxymethyl cellulose (CMC), and lichenan. Temperature and pH optima of the celulase were 45°C and 6.8, respectively. Heat treatment at 70°C for 10min inactivated the cellulase.抄録全体を表示PDF形式でダウンロード (1071K) -
Atsushi OHGUSHI, Tomonori NAKANISHI, Takashi BUNGO, D. Michael DENBOW, ...2001 年 72 巻 5 号 p. 427-430
発行日: 2001/09/25
公開日: 2008/03/10
ジャーナル フリーThe effect of oral administration of conjugated linoleic acid (CLA) on isolation-induced distress behavior in the chick was determined at 5min intervals over a 15min period. The two groups of 6 birds each were orally administered 1ml of CLA or high linoleic acid (HLA) for 4 days. After the fourth day treatment, behaviors were monitored by video camera. Two isomers of CLA were detected in the brain of chicks treated with CLA. However, CLA was not detected in the brain of the HLA group. In overall means, distress vocalizations (DVs) were significantly lower in the CLA than in the HLA group. Similar tendencies were observed in the number of steps and jumps, but not significantly different between two groups. In conclusion, isolation-induced DVs can be modified by oil source and CLA is a useful oil to reduce isolation-induced DVs in the chick compared with HLA.抄録全体を表示PDF形式でダウンロード (324K) -
Mami SHIBUSAWA, Miho INOUE-MURAYAMA, Chizuko NISHIDA-UMEHARA, Yoichi M ...2001 年 72 巻 5 号 p. 431-433
発行日: 2001/09/25
公開日: 2008/03/10
ジャーナル フリーTwo genomic DNA fragments of Japanese quail, DZGif1 and DZGif2, were isolated as DNA sequences with difference of copy numbers between males and females in a previous study. We have determined the chromosomal locations of these DNA fragments by fluorescence in situ hybridization. DZGif1 and DZGif2 were localized to q1.1→q1.2 proximal end and q1.5→q1.6 of the Z chromosome, respectively. These fragments are the first random genomic DNA markers mapped to the Z chromosome in Japanese quail, and they would be useful for constructing the genome map of Japanese quail.抄録全体を表示PDF形式でダウンロード (949K)
- |<
- <
- 1
- >
- >|