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Volume 72, Issue 2
Displaying 1-11 of 11 articles from this issue
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Hiroshi UCHIDA, Takuro OIKAWA, Keiichi SUZUKI, Toshihiro YAMAGISHI2001 Volume 72 Issue 2 Pages 89-96
Published: March 25, 2001
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSRecords and pedigree information of Japanese Black Cattle collected from performance testing and progeny testing in Miyagi prefecture were used to estimate heritabilities (h2) and genetic correlations (rG) for the traits for meat productivity using a two-trait animal model by Gibbs sampling method. The estimates of h2 in growth traits in performance testing were at a low level (h2<0.3) for daily gain (DG) and at a medium level (0.3=<h2<0.6) for initial and final weights. While the h2 estimate of concentrate feed intake was at a medium level, those of roughage intake and total digestible nutrient (TDN) conversion ratio were at low levels. Growth traits had positive rG estimate with food intake and this suggests that attention should be paid to feed intake performances for achieving genetically improved growth traits. The h2 estimates of carcass weight, the old beef marbling standard (BMS) (BMS1), the new BMS (BMS2) and rib thickness were high (h2>=0.6), and those of initial body weight, DG and yield estimates were at medium levels, meanwhile, the h2 of rib eye area and subcutaneous fat thickness were estimated to be low. There were negative rG estimates among DG and BMS 1 or BMS2. The rG estimate (+0.687) between BMS1 and BMS2 was not as high as initially expected and this might be attributed to two different evaluating methods of meat marbling.View full abstractDownload PDF (660K) -
Kazuo FUKAWA, Toshie SUGIYAMA, Seiji KUSUHARA, Osamu KUDOH, Kenji KAME ...2001 Volume 72 Issue 2 Pages 97-106
Published: March 25, 2001
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSDuring the course of developing a strain of Duroc pigs, 1, 381 pigs were used to determine the growth rate from birth to the day at 30kg, the growth rate during the period from 30 to 90kg of body weight, the back fat depth, the eye muscle area and leg scores when the body weight was approximately 90kg. Additionally, body size was measured at 90kg body weight. The pigs were allowed free access to the diet. The contemporary group and gender as the fixed effects, the sire and dam as the random effects and end test weight as a covariate were taken into the mathematical model for the analysis of the data. Genetic parameters were estimated by the animal model restricted maximum likelihood (REML) method. The effect of contemporary group categorized on the basis of the test date was significant for all of the traits measured on the test starting date and thereafter. The mathematical model which contains the contemporary group of one-week period tended to show a better Akaike's Information Criterion (AIC) than groups of two and four-week period. Significant differences between genders (boar, gilt, barrow) were observed in most of the traits. The effect of end test weight as a covariate was significant in all of the traits measured at approximately 90kg body weight. Estimates of the heritability of performance traits and body measurement traits generally varied from moderate to high. The heritability of leg score traits was low. Although an unfavorable genetic correlation between back fat depth and leg score traits was observed, the genetic correlation between leg score traits and daily gain during the period from 30 to 90kg of body weight was favorable. The results suggest that the simultaneous improvement of the growth rate and leg score traits is not difficult in Duroc pigs, but there might be difficulty in the improvement of obtaining less back fat depth and better leg soundness.View full abstractDownload PDF (817K) -
Hiroyuki SUZUKI, Ikue FUKUDA, Koji TOYOKAWA2001 Volume 72 Issue 2 Pages 107-116
Published: March 25, 2001
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSChanges in follicular epithelial cell-oocyte connections during the development of hamster ovarian follicles were studied by scanning electron microscopy using the Osmium-Dimethylsulfoxide-Osmium (ODO) maceration method. Follicular development was also examined histologically. In primordial follicles, the flattened follicular epithelial cells were closely associated with the oocyte. In primary follicles, polyhedral follicular epithelial cells surrounding the oocyte possessed rarely microvillous processes. The zona pellucida (ZP) appeared between the oocyte and the surrounding follicular epithelial cells when they were proliferated by 3 layers. By ODO maceration for 1-2 days, the matrix of ZP in the growing preantral follicles was completely dissolved, thereby tortuous and ramified cytoplasmic processes of the follicular epithelial cells toward the oocyte were exposed. These processes increased progressively in thickness and in number as the follicle developed. In antral follicles, the cumulus cell processes were elongated, but still maintained. The ZP of the antral follicular oocyte showed increased resistance to ODO maceration compared to that of the growing follicular oocyte. Further, layered heterogeneity of the ZP was noticed in the solubility to ODO maceration, suggesting that subtle changes do occur in the properties of the ZP matrix during residence in the follicle. It is revealed three-dimensionally in the hamster ovarian follicles that the cytoplasmic processes of the follicular epithelial cells develop rapidly, coincidently with the ZP formation, at the early-growing follicle stage and they are maintained until the antral follicle stage.View full abstractDownload PDF (3896K) -
Miwa IWAMOTO, Narito ASANUMA, Tsuneo HINO2001 Volume 72 Issue 2 Pages 117-125
Published: March 25, 2001
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSFactors affecting nitrate and nitrite reduction in the rumen were examined. Nitrate and nitrite reduction by mixed microbes harvested from the goat rumen was increased by feeding a high-roughage diet, which contained a much higher amount of nitrate than concentrate. The activities of nitrate reductase and nitrite reductase per bacterial mass appeared to be increased by feeding a high-nitrate diet, suggesting that these enzymes are induced by substrates. Nitrate and nitrite reduction was confirmed to be the fastest at neutral pH and affected by electron supply. The supplementation of electron donors, such as formate, H2, and lactate, stimulated nitrate and nitrite reduction, especially nitrite reduction, which decreased nitrite accumulation. As a result, addition of formate or lactate in the presence of nitrate alleviated the inhibitory effect of nitrite on fermentation, and greatly reduced methanogenesis.View full abstractDownload PDF (658K) -
Hajime KUMAGAI, Yot CHAIPAN, Katsunosuke MITANI2001 Volume 72 Issue 2 Pages 126-133
Published: March 25, 2001
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSEffects of periparturient vitamin A supplementation on vitamin A concentrations in colostrum and milk from dairy cows, and plasma retinol concentrations, feed intake and growth of their calves were studied. Eleven primiparous and 10 multiparous Holstein Friesian cows were assigned into one of three groups: 1) control; 2) 700, 000IU/week of vitamin A supplemented in diet from 30 days before expected calving date; 3) 700, 000IU/week of vitamin A supplemented in diet from 60 days before expected calving date. The supplementation was done by mixing with concentrate weekly and lasted until 45 days after calving. Calves were fed with colostrum provided from their own cows until 5 days and with whole milk until 45 days of age. All calves were fed with calf starter and Italian ryegrass hay ad libitum from 7 days of age. The supplementary vitamin A significantly increased vitamin A concentrations in colostrum and milk on 5, 15 and 45 days after calving. Primiparous cows had significantly higher vitamin A concentrations in colostrum and milk than multiparous cows on 1, 5 and 15 days after calving. No significant difference in plasma retinol concentrations of calves from cows among treatment groups was observed. The supplementation for cows had no significant effect on liveweight, daily gain and feed intake of their calves during 90 days after birth. Plasma retinol concentrations of calves on 90 days of age were positively correlated with daily gain and starter intake after weaning. Although 700, 000IU/week vitamin A supplementation from 60 days or 30 days for cows before expected calving increased vitamin A concentrations in colostrum and milk, it had no effect on plasma vitamin A content and growth of their calves. It is suggested that calves ingested more calf starter had better liveweight gain and higher plasma retinol concentrations.View full abstractDownload PDF (583K) -
Osamu KAWAMURA, Kiichi FUKUYAMA, Mitsuhiro NIIMI2001 Volume 72 Issue 2 Pages 134-138
Published: March 25, 2001
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe effects of an additive containing cell wall degrading enzyme on the ensilage losses were estimated under a farm condition. At ensiling Italian ryegrass with and without the additive, the nylon-net bags containing grasses were placed into each of the silage bulks. The bags were retrieved when the silages were unloaded, and their contents were subjected to the chemical analyses, in vitro digestion with rumen microbes and microscopic observation. Enzyme treatment improved the silage fermentation. The ensilage loss of cell wall components was highest in hemicellulose. In hemicellulosic monosaccharides, the loss of xylose was lowest, followed by uronic acids, arabinose, galactose and glucose. The losses in treated silage were significantly higher than the control silage in almost all the cell wall components. The losses of digestible-dry matter (DM) and digestible-neutral detergent fiber (NDF) in vitro were also significantly higher in the treated silage. The selective degradations of the readily digestible plant tissues (e. g. mesophyll and pith parenchyma) were observed in the treated silage.View full abstractDownload PDF (1086K) -
Eruden BAYARU, Syuhei KANDA, Toshihiko KAMADA, Hisao ITABASHI, Sada AN ...2001 Volume 72 Issue 2 Pages 139-146
Published: March 25, 2001
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSFour Holstein steers fed with Sorghum silage were used to examine the effect of fumaric acid supplementation (20g/kg. diet dry matter (DM)) on methane production, rumen fermentation, blood metabolism and feed digestibility. The protozoal population in the rumen was unaffected by fumaric acid supplementation. The postprandial ruminal concentration of ammonia-N decreased, and that of total volatile fatty acids tended to be higher with fumaric acid supplementation. The proportion of ruminal acetic acid was unaffected, but that of propionic acid increased and that of butyric acid decreased by fumaric acid. The postprandial blood plasma concentration of glucose was increased, whereas that of urea-N was decreased by fumaric acid. The plasma concentration of most of free amino acids was unaffected. Daily methane production decreased by 23.0% and carbon dioxide production decreased by 20.5% with fumaric acid supplementation. Apparent digestibility of dry matter and of neutral detergent fiber were not influenced by fumaric acid. These results indicated that fumaric acid was converted to propionic acid by rumen microorganisms, and that methane production from the rumen was reduced without lowering the ability to digest dietary fiber. However, some dietary conditions that alter the effectiveness of fumaric acid and the long term effect remain to be examined.View full abstractDownload PDF (526K) -
Yukio AKIBA, Kan SATO, Kazuaki TAKAHASHI, Masaaki TOYOMIZU, Ko-ichi MA ...2001 Volume 72 Issue 2 Pages 147-153
Published: March 25, 2001
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSTwo experiments were conducted to investigate age-dependent changes of meat color of broiler chickens and the effects of feeding Phaffia rhodozyma, a yeast containing high levels of astaxanthin (Ax), with special reference to the feeding duration and bird age at the beginning of feeding. Experimental diets were supplemented or not with cell wall-fractured Phaffia yeast, with the yeast-supplemented diet containing 20ppm Ax. The feeding of the experimental diets commenced from 3 to 8 weeks of age in Experiment 1, and the diets were given for 2 weeks from each of 1, 2, 3, 4, 5 and 6 weeks of age in Experiment 2. The lightness (L* value) of all edible meats was slightly influenced by the age of birds but not by the feeding with the yeast-supplemented diet. The redness (a* value) of thigh (Sartorius), breast (Pectoralis superficialis) and sasami (Pectoralis profundus) meats tended to decrease with the age on a week-to-week basis, while that of thigh meat (Semitendinosus) was not affected by age. Feeding with the yeast-supplemented diet from 3 weeks of age increased a* values in all edible meats, with most of the increases being statistically significant. The extent of the increase in a* values was slightly pronounced in breast and salami meats when the yeast-supplemented diet was fed for 5 weeks prior to market (at 8 weeks of age). The yellownesss (b* value) of breast and sasami meats increased with a prolonged feeding with the yeast-supplemented diet after 3 weeks of age. The feeding for 2 weeks with the yeast-supplemented diet in Experiment 2 increased a* values in all edible meats irrespective of the age at the beginning of feeding. The b* values of thigh and breast meats were significantly, but to a small extent, increased by feeding for 2 weeks with the yeast-supplemented diet. It is suggested that the feeding with Phaffia yeast-supplemented diets intensifies mainly the redness of broiler meats, while prolonged feeding of the yeast diet intensifies meat yellowness.View full abstractDownload PDF (504K) -
Noboru MANABE, Masakazu IRIE, Mitsuru MITSUMOTO, Yoshihiro FURUYA, Mis ...2001 Volume 72 Issue 2 Pages 154-163
Published: March 25, 2001
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSUsing an immunohistochemical microquantification technique, in which frozen sections mounted on glass slides are used as analogues of the antigen precoated wells of the enzyme-linked immunosorbent assay-plates and the structure is well preserved, we examined the contents of fastmyosin isoforms in different portions of 17 hind limb muscles of female Duroc pigs. High fast-myosin levels (more than 200mg/g of total protein) were observed in the gluteus superficialis, gluteus medius, vastus lateralis, biceps femoris and tensor fasciae latae muscles, and low levels (less than 75mg/g) in the gluteus profundus, vastus intermedius and semimembranosus muscles. Fast-myosin-positive fibers were distributed more in the superficial regions than in the deeper regions in the hind limb muscles. The highest population of type I fibers was seen in the vastus intermedius muscle (78%), and the lowest in the gluteus medius muscle (10%). The highest number of type IIA fibers was seen in the rectus femoris muscle (29%), while the lowest was seen in the semimembranosus muscle (14%). The highest number of type IIB fibers was found in the gluteus medius muscle (73%), and the lowest in the vastus intermedius muscle (7%). Good correlation between the microquantification and histochemical analysis was seen. The histological structure of the muscles was well preserved during microquantification, and this technique could be used in research projects to study the contractile properties of the muscles and evaluate the meat qualities of pig muscles.View full abstractDownload PDF (2291K) -
Ken-ichi TAKEDA, Shusuke SATO, Kazuo SUGAWARA2001 Volume 72 Issue 2 Pages 164-168
Published: March 25, 2001
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe objective of the present study was to investigate changes in the affiliative behaviour of 5 Japanese Black calves after grouping together in a pen through 5.5 months. The maintenance of these affiliative relationships was thereafter observed for one month after beginning to graze with the other group. The average frequency of rubbing and physical contact at 1 month after grouping was 0.4 times per calf per hour. In the following month, it increased to 1.1 times per calf per hour, and then leveled off. Allogrooming was rare in the first 2 months in the pen and then began to increase remarkably. The number of allogrooming pairs also increased during this time, from 2 pairs in the first month to 6 pairs in the fourth month. At 5.5 months after grouping, the 5 heifers were grazed with the other group of 27 animals on pasture. The focal heifers chose their pen mates as their nearest neighbours more frequently (P<0.05), and allogroomed with them more frequently than with the other animals (P<0.05).
The affiliative relationships among the 5 calves in this study changed through the 4 months of being reared together in the same pen. When the 5 calves grouped together with other animals, the stronger affiliative relationships among them were maintained for at least 1 month after grouping with unfamiliar animals.View full abstractDownload PDF (416K) -
Takehito TSUJI, Katsunori SATO, Tetsuo KUNIEDA2001 Volume 72 Issue 2 Pages 169-171
Published: March 25, 2001
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSIn the present study, we isolated promoter region of mouse insulin receptor-related receptor (Irr) gene and analyzed its expression in various mouse tissues and embryos in different stages. The nucleotide sequence of the promoter region of the Irr gene showed the presence of putative promoter elements and binding sites for trans-acting factors. The expression analysis revealed the strong expression in kidney, stomach, and embryo at the stage of 14.5 days. These findings were basically consistent with the previously reported findings of rat and human, but we found several differences in the sequence and expression pattern of the gene between mouse and rat or human.View full abstractDownload PDF (1042K)
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