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Volume 68, Issue 8
Displaying 1-11 of 11 articles from this issue
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Ikuo OSAKA, Koichi HODATE, Fumiaki ITOH, Yoshiaki OBARA, Hiroshi FUSE1997 Volume 68 Issue 8 Pages 727-734
Published: August 25, 1997
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSFour Holstein heifers were used to study the effect of cold and heat exposure on changes in plasma concentrations of hormones and metabolites. The heifers were kept in a room with a regulated, artificial climate. Temperatures were 20°C (thermoneutral), 0°C (cold), and 30° (hot). The heifers were fed hay and a commercial concentrate once daily. Venous blood samples were taken through a jugular vein catheter at 0900h, after 1, 2, 3, 6, 10, and 16 days of exposure to each environment. Rectal temperature and heart rate were unaffected by thermal stress, but respiration rate decreased during cold exposure and increased during heat exposure. The plasma insulin concentration decreased in the early stage of the cold and heat exposure. The plasma glucagon concentration was unchanged by such thermal stress. Plasma GH decreased from 6 days of cold exposure. A significant decline in plasma glucose was found following chronic heat exposure, whereas plasma glucose increased in the cold environment, The plasma non-esterified fatty acid (NEFA) concentration decreased following heat exposure. These results suggest that plasma insulin decreased in the early part of the cold and heat exposure, however, despite the restoration of basal insulin concentrations, metabolic substrates were maintained at the altered levels.View full abstractDownload PDF (623K) -
Teru ISHIBASHI, Akemi YAMAMOTO1997 Volume 68 Issue 8 Pages 735-740
Published: August 25, 1997
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSIn order to confirm that the lysine (Lys) requirement increased with dietary amino acid (AA) levels and that the Lys requirement determined from plasma Lys concentration agreed well with that determined from data of laying performance, the Lys requirement was determined in a practical farm using a large number of laying hens. Laying hens at 78 weeks of age were divided into 13 groups, housed individually and given free access to the experimental diets with 110 and 125% AA of NRC requirements (1994) and water for 47 days. The two basal diets contained graded six Lys levels. Egg weight was recorded every three days, feed intake was recorded every six days and body weight was recorded at the beginning and end of the experiment. Blood samples were taken at the last day of the experiment for the determination of plasma Lys concentration. The maximum egg production rate and ratio of egg mass: feed intake on the 110% diets were inferior to those on the 125% diets. The Lys requirements were estimated to be 0.56, 0.56 and 0.57% for the 110% diet, and 0.61, 0.59 and 0.61% for the 125% diet, respectively, from the data of egg production rate, ratio of egg mass: feed intake and plasma Lys concentration. These results indicated that 110% AA of NRC (1994) was deficient for the maximum laying performance and that the Lys requirement increased with increasing dietary CP or AA levels.View full abstractDownload PDF (398K) -
Yasuo KOBAYASHI, Akihiko EBATA, Masaaki WAKITA, Sadao HOSHINO1997 Volume 68 Issue 8 Pages 741-747
Published: August 25, 1997
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe chimeric plasmids, pYK4 and pYK7, replicable in both Escherichia coli and Butyrivibrio fibrisolvens, transformed B. fibrisolvens strains OB156 and OB156C via electroporation. These host strains were more transformable as field strength was increased, though the optimal setting for efficient and safer electroporation was considered to be 20kV/cm with 200 ohm of resistance and 25μF of capacitance. The amount of plasmid DNA was 0.1μg for most efficient electrotransformation. A selective marker gene coding for erythromycin resistance was well expressed in the B. fibrisolvens transformant, which showed normal growth with erythromycin even at a level of 800μg/ml. Although the transformant was free from selection pressure of this antibiotic for 2 weeks with 24h-interval subculturing, the plasmid vector in the transformant was fairly stable, being retained at 64-77%.View full abstractDownload PDF (457K) -
Reinhard PINONTOAN, Jun-ichi OKUMURA, Tatuso MURAMATSU1997 Volume 68 Issue 8 Pages 748-751
Published: August 25, 1997
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSWhole-body protein synthesis in chicken embryos was determined at 3 days of incubation age by using an in vitro culture system with or without stretched extra-embryonic membranes. Embryo cultures were conducted in a Petri dish containing synthetic serum-free medium with [3H] phenylalanine in a CO2 incubator for up to 90min. Stretch made on the extra-embryonic membranes enhanced the incorporation rate of phenylalanine into whole-body protein. However, the embryo cultured without the extra-embryonic membranes showed even a higher phenylalanine incorporation rate at 90min compared to the one with stretched membranes. It was concluded, therefore, that whole-body protein synthesis of chicken embryos should be measured without extra-embryonic membranes under the present stationary culture system.View full abstractDownload PDF (859K) -
Kazumi KITA, Kanokwan HANGSANET, Jun-ichi OKUMURA1997 Volume 68 Issue 8 Pages 752-755
Published: August 25, 1997
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSWe examined changes in hepatic insulin-like growth factor-I (IGF-I) and β-actin mRNA levels in chickens during early stages of growth after hatching. At 0, 1, 2, 4, 6 and 8 wk of age, hepatic IGF-I and β-actin mRNA levels were measured by using a ribonuclease protection assay. The IGF-I mRNA level in the liver significantly increased from 0 to 1wk of age, and thereafter the level tended to increase toward 8wk of age, but not significantly. The level of hepatic β-actin mRNA was maintained throughout the experiment. The IGF-I mRNA/β-actin mRNA ratio significantly increased form 0 to 6wk of age, and then tended to decrease but not significantly. These results indicate that hepatic IGF-I gene expression in chickens rapidly increases at early stages of growth after hatching.View full abstractDownload PDF (247K) -
Makoto ITOH, Keizou ARIHARA, Yo KONDO1997 Volume 68 Issue 8 Pages 756-759
Published: August 25, 1997
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe molecular species compositions of triacylglycerols isolated from M. longissimus thoracic of fattened beef cattle (Japanese Black, Japanese Shorthorn, and Holstein steers) were determined by gas chromatography. There were twenty-five molecular species in triacylglycerols. Major species having more than 10% of total molecular species for at least one breed were palmitoyl (P)-P-oleoyl (O)-glycerol (PPO), P-P-linoleoyl (L)-glycerol (PPL), P-stearoyl (S)-O-glycerol and P-O-O-glycerol (POO). The concentration of POO was the highest in these species. The concentration of POO in triacylglycerol was closely associated with the concentrations of PPO and POL.View full abstractDownload PDF (262K) -
Masahiro SATOH, Tsutomu FURUKAWA1997 Volume 68 Issue 8 Pages 760-766
Published: August 25, 1997
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe accuracy of selection (RIg) for an index based on family selection in a pig population was calculated using information on the individual its relatives and ancestors dating back to generation five (F-5). The candidate for selection was found in the current genration F-0. The sire and dam including their full and half sibs were found in generation F-1, the grand parents and their full and half sibs were found in generation F-2, F-1 was defined as animals in the ith generation back. Each animal was assumed to have one record for a breeding trait. Inbreeding coefficient of all animals was considered to be zero. Six different heritability (h2) levels (0.1 to 0.6) for the traits were used. Furthermore, mating rations (number of dams per sire) were varied from one to five and number of sibs per litter was varied from one to eight. RIg increased with number of sibs per litter for h2<0.3. Information from half sibs of candidate and direct ancestors was not useful for increasing RIg when four sibs or more per litter had their records for a trait with h2_??_0.3. RIg was maximal when records from F-0 to F-3 for a trait with h2_??_0.3 and records from F-0 to F-4 for a trait with h2<0.3 were used. It was concluded that information from F-0 to F-4 was sufficient for estimating breeding values in the pig population and that use of ancestral information to increase RIg was most useful at low heritability.View full abstractDownload PDF (485K) -
Eisaburo DEGUCHI, Masao AKUZAWA1997 Volume 68 Issue 8 Pages 767-773
Published: August 25, 1997
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThis experiment was carried out to examine the effects of fighting after grouping unfamiliar piglets on the plasma cortisol concentration, total and differential leukocyte counts and the phagocytic function of monocytes and neutrophils. Twelve, 4 littermates×3 litters, 45±0d old, castrated male, (Large White×Landrace)×Duroc piglets were used. One litter (moved-pigs) was moved to the pen where the other litter (housed-pigs) was housed, and then they were reared together for 8d. The remaining one litter was not grouped and used as control pigs. Immediately after grouping, housed-pigs attacked violently against moved-pigs and kited on their ears, neck and shoulders for 6h. The aggression of moved-pigs against housed-pigs was not scarcely seen. The changes of plasma cortisol concentration, the number of total and differential leukocytes and the phagocytic function of monocytes and neutrophils were not seen in control pigs throughout the experiment. The results in moved-and housed-pigs were as follows: 1) plasma cortisol concentrations at 1h after grouping were significantly higher than those at 1h before grouping and compared to those in control pigs, and then decreased to the physiologically normal levels at 24h after grouping; 2) the number of monocytes and phagocytic functions of monocytes and neutrophils on the 1st d and the 8th d after grouping were significantly decreased than those at 1h before grouping and compared to those in control pigs, while the neutrophil counts were almost same throughout experiment; and 3) significant differences of plasma cortisol and these immune parameters were not seen between moved-and housed-pigs. These data suggest that fighting after grouping unfamiliar piglets is an actual stressor and the phagocytic functions of monocytes and neutrophils are suppressed at least for 8d after grouping.View full abstractDownload PDF (558K) -
Hiroshi DOHI, Akihisa YAMADA, Shigeki ENTSU, Takayuki SUMIKAWA1997 Volume 68 Issue 8 Pages 774-779
Published: August 25, 1997
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe automatic recorder for standing behaviors of cattle consisted of a pressure-sensitive switch and a recorder that stored the times of the application and removal of pressure from the switch. When an estrus cattle fitted with the switch to its rump is mounted by cattle, the time and duration of the standing behavior are automatically recorded with a pulse memory recorder. The automatic recorder was examined for its usefulness in detecting the onset and end of estrus, and in estimating the optimum insemination time. In experiment 1, six heifers, one of which was tested twice, demonstrated that there were periods of frequent mounted responses lasting three seconds or more. These results suggested that the device was useful for determining the period of standing estrus. In experiment 2, six cows in a group of 50 heads were treated with prostaglandin F2α and fitted with the device. The group were observed twice per day and the six cows were inseminated by a herdsman at the optimum time which was estimated based on his periodic observations. Four cows were inseminated during the period of the optimum insemination time on the basis of the onset and end of estrus, which were determined using data from the automatic recorder, and all the four were pregnant. One cow that was inseminated beyond the limit of optimum time determined using the device, was not pregnant. These results demonstrated that it was possible to inseminate estrus cattle at the optimum time if real-time data on standing behaviors is obtained through the use of a telemetry system incorporating a pressure sensitive switch.View full abstractDownload PDF (433K) -
Akira WATANABE, Mitsuto MATSUMOTO, Shirou KUSHIBIKI, Hiroyuki SHINGUU, ...1997 Volume 68 Issue 8 Pages 780-786
Published: August 25, 1997
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe effects of pre-chill removal of kidney fat on tenderloin quality were studied using eleven fattening Japanese Shorthorn cattle. At 30min post-mortem, tenderloin on left side of each carcass was chilled by kidney fat removal and running water (12-15°C) for 5min (RF-treatment). The other side was left intact (IF-treatment). Both sides were then stored at 3°C for 10 days before the tenderloins were excised from carcasses. RF-treatment accelerated the chilling rate, resulted in significant increased toughness (P<0.05), reduced transmission value (P<0.01), higher moisture content (P<0.05), increased cooking loss (P<0.05), and lower Hunter "L", "a" and "b" values (P<0.01). No significant difference was observed in water holding capacity. The sensory panelist tended to prefer the steak when the moisture content was 2.4% greater for the RF-treatment. In steaks where the moisture difference is over 2.9%, preference was extremely significant (P<0.01) because of the juiciness (P<0.01) resulting from RF-treatment. In the present study, four out of eleven pairs of tenderloins (36%) had a moisture difference between the treatments greater than 2.4%. These observations suggest that pre-chill removal of kidney fat would improve the moisture content of the tenderloin, which would be preferred by the consumer.View full abstractDownload PDF (529K) -
Hidetoshi MORITA, Ryoichi SAKATA, Yasuyuki TSUKAMASA, Atsushi SAKATA, ...1997 Volume 68 Issue 8 Pages 787-796
Published: August 25, 1997
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSStaphylococcus carnosus and Staphylococcus xylosus which were converted from metmyoglobin in MRS broth to a red myoglobin derivative (unknown) formed in Parma ham and nitrosylmyoglobin, respectively were used. Salamis (ca. 240g) without sodium nitrite addition were prepared using these staphylococcal strains as starter cultures. All salamis were ripened at 20°C for 23 days at 80% relative humidity. Salamis inoculated S. carnosus or S. xylosus assumed red color even without nitrite or nitrate addition and with only a small amount of sodium chloride. The physiological features (pH value, residual NO2-, water content, water activity and sodium chloride concentration) of these samples were essentially the same as those of cured salami. The bacterial safety of all samples was confirmed on food hygiene, resulting from investigation of bacterial count, acidogenic bacterial count, coliform count, staphylococcal count and salmonella count. Inoculation of S. carnosus or S. xylosus as starter cultures contributed to reduced discoloration of salami with sodium nitrite.View full abstractDownload PDF (622K)
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