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Volume 69, Issue 2
Displaying 1-11 of 11 articles from this issue
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Arata KOGA, Kenichi KURATA, Ryohei FURUKAWA, Masahito NAKAJIMA, Hideya ...1998 Volume 69 Issue 2 Pages 81-89
Published: February 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSFrom previous findings that the physiological responses of buffaloes to hot conditions were characterized by an increase in blood volume, a decrease in hematocrit (Ht) and an increase in skin temperature, we hypothesized that an increase in blood volume in buffaloes contributes to heat transportation from the body core (rectum) to the surface (skin). To test this hypothesis, the first experiment was done to determine if Ht value, which is easy to measure, reliably alters with total blood volume. The second experiment was done to find the relationship between Ht value and the rectal-skin temperature difference. In experiment 1, four swamp buffaloes and four Holstein cattle were successively exposed to environments of 20, 30 and 35°C. Hematocrit value decreased and blood volume increased with the increase in rectal temperature in buffaloes, when they were exposed to hot conditions (30 and 35°C). Correlation coefficients between blood volume or Ht value and rectal temperature were significant for buffaloes. The respective correlations for cattle were not significant. In experiment 2, the animals were successively exposed to acute temperature changes from 20 to 30°C, from 30 to 35°C and from 35 to 20°C. With an increase in environmental temperature, Ht value rapidly decreased in buffaloes, but not in cattle. On the other hand, when environmental temperature decreased, Ht value gradually increased only in buffaloes and this change was associated with a significant decrease in rectal temperature. As a result, the rectal-skin temperature difference in buffaloes was small with the decrease in Ht value and was large with the increase in Ht value. From these results, it was concluded that an increase in blood volume in buffaloes was rapidly caused by the exposure to hot conditions and contributed to reduce the rectal-skin temperature difference and to increase the temperature difference between skin and environment. These characteristics of buffaloes may be advantageous to increase sensible heat loss from the skin surface during a wallowing.View full abstractDownload PDF (662K) -
Akio OKA, Taiji DOHGO, Masakatsu JUEN, Takemitsu SAITO1998 Volume 69 Issue 2 Pages 90-99
Published: February 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe effects of vitamin A on the beef quality, weight gain, and serum concentrations of thyroid hormones, insulin-like growth factor-I (IGF-I), and insulin in Japanese Black steers were investigated. Eight Japanese Black steers which were 14 months old were divided into two groups: high vitamin A group (H) and low vitamin A group (L). The animals in H were injected with 303 mg of vitamin A intramuscularly every month. All steers were given vitamin A added to the feed (approximately 100μg/kg feed) at the age of 21-23 and 26-27 months to prevent manifestation of clinical VA deficiency. Although there was no difference in feed intake between H and L, the average daily gain (ADG) in H was greater than that in L. The beef marbling in L was significantly better than that in H. The backfat depth in H was significantly thicker than that in L. The serum IGF-I concentrations in L gradually decreased and after the age of 18 months were significantly lower than those at the beginning of the experiment. The serum triiodothyronine concentrations in L were significantly lower than those in H during some periods. The change in the plasma glucose concentrations after the insulin injections (0.2U/kg body weight) was similar in H and L. The glucose infusions (0.2g/kg body weight) caused a marked increase in the plasma insulin concentrations in H and L, and both H and L showed similar areas under curves of plasma insulin levels which were above the basal levels. These results suggested that restricted vitamin A intake led to lower ADG, better beef marbling and lower serum IGF-I and triiodothyronine concentrations.View full abstractDownload PDF (657K) -
Kazunari USHIDA, Takashi SAKATA1998 Volume 69 Issue 2 Pages 100-107
Published: February 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSLactate and succinate sometimes accumulate in the cecum and colon of monogastric animals, often resulting in disturbed gut function. The present study assessed the critical point of digesta pH at which lactate and succinate begins to accumulate during fermentation of oligosaccharides under the pig cecal in vitro conditions. Xylosylfructoside, isomaltooligosaccharides and raffinose were incubated with pig cecal digesta dissolved in one of seven buffers with different pHs (4.0, 4.5, 5.6, 5.8, 6.0, 7.0 and 7.5). Lactate, acetate, propionate and butyrate were predominantly produced. The production of acids was significantly affected by initial pH of culture, oligosaccharides and two-way interaction effect between sugar and pH except for formate. Lactate accumulated under conditions of initial low pH. The critical initial pH that induced lactic acid fermentation depended on the type of oligosaccharides; 5.0 for isomaltooligosaccharides and 6.0 for raffinose and xylosylfructoside at 6h incubation. Lactate molar ratio decreased along with incubation except for xylosylfructoside. Induction of lactic acid fermentation in large intestine can be avoided if digesta pH is maintained at least above 6.0 when oligosaccharides are fed to the pig.View full abstractDownload PDF (581K) -
Reiko WATANABE, Shinobu FUJIMURA, Motoni KADOWAKI, Teru ISHIBASHI1998 Volume 69 Issue 2 Pages 108-116
Published: February 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSIn order to compare the responses of plasma amino acid (AA) concentrations of glycine (Gly) and serine (Ser) to the dietary excess threonine (Thr) in rats and chickens, adult male Wistar/ST rats weighing 304.5±5.2g were fed diets with five graded levels of Thr from 0.32 to 0.67%. The composition of experimental diets was similar to that of the basal diet used for laying hens. Tissue concentrations (TC) of three AA, Thr, Gly and Ser, expressed as μmol/g tissue and the enzyme activities expressed as μmol/g tissue/30min relating to conversion of Thr to Gly and interconversion of Gly and Ser in homogenates of liver, kidney and duodenum were determined. In the liver, when dietary Thr increased from 0.32 to 0.42%, TC of Thr increased from 0.50 to 0.73 μmol/g, and then increased linearly with increasing dietary Thr levels. When dietary Thr levels were higher than 0.42%, TC of Thr in the kidney and duodenum were higher 45 and 75% at 0.67% dietary Thr level compared to those at less than 0.42% dietary Thr level, respectively. TC of Gly in the three tissues remained constant regardless of dietary Thr levels, but those in the kidney were two times higher than those in other two tissues. TC of Ser in the liver tended to increase, however, those in the kidney and duodenum were not affected by dietary Thr levels. In the liver, Thr aldolase activity decreased slightly, and then increased at dietary Thr levels exceeded 0.42%. However, all enzyme activities except Ser-hydroxymethyltransferase in the liver were not affected by dietary Thr levels. In contrast to the data of laying hens reported previously, the activity of liver Ser-hydroxymethyltransferase converting Ser to Gly decreased with increasing dietary Thr levels. These responses of enzyme activities in the rat liver might be one of the reasons for the difference in the responses of TC and plasma concentrations of Gly and Ser to the dietary excess Thr in rats and chickens.View full abstractDownload PDF (571K) -
Masahiro SATOH, Tsutomu FURUKAWA1998 Volume 69 Issue 2 Pages 117-122
Published: February 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSRestricted best linear unbiased prediction (restricted BLUP) is derived by imposing restrictions directly within a multiple trait mixed model. As a result, the restricted BLUP procedure requires the solution of high-order simultaneous equations. In the present paper, a simple method for computing BLUP of breeding values with the change in some traits restricted to zero is presented. The technique is valuable, particularly when a large number of restrictions are imposed. In this case, the values of economic weights for restricted BLUP of breeding values of traits do not affect the total genetic merit.View full abstractDownload PDF (347K) -
Thuy Thi LE, Tuyen Xuan DUONG, Keijiro NIRASAWA, Hideaki TAKAHASHI, Ts ...1998 Volume 69 Issue 2 Pages 123-125
Published: February 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe V1 duck is a grandparent line of Cherry Valley Super Meat Duck which was bred in England. The V1 duck was imported to Vietnam Institute of Animal Husbandry in 1991 and used for selection experiments. A total of 1040 records of V1 duck raised in Vietnam were used to estimate genetic parameters and the genetic trend of body weight. Body weight at 8 and 24 weeks (BW 8 and BW 24) were measured through 4 generations. Best linear unbiased prediction method with an animal model and restricted maximum likelihood were applied to estimate breeding values and heritabilities, respectively. Means of BW 8 and BW 24 were 2, 202 and 3, 297 g for male and 2, 168 and 3.071g for female. Estimated heritabilities were 0.104 for BW 8 and 0.128 for BW 24, respectively. Genetic trends were not significant for either BW 8 or BW 24.View full abstractDownload PDF (199K) -
Masahiro SATOH, Tsutomu FURUKAWA1998 Volume 69 Issue 2 Pages 126-132
Published: February 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSEffects of population size, and interval of markers on a chromosome in reference family on the efficiency of linkage analysis was studied using computer simulation. The genetic linkagemap was constructed using a two generation reference population of intercross. Three types of reference populations were used for investigating the effect of reference population size: The first comprised 6 F1 sires and 10 different numbers of F1 dams (6 to 60) derived from a cross between three grandsires from a different breed with six grandams from another breed. Each F1 dam produced eight progenies. The second comprised 12 F1 sires and 12, 24, 48 or 96 F1 dams derived from a cross between six grandsires and 12 grandams. F1 dams produced 192 F2 progenies altogether. The third comprised 24 F1 dams and 12 or 24 F1 sires derived from across between 1, 2 or 3 grandsires and 6 or 12 grandams and each F1 dam produced eight progenies. All F1 dams were mated randomly to each type of F1 sires from reference population. Chromosomal map length of 1.2 Morgans, and an average interval between markers of 0.05, 0.10, 0.15 or 0.20 Morgans on a chromosome and two alleles of markers were assumed. The considered markers were placed at random intervals on a chromosome. Chromosomal map length and recombination rate between markers with the lod scores (Z) were estimated using genotypic data from the reference population. Efficiency of linkage analysis increased consistently, but the rate declined steadily as the number of F2 animals increased. The shortest average interval between markers was not always the best efficiency for mean square error of chromosomal length and rate of no double heterozygote between markers. The efficiency of linkage analysis increased slightly as the number of grandparents and F1 sires increased when number of F1 dams (F2 animals) was kept constant.View full abstractDownload PDF (492K) -
Yoshinobu TANAKA, Toshihiko NAKAO, Wenchang ZHANG, Masaharu MORIYOSHI, ...1998 Volume 69 Issue 2 Pages 133-139
Published: February 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSTo describe the mechanism of increasing day-time calving by night-time feeding, plasma concentration of Prostaglandin E2 (PGE2) and cortisol were determined during a prepartum period. Fifty-five Holstein Friesian cows in the late pregnancy were divided into two groups, 28 cows were fed for 97.99% of TDN 7.35kg per cow in the evening, while other 27 cows were fed regularly in the morning and afternoon and served as controls. Blood was collected twice a day, in the morning between 4:00 and 5:00 and in the evening between 18:00 and 19:00 from 23 of the 55 cows for the measurment of PGE2 and cortisol. Percentage of cows delivered in the day-time was 64.3% in the night-time feeding group and 51.9% in the regular-feeding group. In the night-time feeding group of cows, plasma PGE2 in the evening was not specifically increased and plasma PGE2 was higher in the morning than in the evening during the last 7 days of pregnancy, while no such a trend was seen in the regular feeding group. Among cows with night-time feeding the diural pattern of plama PGE2 was more apparent in cows which delivered in the day-time than those calved in the night-time. Changes of plasma PGE2 in cows during a prepartum period are closely associated with plasma cortisol. The results indicate that a restraint of plasma PGE2 increasing in the evening and a rise of plasma PGE2 in the morning after night-time feeding plays an important role in increasing day-time calving.View full abstractDownload PDF (503K) -
Eisaburo DEGUCHI1998 Volume 69 Issue 2 Pages 140-145
Published: February 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThis study was undertaken to examine the activities of neuroendocrine system and the changes of number and function of leukocytes in peripheral blood in a short period after grouping unfamiliar piglets. At 34d old, 12 piglets (4 littermates×3 litter) were moved and placed to a new pen, and they were reared together for 3d (grouped-piglets). The other 6 piglets of 1 litter were not moved and used as control piglets. Aggressive encounters among grouped-piglets were observed for 8h after grouping. Plasma cortisol, glucose and nonesterified fatty acid (NEFA) concentrations and total and differential leukocyte counts at 15min before grouping (before) and at 45 and 180min after grouping, and phagocytic function of neutrophils before and at 180min after grouping were determined. In grouped-piglets, the concentrations of plasma cortisol, glucose and NEFA at 45 and 180min after grouping were significantly higher than those before grouping and compared to those at the same times in control piglets, indicating that both hypothalamic-pituitary-adrenal cortex and sympathetic-adrenal medulla axes are activated in response to aggressive encounters after grouping unfamiliar piglets. In grouped-piglets, leukocytosis, neutrophilia, lymphocytopenia and monocytepenia at 45 and 180min after grouping, and decreases of phagocytic function of neutrophils were also seen after grouping.View full abstractDownload PDF (437K) -
Guoqi ZHAO, Hiraku SASAKI, Masayoshi KUROSAWA, Masato SAKAI, Yoshiya N ...1998 Volume 69 Issue 2 Pages 146-153
Published: February 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSFour sheep, fitted with ruminal and duodenal cannulas and given only orchardgrass hay, were used for in sacco and in vivo estimation of the ruminal degradation of the hay ribonucleic acid (RNA) and for measurement of duodenal digesta flow. Other four rumen cannulated sheep given orchardgrass hay were used to isolate bacterial and protozoal samples from strained rumen content and to determine the concentration of RNA (purines), diaminopimelic acid (DAPA) and phosphatidylcholine (PC) as markers of rumen microbes. Samples of hay and duodenal digesta were also analyzed for these markers. The degradation characteristics in sacco of hay RNA, dry matter (DM) and crude protein (CP) were measured by incubating hay sample in polyester bags in the rumen. The results were fitted to the exponential equation p=a'+b'{1-e-c(t-Lt)}, where p is disappearance for each constituent from the bag after t (h), a' the solubility (washing loss), b' the insoluble but potentially fermentable material, c the constant of degradation rate of b' and Lt the lag time of degradation. Particle outflow rate (k1) from the rumen was estimated using chromium mordated hay. Effective degradability (ED) of each constituent of hay was given by the equation ED=a'+bc/(c+k1)e-(c+k1)Lt. Average ED of RNA was 79.4% which was remarkably higher compared to them of DM (49.3) and CP (60.4%). The average flow of DM to the duodenum of sheep was 10.4gDM/kgBW/d. Concentrations of RNA in hay, bacteria, protozoa and duodenal digesta were 5.2, 123.5, 77.5 and 29.8mg/gDM, respectively. DAPA was found only in bacteria (2.0mg/gDM) and duodenal samples (0.4mg/gDM). PC was obtained in protozoa (19.2mg/gDM) and in duodenal digesta (1.9mg/gDM). On the basis of these data, average total RNA (310), DAPA (4) and PC (20mg/kgBW/d) duodenal flow was calculated. The average amounts of bacteria reaching duodenum calculated by DAPA as a marker, and of protozoa calculated by PC, were 1, 829 and 1, 022mg/kgBW/d, respectively. Using these amounts and concentrations of RNA in bacterial and protozoal samples, it was estimated bacterial and protozoal RNA flux to duodenum: 226 and 79mg/kgBW/d, respectively. The sum of bacterial and protozoal RNA was subtracted from the total duodenal RNA flow. The result was assumed as an amount of ruminally escaped RNA with hay origin: 5mg/kgBW/d. Undegraded feed RNA was devided by the intake of RNA with hay (104mg/kgBW/d), expressed as percent (5.0) and subtracted from 100 in order to get rumen degradability in vivo of grass hay RNA: 95.7%. Consequently, the proportions of bacteria amount, estimated from the undegraded hay RNA in sacco and in vivo, to that calculated from the total RNA duodenal flow, were 6.8 and 1.3%, respectively.View full abstractDownload PDF (653K) -
Koichi KAKU1998 Volume 69 Issue 2 Pages 154-160
Published: February 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe purpose of this study is to analyze the propriety concerning the price volatilities of the Japanese domestic broilers, if broilers would be traded on the futures markets in Japan. The main findings are three things.:(1) On the U.S. futures markets, the livestock products' futures contracts have been traded and the ratio to the total volume of which all futures markets were combined was 14.11-9.41% from 1990 to 1996 (fiscal year). (2) From 1988 to 1995, the average coefficients of variation per year (%/year) on the Japanese domestic broilers were 7.20 (bonelessleg meat) and 6.85 (boneless breast meat), which were lower than those of the Japanese domestic agricultural futures commodities and the CME's futures commodities concerning pork (i.e. Live Hog, Frozen Pork Bellies), but which were higher than those of the CME's futures commodities concerning beef (i.e. Live Cattle, Feeder Cattle). (3) From 1992 to 1995, judging from the analysis of relationship between yearly coefficient of variation and yearly volume of agricultural products' trading on Japanese futures markets, I suppose, the price volatilities of the Japanese domestic broilers boneless meat, which were both boneless leg meat and boneless breast meat, had suitability which could be traded on the broilers futures markets in Japan.View full abstractDownload PDF (473K)
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