All issues
Volume 69, Issue 4
Displaying 1-13 of 13 articles from this issue
- |<
- <
- 1
- >
- >|
-
Tsuyoshi TAKAHASHI, Hiroaki IWAISAKI, Yohji ITOH1998 Volume 69 Issue 4 Pages 321-325
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSIn this paper, we describe how the procedure using canonical transformation for the restricted best linear unbiased prediction with the so-called zero restrictions considered (RBLUP CT) can be applied to the proportionally restricted best linear unbiased prediction of breeding values. Then we examine the property of simultaneous equation systems required in the presented procedure (PRBLUPCT) by investigating the ranks and the numbers of positive eigenvalues of the key matrices. Denoting the numbers of traits in the multi-trait animal model and the restricted traits by q and r, respectively, it is shown that while in the RBLUP CT with zero restrictions the number of the independent equation systems is q-r, that in the PRBLUP CT becomes q-r+1. That is, as r increases, the number of the independent equation systems to be solved decreases, and in the case of all traits restricted proportionally, for instance, the rank and the number of positive eigenvalues of the key matrix become unity and it is needed to solve only one system of the usual BLUP equations for the single transformed variable.View full abstractDownload PDF (340K) -
Mikito HIGUCHI, Yoshitaka NAGAMINE, Hirofumi HANADA, Takashi AWATA1998 Volume 69 Issue 4 Pages 326-332
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSFor the improvement of Japanese Shorthorn (JS) calves in growth on pasture, Santa Gertrudis (SG)×JS F1 calves were produced by artificial insemination (AI) of SG semen into JS cows. The backcrosses (F1×JS and JS×F1) were produced both by mating an F1 sire with JS dams, and by AI with JS semen to F1 cows. All the calves were born from February to April, then kept on pasture with their dams from May to October. Birthweight, gestation length and average daily gain in the grassland were compared among F1, F1×JS, JS×F1 and straightbred JS. F1 calves showed significantly higher birthweights than purebred JS calves. The average daily gain in the grassland was also greater, although not significant, for F1 than for JS. JS×F1 calves exhibited comparable growth to F1 calves on pasture, whereas, F1×JS calves grew slower than JS calves. These results indicate that the utilization of SG×JS F1 calves is one of the effective ways to improve the growthof calves on pasture, and that, in the utilization of the backcrosses, keeping JS×F1 calves with F1 dams is prefera-ble to-keeping F1×JS calves with JS dams.View full abstractDownload PDF (486K) -
Kenji OYAMA, Fumio MUKAI1998 Volume 69 Issue 4 Pages 333-340
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSUsing predicted breeding values (PBV) of an actual beef cattle population, application of a simple genetic algorithm (GA) was done to design the optimum mating, with constraints on inbreeding coefficient of each progeny, inbreeding level of the next generation, and mating frequency of sires. As the breeding stock, 15 sires and 400 dams were selected according to PBV of judging score for breeding females (JS-Data) or beef carcass marbling score (BMS-Data). Aggregate genetic merit (AGM) of eight traits (judging score, two reproductive traits, and five carcass traits) weighing differently was regarded as the breeding objective. When appropriate operator values were used, GA found satisfactory mating designs under pre-determined constraints. The losses in gains of AGM by imposing the constraint of 0.30 on mating frequency were only 31.3% in JS-Data and 35.6% in BMS-Data compared with the mating designs without constraints. Genetic gain of beef marbling score was 28.3% higher in the evaluation from BMSData than JS-Data. Efficiencies of GA to design mating were demonstrated.View full abstractDownload PDF (582K) -
Convergence Property of the Estimate of Variance Ratio in the Tilde-Hat Procedure with Balanced DataKohichi YAMAGISHI, Hiroaki IWAISAKI1998 Volume 69 Issue 4 Pages 341-346
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe tilde-hat (TH) procedure is one of the pseudoexpectation (PE) methods for variance component estimation and is an approximation to the restricted maximum likelihood (REML) method. This procedure is sometimes used for estimating variance components and thereby genetic parameters using large data sets. Considering a balanced data-structure, in this paper, we examine the convergence property of the TH estimate of the variance ratio relative to the REML method using the expectation-maximization algorithm (EM-REML). A cross-classified mixed linear model containing one random effect except for the residual term is assumed. Under the current data-structure, the TH estimator is found to be identical to the REML estimator. However, the function representing the relationship between two successive estimates in the iteration is nonlinear in the case of EM-REML, while that in the TH estimation is shown to be linear. Using the functions derived, it is revealed that when normal convergence occurs with balanced data, the TH estimate always converges faster than the EM-REML estimate. Some discussion is given about the fact that the different PE methods applied to unbalanced data lead to different convergence patterns.View full abstractDownload PDF (410K) -
Yumi KAWAKITA, Hiroyuki ABE, Ryozo TAKADA, Mamoru SAITOH, Toshikazu MI ...1998 Volume 69 Issue 4 Pages 347-354
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSRecent study has revealed that dietary γ-linolenic acid (GLA, 18:3(n-6)) reduces body fat contents and enhances activities of liver carnitine palmitoyltransferase and peroxisomal β-oxidation. However, we considered that GLA might affect not only enzymes involved in lipid metabolism but also in glucose metabolism. Insulin-responsive glucose transporter (GLUT 4) represents the rate-limiting step in glucose metabolism and considered to have an important role for energy accumulation. Present study was conducted to determine whether GLA affects GLUT 4 protein expression in pig tissues. Nine pigs (70kg, castrated males) were allotted to two groups and fed either 90g/day GLA-enriched oil (n=5) or soybean oil (n=4, control) with a formula diet for 6 weeks. The GLA-enriched oil contained 25.3% GLA of fatty acids. The GLUT 4 protein levels were determined by immunoblotting using GLUT 4 antiserum and an enhanced chemiluminescent (ECL) system. GLA treatment significantly reduced GLUT 4 protein contents in M. vastus lateralis compared with control (P<0.05). The GLUT 4 contents in the GLA treatment group also tended to be lower in M. longissimus dorsi and subcutaneous white adipose tissue. These results show that nutritional control may affect GLUT 4 expression in pig tissues.View full abstractDownload PDF (1138K) -
Masaya KATSUMATA, Yuji KAJI, Eisaku TSUNEISHI1998 Volume 69 Issue 4 Pages 355-358
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSPlasma free fatty acids (FFA) response to single intravenous administrations of epinephrine was investigated in growing-finishing pigs. Four gilts weighing about 65kg were fitted with a jugular catheter a week before the first epinephrine administration trial. Five doses, 0.1, 0.2, 0.4, 0.8, and 1.6μg/kg body weight (μg/kg BW), of epinephrine were intravenously administered through the catheter. Each pig was administered one dose each day, and dose levels were randomly allocated to each animal. Blood samples were drawn through the catheters at -30, -15, 0, 5, 10, 15, 20, 30, 40, 50, 60, 90, and 120 minutes after the epinephrine administration. Area under curve (AUC) of FFA was significantly increased by the epinephrine administrations (P<0.05). The estimated dose producing half-maximal response (ED50) and maximal responsiveness (Rmax) for the AUC of FFA were 0.311±0.113μg/kg BW and 573±167 (μEq/l)•min, respectively. From these results, it seems that in vivo mobilization of body fat in growing-finishing pigs can be estimated by single intravenous administrations of epinephrine.View full abstractDownload PDF (259K) -
Masako YAMADA, Yuji NAKAZAWA, Akiyoshi HOSONO1998 Volume 69 Issue 4 Pages 359-364
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSDesmutagenicity of various types of commercial ripened cheese against the mutagenicity of an amino acid pyrolysate, Trp-P 1, using the streptomycin-dependent strain (SD510) of Salmonella typhimurium TA 98, was studied. All kinds of cheese showed high desmutagenicity and were dose-dependent. The desmutagenicity of Camembert, Blue, Emmental, Gruyère and Pont-1' Evèque cheeses using secondary starter were higher than those of Cheddar, Gouda, Edam and Parmesan cheeses using only lactic acid bacteria as starter. Especially among the cheeses tested, the desmutagenicity of Camembert and Blue cheeses showed a rapid increase with increase in the amount of cheese suspensions, and reached a maximum of 100% at 150 and 250μl of cheese suspensions, respectively.View full abstractDownload PDF (417K) -
Kazuhiro SHIMADA, Chitoshi KITAMURA, Tetsuro NOMURA, Takashi HAYASHI1998 Volume 69 Issue 4 Pages 365-369
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSRecords of 11, 944 steers born in Shimane prefecture and slaughtered between 1988 and 1997 were used to estimate the variance components of additive maternal genetic effects and maternal permanent environmental effects (PE) for carcass traits. Considered traits were carcass weight (CW), rib eye area, rib thickness, subcutaneous fat thickness, yield estimate and marbling score. Additive direct heritabilities were high (0.47-0.62) for the carcass traits under the model 1, just included the additive direct genetic effect as the random effects. Model 2 included additive maternal genetic effect additional to the model 1, and estimated maternal heritability for CW was 0.17, while ones for the other traits were 0.01-0.04. Under the model 3 including PE, maternal heritability for CW was 0.12 and the share of PE was 0.05. Correlation coefficients between direct breeding values from models 1 and 2 were high (0.862-0.995).View full abstractDownload PDF (368K) -
Osamu DOCHI, Kazuyuki KONISHI, Kei IMAI, Munetaka TOMIZAWA, Hiroaki OK ...1998 Volume 69 Issue 4 Pages 370-375
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe purpose of this study was to evaluate the effect of repeated superovulation assisted by Syncro-Mate B implants (SMB) on embryo production in Japanese Black cattle. A total of 11 cattle were implanted s. c. with SMB in pinna and injected i. m. with 3mg of norgestomet and 5mg of estradiol valerate at the same time without considering stages of the estrous cycle. Six or seven days after SMB implantation, superovulation treatments were initiated with twice-daily injection of FSH with decreasing dosage manner for 4 days (total FSH 28AU). After 48h or 55h of the first FSH injection, all cattle were injected i. m. with 750μg cloprostenol. All cattle showing estrous behavior were inseminated artificially with frozen semen of Japanese Black bull. Six to eight days later, embryos were collected from uterus by flushing out. The embryo collection was repeated five times at an interval of 28 days. The repeated treatment of superovulation affected the proportion of transferable embryos (P=0.0117) and the number of transferable embryos (P=0.0501). The proportion of transferable embryos at 2nd treatment was significantly higher than that of the other treatment cycle (P<005). The number of transferable embryos after the 3rd treatment were significantly lower than that of the 1st and 2nd treatments (P<0.05). The average of the sum of oocytes/embryos, transferable embryos and good quality embryos were 45.2±25.0, 22.8±18.6 and 10.0±8.7, respectively. The response to superovulation treatment varies largely among individuals. The present study demonstrates that SMB can be effectively applied for embryo collection on repeated treatment of superovulation at an intervals of 28 days in cattle.View full abstractDownload PDF (470K) -
Eisaburo DEGUCHI1998 Volume 69 Issue 4 Pages 376-380
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThis study was carried out to clarify the stressors occurring during grouping of unfamiliar piglets. Twenty eight piglets from G litters, 65±0d old, (Landrace×Large White)×Duroc piglets were used. In experiment 1, 8 littermates×1 litter and 4 littermates×2 litters were used. Four piglets from a litter (moved-pigs A) and 4 piglets (moved-pigs B) from 8 littermates were respectively moved to each of two new pens, and the remaining 4 piglets from 8 littermates were not moved and housed in their own pen (rested-pigs). The other 4 littermates were not moved and used as control pigs. In experiment 2, 4 littermates×3 litters were used. Four littermates (side-housed pigs B) were moved to a new pen next to the pen where the other 4 littermates (side -housed pigs A) were housed. A fence made of iron bars divided the border between two pens where the side-housed pigs A or B. The remaining 4 littermates were not moved and used as control pigs. At 24h after the initiation of experiment 2, the fence between pens ware removed and then side-housed pigs A and B were grouped (experiment 3). Four littermates used as control pigs in experiment 2, were also used as the control pigs in experiment 3. The behavior of piglets was observed during the first 25min after the initiation of the experiments 1, 2 and 3. Blood was obtained from all piglets 30min before and 25min after the initiation of each experi ment and the concentration of plasma cortisol was determined. The behavior observed during the first 25min, from the initiation of experiment to the time of sampling blood for the determination of plasma cortisol, was sniffing the floor and walls of new pens in the move-pigs A and B, and walking about and gathered in the rested-pigs in experiment 1, seeing side-housed pigs B in the side-housed pigs A and sniffing a new pen and seeing side-housed pigs A in the side-housed B in experiment 2, and fighting among piglets in experiment 3, respectively. There was no significant difference in the concentration of plasma cortisol in the control pigs in experiments 1, 2 and 3. On the other hand, the concentrations of plasma cortisol at 25min after the initiation of experiment in moved-pigs A and B and rested-pigs in experiment 1, side-housed-pigs A and B in experiment 2 and grouped-pigs in experiment 3 were significantly higher than those at 30min before experiment and compared to those at the same time in control piglets, respectively. These results show that separation from a group of littermates, exposing to a new pen, seeing unfamiliar pigs and fighting are psychological or physiological stressors in pigs and pigs are in stress caused by these stressors after grouping unfamiliar pigs.View full abstractDownload PDF (409K) -
Hiroshi SATO, Takashi KUROSAWA, Shin OIKAWA, Sachiko ENDO, Seiko SUDO, ...1998 Volume 69 Issue 4 Pages 381-386
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSTo clarify the milk citric acid level and its relations to milk quality in dairy cows, monthly milk samples were taken for 1 year from lactating dairy cows (165 and 348 samples from primiparous and multiparous, respectively) in 2 dairy farms, and citric acid and other milk constituents were measured. The mean and range of milk citric acid levels were 0.15 and 0.09-0.24%. There were many cases of higher citric acid levels in the early postpartum period, however, there was no difference in citric acid levels between primiparous and multiparous cows. In cases where citric acid concentrations were lower than 0.15%, milk lactose level was lower in the many samples. Relative fat and relative protein to citric acid levels (fat/citr. and protein/citr.) showed higher positive correlations than the relations between fat and protein levels, though no clear relations were observed between milk citric acid and fat or protein levels.View full abstractDownload PDF (346K) -
Satoshi ANDO, Kazuo OTSUKI1998 Volume 69 Issue 4 Pages 387-391
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe relationship between heart rate and heat production of Holstein heifers was studied in two conditions. One was during exercise walking, and the other was during food intake. Five Holstein heifers were used in the study. In the walking exercise, heifers were walked on a treadmill at speeds of 6.7, 11.5, 16.7, 23.0, 30.0, and 40.0m/min. For increased levels of food intake, heifers were fed formula food in 500g increments until a total of 3, 000g had been consumed at intervals of 15 minutes. Heart rates were counted from E. C. G., and heat production was calculated from O2 consumption using a head chamber. All regression equations were significant, and correlation coefficient of walking exercise was higher than that of increased levels of food intake. As a result of covariance analysis, the equations obtained from walking exercise and from increased levels of food intake were identified in two heifers. In the other three heifers, regression coefficients were identified, but regression constants were not identified. Regression coefficients were identified between walking exercise and increased levels of food intake. In this experiment however, regression constants were not identified. This was due to the method of establishing food intake. When calculating regression equations between heart rate and heat production, it is necessary to ensure that rate of food intake is the same as in the field.View full abstractDownload PDF (364K) -
Kazuhisa HONDA, Miki SUZUKI, Masahiro NUMATA, Toyoo NAKAMURA1998 Volume 69 Issue 4 Pages 392-399
Published: April 25, 1998
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSFor efficient utilization of animal by-products as food materials, we studied the processing of beef trimmings, liver, red blood cells (RBC) and cartilage by enzymatic treatment. As a result, the sufficient amount (53.9-75.0%) of protein which was the main nutritious component contained in the above organs was solubilized as a peptide form (M. W.<3, 000-6, 000) by the enzymatic treatment. It was considered that the nutrients of these organs were efficiently processed to create an easily absorbable protein source. The taste of cartilage extract (CE) was palatable, but that of RBC extract (RBCE) was not. It was considered that the better taste of CE was due to its characteristic amino acid composition, while the bitter taste of RBCE was due to the high content of bitter amino acids. Therefore, it is difficult to use enzymatic treatment alone for processing of RBC. The physiologically functional component (PFC; carnitine, heme iron, collagen, condroitin sulfate, calcium) were also extracted and concentrated by the enzymatic treatment. However, considering the taste of these extract, it is necessary to further purify PFC and/or improve the taste. Beef extract (BE) had the highest iron solubilizing ability among these extracts. It was supposed that the effect of BE was influenced by the amino acid composition.View full abstractDownload PDF (504K)
- |<
- <
- 1
- >
- >|