Amplified fragment length polymorphism (AFLP) technique is new DNA marker method that detect numberless polymorphic bands, based on the selective amplification of restriction fragments. We applied the technology to five cattle breeds (Japanese Black, Japanese Brawn, Korean native, Hereford, Limousin) in Asia and Europe. Four primer combinations produced 95 polymorphic bands among breeds. Band sharing values based on those bands showed 0.659-0.776 between the breeds, and 0.753-0.854 within the breeds. Phylogenetic tree constructed by Unweighted pair group method average (UPGMA) method illustrated two major clusters, which were Japanese/Korean cattle cluster and European cattle cluster. The tree and band sharing values showed that Japanese Brown cattle was genetically located between Asian and European cattle breeds, indicating that Japanese Brown has been influenced by European breed. These results reflected the genealogy of these breeds. This study suggested that AFLP method is a easy and powerful tool for investigating the genetic relationships in cattle populations.

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The differences of the ratio of fat/lean area (RFA) in M. longissimus dorsi calculated by image analysis method using digital images taken by different video camera were examined on exactly the same cross section of carcass. The images of ribeye from 22 Japanese Black steers were taken almost at the same time by three kinds of digital video cameras, and the RFAs from those images were compared. The influence of the season on the relationship between the RFA and Beef Marbling Standard (BMS) number assigned by grader was investigated for the image of ribeye from 2, 216 Japanese Black cattle. The images were recorded from April, 1999 to March, 2000. The RFA from one of the three video cameras was significantly higher than the RFA from other two cameras (P<0.01). However, the influence of the input device on the calculation of the RFA could be removed by using the linear regression equation. The partial regression coefficients of the RFA to BMS number for season 1 (Apr-Jun, n=492), 2 (Jul-Sep, n=511), 3 (Oct-Dee, n=985) and 4 (Feb-Mar, n=228) were 0.245, 0.244, 0.243 and 0.238, respectively. Similarly, the intercepts of season 1, 2, 3 and 4 were -2.59, -2.27, -2.09 and -2.23, respectively. These results indicated that the effect of season was not recognized for the grading of BMS number.

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Effects of protein supplementation to culture medium (synthetic oviduct fluid, SOF) and oxygen tension (5% O₂ or 20% O₂) during embryo culture on in vitro development of somatic cell cloned embryos were examined under non-coculture system. And then pregnancy rates of heifers by embryo transfer using the cloned embryos derived from various culture methods were assessed. The developmental rates of the embryos to the blastocyst stage were not different between embryos cultured under 5% O₂ (44/114, 38.6%) and 20% O₂ (37/108, 34.3%) tensions in SOF supplemented with bovine serum albumin (BSA) (SOF+). In contrast, when cultured in SOF without BSA (SOF-), the rate significantly decreased to 21.4% (27/126) in embryos cultured under 5% O₂. Furthermore, no blastocysts were obtained from embryos cultured under 20% O₂ (0/125, 0%). After the cloned embryos were transferred to recipients heifers, 17 pregnant recipients were obtained by embryos cultured in various culture conditions. However, 9 of them resulted in abortions from 40 to 60 days of gestation. These results indicate that BSA containing SOF medium can support full term development of somatic cloned embryos under a high (20% O₂) and a low (5% O₂) oxygen tension, and protein free SOF medium also supports the embryonic development only in 5% O₂, but not in 20% O₂. Therefore, it may suggest that proteins including serum and albumin protect embryos from damages induced by a high oxygen tension, such as free radical, causing "in vitro block" of bovine embryos in culture.

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Daily ultrasonic monitoring was conducted to examine the dynamics of bovine follicular development categorized into four by their diameter (large (1): _??_10mm, large (2): 7mm_??_and 10mm<, middle: 4mm_??_and 7mm<, small: 2mm_??_and 4mm<) under low nutrient colldition (90% of TDN requirement) and normal nutrient condition (100% of TDN requirement) in dairy cows. Four Holstein cows were used in this study. Two cows (No. 1, No. 2) were observed daily during three estrous cycles under 90%, 100%, 90% of TDN requirement, and the other two cows (No. 3, No. 4) were observed under 100%, 90%, 100% of TDN requirement. Ali cows consisted of two waves of middle size follicles with only one large follicle. In the first follicular wave, detection, end of growth phase, maximum diameter and onset of regression of dominant follicle were not different in the two conditions. In the second follicular wave, detection, maximum diameter and interval from detection to ovulation of dominant follicle were not different in the two conditions of dominant follicle. But, the number of small follicles tended to decrease in low nutrient condition. This result suggested that emergence of follicular wave and ovulation were observed in low nutrient condition, but the number of small follicles decreased.

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The aim of this study was to examine the relationship between the properties of cervical mucus, concentration of serum progesterone, and the pregnancy rate in recipients. The recipients were divided into four groups according to the difference in the proportion of epithelial cells with a collapsed nucleus in the cervical mucus (-group; 0%, ±group; under 20%, +group; 20 to 80%, ++group; over 80%). The -group an ±group recipients had higher pregnancy rates after embryo transfer than the other groups, and the former had a higher concentration of progesterone before embryo transfer than the latter (P<0.05). When recipients were classified based on the pH of the cervical mucus, all recipients with a cervical mucus pH under 6.9 or over 7.7 were nonpregnant. But there was no relation between the concentration of progesterone, pH of the cervical mucus and the pregnancy rate after embryo transfer. These results show that estimation of the concentration of progesterone in recipients is possible by examining the cervical mucus, and is effective in improving the pregnancy rate after embryo transfer.

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Chemical composition and energy value of dried meal from food waste were assessed to use as feedstuffs for swine and cattle. Five kinds of food waste were provided in this study: those coming from school lunch (inedible waste, half-eaten residue and mixture of inedible waste with half-eaten residue), inedible dried waste meal prepared from central kitchen of convenience food store and dried waste meal including various kinds of food waste of many company, produced on a large scale factory. Mean protein concentration of five meals exceeded 16% as dry matter basis, but very large variation was shown in the case of school lunch residues. Predicted total digestible nutrient (TDN) values for swine and cattle using two enzymatic methods ranging from 77-87% and 51-102%, respectively. Measured TDN for sheep using dried waste meal produced on a large scale factory were 93.0 and 88.7%, corresponding to the added level of dried meal, which were 15 and 30% as air dry matter basis.

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The molar ratio of calcium (Ca) and inorganic phosphorus (Pi) bound to the paracasein of Mozzarella cheese has been found to be less than 1.0, but that of natural cheeses was more than 1.4. In order to clarify the low of Ca/Pi ratio in the paracasein of MC, the sediments or curds were obtained by centrifuging of bovine milk or the coagulated milk after treatment with starter and rennet under various conditions of MC preparation, and then dissolved in 5M urea. The contents of protein, Ca and Pi in the urea solutions were determined, and Ca/Pi ratios of casein and paracasein were obtained. The Ca/Pi ratio of casein micelles did not change with addition of 20-100mg NaCl to 100ml milk. In the paracasein of curds from the coagulated milk added different amounts of starter and rennet, the Ca/Pi ratio was higher than that of casein micelles in milk. The paracaseins of curds from the coagulated milk also indicated the increase of Ca/Pi ratio at low pH. Among the milks added NaCl (CM) with the pH adjusted to 5.5 with lactic acid (LM), and the coagulated milk at pH 5.5 (RM), the Ca/Pi ratio increased in this order RM>LM>CM when each milk was kept at 5°C for 3h. In the whey drained curds at pH 6.0 from the coagulated milk added different amounts of starter and rennet, the Ca/Pi ratio of paracaseins were similar to that of casein micelles, but the bound Ca/Pi ratio increased with the increased amount of starter. The paracaseins of whey drained curds at pH 6.0, followed by addition of 2.0% NaCl and heated at 65-80°C for 2min did not decrease the bound-Ca/Pi ratio. However, in the curds stored at 5°C for 30 days, the ratio decreased to less than that of casein micelles heated at low temperature, and was 1.1 at 65°C. Consequently, the content of serum remaining in the curd was assumed to be responsible for the change of bound-Ca/Pi ratio in paracasein.

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Reproductive performance and farrowing behavior in Japanese wild boars under captive conditions were investigated in order to obtain a basic knowledge for the suitable rearing system of wild boars. In this study on reproductive performance, the data on 35 wild boars from 1993 to 1997 were used for the analysis. The average litter size in each year was from 3.3 to 5.6, and that for 5 years was 4.4. The sex ratio was 1:1, and there was no difference of sex ratio in each litter. Three wild boars of 8 were successfully recorded with videotape during farrowing. The behavior of wild boars was observed from 1h before to 1h after farrowing using a continuous sampling method. They each farrowed 4, 4 and 5 newborns. There was a considerable difference in the farrowing behavior from the start to the completion among these 3 wild boars. The farrowing times of 3 wild boars were 54min, 41min and 320min. One mother killed all her infants by the next morning. The mother bit and kicked them at nursing. The behavioral pattern of the mother that killed her infants was not similar to that of the others. During the farrowing and post-farrowing periods, the killer mother had more time walking and exploring than others. The number of animals might not be enough to clarify the farrowing behavior, but it was the first case that the farrowing scene and infant killing of Japanese wild boars were videotaped. These records are very precious and suggest the course of future study about the possibility of discrimination between normal mother and infant killing mother in wild boar farming. All mothers touched their newborn litters with their nose or mouth just after expulsion. The wild boars farrowed more easily compared with the domestic pigs, and differences in care-giving behavior between the domestic pigs and the wild boars towards their newborns just after expulsion were recognized. The results of present research suggested that suitable rearing system of wild boar is needed.

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An electrocardiograph and an electrocardiogram lead were devised for monitoring a bovine fetus. The electrocardiograph is made of a three-channel fetal electrocardiogram and a one-channel electrocardiogram for the mother. Body-surface electrodes were placed within a 25 cm square on the right side in a position in a line that fell perpendicularly from the fourth lumbar vertebra and a line extended from the knee joint. Nine electrodes were fixed in the 25 cm square at 12 cm intervals. The method for the electrocardiogram induction had each electrocardiogram lead part crossing at the bipolar lead. The electrocardiogram alnplifier used to monitor the fetus had a frequency bandwidth of 10Hz-30Hz and an amplification degree of 0-200dB.The pregnancy period measured and monitored by the fetal electrocardiogram was from day 137 to day 224. The fetal electrocardiogram could be detected in all channels or in some channels of the fetal-monitoring equipment from the 157th day until the 224th day. When the fetal-monitoring equipment was used continuously for 24h, the fetal electrocardiogram could be detected regardless of the mother's bodily motion. Furthermore, it was possible to obtain a heart rate from an R wave of the fetal electrocardiogram. From the results of this study, the fetal-monitoring equipment proved to be of practical use.

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In order to obtain a better understanding on the character of thermoregulatory behavior in pigs, the diurnal variation of resting position were studied in three miniature pigs exposed to environmental temperature of 25, 29 and 33°C for 4 days. During the first 2 days they received feed at total digestible nutrient (TDN) level of 60g/kg0.75 d and fasted after 2days at each environmeratal temperature.At 29 and 33°C, miniature pigs spent the larger part of 24 hour in lateral lying (light: 66%, darkness: 92%). An increase in sternum lying was observed at 25°C. Miniature pigs spent the larger part of 24 hour in sternum lying (light: 70%, darkness: 60%) during fasting at 25°C. Mean surface temperature (mTs) was greater during the lateral lying than during the sternum lying, and the difference of mTs was 0.3°C. Therefore, the change of resting position regulated the heat loss and it was an indicator which showed the effects from the thermal factor.

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For the assessment of thermoregulation with respect to behavior, the relationship between physical activity and heat production were studied. Four female Landrace piglets were exposed to environmental temperatures (Te) of 18, 25, 32 and 38°C daily for 10h. Physical activity (ACT) and heat production (HP) were measured. ACT decreased with the increase of Te. The frequency of exercise (at ACT of 250 counts/min or more) was 74, 44, 26 and 16% and the frequency of rest (with ACT below 25 counts/min) was 0.4, 7.3, 18.7 and 9.0% at Te 18, 25, 32 and 38°C respectively. HP were stabled in 18.4-20.6kJ/kg0.75h. The energy costs of ACT, estimated from the coefficients of linear regressions of HP for ACT were 24J/kg0.75h per counts/min at Te 18-38°C. Therefore, with the increase of Te, ACT was thought lowering to control the rise of HP in the pigs by thermoregulation.

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