Using multiple regression in which individual profits were taken as dependent variables, some profit functions were derived from carcass records for 1, 258 head of pigs slaughtered in Kumamoto prefecture in 1991. Economic values on days to markets and carcass traits were derived from partial differentiation of the optimal profit function. The profits of individual pigs were obtained using a bio-economic model of a pig farm. When a linear equation was adopted, the standard partial regression coefficients of profit on back fat thickness in center of carcass (BFc), days to market (DAY) and coefficients of variation on back fat thickness (CVBF) were large, while that dressing percentage (DP) and back and loin length (BLL) were small. The ratio of contribution (R²) was 0.67. Since there was a curvilinear relationship between the profit and traits, a quadratic equation was adopted. This caused R² to increase to 0.85. Only linear terms were, however, taken for DP and CVBF in the model, because they did not have an optimum level. The economic values (Yen head^-1) obtained were: -86 (day^-1) for DAY, 128 (%^-1) for DP, -57 (cm^-1) for BLL, -295 (mm^-1) for BFc, and -39 (%^-1) for CVBF. Although the economic values derived from approximation of non-linear equations to linear forms were not always optimum in the evaluation of an individual pig, the effects on genetic improvement may be relatively small because of low selection intensity in pig breeding structure. The present approach has a disadvantage in that the partial regression coefficients varied in the adopted equation and may be influenced by correlations among traits. It appears, however, to be useful in those Japanese pig breeding situations where unit prices can not be clearly defined and traits had an optimum level.

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More than 4 times of repeated surgical embryo recoveries were performed on total of 28 embryo donors. Nine donors were treated 4 times for embryo recovery, 8 donors were treated 5 times, 4 donors were treated 6 times, 3 donors were treated 7 times, one donor was treated 8 times, one donor was treated 12 times and 2 donors were treated 16 times.
Nine donors were surgically operated for recovery of embryo by natural ovulation. For these animals, ovarian performances did not vary across trials within the same donor, but it varied across donors. When embryo recovery was performed at three weeks interval, it did not affect ovarian functions. The shortest interval was 12 days. Even in this case, we observed normal embryos and normal ovulation.
Nineteen of 28 donors were treated for embryo recovery in natural and PMSG-treated ovulation. Effects of PMSG treatment on ovarian performances were investigated in single PMSG treatments (13 head), continual PMSG treatments (4 head) and intermittent PMSG treatments. Some of the donors showed significant increase or decrease in the ovulation rate, but other donors showed no specific tendencies in the number of ovulation. PMSG treatments did not affect ovarian performances or embryo recovery.

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The ovarian performances were investigated in the 576 cases of hormonally (PMSG, hCG, FSH, altrenogest) administrated swine.
When treated with above 1000IU PMSG doses, the number of corpus luteum varied greatly, the rate of normal embryo decreased, and the number of residual follicle and the number of ovarian cyst increased. When treated with 500 or 750IU hCG doses, embryo quality was better than that of the control. Altrenogest did not affect any ovarian functions, such as ovulatory response to PMSG. The effects of FSH's reductional dose were investigated. When the total doses ranged from 12.0 to 13.5AU FSH, the ovulated points varied from 0 to 135 and the ovulated animals showed high abnormality in their embryos. In these groups, the animals had a high number of residual follicle and ovarian cyst. At the total dose of 7.75AU FSH, only one of the six animals ovulated and had seven corpora lutea.

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The correlates of postoperative disorders were analyzed on the 556 cases of swine embryo recovery performed during the last eight years. The total number of wasted embryo donors was 127. Forty point nine percent of them were wasted by the adhesion of reproductive organs. Eleven percent were wasted by reproductive disorders such as anovulation and anaphrodisia, and 5.5% were wasted by infectious disorders such as purulence and endometritis. As the adhesion of reproductive organs was the most frequent reason for wastage, it was analyzed in detail. Out of the 330 cases that were operated more than two times as embryo donors, 52 cases (15.8%) were in severe adhesion. When the total experimental period was divided into three phases, the incidents of adhesion decreased in phase by phase. It was presumed that this results from the improvement of operating methods, skills and equipments. It was suggested that ovarian cyst was related to the high dose of PMSG.

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Present study was carried out to investigate some conditions of PCR for detection of porcine male-specific repeated DNA sequence in white blood cells. Two sets of oligonucleotide primers designed on the basis of porcine male-specific repeated DNA sequence data (MCGRAW et al., 1988) were used. The first primer set (Male-specific, M; 5′-TCATGGACCAGGTAGGGAAT-3′ and 5′-GAAAGACACGTCCTTGGAGA-3′, SEKIGUCHI et al., 1992) amplified 491 base pairs (bp). The second primer set (Nested, N; 5′-AAGTGGTCAGCGTGTCCATA-3′ and 5′-TTTCTCCTGTATCCTCCTGC-3′), which located in inner region to be amplified by the first primer set, amplified 236bp. The PCR was performed using either primer sets for 30-60 cycles of amplification (denaturation at 94°C for 1min, annealing at 55°C for 1min, and extension at 72°C for 1min) with template cells. When the template cells were 5×10⁴ cells from both males and females in the pig, cattle or human, the male-specific DNA could only detect in the boar with 30 cycles of PCR. Detection of the fragment in porcine cells diluted serially revealed that the more than 50 and 10 template cells were required for M and N primer set, respectively. Increase in cycles of PCR or amplification (30 cycles) of PCR product with the same primers were not effective for reducing the template cell number, either. Meanwhile, the amplification of PCR product, which obtained with M primer set, with N primer set were effective for reducing the template cell number, and allowed to detect male-specific DNA from a single cell.

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