In order to investigate the effective use of food by-product, the diet containing stale pasta and the silage consisting of stale bread and tofu cake were fed to growing-fattening pigs. Two experiments were carried out with LD crossbred (Trial I) and LWD crossbred (Trial II). Swine were divided into three experimental groups with different diet: mixture diet as control, pasta diet with 40% stale pasta (Trials I and II), and bread and tofu cake diet with 76% (Trial I) or 90% (Trial II) stale bread and tofu cake. Rations were fed on till their average weight reached 105kg, and the growth efficiency and the meat quality were examined. Daily gain (DG) of stale bread and tofu cake diet at Trials I and II showed superior results compared with the control. Although the DG of pasta diet at Trial I was a little lower compared with the control, DG of Trial II was higher than that of the control. The body fat of swine at pasta diet was rich in saturated fatty acid, and its melting point was higher than that of bread and tofu cake diet. As for dressing percentage, back fat thickness and meat color, significant difference was not observed at each diet, therefore the diet that contains food by-products is useful for growing-fattening pigs.

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We studied the effect of illumination color on the growth, meat production and fatty acid composition in lipid and muscle tissues of pigs. Twenty-four three-way crossbred pigs (Landrace×Large White×Duroc) were used. The pigs were divided into 4 groups of 6; red lamp, blue lamp, incandescent lamp, and no lamp (control) groups. Initially, all of them were fed the food for growing stage of fattening pig approximately 30 to 65kg of body weight, and then they were fed the food for finishing stage of fattening pig until about 105kg of body weight under the specified illumination which came from in two lamp heads.
There were not significant difference in daily weight gain and the amount of feed convertion ratio among the four groups. Result of dressed carcass percentage and back fat thickness showed no significant difference among the four groups.
As for the fatty acid composition of back fat, the blue lamp group showed the lowest value in C18:0 content, and a significant difference was seen between that group and the control (P<0.05). In C18:2 concentration, the lowest value of the control group was significantly different from that of red lamp group (P<0.05).
There were no significant differences in loin lipid content among any group. However, when the fatty acid composition of intramuscular fat was examined, the control group showed the highest C14:0 concentration value, and which was significantly different from that of the incandescent lamp group (P<0.05). In the concentration of C18:0, the red lamp group showed the highest value, and significant differences between the four groups were seen as follows: between red lamp group and control group (P<0.05), between red lamp group and blue lamp group (P<0.05), and between red lamp group and incandescent lamp group (P<0.05). In comparison of saturated fatty acid content, red lamp group showed the highest value, and significant differences between the four groups were seen as follows: between red lamp group and blue lamp group (P<0.05), between red lamp group and incandescent lamp group (P<0.05), and between blue lamp group and incandescent lamp group (P<0.05). Moreover the red lamp group demonstrated lower levels of unsaturated fatty acid concentration, and significant differences were seen among that group and the blue and incandescent lamp groups (P<0.05). The red lamp group also showed the highest proportion of saturated fatty acid to unsaturated fatty acid concentrations, indicating blue lamp group and incandescent lamp group different significantly from each other (P<0.05).
Significant differences were not seen in triglyceride, total cholesterol, and HDL-cholesterol quantity among any of the groups. However, the blue lamp group had the lowest value for the proportion of HDL-cholesterol to total cholesterol, and a significant difference was seen when compared to the red lamp group (P<0.05).

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The perpose of this experiment was to investigate the effects of freezing in the magnetic fields on the viability, acrosome integrity and GOT releasing of boar spermatozoa. Sperm rich fraction was extended by pre-extender and stood for 3 hours at room temperature. After centrifugation, precipitated spermatozoa were suspended in the first diluent and cooled to 5°C taking about 90 minutes prior to the second dilution. Finally diluted semen was filled into straws and frozen in liquid nitrogen vapour in magnetic fields. Each magnetic strengthes in three cases of magnetic fields prepared by 10, 000 and 4, 000 gauss of permanentmagnets were 7, 450, 1, 550 and 240 gauss, respectivly, by the gauss meter.
The results obtained were as follows;
1. The exposing of magnetic fields in process of freezing were beneficial for the improvement of sperm viability after thawing. Acrosomal integrity and GOT release were not different between each exposing of magnetic fields.
2. The effect of magnet to sperm viability was obtained in maxi-straw (Φ5mm) freezing, but not in mini-straw (Φ2mm) freezing.
3. Sperm viability in maxi-straw after freezing in magnetic field was not inferior to that in mini-straw. It seemed that 1, 550G was little superior to 240G.
4. Normal piglets were farrowed after insemination of frozen semen in 1, 550 gauss of magnetic strength.
From the above results, it was indicated that the freezing in magneticfield was beneficial for the improvement of sperm survival rate and the maintenance of sperm motility after thawing. And also more effective production of frozen semen and more economically storing will be possible.

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Experiments were conducted to find the optimal condition for freezing boar spermatozoa packaged in 0.5ml plastic straws using polystyrene foam container and liquid nitrogen (LN₂). Spermatozoa from six fertile boars (two Large White, two Durock and two Landrace boars) were suspended in BF5 diluent containing 2.5% (v/v) glycerol and packaged in 0.5ml plastic straws at 5°C. Straws were frozen at 4 to 20cm above LN₂ surface. The straws were first placed on a hard rubber rack and then transferred into the freezing container at the height of 4, 10, 15 and 20cm from the surface of LN₂, or were placed directly on a steel rack (4cm) which was previously cooled in the container. After 20min, straws were plunged into LN₂. Cooling rates of these samples at the temperature zone of -15 to -30°C ranged from 3.5 to 90.5°C/min. Frozen semen was thawed by incubating straws in a water bath at 50°C for 8sec. The terminal temperature after the thawing process was 27°C, and warming rate from -196 to 27°C was 1672°C/min. Frozen-thawed semen was diluted 1:10 with BTS at 30°C, and progressive motility and acrosomal integrity were evaluated during 6hrs incubation at 37°C. Motility rate was highest in semen that was frozen at 4cm above LN₂ using a rubber rack. The proportion of spermatozoa with normal acrosome was best maintained in semen frozen at 4cm above LN₂ using a steel or rubber rack. These results indicate that the cooling rates of 35 to 90°C/min at the temperature zone of -15 to -30°C are optimal for freezing boar semen packaged in 0.5ml plastic straws. After addition of glycerol, diluted semen was incubated for up to 6hrs at 5°C (glycerol equilibration) and then frozen at 4cm above LN₂ using a rubber rack. The glycerol equilibration times had little influences on the viability of spermatozoa after thawing. The simple freezing method developed in this study would be applicable when semen is used for surgical insemination or in vitro insemination.

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The effect of cooking was examined on the compounds relating to the pork taste and flavor. Pieces of the longissimus muscles from eight animals in each Duroc (D), Landrace (L) and Meishan (M) pigs were vacuum-packed and then incubated at 70°C for 1h. The total free amino acids (TAA) contents were 8.72 and 6.92μumole/g in raw and cooked meat, respectively. The free glutamic acid (Glu) contents were 0.44 and 0.36μmole/g, respectively. The difference in the TAA content among breeds was significant in the cooked (D>L, M) and raw (D>L>M) meat. The Glu contents were not significant both in the cooked and rawmeat. The significant relationships between the raw and cooked meat were found in the TAA content (r=0.76) and in the Glu content (r=0.59). These results indicated that cooking at 70°C did not affect the TAA, because the decrease of TAA could beexplained by dissolution into the cooking-loss (28%) water. The oligo-peptide content was increased by cooking from 2.31 to 2.55μmole/g, and showed a significant correlation (r=0.79) between before and after cooking. The 5′-inosine monophosphate (IMP) content was decreased by cooking from 3.94 to 3.35μmole/g, and showed a significant correlation (r=0.43) between before and after cooking. The thiobarbituric acid reactive substances (TBARS) content was drastically increased by cooking from 0.48 to 10.02n mole/g. Increases of TBARS were not related to the contents in the raw meat (r=0.04). The significant difference in TBARS among breeds was found in the cooked meat (D>L, M) but not in the raw meat. These results suggest that TBARS are major components for flavor and taste created by cooking, and that the prediction of those is difficult in raw meat.

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In the present study, the contents of nucleic acid-related (NAR) substances such as ATP, ADP, and Hx in pork were measured to investigate whether the freshness of pork could be estimated from these contents. Firstly, experimental pork samples were obtained from 12 crossbred (WLD) and 8 Duroc pigs after 24hrs of slaughter. These samples were stored at 4°C for up to 18 days, and the changes of NARs contents were recorded during storage. The contents of ATP, ADP and AMP were approximately 0.2μmoles/g meat throughout the preservation period. The content of IMP was highest on the first day of preservation, and then decreased gradually during subsequent preservation period, whereas those of HxR and Hx increased. To evaluate the freshness of fish, following formula has been used.
K=(HxR+Hx)÷(ATP+ADP+AMP+IMP+HxR+Hx)×100
In pork, however, little changes in the contents of ATP, ADP and AMP were observed. For the estimation of freshness of pork, therefore, following modified formula was established.
mK=(HxR+Hx)÷(IMP+HxR+Hx)×100
Highly significant positive correlation was observed between mK values and the postmortem days in the experimental pork samples. Provided pork is stored at 4°C, postmortem days can be estimated by formula shown below.
y(day)=-0.811+0.033mk(%)+0.003mk(%)²(R²=0.881)
Secondly, imported and domestic pork samples were obtained from a supermarket, and the contents of NARs were measured. IMP contents in domestic and imported pork samples were 4.20 and 1.55μmoles/g, respectively. HxR and Hx contents and mK values of imported pork samples were higher than domestic ones. Provided these pork samples were stored at 4°C during marketing process, the preservation periods of the domestic and imported samples are estimated to be 3-14 and 18-25 days, respectively.

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