The rhythmic variations during a day in superoxide (O₂^-) production, Fc receptor (FcR) positive rate and antigen-presenting activity of abdominal macrophages were investigated in 6-to 9-week-old White Leghorn chicks. It was evident that these features of macrophages showed clear rhythmic patterns in a day. The rhythmic pattern of O₂^- production showed a peak during light period in both zymosan-stimulated and unstimulated macrophages. The pattern was not synchronized with those observed in bactericidal activity of chicken abdominal macrophages. FcR positive rate of abdominal macrophages showed a peak under light and dark conditions, respectively. This pattern synchronized almost completely with the rhythm of bactericidal activity, but rhythmic correlations were not observed between FcR positive rate and phagocytic activity. Macrophages added to the lymphocyte culture accelerated lymphocyte activity by presenting antigens to them, as shown by SI values exceeded 1.0. Antigen-presenting activity of macrophages exhibited a rhythm with two peaks during the light period. The rhythmic pattern was not synchronized with the activation pattern of in vitro phytohemagglutinin (PHA) -stimulated chicken peripharal lymphocytes. The formation of the rhythm in T cell activation possibly depends on other factors or intrinsic change in T cell activity.

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Chicken serum insulin-like growth factor-1 (IGF-1) was extracted with an acid ethanol solution and submitted to a heterologous radioimmunoassay (RIA) after lyophilization. In the RIA, recombinant human IGF-1 (rhIGF-1) was used for standards and radioactive ligand. Anti-rhIGF-1 antiserum used was provided by the NIDDK. The inhibition curves for extracts of two-fold serial dilutions of chicken sera were essentially parallel to those for the standard and human sera. The recovery of rhIGF-1 added to chicken sera was 100.1±0.7% (n=30). The intrrassay and interassay variability (CV) for the RIA was 6.9% (n=10) and 7.6% (n=3), respectively. The limit of sensitivity for measurement of IGF-1 extracted from chicken serum was 5 pg/assay tube. Hypophysectomy significantly reduced serum levels of IGF-1 by 80% as compared to sham-operated control chicken. Dwarfing gene (dw) also significantly reduced serum IGF-1 by 89% compared to normal control. These results indicate that the present heterologous RIA was validated for measurement of immunoreactive IGF-1 levels in chicken serum.

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Broiler industry in korea has advanced greatly in recent years. But there are some problems in the production and marketing. In order to clarify the issues, a comparison of broiler production and marketing between Korea and Japan was carried out. The broiler production and marketing data compiled by both governments and other sources were used and processed in this study. Some findings are as follows:
1) Broiler hatcheries having contract hatching-egg production and their own production was common in Japan, but few in Korea.
2) Thus, the price of day-old chicks fluctuates greatly in Korea compared to Japan.
3) Broiler production has been concentrated in the urban area of Seoul and other cities. However, it is decentralized in southern and northern Japan. Live-bird transportation is popular in Korea, while portioned, cut-meat transportation has preveiled in Japan.
4) The income ratio (=Income/Gross brolier's sales) has been higher in Korea than Japan.
5) Broiler live-bird price has fluctuated greatly with a 4-year cycle in Korea, but the price has decreased in recent years in Japan.
6) Broiler integration was 23.1% in Korea, against 75% (contract, 50%, own-production, 25%) in Japan according to data in 1989.
7) The number of live bird wholesaler has been greater and marketing margin have been higher in Korea.
8) The concentraion of broiler processing plants in restricted are as has been greater in Japan than in Korea.

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A simple, rapid and sensitive analytical method for determination of sulfamonomethoxine (SMM), sulfadimethoxine (SDM) and sulfaquinoxaline (SQ) in various tissues of chicken (blood, muscle, liver, kidney, ovary and fat) was investigated by high-performance liquid chromatography (HPLC).
The extraction of sulfonamides from the samples was performed using 80% (v/v) acetonitrile solution and n-hexane to minimize the amount of fat contents. The column chromatography was carried out using alumina acidic, basic (B), neutral and silica gel. The alumina B column was most effective to remove impurities involved in fats and proteins from extract. The recoveries of sulfonamides were from 97.1 to 104.0% with 30ml of 90% (v/v) acetonitrile solution in this procedure. The refined samples containing sulfonamides were labeled with fluorescamine and were applied to HPLC column packed with LiChrosorb RP-18.
The average recovery of SMM, SDM and SQ from various tissues of chicken fortified at 1.0ppm (5μg/sample 5g) were from 85.2 to 101.9% with coefficient of variation within 4.9%. The detection limits were 2 ppb for SMM and SDM, and 4 ppb for SQ.

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The present study was carried out to examine the effects of Aigamo ducks herding on weeding and pest control in paddy rice farming. Three paddy fields were used as control (no ducks and no agrochemicals), agrochemicals (agrochemicals were used according to the standard established by Kagoshima Prefecture) and Aigamo (no agrochemicals but keeping ducks) plots. Thirty five Aigamo ducks in four weeks of age were introduced to the plot (10 a) initially and the number was adjusted to seventeen later. Aigamo ducks were kept in the plot for two months, at which the ear of rice plants have formed.
1. One hundred fourteen weeds with 3 species per a 120cm by 120cm square in the control plot and 18 weeds with 2 species in the Aigamo plot were found in paddy fields but no weeds found in the agrochemicals plot at one month after rice-planting.Secondly, 52 weeds with 4 species in the control plot, 15 weeds with 2 species in the agrochemicals plot and 1 weed with 1 species in Aigamo plot were found at two months after rice-planting. These results indicate that the growth of weeds was controlled better by the Aigamo ducks than the agrochemicals as time goes on.
2. The outbreak of plant hoppers in the Aigamo plot was controlled in the first period on July but not controlled in the second half on July. Plant hoppers in the agrochemicals plot were not found during experimental period.
3. The outbreak of green rice leafhoppers in the control and Aigamo plot was found but never found in the agrochemicals plot during experimental peroid.
4. Number of rice plants damaged by grass leaf rollers was not different between the control and Aigamo plot but remarkably decreased in the agrochemicals plot.
5. Number of rice plants damaged by rice-plant skippers in the Aigamo plot was fewer than that in the control plot and rice plants damaged by rice-plant skippers were not found in the agrochemicals plot.
6. A lot of big mud snails were found in the control and agrochemicals plot but not found in the Aigamo plot. These results indicate that the outbreak of big mud snails were controlled by Aigamo ducks.

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Nitroblue tetrazolium (NBT) reducing activities and myeloperoxidase concentrations in the heterophils taken from abdominal cavity or peripheral blood were investigated in the chicks starved for 24 or 48 hours. In abdominal heterophils, NBT reducing activity decreased in proportion to the starvation periods, although the activity of peripheral blood heterophils was not changed by starvation. On the other hand, myeloperoxidase concentrations in the both heterophils were not affected significantly by starvation. Large differences between abdominal heterophils and peripheral blood heterophils were observed in their NBT reducing activities and myeloperoxidase concentrations, suggesting that there may be some heterophils subpopulations in chicks. The present results propose a possibility that inhibitory effect of starvation on the bactericidal activity of abdominal heterophils may be attributed to the specific effect of starvation on superoxide production system in oxidative killing mechanism of phagocytes in chicks.

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Fat-storing cells of the liver from chickens at three stages of development were observed by the methods of gold chloride reaction, vitamin A fluorescence and electron microscopy to examine the kinetics of vitamin A.
In the chicken liver, vitamin A fluorescence emitted by fat-storing cells was noted 15 days of incubation, and the fat-storing cells were observed to react to gold chloride for the first time 10 days after hatching. Thereafter, these cells gradually increased, becoming numerous 120 to 150 days after hatching. In laying hens, however, only a few of these cells were noted.
Ultrastructural observations revealed a few fatty drops containing vitamin A in the fat-storing cells 15 days into incubation, and numerous fatty drops 90 to 150 days after hatching. In laying hens, however, only a few of these fatty drops were noted.
These results suggested that before and after hatching vitamin A was stored by only a few of fat-storing cells, while in the late stage of growth it was stored in many fat-storing cells. In laying hens, however, only a small amount of vitamin A was stored.

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This study was conducted to elucidate the growth and behaviour of Aigamo ducks in paddy fields. Thirty Aigamo ducks were introduced to the paddy field (10 a) on 4 weeks of age at the second week after rice-planting. Twenty-two Aigamo ducks were housed with formula feed for the late stage of broiler as control experiment. The body weight, tibia length, beak length and body length were measured once every week. The patterns of behaviour of 5 Aigamo ducks in paddy field were observed for 24 hours.
Final body weight and daily gain of Aigamo ducks kept in paddy field were 976g and 8.3g, respectively, and those of Aigamo ducks housed in pen were 970g and 8.2g, respectively. Consequently, the body weight gains were not different between two treatments. Moreover final body length, tibia length and beak length were not different between two treatments.
Feed intake behaviour showed three peak for 24 hours, namely at 2∼3p.m., 9∼11p.m. and 2∼7a.m., and that at 2∼7a.m. showed the highest among the three peaks. Resting behaviour showed two peaks for 24 hours, namely 8∼10p.m. and 5a.m.∼2p.m., and that at 5a.m.∼2p.m. showed higher. These results indicated that Aigamo ducks were nocturnal in their habits as wild ducks.

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