[in Japanese]

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In the Japanese quail, ovulatory responses of the largest follicle to LH, P₄ or synthetic LHRH administered at various times during an ovulatory cycle were studied. Each of the hormones at several dosages was injected 24, 21, 18, 15, or 12h before the predicted time of Cs ovulation. Premature ovulation occurred when oLH was injected during the earlier period of an ovulatory cycle (i.e. 21 and 18h before ovulation). In contrast, P₄ given during the same period failed to induce premature ovulation. The discrepancy between LH and P₄ on the ovulation-inducing effect fround during the ealier period of an ovulatory cycle might be due to a low responsiveness to P₄ of hypothalamo-pituitary axis. In addition, it was also found that the largest follicle could not ovulate by LHRH injected during the same period. These results may suggest that the pituitary gland remains in a low responsiveness to LHRH and P₄ on the release of LH until 18h before Cs ovulation while the largest follicle has already acquired a high ovulability in response to LH at the same time.

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Nitrogen balance and excretion of urinary nitrogenous compounds were investigated using colostomyed cockerels fed a casein diet containing excess lysine, excess arginine, α-aminoisobutyric acid (AIB) and urea at various combination. When cockerels were fed the arginine deficient basal casein diet supplemented with excess lysine (2% L-Lysine HCI), the negative nitrogen balance was observed. When excess arginine (2% L-Arginine HCI) or 0.5% AIB was supplemented to the basal diet, the positive nitrogen balance was observed. This observation was mainly depended on the decreas of urinary excretion of uric acid nitrogen. The urinary excretion of urea nitrogen was significantly decreased in birds fed the diet added with 0.5% AIB. The addition of AIB with excess arginine to the basal diet resulted in a significant increase of urinary exceretion of arginine. The supplementation of 1.0% urea without AIB caused a marked increase in the urinary excretion of nitrogen especially urea and uric acid, and reduced nitrogen retention. The increase in urinary total nitrogen was about 1.4 times as much as the amount of urea nitrogen supplemented. When the urea was supplemented with AIB, the increase in urinary excretion of total, urea and uric acid nitrogen was reduced.
It is considered that urea added to a excess lysine diet which contains excess or deficient arginine is not only unutilizable by cockerels but promotes the excretion of uric acid and lowers the biological value of the dietary protein. It seemed that urinary excretion of urea which derived from dietary urea was not affected by dietary excess and deficiency of arginine and excess of lysine but was reduced by addition of AIB to the arginine deficient diet containing excess lysine. It is concluded that AIB inhibits increase in the urinary excretion of uric acid which resulted from supplementation of urea to the excess lysine diet containing low or excess arginine, and thus AIB may prevent a lowering of biological value of the dietary protein.

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The influence of dietary protein levels on hepatic lipid accumulation and on the activities of lipogenic-related enzymes in the liver were studied in duckling fed isocaloric diets containing corn or barley as the carbohydrate source. The liver triglyceride content, in the corn-soybean diet, was significantly higher in the low protein diet (15%) than in the high protein diet (20%). Aslo, in the low protein diet feeding, the liver triglyceride content was significantly higher in ducklings fed the corn-soybean diet than in those fed barley-soybean diet. Plasma total cholesterol concentration, in the barley-soybean diet, was significantly lower in the high protein diet than in the low protein diet. Plasma phospholipid concentration was not significantly different between the corn-soybean diet and the barley-soybean diet, but it was significantly higher in ducklings fed the low protein diet than in those fed high protein diet.
The activities of glucose-6-phosphate dehydrogenase (EC 1.1.1.49; G6PDH), NADP-malate dehydrogenase (EC 1.1.1.40; NADP-MDH) and citrate cleavage enzyme (EC 4.1.3. 8; CCE) in the liver, in ducklings fed the corn-soybean diet, were significantly higher in the low protein diet than in the high protein diet. In ducklings fed the low protein diet, NADP-MDH and CCE activities in the liver were significantly higher in the corn-soybean diet than in the barley-soybean diet.
In the present experiment, the activities of hepatic G6PDH was about three times that of NADP-MDH. Furthermore, this value for ducklings was markedly higher compared with that for chickens reported. This may suggest that pentose-phosphate dehydrogenase in the duckling liver, unlike the chicken liver, is probably the major source of reducing equivalent for the support of fatty acid syntheis.

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This study was carried out to investigate the maximum profit by the most suitable selling time and the rearing density. Profit was calculated by following equation.
Profit={live weight of broiler (kg)×unit price (kg)}
-_??_{number of chicks (bird)×chick price (bird)}
+{amount of feed (starter, finisher)×feed price (kg)}
+{electric fee and heavy oil fee}_??_
Experiments were conducted in autumn in 1981 and 1983. Day old chicks were divided into 9 groups in each year based on 3 stages of days old (35, 49 and 63) and 3 leves of rearing density (80, 140 and 200kg/3.3m²)
The results were summarized as follows:
1. Livability and body weight at the rearing density of 200kg/3.3m² was inferior to those at 140kg/3.3m² and 80kg/3.3m². Feed convertion at the rearing density of 140kg/3.3m² was superior to other two densities.
2. The maximum profit per 3.3m2 of floor space was obtained at the rearing density of 194kg/3.3m². And selling time was no significant.
3. The maximum profit per 1kg of live weight was obtained at 47.9days in 1981 and 49.5 days in 1983 year. And rearing density was no significant.

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Apparent (AMEn) and true metabolizable energy (TME and TMEn) values were deter-mined in 19 feed ingredients (cereal grains, oil-seed meals, animal proteins and brans) using a conventional method (a practicaldiet as basal diet, Cr₂o₃ as indicator) and with the Sibbald method (1976).
The relationships between AMEn (X, cal/g) and THE (Y₁, cal/g) and AMEn and TMEn (Y₂, cal/g) were given by the following regression equations, respectively.
Y₁=1.0821X+161 (r=0.9791)
Y₂=1.0487X+ 40 (r=0.9812)
Coefficients of variation in AMEn, THE and TMEn determinations were 3.02, 3.30 and 2.70% respectively, which indicated similarity for these methods.

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