The experiment was conducted to determine the effects of acclimation to heat on thermoregulatory responses of laying hens when exposed to a new higher ambient temperature. The birds were subjected to non-exposure or exposure to 32°C from 1 to 3 days, and then all to 36°C ambient for 8 hours. Abdominal temperature, back skin temperature, shank skin temperature, heart rate, respiration rate, standing time and standing counts were measured during exposure period. When birds were exposed to 32°C, their abdominal temperature, back skin temperature, shank skin temperature and heart rate were greater on the 1st day than the 3rd day, and decreased obviously after lighting off, whereas respiration rate was lower on 1st day than 3rd day before lighting off and increased further for a short while after lighting off. At 36°C, abdominal temperature, back skin temperature, shank skin temperature and heart rate decreased with days of exposure to 32°C. Respiration rate of the birds unexperienced to 32°C did not increase further after lighting off. The unexperienced birds had markedly lower standing time and more standing counts than those of the experienced birds. These results showed that the effects of acclimation to heat on thermoregulation and standing-lying behavior are recognized when the birds were exposed to a high ambient temperature only for 3 days, and the standing behavior of chickens is clearly associated with thermoregulation at the high ambient temperature.

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To elucidate the relationship of the position of egg in sequence to the quality of eggshell, the strength and thickness of shells of eggs in various lengths of sequences was measured. The strength of eggshells was not different between the first and second eggs in 2-egg sequences, but a higher strength was observed in the first and last eggs of 3-egg sequences compared with that of the second egg. In 4- and 5-egg sequences, the strength of eggshells tended to be higher for the first and last eggs than for the last egg but one. No difference was found in the thickness of eggshells between the first and second eggs in 2-egg sequences, but in sequences of 3 eggs or more the eggshell of the first and last eggs was thicker than that of the last egg but one. The strength and thickness of eggshells of the first and last eggs tended to be higher as the sequence length increased. The results indicate that eggshell quality may change in relation to the position of egg within a sequence and the sequence length in laying hens.

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A study was carried out to examine the effects of lines on the clutch traits and the prediction of egg production in laying hens. Data of oviposition time were recorded at four stages from the 120th day to the 330th day of egg production for two years. The duration of observation in each stage was 30 days. The four lines were abbreviated as H, L, J and X. The H and L lines were obtained from long-term divergent selection for high and low yolk-albumen ratios. The J and X lines were the commercially obtained. The clutch traits were intra-clutch mean lag of oviposition time (LAG), mean delay of pause day between clutches (DELAY), the rate of internal laying (IP), the number of clutches (CN), the average length of clutches (CL) and the average size of clutches (CS).
There were significant differences between lines and stages for all clutch traits. LAG values in the J and X lines (0.28 hours and 0.22 hours, respectively) were significantly shorter than those in the H and L lines (1.04 hours and 1.32 hours, respectively). Accordingly, the values of CL and CS were significantly larger, and CN values were significantly smaller in the J and X lines. The values of DELAY in the H and L lines significantly differed from those in the J and X lines. IP values were 9.94%, 7.75%, 4.22% and 5.54%, respectively, for the H, L, J and X lines.
The clutch traits obtained from the first stage were used to predict total egg number of 270 and 360 days of laying periods (EP270 and EP360) by the multiphasic model. Correlation coefficients between actual and predicted values of the four lines were 0.72 and 0.67 for EP270 and EP360, respectively. The correlation coefficients in the J and X lines that laid more than 300 eggs in 360 days of laying period ranged from 0.75 to 0.88, being higher than those in the H and L lines (0.60∼0.75) with 240 eggs in the same laying period.

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Egg albumen of four species of jungle fowl was analyzed by polyacrylamide gel electrophoresis (PAGE) and micro two-dimensional electrophresis (2DE), and compared among those species. The jungle fowl egg albumen was fractionated by PAGE to prealbumen (Pa), ovoalbumen (Ov), conalbumen (TfEW) and ovoglobulin (G2-4).
Polymorphisms were recognized in all of the fractions except TfEW. A new variation (C-type) was discovered in the G2 fraction of Gallus lafayettei. In addition, TfEW recognized as an electrophoretic band by PAGE was isolated into three to four continuous spots with 2DE and the existence of isoelectric points with slightly differing molecules was recognized in the TfEW. Three or four clearly-distinct continuous spots in the TfEW were detected exception of Gallus varius.

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Two experiments were conducted to determine whether nitrogen excretion could be lessened without any decrease in the performance of broiler chicks. In experiment 1, four diets formulated to contain 23, 21, 19 and 17% crude protein (CP), respectively, were fed to 7-day-old male chicks for 14 days. In experiment2, three low CP diets (19, 17 and 15% CP, respectively) were fed to 14-day-old male chicks for 14days. Essential amino acids content of all diets was adjusted by adding crystalline amino acids to satisfy the requirements of the Japanese Feeding Standard (1992).
Body weight gain and feed efficiency of chicks fed the 19% CP diet were the same as those of chicks fed the 21% CP diet. But body weight gain of chicks fed 17% CP diet was significantly lower than that of chicks fed the 21% CP diet. In experiment2, body weight gain and feed efficiency of chicks fed the 17% CP diet were the same as those of chicks fed the 19% CP diet. The amounts of nitrogen excreted for 4 days were 3.93, 3.26, 2.35, and 2.19g for the 23, 21, 19 and 17% CP diets, respectively, in experiment1 and 4.07, 3.71 and 3.33g for 19, 17 and 15% CP diets, respectively, in experiment2. Abdominal fat weight significantly increased with a decrease of dietary CP in both experiments.
It follows from the present results that dietary CP in broiler diets may be reduced from 21 to 19% and nitrogen excreted, to 10-20% without reducing performance by crystalline amino acid supplementation. But lowering dietary CP may lead to increased abdominal fat weight.

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Involvement of gestation on the preference of diets containing 20% medium chain (MCT) or long chain triacylglycerol (LCT) was investigated in the chicken. Oxethazaine, a local anesthesia, was applied to paralyse the sense of the tongue. Oxethazaine (2mg/l) was dissolved in 0.01% hydrochloric acid solution. Just before choice feeding trial, oxethazaine or vehicle was applied on the tongue of birds by using the swab. In the vehicle treatment group, birds dignificantly preferred LCT diet over MCT diet. On the contrary, preference for oil was eliminated by the oxethazaine treatment. Data suggest that oil preference in the chicken might be partly controlled by gustation.

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Behavioural activities were observed to compare the effects of ducks free-ranged in paddy field on weeding and pest control among Mallard, Cherry valley and their crossbred (F₁). Eight ducklings on the 1st day posthatching were assigned to each paddy field (4.5a) at the 1st week after rice-planting and the ducks were free-ranged until 11 weeks of age in the paddy fields. Eating, moving and resting behaviours of the ducks were observed for 24 hr twice during the free-ranging period. In addition, the frequency of consuming pest insects within an hour was recorded for 7 consecutive days. The pest infestation was also examined. The results obtained were as follows:
1. Mallards were apt to spend more time eating and moving in paddy field than Cherry valley, followed by F₁.
2. Resting time tended to be longer in the order, F₁, Cherry valley, Mallard.
3. The frequency of eating behaviour per hour of Mallard tended to be higher than that of F₁ and Cherry valley, however the difference was not significant.
4. Outbreak of weeds and harmful insects in the paddy field showed that no marked differences were found in weeding and pest control (especially, plant hoppers, green rice leafhoppers and big mud snails) among 3 breeds.

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