During two years from 1976 to 1978, 11 instances of the broodinesses of domestic ducks were observed in the open yard feeding. In two cases the broodinesses reached successfully the hatching and rearing.
Female ducks laid sporadically at first, but thereafter the egg-laying places became limited to one particular point in the shed.
Down feather plucking and nest-material throwing (sideways building) were seen as the nest building behaviour.
The so-called nest down, which was darker than the ordinary down, grew during the nest building and incubation period.
Female ducks plucked nest downs and used them as nest materials. The nest material carring behaviour was observed as the variation pattern derived from the sideways building that was primarily the nest building behaviour itself. It is considered that the nest-material carring behaviour in the duck is at the primitive stage in the evolution of this behaviour pattern.
Nests were built up of straws and nest downs by the sideways building.
The male duck did not participate in the nest building during our observations.

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The phenomena of social facilitation of feeding behaviour in chicks were investigated.
Forty-eight White Leghorn chicks were divided at random into three groups: 8 chicks were caged individually (Group 1), 16 chicks were caged in pairs (Group 2) and 24 chicks were caged by three chicks (Group 3). They were brought up from 1 to 5 weeks of age in 8 brooding cages per group. The living space per chick was 15×25×21cm equally in each group. Chicks in each brooding cage were visually isolated from each other.
The total amount of feed intake and the body weight of chick were measured weekly for each group throughout the experimental period, and the amount of feed intake within first 30 minutes after feeding were measured only from 4 to 5 weeks of age. Synchronization on feeding behaviour in Group 2 and Group 3, and duration time of feeding behaviour in three groups were investigated by both direct observation and photographing intermittently at intervals of 10 seconds.
The amounts of feed intake, the body weights and their weekly gains were increased in proportion to colony sizes from 1 to 3 birds, and there were significant differences among three groups. The variation of body weights was smaller and the feed efficiency was better in Group 2 than the other groups.
It was observed that chicks in every groups had intaken about 10% of total amount of feed in a day within first 30 minutes after feeding, and this amount of feed soon after feeding was more in Group 1 and less in Group 3 than in Group 2.
In Group 2 and Group 3, the frequencies of the case where plural chicks were feeding together at the same time were significantly higher than where a bird alone. The total fregency of feeding behaviour within an unit time in Group 3 had a tendency to be more frequent than in Group 2. Duration time of feeding behaviour was inclined to be longer in Group 1 than other the groups.
It was concluded that feeding behaviour in chick was socially so facilitated that group feeding brought synchronization of feeding and increase in feed intake per chick, and that chick in Group 1 had the lower threshold of feeding stimulus because of the lack of social stimulus for facilitation of feeding behaviour.

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The present studies were conducted to investigate the gene on E-locus determining yellow down-wheaten type plumage in the Gifu Native Fowl. The birds used for this purpose were the Gifu Native Fowl, wild type Japanese Nankin Game and wild type Japanese Longtailed Fowl. Results obtained were as follows.
In order to know the plumage type of e^Wh e⁺ genotype, Gifu Native Fowl hens (e⁺ e⁺) were mated with each of two wild type Japanese Nankin Game cocks expected to have e^Wh and e^y. These matings resulted in producing F₁ chicks of four types; brown striped down, diluted-striped down, non-striped light buff down and yellow down. Consequently, it was indicated that genotype of F₁ chicks with a brown striped down might be e⁺ e^y and that of chicks with a diluted-striped down, non-striped light buff down or yellow down might be e^Wh e⁺, since former F₁ female chicks exhibited wild type plumage and latter three types of female chicks exhibited intermediate type or wheaten type plumage at adult.
A cock of the Gifu Native Fowl with a yellow down were mated with hens of the Gifu Native Fowl (e⁺e⁺). All of the F₁ chicks produced from this mating showed brown striped down, suggesting that the genotype of the F₁ chicks should be e⁺ e^y since e⁺ is dominant over e^y.
Then, three Gifu Native Fowl cocks with a yellow down of the same origin as above were mated with Gifu Native Fowl hens carrying e⁺ e^y to know the genotype of three cocks. About equal number of brown striped down and yellow down chicks was obtained from this mating, indicating that the genotype of the Gifu Native Fowl cocks should be e^y e^y.
The same procedure as mentioned above was aplied to know the genotype of Gifu Native Fowl cocks with a yellow down, in which female wild type Jananese Long-tailed Fowl carrying e⁺ e⁺ was used instead of female Gifu Native Fowl. This mating resulted in producing 70 chicks with a brown striped down and 6 chiks with a diluted-striped down. However, these two types of chicks have shown the same plumage (wild type plumage) when attained adult, suggesting that both types might carry e⁺ e^y on the E-locus.
From the present results it was suggested the genotype of E-locus in Gifu Native Fowl cocks with a yellow down could be e^y e^y.

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The domestic ducks fed in the open yard showed the incubation behaviours in eleven cases during the observation period over two years. In two cases among them, the hatchings and rearings were followed successfully.
The occurrence of incubation was limited from late in May to late in September, mostly in July. It seemed that two females in the same pen started in and terminated their incubation behaviours synchronously in time.
The females at the stage of incubation carried out not only egg turning with their bills in the nest, but egg-retrieval in the similar way. When they left their nest, the eggs in it were frequently covered with the materials of which the nest was composed. Throughout the incubation period, the frequency of bathing was decreased remarkably. Instead of it, "pseudo-bathing" movement was observed and it is regarded as a kind of vaccum activity.
The vocalization of females altered during brooding period, and its alteration was remarkable at the late stage of incubation. They quacked very frequently in a laud and deep voice whenever they returned to their nests. The females became generally so aggressive that they showed some peculiar threatening and attacking behaviours. Additonally, it was observed for them to throw ont the nest materials. These movements may be considered as a displacement nest-building behaviour which express the threatening sense.
The drake did not directly participate in the incubation. However, it seems that he supported female through his activities getting rid of ducks in the other groups.

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The effects of fasting for 4 days and subsequent refeeding or refeeding combined with insulin administration for a similar length of time on the hepatic lipogenesis of 6-week-old meat-type growing chicks, were investigated. No difference in body weight was observed between the refed and the refed-insulin groups and both groups were significantly heavier than their fasted counterparts. Abdominal fat score was practically the same for all the three groups studied. As for liver weight, the value for the refed birds significantly increased with the reintroduction of feed and further rose to almost double the fasted birds' score when insulin was injeced subcutaneously.
Among the lipid fractions, liver triglyceride demonstrated the most drastic increase as a result of refeeding. Such an increase was further boosted with the administration of insulin that brought the hepatic triglyceride score to a level that was 29 times more than that of the fasted lot. Likewise, serum triglyceride markedly increased with refeeding, however, this level dropped by 25% in reaction to insulin thereby suggesting that that hormone has the effect of suppressing the release of hepatically synthesized triglycerides into the blood stream. Both cholesterol and phospholipid contents in the liver remained unaltered even after refeeding or insulin treatment. Serum cholesterol, however, displayed a negative reaction to refeeding when its score sank by 23% when feed was reintroduced. This reduced level further plummeted when insulin was administered. In contrast, serum phospholipid responded positively to refeeding and insulin treatment as evidenced by its increased values. Like serum triglyceride, both NEFA and β-lipoprotein responded quite positively to refeeding but dropped significantly as a result of insulin administration.

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Two experiments were conducted to investigate the possibility of single cell proteins (SCP) as a pellet binder.
In Experiment 1, the possibility of yeast (SCP-T) and bacteria (SCP-L, SCP-J) as a pellet binder was examined. The experimental diets were prepared by adding SCP to the basal diet at the level of 1, 3, 5, and 10%. These diets were non-steam pelleted by using a laboratory pellet mill (2 HP CPM model CL-Type 2) with a 5/32 inch die.
Not only yeast but also bacteria certainly improved the pellet quality. To obtain the same durability as bentonite (2.5%) or lignin sulfonic acid (2.0%) addition, 2.9% of SCP-T, 1.8% of SCP-L or 0.9% of SCP-J was needed.
In Experiment 2, the effect of pelleting condition on ability of SCP as a pellet binder was studied with yeast (SCP-K) and bacteria (SCP-L). The experimental diets were the same as those in Experiment 1. These diets were steam pelleted or non-steam pelleted by using a laboratory pellet mill with a 5/32 inch die.
SCP improved the pellet quality larger in non-steam pelleting than steam pelleting. To obtain the same durability as bentonite (2.5%) or lignin sulfonic acid (2.0%) addition, 3.4% of SCP-K or 4.2% of SCP-L was needed in non-steam pelleting and 0.9% of SCP-K or 2.0% of SCP-L was needed in steam pelleting.
It was indicated that SCP improved the pellet as bentonite or lignin sulfonic acid in both non-steam pelleting and steam pelleting.

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The experiment was conducted with White Leghorn laying hens to determine the effect of supplementating practical diets (CP 14%, lysine 0.61) with lysine.
Adding L-lysine to the diets did not improve egg production but inclined to increase body weight gain on the early stage of lay.

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A questionnaire to members of Japanese Society of Food and Nutrition on peelability of egg shell, taste of egg yolk and albumen, and color of yolk of hard-cooked eggs was conducted.
Two kinds of hard-cooked eggs were prepared. One was fresh eggs which were laid in the morning. i, e.. from 17:00 to 9:00, and the other was eggs stored 4 or 5 days at 23°C. Average color score of fresh yolk of the stored and fresh eggs were 7.9 and 9.7, in average, respectively, by Roche Yolk Color Fan. The diets fed hens laid the stored and fresh eggs contained 18.0 and 17.9ppm of total xanthophyll, respectively.
Among 58 answers, 56 replied that egg shell of the stored eggs was quite easily peeled, while 44 replied that shell of the fresh eggs was hard to peel.
Among 58, 49 preferred hard-cocked albumen of the stored eggs to that of the fresh eggs, mostly because of favorable texture. Little difference was observed on the preference of taste of egg yolk between the stored and fresh eggs.
Among 58, 40 persons answered that tone of yolk color of the stored eggs was normal or good, with average score of 0.85, and 50 answered that of the fresh eggs was normal or good, with average score of 1.59. Among 58, 30 persons answered that yolk color of the stored eggs was normal or dark, with average score of 0.70, and 38 answered that of the fresh eggs was normal or dark, with average score of 1.09.
The questionnaire revealed that the member of the Society, who has special inierest in food and nutrition, felt that yolk color of the eggs tested, having about 9 score of Roche Yolk Color Fan, was satisfactory. It was also revealed that dietary total xanthophyll of 18 ppm will be enough to produce such eggs.

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