The method proposed by FALCONER for estimating heritability to disease was extended to the case of hen's liability to laying anormal eggs. Appropriate formulae for calculating heritability and its standard error were presented with a numerical example of double-yolked egg. The heritabilities of liability to laying double-yolked eggs were 0.404±0.223 from full-sib relationships and 0.422±0.341 from half-sib relationships.

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Experiments were conducted to determine the influence of reduced pressures during storage on the motility and fertility of fowl spermatozoa. The stocks used in these experiments were commercial White Leghorn birds. Semen was collected by a one-man technique from 18 to 24 males of less than one year old. The pooled semen was thoroughly mixed and 1ml quantities were pipetted into specially designed flasks of about 110ml capacity, each of which contained 3ml of a phosphate buffer with antibiotics. After mixing, these flasks were placed directly into ice until brought to the laboratory. Each flask was connected to a vacuum system which consisted of a manometer, a glass chamber for minimizing the fluctuations of pressure, and a vacuum pump.
When the required pressure was achieved through pumping, a cock connected to the pump was closed to keep the pressure. While maintaining this pressure, the neck of the flask was then sealed with a gas flame and stored for 2 to 7 days at 0°C. The pressure is expressed as the height of a mercury colum (mmHg), 760mmHg representing 1atm. (absolute). After storage, the semen samples were taken from the flasks by cutting the flask's neck with a glass cutter. The samples were concentrated by centrifugation (2, 000 r.p.m. for 15min.) and resuspended to the volume at ejaculation with a phosphate buffer containing 4mg/ml fructose. Eight hens in each treatment were inseminated vaginally with 0.1ml of the reconstituted semen. Eggs were collected from the second through eighth day after insemination and incubated for 4 or 5 days.
When semen was stored for 2 days at 13, 25, 50, 100mmHg, and atmospheric pressure, average fertility was 98.1, 71.8, 92.0, 65.7, and 48.4%, respectively. In contrast, the motility of spermatozoa declined with decreasing pressure.
When semen was stored for 4 days at 13mmHg, addition of 4mg/ml or 8mg/ml fructose to a phosphate buffer before storage resulted in improved fertility (68.6 and 65.3% respectively) as compared to the buffer without fructose (29.5%). On the other hand, storage at atmospheric pressure gave low fertility (4.9%). No apparent difference in motilily was observed among these treatments.
An attempt was made to determine whether the fertilizing capacity of spermatozoa could be maintained for 7 days under 13mmHg. A hypertonic phosphate buffer (Δ=-0.93°C) was also compared with the isotonic buffer used in the above experiments. Storage with the hypertonic buffer resulted in negligible fertility regardless of addition of fructose, while a considerable fertility (26.0%) was obtained with the isotonic buffer containing 4mg/ml fructose.
It is suggested that an environment of 13mmHg during storage of fowl semen is beneficial in the maintenance of the fertilizing capacity of spermatozoa held at 0°C and that under these conditions addition of fructose is necessary for the prolonged storage of semen.

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Both oxazolidinethione (OZT) and isothiocyanate (ITC) are known as main cleavage products of glucosinolates in rapeseed meal. Experiment 1 was conducted with day-old White Leghorn male chicks to study antithyroid effects of OZT and ITC. The basal diet used in this study consisted mainly of corn and soybean meal and it contained 0.67μg iodine/g diet. Thyroid glands of chicks administered OZT (premixed in the basal diet at 0.05% level) for 14 days were enlarged about three times that of the control chicks fed the basal diet. On the other hand, thyroid glands of chicks administered ITC (resolved in ethyl alcohol and premixed in the basal diet immediately before feeding at 0.05% level) for 14 days were slightly enlarged. Thyroidal ¹³¹I uptake in the chick was stimulated by OZT and it was suppressed by ITC. The stimulating effect of OZT contradicted the suppressing effect of ITC when both were administered to the chick simultaneously. The results of the present study indicate that antithyroid effects of ITC are considerably weaker than that of OZT.
In experiment 2, effects of autoclaving on elimination of OZT and ITC in the rapeseed meal of B. napus and B. campestris were examined. After autoclaving at different conditions, OZT and ITC in the rapeseed meal were determined. The higher the temperature and the longer the time of autoclaving, the smaller amount of OZT and ITC remained in the rapeseed meal. But, the rate of diminution of OZT did not coincide with that of ITC in the autoclaved rapeseed meal. Contents of OZT and ITC in the rapeseed meal of B. campestris were lower than those in the rapeseed meal of B. napus and the rates of diminution of these compounds in the autoclaved rapeseed meal were different between the spacies of rapeseed.
In experiment 3, thyroid weight and thyroidal ¹³¹I uptake in the chicks, fed rations containing autoclaved rapeseed meal at 24% level for 14 days, were investigated. Thyroid weight index (thyroid weight in experimental group/thyroid weight in the control group) in the chicks fed the autoclaved rapeseed meal containing diet did not increase so much as expected from the content of OZT in the ration. And, thyroidal ¹³¹I uptake in the chicks fed the autoclaved rapeseed meal diet was almost the same as that in the chicks fed the control diet. These results may indicate that the amount of OZT which might be formed in the intestinal tract of the chick is very small when myrosinase activity in rapeseed meal has been inactivated beforehand.

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In order to investigate the role of ckicken ceca in water absorption, this experiment was carried out using 8 month-old single comb white Leghorn cockerels weighing about 2kg. Chickens were operated on to remove all, 2/3 or 1/5 of the cecal bodies, and the control birds were sham-operated. As a result, the amount of excreta of the chickens increased when more than 2/3 of the ceca were removed. Dry matter excretion and apparent water balance (total water intake minus water output into the excreta) were not changed by the operation. Since urinary water excretion is not changed by the operation as previously reported (Y. NAKAHIRO, Y. ISSHIKI and I. TASAKI, Jap. J. Zootech. Sci. 44: 605, 1973), the increase of excreta is considered to be due only to the increase of fecal water excretion. This suggests that the ceca play a significant role in water absorption, and the birds in which more than 2/3 of the ceca were removed were likely to drink more water than the control birds, in order to conpensate for the poor absorption. (Studies on the function of ceca of chickens. Report 8)

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[in Japanese]

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[in Japanese]

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[in Japanese]

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From middle May, 1974 to middle April, 1975, the interior quality of the quail eggs purchased from the 3 retail stores in Gifu and Nagoya area was studied. A significant seasonal variation either in yolk height, yolk index or albumen height of the eggs was observed. The interior qualities of the eggs from the retail stores was low during the hot months (June-August), and high during the cold months (October-March). High (25%) incidence. of rotten eggs was occured in July, indicating the long time storage of quail eggs in retail stores.

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