The present investigation was carried out to determine whether Japanese quail had any hereditary factor to participate in their susceptibility to REV-T. The susceptibility was compared among families of Japanese quail.
1. Of the 275 birds, 170 died by 21 days post inoculation, showing a mortality of 61.8 per cent. The average number of days of survival was 15.1 days.
2. The mortality in each family was scattered within a range from 20.0 to 90.9 per cent. The χ² test indicated that there were significant differences in the mortality among the families.
3. The average number of days of survival in each family was dispersed within a range from 10.7 to 19.5 days. The F test revealed that there were significant family differences in the average number of days of survival.
4. The difference in mortality between two groups (low and high susceptibility) derived from the difference in the number of death occurring in the early stage of infection up to 14 days post inoculation, and in the time of appearance of a peak of death between these families.
5. It was presumed that some hereditary factors might have participated in susceptibility to REV-T, and that one of the most remarkable differences between the family group showing low susceptibility and that showing high susceptibility may consist in the early stage post inoculation.

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One-hundred and ninety-two one-day-old White Leghorn male chicks and 16 Wister-strain weanling male rats were fed diets containing bacteria or yeast grown on methanol or casein-amino acid mixture as a sole source of protein with various treatment or supplementation.
Feed intake of rats fed the bacteria diet and of chicks fed the diet with or without supplementation of selenium or fortification of lard and cellulose was about half of that fed the yeast diet as control. The former chicks gained only 1-3g or rather lost body weight during initial 6-7 days. Body weight of the former rats was about half of that of the latter, and 2 rats out of 8 died within 24 days of experimental period.
Extracts of bacteria by either urea solution or ethylene glycol added to the yeast diet had little effect to depress both feed intake and body weight. The corresponding residues fed in place of bacteria improved feed intake and body weight. The findings revealed absence of endotoxin, which could be easily extracted by urea or glycol, in the bacteria.
Feed intake and body weight gain of the chicks fed either the casein-mixture diet or bacteria diet were improved in proportion to dietary level of supplemental potassium.
Potassium content of 3 samples of bacteria was much lower than that of 4 samples of yeast. It was concluded that low appetite of chicks and rats, resulting in slow growth and death, was due to lack of potassium in the bacteria diet.

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Availability of phosphorus in 25 feed ingredients was determined by biological assay on toe ash content reported previously1) in 10 experiments with 1, 830 chicks.
Phosphorus in feed ingredients of animal origin, i.e., fish meals and meat and bone meals, was highly available, while availability of phosphorus in plant oil cakes was very low, being almost zero.
Availability of P in yellow corn and milo was as low as almost zero. Generally speaking, P in wheat, wheat bran and barley was available with availability of higher than 60. Significant strain difference in P availability was observed between two strains of wheat, i.e., Glenlea and Pitic 62, which were bred in Canada for feed use. Availability of P in Pitic 62 wheat was over 100, while that in Glenlea wheat was 37. Availability of P in rice and rice brans, raw, roasted or defatted, was 15 in average.
Phosphorus availability of 1:1 mixture of fish meal and soybean meal was 49, which was close to an average of P availabilities of fish meal and soybean meal determined separately, i.e., 119 and 7, respectively. The finding suggests that content of available P in formula feed could be estimated as a sum of available P in each of the ingredients.
It was pointed out that errors in estimation of P availability of ingredients, such as plant oil cakes and yellow corn, which have very low content of available P, was much larger than that of ingredients with level of available P, such as fish meal. This is partly due to mathematical reason and partly due to variation of toe ash content of chicks fed a diet containing low level of additional available P.

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To understand physiological meanings of phosphorus (P) availability determined by bioassay recommended previously1), carcass P retention of chicks fed diets of various levels of added P from various feed ingredients was determined. One hundred and twenty one-week-old White Leghorn male chicks reared on a restricted feeding program were grouped in 24 lots of 5 chicks each, and 15 chicks in 3 lots were sacrificed immediately to determine initial carcass P content. Three lots each were fed one of 7 experimental diets, and after 10 days, feed intake and body weight were recorded and the chicks were srcrificed to determine carcass P content and toe ash content. Phosphorus from either standard tricalcium phosphate or one of 5 test materials was added to low P standard diet, which contained 0.3% of P from soybean meal.
From toe ash content, P availabilities of 5 test meterials, i.e., yellow corn, soybean meal, def atted rice bran, wheat bran, and fish meal, were determined by 3-point slope ratio assay as described previously1). Phosphorus availabilities were also estimated by 3-point slope ratio assay from carcass P retention. Both availabilities from toe ash and P retention were agreeable.
Intake of additional available P was calculated by multiplying feed intake by additional available P, which was a product of P availability from toe ash content and additional P level in the diet. Linear relationship was observed between intake of additional available P and carcass P rentention.
These findings suggest that the change in toe ash content represents the change in carcass P retention.
Chicks fed the low P standard diet took 363mg of P and retained 223mg of P in the carcass in average. From the data in this experiment, it was discussed that carcass P content could be divided into 2 parts. One was 0.30-0.32% of carcass which might be required basically to keep chicks apparently healthy without symptoms of rickets and with considerable rate of growth and feed efficiency. The rest of carcass P might be additional to this basic requirement, and mainly deposited in the bone. Chicks may have ability to obtain the former part of P from soybean meal with as high retention rate as 59%. On the other hand, little P in soybean meal over the basic requirement is available to be stored in the bone. Bioassay procedure recommended previously1) determines the availability of P in various P sources supplied to chicks over the basic requirement for P.

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Selenium content in 21 single cell proteins of various species grown on various carbon sources with and without supplemental selenium in the culture media was determined and compared with that in two kinds of brewer's yeast.
Single cell proteins with selenium content less than 0.03ppm resulted in exudative diathesis of chicks in 5 weeks, when fed as a sole protein source in semi-purified diet. Supplementation of selenium as sodium selenite to the diets at the level of 0.5ppm prevented exudative diathesis completely. Two kinds of brewer's yeast and an yeast grown on methanol with supplemental selenium contained 0.18, 0.17 and 0.30ppm of selenium, respectively, which produced no exudative diathesis of chicks. A yeast grown on methanol, of which selenium level was below sensitivity limit of selenium determination, i.e., 0.01ppm, produced neither exudative diathesis nor encephalomalacia of chicks, when fed as a protein source of natural-type diet composed mainly of yellow corn and defatted rice bran.
Biologically active selenium content in yeast grown on methanol increased with supplementation of selenium in the culture media, although clear-cut linear relationship between selenium contents in the media and in the yeast was not observed.
It is concluded that selenium content in single cell protein is related to the selenium level in the culture media, and that selenium deficiency symptoms of chicks are only observed when selenium-deficient single cell protein is given to chicks as sole protein and selenium sources in semi-purified diet.

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[in Japanese]

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Mostly fertile eggs which were collected from White Leghorn laying hens inseminated artificially with 0.02ml cock semen per hen and infertile eggs which were collected from another flock of White Leghorn laying hens were analyzed for moisture, crude protein, crude fat and crude ash concentration. No difference was observed in the compositions in egg white and yolk between the two groups except the case of crude protein in egg white in which the concentration was higher in the infertile eggs. No difference was observed between the two groups in the preservation of interior quality of the eggs stored for 1, 5, 10, 20, 30, 40, 60, 80, and 100 days either in an unairconditioned room or in a box kept at 25°C.

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