Effects of rapeseed meal on growth and thyroid function of broiler chicks were investigated using three types of rapeseed meal, B. campestris, B. napus and B. napus cv. Bronowski. Goitrin and isothiocyanate contents were 0.18 and 0.04% in B. napus cv. Bronowski (RSM-B), 0.28 and 0.18% in B. campestris (RSM-C), and 0.89 and 0.27% in B. napus (RSM-N), respectively. Each RSM was included at the 10% level, and diets were maintained isocaloric and isonitrogenous by altering the levels of soybean meal and yellow grease. The results obtained were summarized as follows:
1) Body weight at 4 and 8 weeks of age and feed conversions in chicks fed rapeseed meal were almost equal to those in the control chicks fed soybean meal.
2) Thyroid weight of chicks fed rapeseed meal was 1.3 to 3.0 times larger than that of the control chicks. Enlargement of thyroid in chicks fed RSM-N, which contained 0.89% goitrin, was particularly noteworthy.
3) Thyroidal uptake of ¹³¹I (24 hours) of rapeseed meal-fed chicks was elevated 1.1 to 2.3 times that of the control group. Thyroidal uptake of 131I per 100mg of the thyroid gland, however, was not affected by rapeseed meal feeding.
4) Plasma PB ¹³¹I, which reflects circulating level of thyroid hormone, seemed to be not or to be very slightly depressed by rapeseed meal feeding.
5) Percentage of ¹³¹I-iodothyronines in the thyroid lobes was slightly decreased by feeding of rapeseed meal. However, the content of PAS-stainable (thyroglobulin) in the follicles of the thyroid lobes of chicks fed rapeseed meal was similar to that of the control chicks.
6) It was concluded in this experiment that thyroid function in chicks fed rapeseed meal was kept fairly good, despite of the enlargement of thyroid gland.

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It is known that wild type Japanese Nankin Game male exhibits wild type plumage and female exhibits wheaten type plumage. Present study was conducted to determine the alleles of E-locus in the wild type Japanese Nankin Game. Males and females of wild type Japanese Nakin Game which have been maintained in Fukuoka prefecture and a female which has been maintained in Kagoshima prefecture, and females of wild type Japanese Long-tailed Fowl carrying e⁺e⁺ at E-locus were used. The results obtained were as follows.
Mating between Japanese Nankin Game males from Fukuoka prefecture and Japanese Long-tailed Fowl females produced 12 yellow down, 16 diluted-striped down and 20 striped down chicks. Appearance of three down phenotypes suggests that the Japanese Nankin Game males may be heterozygous for alleles of E-locus and one of the alleles is considered to be e^Wh, since it has been demonstrated that this gene exhibits yellow down and is incompletely dominant to e⁺. Mating between these heterozygous males and femalese of Japanese Nankin Game from Fukuoka prefecture produced yellow down phenotype in all of 26 progeny, From this result, it is presumed that E-locus of these Japanese Nankin Game males may be e^Wh e^y and that of females may be e^Wh e^Wh, e^Wh e^y or e^y e^y, since it is known that ey exhibits yellow down and is recessive to e⁺.
On the other hand, mating between Japanese Nankin Game males (e^Wh e^y) and one female from Kagoshima prefecture produced 18 yellow down, 13 diluted-striped down and 4 striped down chicks. Appearance of striped down chicks indicates that this female carries e⁺, and genotype of this female is presumed to be e^Wh e⁺, because the plumage of this female is wheaten type.

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Progesterone and estradiol contents and concentrations of the hierarchical follicles of the hen during the ovulatory cycle were measured with a radioimmunoassay. Progesterone content was always the highest in the largest follicle at 10, 4 and 1-0.3 hours before ovulation, and the value increased and reached a peak at 1-0.3 hours before ovulation, and rapidly decreased after the ovulation in the ruptured follicle. Estradiol content was the largest in the 3rd or 4th largest follicles during the ovulation cycles, and the lowest in the largest follicles among the large 6 follicles of the ovary. Amounts of in vitro release of either progesterone or estradiol from the hierarchical follicles of the ovary corresponded the hormone content of the corresponding follicles.
[4-¹⁴C]-Labelled pregnenolone and progesterone were incubated with the homogenates of the largest and the 2nd largest follicles of hen ovary obtained at 10, 4 and 1-0.3 hours before ovulation and immediately after ovulation. The conversion of pregnenolone to progesterone (and other products) was always higher in the largest follicle than the 2nd largest follicle. The conversion of progesterone to 17α-hydroxyprogesterone (and other products) was always lower in the largest follicle than the 2nd largest follicle, and it decreased rapidly in the largest follicle at 1-0.3 hours before ovulation. Relatively higher combined activities of Δ⁵-steroid-3β-hydroxysteroid dehydrogenase and Δ⁵-Δ⁴ isomerase and significuntly lower activity of 17α-hydroxylase in the largest follicle at 1-0.3 hours before ovulation may account for the high concentration of progesterone in the follicle.

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To improve feed efficiency highly associated with net economy in layer chickin, a selection experiment for three generations in a closed flock of Rhode Island Reds was conducted by use of an index consisting of part records of egg mass, feed intake and body weight. The index was calculated on the basis of estimated parameters in the initial generation and the same index was used throughout the three generations.
Results of the selection were summarized in Table 7. The net economic value was improved by 162% for the period (up to 273 days of age) in which the part records were taken and 155% for the whole year period (up to 469 days of age).
All traits were improved towards the intended directions, although the ratios of realized to expected genetic gain varied substaintially among traits measured. Parts of such discrepancies between expected and realized gain in various traits could be ascribed to the bies of estimated population parameters such as heritabilities and genetic correlations.

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Three inbred lines K1, K2 and K3 were developed from crossbreds by one-sire sib matings. The mean inbreeding coefficients of the lines ranged from 0.33 to 0.42 for the last generation. Regression coefficients of hatchability on inbreeding coefficient ranged from -0.27 to -0.87 for the individual lines, and -0.53 for the pooled estimate.
The estimated lower and upper limits of lethal equivalents per zygote were 0.84 to 2.92 and 1.22 to 2.92, respectively. The estimated values of B/A ratio were high in two of the three lines, and the pooled estimate was also as high as 14.28.

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Using 40 White Leghorn male chicks, variations of protein and energy intakes were determined on a separate protein feeding system, which gave free choice of intake of a protein and a protein free diet. Isolated soybean protein and milk casein were used as protein sources. Body weight gain for 2 weeks on the separate feeding system was the same as that on the corresponding mixed diet system (20% protein diet) for both proteins, although body weight gain on milk casein was less than that on soybean protein. Protein intakes on the separate protein feeding systems were slightly less than those on the mixed diets when either soybean protein and milk casein was used. Energy intake of chicks fed soybean protein by the separate feeding system was less than that of chicks on the mixed diet feeding system. The reverse was true in the case of milk casein. Protein and energy utilization ratios of chicks fed by the separate feeding system were 89 and 90% on the soybean protein mixed diet. From these results it seems that a separate protein feeding system can be effectively used in methods of estimation of growth, feed intake and other nutritional studies with chicks.

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Experiments were conducted to study the fate of ¹⁵N supplied as ¹⁵N-labelled urea in terms of excretion and incorporation into body tissue protein.
The ¹⁵N of dietary ¹⁵N-labelled urea was incorporated into the trichloroacetic acid insoluble fractions of blood plasma, liver, kidney and pectoral muscle. The result indicates that dietary urea is used in protein synthesis by the chick.

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Effects of feeding "double low" rapeseed (Tower) meal (RSM-T) and Bronowski rapeseed meal (RSM-B) on performance of broiler chicks were investigated. Each of the meals was included at the level of 10%. Diets were maintained isocaloric and isonitrogenous by altering the levels of soybean meal and yellow grease. Goitrin and isothiocyanates contents of RSM-B were 0.12 and 0.06% and those of RSM-T were 0.14 and 0.05%, respectively. Body weight at 4 and 8 weeks of age and feed conversion in chicks fed rapeseed meal were almost equal to those in the control chicks fed soybean meal.
At 8 weeks of age, thyroid weight of chicks fed rapeseed meal was 1.5-1.8 times larger than that of chicks fed the control diet. Weight of liver, heart, kidney, spleen, pancreas and abdominal fat, were not influenced by feeding any of these rapeseed meals.

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