Four generations of selection were conducted in small populations to reduce body weight of chickens at 150 days of age. The base population was divided at random into three groups. One of those was directly selected against body weight (small body weight line), and the second was selected by a selection index designed to reduce body weight but to increase egg production to 270 days of age and to hold egg weight constant (index line). The third group was maintained as a control line.
Although effective selection responses were observed in both of selected lines, the responses were higher in the small body weight line than in the index line for both characters of body weight and egg production. It was contrary to expectations. The effective selection differentials were smaller than the expected selection differentials in both selected lines. The realized heritability for body weight at 150 days of age was about 0.3.
Changes of gene frequencies at four blood group loci were examined in each line. In the control line there were observed no obvious changes in the gene frequencies over four generations. In the selected lines, however, the gene frequencies showed a consistent trend of increase of higher frequent genes. The trend was much conspicuous in the small body weight line.

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The average fertility of chicken-quail cross eggs was 13.9% in the weekly insemination and 47.9% in the semi-weekly insemination. Thirty-six hybrids were obtained from 2370 eggs of quail inseminated with chicken semen of four breeds (Hinaidori, Rhode Island Red, Barred plymouth Rock and White Leghorn). The white plumage gene (I gene) of W.L., barred plumage gene (B gene) and slow feathering gene (K gene) of B.P.R. behaved as dominant traits in F₁ hybrids, just as in chickens. The data suggest the homology of these genes between chicken and quail. Maximum body weight of F₁ hybrids was influenced by the chicken breeds. Fifteen hybrids examined by leukocyte culture were all males with ZZ chromosomes.

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The effects of fasting-refeeding and dietary protein level on the hepatic lipogenesis of growing meat-type birds, were investigated. All the birds were fasted continuously for 4 consecutive days and then refed for 1 day, 2 days and 4 days with diets containing normal (21%), low (12%) and high (30%) levels of dietary protein. Four days of fasting greatly reduced body weight and a similar length of refeeding, regardless of protein level, proved insufficient to recover the lost weight. Liver weight responded positively to refeeding with the low-protein group registering the highest score.
Among the lipid fractions determined, triglyceride demonstrated the most dramatic increase that was inversely proportional to the dietary protein level, Serum cholesterol, NEFA and β-lipoprotein tended to show the same reaction, i. e., higher values were obtained when the protein level was low. Worth noting was the serum cholesterol score for the 30% group which significantly decreased as protein level increased thereby suggesting the hypocholesteremic influence of high protein levels in the diet.
In almost all the parameters that positively responded to both refeeding and the protein content of the diet, the response was such that an increase-decrease pattern was established whereby the highest increase emerged on the 2nd day of refeeding, then tapered off on the 4th day to a level that was still greater than the 1st-day refeeding value. Further, that lipid biosynthesis was greatly enhanced when the protein level was low could probably be ascribed to the increased carbohydrate content of such low protein diets which in turn provided a ready supply of glucose that accelerated the production of acetyl-CoA, thus favoring the formation of large quantities of reducing equivalents which have been implicated to be the limiting factor in fatty acid biosynthesis.

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Composition of an amino acid mixture, which has been used as sole nitrogen source in a purified amino acid diet for starting chicks in this laboratory, were re-examined to confirm whether requirement of some of essential amino acids given in Japanese Feeding Standard is too high or not.
Total 1, 926 8-day-old White Leghorn male chicks were used in 5 experiments. The chicks were fed either a control diet containing soybean meal and fish meal as main protein sources or amino acid diets of various composition. Body weight gain and feed intake for 8 or 10 days were recorded. In Expt. 5, available energy and gross protein value of an amino acid mixture A6 were determined biologically as described previously.
Phosphate, sulfate and chloride in mineral mixture of the amino acid diet were replaced by carbonate and hydroxide to increase pH of the diet, thus to improve palatability. The attempt was not succeeded.
Part of L-glutamic acid in the mixture was replaced by graded levels of L-arginine. Growth response of chicks fed the mixtures were curvilinier as shown in Fig. 2, and a mixture having 4.8:3.2 of glutamic acid and arginine ratio gave almost maximum response.
Graded levels of L-histidine, L-isoleucine, L-leucine, L-lysine, L-threonine, L-tryptophan, L-valine, and L-proline in the mixture were fed to chicks to find the adequate level for each of the acids. As a conclusion, a mixture shown in Table 1 as A6 was found adequate. In this mixture A6, levels of glycine, histidine and leucine were lower than those given in Japanese Feeding Standard. The mixture contained 13.43% of L-arginine and 49.65% of L-glutamic acid. The diet containing the mixture A6 as nitrogen source had pH of 5.1, which was higher than 4.4 of the original amino acid diet.
Gross and available energies of the mixture A6 were 4.50 and 4.00kcal/g, respectivery. The mixture A6 contained 0.35% of moisture and 83.40% of crude protein (6.25N). Gross protein value of the mixture was 109.

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Embryos died in the late stage of hatch in 20 hatchability tests carried out as a 5-year project in collaboration of 7 prefectural experiment stations, Nagoya University, and National Institute of Animal Industry were examined teratologically, and classified into 28 types of deformity. Statistical analysis of the incidence of each type of deformity revealed that neither the difference in the diets fed to the hens nor the difference in other experimental conditions such as the strain and generation of the hens could explain the variation of the incidence.
Accordingly, all the data were pooled with those of 192 lots of almost identical experiments to estimate the population mean, standard deviation of the data after angular or square root transformation, and 99% fiducial upper limit of the mean. Among 78, 311 fertile eggs tested in 752 lots, 1, 216 embryos were deformed. The deformity of the beak, including the short beak, was the most popular, being 578 cases in total, followed by the poor development and the umbilical hernia. The deformity in the brain and the eye was also popular, being 297 cases in total.
Equation 1 was found fit to describe the relationship between hatchability (y%) and mortality of embryo at early stage (x₁%) and percent of deformed embryo (x₂%).
y=94.36-1.0519x₁-1.5586x₂……(1)
The percent x₂ can be estimated from y and x₁, both of which are commonly determined in ordinary hatcheries as a routine work.
It was recommended to test hatchability in the experiment monitoring the presence of unknown or unexpected teratogenicity in a feed ingredient. Most of deformed chicks cannot break the egg shell by themselves, and died in the shell. Therefore, hatchability is a good criterion for teratogenicity without special knowledge and technique on teratology, anatomy and histology. Fiducial limits and Equation 1 are useful guides in hatchability tests.

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Two experiments were conducted to investigate the palatability and utilization of some whole grains for finishing brolier chickens. Whole or ground barley, wheat, milo or paddy rice was included 63% in the diet as only grain source. These diets were adjusted to meet the protein and energy requirement, and fed female broiler chickens. The test period was from 6 to 8 weeks of age.
Feed intake was not affected by the dietary grain source, but chickens consumed much more whole grain diets than ground grain diets. Weight gain was also not affected by the dietary grain source. In Experiment 1, the growth was not significantly different between chickens fed whole grains and those fed ground grains. In Experiment 2, however, chickens fed whole grains were superior growth than those fed ground grains. Feed efficiciency was significantly increased in chickens fed ground grains in Experiment 1, but not significantly different between chickens fed ground grains and those fed whole grains in Experiment 2. Metabolizable energy of paddy rice and wheat diets were not affected by grain size (whole or ground), while ground barley and milo diets showed significantly higher metabolizable energy than whole barley and milo diets.
Percentage of whole grains in the left-over diets was much less than in the original diets. This indicates that finishing broiler chickens prefer whole grains. Whole grains were almost not observed in the excreta and intestinal digesta of the chickens.

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Selenium content of 29 commercial feedstuffs was determined and biological availability of selenium was evaluated on three samples out of them.
The selenium contents ranged from 0.03 to 2.61ppm. There was a tendency that selenium levels of feedstuffs of animal origin were higher than those of plant origin. Selenium content of fish meal was the highest in all the samples.
Biological availability of selenium in soybean meal, alfalfa, fish meal and selenometionine was evaluated to be 33, 85, 82 and 92%, respectively, based on the activity of plasma glutathione peroxidase, suggesting that selenium in soybean meal is less available. Availability of selenium in fish meal based on the incidence of exudative diathesis was 74%.

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