An experiment was conducted to determine if changes in the level of dietary amino acids fed to laying hens as a single amino acid or a natural protein reflected on changes in plasma amino acid content.
A basal diet was formulated in which all essential amino acids were not less than NRC requirements. A high-protein diet was made with the addition of 10% fish meal to the basal diet, and a high-valine diet was made by the addition of 0.3% valine to the basal diet.
The concentrations of eight plasma amino acids (threonine, valine, methionine and cystine, isoleucine, leucine, lysine, and arginine) increased within 7 days and thereafter remained constant on the high-protein diet. But those of five amino acids (serine, glutamic acid, alanine, tyrosine, and phenylalanine) were kept constant throughout the experiment. On the valine diet, the concentration of plasma valine increased until 14 days, but those of other amino acids remained constant.
The data suggests that plasma amino acids levels may serve as a more effective and rapid evaluation of changes in dietary status than a long term feeding test.

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Cellulose powder, pectin, alginic acid and finely ground rice straw were used as the dietary fiber source. Experimental diets were composed of soybean protein, corn starch, cornoil and some minor ingredients with 10% of above mentioned dietary fibers. A total of 8 colostomized White Leghorn male chickens were forced-fed 70 g/day of the experimental diets for 7 days alternatively so as to make a 4×4 Latin-square design. The amount of fresh feces was significantly higher in the pectin and alginic acid diets, however, water content in the feces was also higher in these diets. Consequently, the dry matter excreted were not different between the treatments, which resulted in no difference of dry matter and energy digestibilities among the diets. Protein digestibility was higher in the cellulose diet and lower in the pectin diet due to the significant difference in fecal nitrogen excretion. Urinary nitrogen was very low in the cellulose diet, and reflecting it biological value of protein was higher in the cellulose diet. Acid detergent fiber was digested by chickens to a small extent, but hemicelluloses seemed to be not digested, because the digestibility of neutral detergent fiber was the same to that of acid detergent fiber.

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Experiments were conducted to evaluate several factors affecting on reduction of bacteria contaminating chicken house floor by washing with jet stream. Reduction of bacteria contaminating materials for the house built by washing also examined. It was considered that main factors affecting on reduction of bacteria by washing with jet stream would be amount of water jetted out, pressure of jet stream, temperature of the stream and brushing the house floor where the stream lashed down.
Amount of water used washing was 4, 6 and 8l per m². No significant difference was observed reduction of bacteria among amounts of water jetted. High pressure of jet stream 80 and 150 kg/cm² reduced bacteria as same as stream with normal pressure 25kg/cm². High temperature jet stream at 100°C reduced bacteria as same as normal temperature stream at 24°C. Reduction of bacteria was approximately 10^-1 or less than that of bacteria before washing.
Washing on the floor by the stream with brushing was effective to reduce bacteria contaminated. Reductions of bacteria by washing with brushing were 10^-1.4 to 10^-2.4 of bacteria before washing. Washing was conducted to combine the terms which would be effective to reduce bacteria. The terms combined were 8l per m² of water, 80kg/cm² of stream pressure, temperature of the stream at 100°C and detergent was sprayed before washing to increase the reduction of bacteria. Brushing on the floor was carried out 9 times when the stream lashed down. Reduction of bacteria was 10^-2.5 of bacteria contaminatd before washing. It is considered that this degree of bacterial reduction would be marginal by washing using jet stream.
Bacteria contaminated fancy plywood, plastic and zinc iron boards without rust were removed easily by jet stream. Reductions were 10^-3.2 to 10^-4.1 of bacteria contaminated before washing. On the contrary, bacteria contaminating concrete, wooden, plywood, rusty zinc iron and slate boards were not removed easily. Reductions were 10^-0.9 to 10^-1.3 of bacteria contaminated before washjng.

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An investigation was made of the effects of cage size and housing density on production of SPF chickens kept in pen cages. Unit pen cage (80×80×80cm) and large sized cage which was coupled 3 unit pen cages (240×80×80cm) were used. The SPF cockerels and pullets of 12 weeks of age were housed in the cages at various housing densities. In the unit cage, 1 or 2 cockerels and 6 to 10 pullets were housed and 3 or 5 cockerels and 19 to 30 pullets in the coupled cage. Floor space per chicken was 800, 686 and 582cm², respectively. Productions of the chickens were recorded from 21 to 70 weeks of age.
No significant differences were observed in body weight at 20 weeks of age, sexual maturity, egg weight at 50 weeks of age, percentage of qualified hatching egg, fertility of produced eggs and feed intake among treatments. However, it seems to record better production of the chickens in unit pen cages than that in coupled cages. Percentage of egg production was differed significantly among several treatments. Egg production of 4 treatments out of 6 using coupled cage was lower than that of 4 treatments using unit cage. It happened to struggle among cockerels housed in the same cage at sexual maturity to 30-32 weeks of age. Severe struggle was observed among cockerels housed in coupled cages.
From the results of the experiment, it was satisfactory that number of chickens housed per cage were 1 cockerel and 7 to 10 pullets and floor space per chicken was 800cm². It was considered that pen cage system was competent for keeping SPF chickens to produce hatching eggs.

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The present study was conducted to determine the effect of dietary ascorbic acid (AA, 150 and 1500ppm) on growth and plasma and tissue AA levels of chicks 24 and 26 days of age exposed to high ambient temperature for 7 days.
1) Body weight gain, feed intake and feed efficiency of chicks were significantly decreased at high ambient temperature (40°C) compared with adequate temperature (20°C). However, the supplementation of AA reduced the severity of such adverse effects, as induced by high ambient temperature.
2) Plasma, liver and kidney levels of AA were significantly depressed in chicks reared at 40°C but these reduced AA levels were significantly ameliorated by 1500ppm AA supplementation. For plasma and kidney levels of AA, significant correlations with kidney L-gulonolactone oxidase activity (r=-0.681, P<0.001 for plasma AA, r=-0.579, P<0.05 for kidney AA) were found.
3) Thyroid weight and plasma T₄ content were not significantly altered by the temperature treatment and AA supplementation.
4) These results obtained in the present study suggested that the adverse effects of high ambient temperature on chicks could be alleviated by AA supplementation.

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