Four experiments were conducted to estimate the total sulfur amino acid (TSAA) level for maximum growth performance (requirement) of broilers, to elucidate whether methionine (Met) requirements were affected by TSAA levels, and to confirm whether excessive Met and cystine (Cys) had a negative effect on the performance of broilers. Eight-day-old Arbor Acres strain female chicks were kept individually in wire cages, and fed practical type experimental diets ad libitum for 10 days. Experimental diets were consisted of corn and soybean meal, and contained 3, 200 kcal metabolizable energy/kg of diet, and 16 to 17% crude protein. When essential amino acids, except for TSAA, derived from feedstuffs were less than 95% of NRC requirements, crystalline amino acids were added.
In Experiment 1, to determine the Met requirement at various dietary TSAA levels, Met with 5 graded levels from 0 to 0.80% was added to the diet containing 0.25% Met and 0.22% Cys. In Experiments 2 and 3, to clarify the optimum Met ratio to Cys, Met was added with 5 graded levels by balancing Cys to diets slightly deficient (0.60%), adequate (0.67%), slightly excess (0.74%) and excess (1.30%) in TSAA. In Experiment 4, to clarfy the role of Cys, Cys with 4 graded levels from 0.10 to 1.00% was added to the 0.30% Met and 0.30% Cys diet. As negative control, 1.90% Met diet was reported.
From the results obtained, it was suggested that 0.66% of TSAA was required for the maximum growth performance of broilers from 8 to 18 days of age, and 0.30% of Met was required irrespective of dietary TSAA levels. This meant that the ratio of Met replaced by Cys increased with increasing TSAA levels. When the dietary Met level exceeded 0.7%, the excessive Met caused the depression of growth performance of broilers. However, no negative effects were observed even when the dietary Cys was at 1.90% of diet.

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Abdominal fat deposition and the cellularity, and lipid content and mixed function oxidase (MFO) activity in livers were studied in broiler chickens fed isoenergetic and isonitrogenous diets which were different in the fat and protein sources.
Feeding corn oil (CO) or chicken oil (CH) tended to decrease abdominal fat content compared with feeding yellow grease (YG) at 56 days of age, although no significant differences were observed in general performance. In female chickens, the decrease in the abdominal fat pad was associated with decrease in the adipocyte volume. At 21 days of age, lipid and triglyceride contents in the liver of chickens fed CO or CH were numerically lower than those in YG-fed chicks, and hepatic MFO activity was elevated by feeding CO.
Feeding high fat diet (HF) increased liver triglyceride content at 21 days and tended to increase abdominal fat content at 56 days of age. Feeding fish meal (FM) as a major protein source increased the abdominal fat content in comparison with feeding soybean meal+fish meal (SFM), irrespective of dietary fat content, at 21 days of age. In chickens fed low fat diet (LF) for 21 days, FM decreased lipid and triglyceride contents in the liver and the decrease was associated with an activation of the hepatic MFO activity.

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The enzyme activity and ultrastructure of osteoclasts in medullary bone cultured in the presence of parathyroid hormone (PTH) were examined using laying hens during the formative phase of the bone when an egg was in the magnum of the oviduct. Before and after the culturing in the absence of PTH, osteoclasts on the surface of medullary bone showed moderate activity for both acid phosphatase (ACP) and succinate dehydrogenase (SDH), and strong lactate dehydrogenase (LHD) activity. These cells lacked ruffled borders adjacent to the bone matrix. On the contrary, in the presence of PTH, ACP and SDH activity in osteoclasts increased after 3 hours of culture. Ruffled bordes also apperared at the peripheral cytoplasm apposed to the bone. After 12 hours of culture, the area of the ruffled borders further increased. After 24 hours of culture, almost all the osteoclasts had well developed ruffled borders. These results suggest that PTH stimulates osteoclastic resorption in the medullary bone of laying hens during the formative phase of the bone.

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Hyperuricemia was produced in chickens by artificial infection with nephro-pathogenic infectious bronchitis virus (IBV) and studied. Typical respiratory symptoms were found in all of the chickens after inoculation with the nephropathogenic AM-83 strain of IBV. Sixteen out of 30 chickens died from 4 to 14 days after challenge. The level of uric acid in plasma was very high at the day before death and the values in the majority of chickens was more than about 100mg/dl. The chicken surviving against the IBV challenge had hyperuricemia for a longer time than the dead chickens. A few chickens had hyperuricemia for only one day with very low levels of uric acid.
Chickens in contact with the chickens challenged with AM-83 strain of IBV also died of hyperuricemia, but some of them were resistent to the challenge.
We demonstrated that the hyperuricemia in the chickens infected with IBV was divided into the 4 grades of uncertain, mild, moderate and severe.

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Reduction of bacteria contaminating blocks, carving knives and working boots used at the broiler processing plant was examined by dipping those in hot water. Sterilized blocks and carving knives were used to process broiler meat. Sterilized working boots were also put on by workers for the processing meat. After washing with detergent, the blocks and knives were dipped in hot water kept at 60, 80 and 100°C for 30 and 60 seconds, respectively. The boots were also dipped in hot water kept at the same temperatures and periods without washing.
A number of bacteria 10^4.7, 10^4.9 and 10^3.8 per 1cm² were detected from the blocks, and hafts and blades (metal parts) of the knives, respectively. The bacteria were reduced by washing with detergent and detected fewer than 10^1.0/cm² after dipping. The higher temperature water used, the fewer number of bacteria were detected.A number of bacteria per 1cm² detected from bottom, heel, toe and shank parts of boots were 10^4.6, 10^4.5, 10^4.0and 10^3.6, respectively. After dipping, the bacterial counts per 1cm² were fewer than 10^3.5, 10^3.2, 10^3.2 and 10^3.0 on the bottom, heel, toe and shank parts of the boots, respectively. The higher water temperature was the more effective to reduce bacteria contaminating the boots. No significant difference between dipping periods of 30 and 60 seconds was observed in bacterial number on the block, knife and boot after dipping.
In practice, it is recommened that blocks, knives and working boots used in broiler processing plant are dipped in hot water kept at higher than 80°C for longer than 30 seconds to reduce contaminated bacteria.

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Using White Leghorn hens at 6 months of age, the effects of administration of 4-methyl-2-thiouracil (anti-thyroid agent) 0.1% or thyroid gland powder 0.05% on the function of thyroid gland and egg production were studied. There was no significant difference in egg production and feed intake between treatment groups. Although there was no significant difference in plasma thyroxine concentrations between the control group and administered 4-methyl-2-thiouracil group, the administration of thyroid gland powder significantly elevated plasma thyroxine concentrations. Weight of thyroid gland decreased to 40% of that of the control group by the administration of thyroid gland powder, whereas it increased to 515% of that of the control group by the administration of 4-methyl-2-thiouracil. Total cholesterol concentrations in egg yolk were significantly increased by 4-methyl-2-thiouracil. Total cholesterol concentrations in the plasma were decreased by the thyroid gland powder to 76% of those of the control, whereas they were increased by the 4-methyl-2-thiouracil to 132% of those of the control.

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To compare the influence of dietary natural pigments on egg yolk color, laying hens were fed the rations containing marigold petal meal, paprika extract, paprika powder or corn gluten meal, for 20 days. Roche Color Fan (RCF) scores of egg yolks was significantly increased by the addition of every natural pigment i.e., all the natural pigments fortified pigmentation of egg yolk. Though all additives contained the same amount of xanthophylls, the addition of marigold petal meal or corn gluten meal which were rich in yellow xanthophyll did not increase RCF scores as much as the addition of paprika extract or paprika powder which were rich in red xanthophyll. It is suggested that these differences were owing to the characteristics the measurement, i.e., red color contributed to the RCF scores more than yellow color.
Paprika extract and paprika powder significantly increased Yellow Index (YI) and redness (a-values) with the reflectance colormeter in the egg yolks. Compared to these pigments, the additions of marigold petal meal or corn gluten meal were less effective, which was in accordance with the results of the RCF scores. Contrary to a-values and yellow (b-values), paprika extract group induced the lowest b-values. The addition of the pigments other than corn gluten meal induced the lower light (L-values) than the control and L-values was the lowest when paprika extract was fed.
These results indicated that both paprika extract and paprika powder induced strong red pigmentation in the egg yolk whereas corn gluten meal and marigold petal meal induced yellow pigmentation. Therefore, paprika extract and paprika powder are thought to have been effective pigments to increase RCF scores. Though there were high correlations between RCF scores and YI, a-values or L-values, it was impossible that RCF scores were estimated by first-degree regression from these reflectance colormeter values.

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