The present experiment was undertaken to investigate the effect of environmental temperature on plasma levels of catecholamines (epinephrine and norepinephrine). Chicks were preconditioned by feeding a basal diet (3, 250kcalME/kg and 200gcrude protein/kg) made mainly from ground yellow corn, dehydrated alfalfa meal, and purified soybean meal. The basal diet was fed ad libitum for preconditioning periods (from 12 to 15 days of age). During the experimental period (from 15 to 27 days of age), all the chicks were pair-fed by force-feeding 3 times a day (at 10:00, 15:00 and 19:00) to equalize intakes at the various temperatures. Temperatures studied were 16, 25 and 34°C and relative humidity was maintained at 50-70%. At the end of the experimental period, the birds were killed and blood samples were collected in heparinized test tubes at around 13:00h for determination of plasma levels of epinephrine and norepinephrine. Epinephrine and norepinephrine were measured by HPLC. Circulating plasma levels of epinephrine and norepinephrine in the cold condition (16°C) were significantly higher than the control (25°C). However, hot condition (34°C) had no significant effect on plasma level of epinephrine while it increased norepinephrine. This indicates that catecholamines may have different roles to tolerate the cold or the stressful heat environ-ment.

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This paper reports the results of survey on chicken meat production and marketing in selected Asian countries representing developing (India, Bangladesh, Pakistan), rapid developing (Thailand, Philippine, Iran), and developed nations (Japan, Taiwan, Rep. of Korea) in the region. This survey was done during 1994-1995, coordinated with Asian Productivity Organization (APO). Subsequently the meat production and marketing symposium was held in Tokyo which was attended by those foreign experts participated during the survey. The survey covered all the aspects of poultry industry which included chicken, ducks, geese and quails. The survey data obtained from 1970 to 1993 concerning poultry industry was used. The primary objective is to describe poultry consumption and production patterns. The outlook for the poultry industry is promising. In the past 20 years consumption of chicken meat has increased dramatically in these nations. Consumption of chicken meat will continue to increase as estimated income elasticities for chicken meat indicate a latent demand for this meat comparative to other types of meats. In the coming years this increase will continue, although at a slower pace. In the less developed countries in the region, consumption and production will increase quicker than developed countries.
However, our previous study on meat consumption patterns indicated that the consumption of meat is influenced by taste and preference as well as the level of income. With the increase in household income level, income elasticities of demand for chicken meat has increased and it is highest in Pakistan (1.639) followed by India (0.881) and Taiwan (0.4780). Chicken are native to the monsoonal rice growing areas of Asia and so they have become a suitable alternative to fish which has been their main traditional source of protein. However, the preference of animal protein has been shifting from fish to chicken meat. Chicken is very efficient and economically the best as far as the feed conversion ratio is concerned. Another factor which affects meat consumption is the cultural and religious factor. Certain religions has restriction on consumption of certain meat types but none for chicken meat. Therefore, chicken meat can be called as "Universal Meat".

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Two experiments were conducted to determine whether the ratios of essential amino acids (EAA) to nonessential amino acids (NEAA) in low protein diets affects the performance, nitrogen excretion and abdominal fat deposition of broiler chicks. Low crude protein (19% CP) diets with different ratios of EAA/NEAA (E/N) (0.85, 1.03 and 1.17 in experiment 1, 0.76, 0.99 and 1.29 in experiment 2), and control diets (0.96 in experiment 1, 1.04 in experiment 2, E/N ratio in 21% CP) were fed to 7-day-old chicks for 14 days.
Body weight gain and feed efficiency of chicks fed the 1.17 (experiment 1), 0.99 and 1.29 E/N (experiment 2) diets were the same as those of chicks on the control diets. Excreted nitrogen expressed as percentages of nitrogen intake was lower for chicks fed higher E/N diets compared to the control diets in both experiments, and decrease with increasing E/N in experiment 2. Abdominal fat weight increased with feeding 19% CP diets, but in experiment 2, 0.99 and 1.29 E/N diet chicks showed essentially the same abdominal fat deposition as those on the control diet.
It follows from the present results that 1.29 E/N ratios in 19% CP diets reduce nitrogen excretion (g/4 days) by 20% without lowering performance compared to the control diet, and prevents excess fat deposition by lowering dietary CP.

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Spectrin localizations were immunohistochemically observed by light and electron microscopies in bursa of Fabricius and thymus in chickens. Many bursal lymphocytes were detected as spectrin-positive. These spectrin-positivecells (SPC) were located in the follicular medulla in bursa and the cortical lymphocytes were detected as spectrinnegative. Interestingly, SPC was negligible in thymus. When tissue sections were pretreated with heating at 90°C for antigenicity retrieval of cytoskeletal proteins in aldehyde-fixed-sections before incubation with anti-spectrin, an enhancement on the stain intensity was noted and the degree of enhancement was dramatic. Strong stainings of spectrin were present in the epithelium of the mucosal fold, but was not apparent in follicle-associated epithelium. Furthermore, heat-induced antigenicity retrieval was not assessed in the interfollicular surface epithelium. Although the stain intensity was still weak, thymic lymphocytes were observed as spectrin-positive after heating at 90°C. Among the thymic SPC, epithelial cells were more strongly stained than the lymphocytes after the same pretreatment. Therefore, heating had an enhancing effect on stain intensity of spectrin that is partially susceptible to aldehyde fixation. Ultrastructurally, spectrin was mainly detected as aggregated or diffusive type in the cytoplasm after heating at 90°C. Any difference of subcellular localizations of Spectrin was not seen between the bursal and thymic SPC.

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Apoptosis was studied in chickens with reference to bursal involution. Morphological and biochemical apoptosis occurred first on day 18 of incubation in bursa of normal embryos. Such phenomena were never detected before 18 th day of embryonic life. Therefore, apoptotic induction was stage specific in chicken bursa. Embryos treated with testosterone propionate (TP) showed DNA fragmentation on day 18, 8 days after the TP injection; these apoptotic responses were negligible on other experimental days. Furthermore, apoptotic cells were occasionally seen among the bursal lymphocytes or epithelial cells in the TPtreated embryos. Embryos injected with half dose of TP showed lower levels of DNA fragmentation than the normals, and the cells undergoing apoptosis were low in number. After hatching, apoptosis was detected morphologically and biochemically in normal bursa, especially after the stage of sexual maturation. These findings demonstrate an apparent correlation between apoptosis and normal involution of bursa after maximal stage of tissue maturation and are suggesting for an apoptosis-independent process of bursal involution introduced by TP treatment.

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Membrane fractions of the testis of Japanese quail were shown to possess properties of receptor for melatonin, such as binding specificity, saturation, reversibility, high affinity and limited capacity. The equilibrium dissociation constant was smaller (the binding affinity was higher) at middark than at midlight. The results suggest that there exists a melatonin receptor in the testis of the quail and its binding may change between light and dark periods.

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Circadian rhythms of melatonin content in the pineal gland were examined in 4-week-old layerstrain chicks and silky chicks. In the layerstrain chicks, pineal melatonin levels showed a robust daily rhythm with high levels occurring during the dark phase of the photoperiod. The pattern of daily melatonin synthesis in the silky chicks was generally similar to that in the layerstrain chicks. There were, however, two differences between these two breeds. First, both light and dark phase melatonin levels in the silky chicks were significantly lower than those in the layerstrain chicks. Secondly, melatonin levels dropped more slowly after lights on in the silky chicks than in the layerstrain chicks. These results suggest that mechanisms for regulating pineal melatonin biosynthesis are probably a little different between these two breeds.

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This experiment was conducted to determine the effect of dietary cystine (Cys) on the growth performance and the liver lipid and phospholipid of broiler chicks. Basal diet containing 23% CP (TSAA=0.69%) was supplemented with Cys at 0.098, 0.163, 0.238, and 0.324%. Cystine supplementation resulted in significantly (P<0.05) heavier body weights. However, the growth response was not linear nor directly proportional to the level of Cys supplementation. Dietary Cys improve growth but failed to affect abdominal fat and breast meat weights. Cys caused the significantly increase in fatty liver score and liver lipid but a decrease in liver phospholipid. It is clear that Cys resulted in the increase in liver weight. There were positive relationship between liver weight and fatty liver score, and between fatty liver score and liver lipid content.

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