This paper provides an overview on the role of several endocrine factors in the regulation of the somatic growth (skeletal muscle and bone development) and body composition in meat-type poultry. The hormones of both the somatotrophic axis (GH and IGFs) and the thyrotrophic (T₄, T₃) axis are a prerequisite for normal growth and development. Posthatch hormone therapy does however not stimulate growth but rather to the contrary. In ovo treatment with somatotrophic hormones seems to elicit positive responses in postnatal growth and adiposity. Androgens are anabolic and their plasma levels are positively correlated with growth rate, whereas estrogens are clearly lipogenic. The androgen : estrogen activity ratio may certainly not be underestimated in growth and adiposity regulation, even in juvenile poultry. Leptin has appetite-reducing properties in chickens and hepatic leptin expression is controlled by several hormones. Finally, feed restriction as well as diet composition is used as models to illustrate how endocrine factors interact with the intermediary metabolism in a deterministic and mechanistic way.

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Cytoplasmic calcium ion concentrations [Ca²⁺]_i were measured for the first time in chicken heterophils and macrophages stimulated with Leukotriene B₄ (LTB₄), phorbol myristate acetate (PMA), formyl-methionyl-leucyl-phenylalanine (fMLP) and lipopolysaccharide (LPS) which are known to be activating factors of phagocyte functions. [Ca²⁺]_i in rat neutrophils and macrophages was also measured after stimulation with these activating factors. [Ca²⁺]_i was measured by the Fura-2-AM-loading method using an intracellular ion analyzer. Resting levels of [Ca²⁺]_i in chicken phagocytes were similar to those reported previously in rats. [Ca²⁺]_i of chicken phagocytes was elevated by treatment with LTB₄, PMA and LPS, and the patterns and duration times of the elevation of [Ca²⁺]_i by these factors resembled those in rat phagocytes. However, fMLP did not elevate [Ca²⁺]_i in chicken phagocytes, although the agent elevated [Ca²⁺]_i of rat phagocytes. The degree of elevation of [Ca²⁺]_i in chicken heterophils and macrophages stimulated by LTB₄, PMA and LPS was significantly higher than that in the same kinds of rat phagocytes (neutrophils and macrophages) stimulated with the corresponding factors. The degree of elevation of [Ca²⁺]_i in granulocytes treated with these factors was significantly higher than that in macrophages in chickens and rats. The reasons for these differences are unclear at the present time. It is valuable to examine the reason for these differences.

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Nitrergic innervation of the chicken Harderian gland was investigated by using immunohistochemistry for neural nitric oxide synthase (nNOS) and a confocal laser scanning microscope. Immunoreactivity for nNOS was detected on nerve elements in the pterygopalatine ganglion and the Harderian gland. Most nerve cells in the pterygopalatine ganglion showed nNOS immunoreactivity. These cells had a variety of sizes and shapes. Nerve fibers projecting from these ganglion cells also showed immunoreactivity for nNOS. Dense networks of nerve fibers showing nNOS immunoreactivity were observed in the interstitial tissue of the Harderian gland. Fine immunoreactive nerve fibers were found running in the capsule. No immunoreactive nerve fibers were found contacting with epithelial cells of the collecting duct. The present data suggested that nitrergic nerves have a relation to the regulation of the immune function of the chicken Harderian gland.

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In order to utilize local chicken, aggressiveness and behavioral patterns of six breeds of Asian local chicken were studied from eight to 18 weeks of age. Local breeds studied were Hua-Tung, Hsin-Yi, Ju-Chi and Quemoy from Taiwan, Shek-Ki from China and Nagoya from Japan. Important results were as follows : 1. Most (84%) agonistic interactions were caused by male's aggression ; 2. Most agonistic interactions occurred between birds of the same sex ; 3. The heaviest Chinese ‘Three-Yellow’ breed, Shek-Ki, and the Taiwanese game bird, Hua-Tung, had the highest frequency of agonistic interaction ; 4. Aggressiveness made Shek-Ki to have the fastest feeding speed, the least crouching time, and the highest frequency of stand⁄walking activity ; 5. Quemoy, the smallest and the purest' breed, had the slowest feeding speed and the highest frequency of ground-scratching activity. Implications of these findings on the management of local chickens were also discussed.

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The goal of this study was to determine the mechanism by which the fertility was declined by repeated artificial insemination (AI) in laying hens. The structures of sperm storage tubules (SST) and lymphocytes population in the uterovaginal junction (UVJ) of Rhode Island Red hens showing a declined fertility after repeated AI with Tosa-jidori semen and of virgin hens were examined histologically in experiment 1. Then, the sperm storage abilities of those hens were examined in experiment 2. In experiment 1, the SST was swollen with thinning of epithelium, and the population of lymphocytes was greater in the UVJ of hens showing a declined fertility after repeated AI compared with virgin hens. In hens showing a lower fertility, few sperm were present in SST, and lymphocytes invading into SST lumen after AI were observed (experiment 2). These results suggest that repeated AI may cause the destruction and abnormality in the functions of SST, and anti-sperm immunoresponse may occur in those SST in the birds used for current study. In these birds sperm could not be retained in SST, resulting in decline of fertility. Such abnormality of SST may be one of the factors involved in the decline of fertility by repeated AI in the other breeds that are reported elswhere.

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This study was carried out to investigate the effects of low oral doses of o, p’-DDT on the reproductive parameters and liver histology in adult male Japanese quail over a long period (120 days). The quail were classified into two groups ; the first group (n=20) was orally given 20μg o, p’-DDT in 10μl corn oil daily for 120 days, while the second group (n=16) received only 10μl corn oil in a gelatin capsule and kept as a control. A number of quail, ranging between 4 to 7 birds, were killed at Days 30, 60, 90 and 120 of the experiment and the testicular weights of the control and treated males were recorded. In addition, the liver and testes of the control and treated males were also collected and fixed in 10% buffered formaldehyde for histological examination. Semen from each killed male was collected for evaluation of sperm concentration and motility. The gonado-somatic index, sperm concentration and the diameter of the seminiferous tubules were decreased in treated males when compared with the control ones at different periods of the experiment. On histological examination, lipid infiltration in the liver of some treated male quail was observed at Days 30, 60 and 90 of the experiment. At Day 120 of o, p’-DDT treatment, the liver was highly infiltrated with lipids and the hepatocytes showed intracytoplasmic vacuolation in comparison with the control bird that showed normal liver histology.
In conclusion, administration of low doses of o, p’-DDT orally for a long period of time might affect the reproductive parameters and liver histology in adult male Japanese quail.

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The effect of spermidine, a type of polyamine present in exudates from inflamed tissues and bacteria-infected sites in humans, on calcium mobilization of leukotriene B₄ (LTB₄)-stimulated chicken abdominal macrophages and heterophils was examined in vitro. The intracellular calcium ion concentration [Ca²⁺]_i was elevated immediately and reached a maximum a few seconds after the addition of LTB₄. The elevated [Ca²⁺]_i returned to the basal (resting) level approximately 2min after LTB₄ addition. Pretreatment of cells with spermidine significantly prolonged the duration of [Ca²⁺]_i elevation in LTB₄-treated chicken phagocytes. However, no change was induced in the level of [Ca²⁺]_i elevation by pretreating the LTB₄-treated cells with spermidine. These results suggest that polyamines would enhance the activities of chicken macrophages and heterophils in inflammation sites and bacteria-infected sites through delaying the return to resting levels of stimulated cells, as in the case of human polymorphonuclear leukocytes.

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A black plumage color mutant (BPC) was described in this paper. The BPC quail was a dark colored bird. The chick down feathers on the back and head were black ending with a brown tip. The face and throat were cream-yellow and the ventral surface was a mixture of gray and cream-yellow. The beak and shanks were darkly pigmented but some toes were yellow while others had spotted areas of pigmentation.
When the birds reached to maturity, both males and females had pigmentation, and the feather appearance of dorsal and ventral surface were basically similar. The dorsal feather pattern was similar to that of wild-type except that the wheat-straw shafting was absent. Some of the BPC quails showed small areas of white feather at the junction of the upper and lower beaks and in the throat under the lower beak.
To clarify the mode of inheritance of the BPC characters, mating experiments were performed. The segregation data for F₁, F₂ and backcross generations were analyzed. Genetic analysis showed that the BPC was controlled by an autosomal recessive gene. Therefore, a gene symbol “rb” was proposed.

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This study was conducted by reverse transcription-polymerase chain reaction (RT-PCR) analysis to determine when the protamine mRNA is expressed in testicular germ cells during spermatogenesis in quail. Ejaculated sperm were obtained from the female cloacal gland after mating. Adult male quail were used for collection of the testicular spermatogenic cells. Twenty cells of ejaculated sperm and those of each mechanically dispersed testicular cells including pachytene spermatocytes, round spermatids and elongated spermatids, were picked up using micropipette under phase-contrast microscope. Total RNA was extracted, reverse-transcribed, and amplified by using either quail protamine or chicken S17 ribosomal protein specific primers. The PCR products were run on TAE gel electrophoresis. There was no protamine mRNA expression in spermatocytes, but the expression was detected in round spermatids and elongated spermatids, as well as in ejaculated sperm. These results suggest that protamine mRNA is expressed at haploid stage of quail spermatogenic cells.

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The effect of L-carnitine supplemented into a commercial diet on egg weight, albumen height, Haugh unit, yolk weight and albumen weight of eggs from laying hens was examined. The levels of dietary L-carnitine supplementation were 0, 25, 50 and 200mg/kg. Laying hens were given the diets for 8 weeks. Albumen height and Haugh unit were the highest in the 25mg/kg L-carnitine group. When L-carnitine was added at the levels of more than 50mg/kg, yolk weight was significantly increased. In conclusion, dietary L-carnitine supplementation had a beneficial effect on albumen quality and could modify the components of the edible part of the egg.

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