There have been growing interests in olive oil, which is attributed to the beneficial health effects of the Mediterranean diet. Numerous studies suggest that oleic acid, the major fatty acid in olive oil, may contribute to less incidence of coronary heart disease(CHD) in the Mediterranean area. Although the major effects of high monounsaturated fatty acid(MUFA) consumption on lowered plasma cholesterol are generally attributed to the consequential replacement of saturated fatty acid in diets, some studies have shown a modest cholesterol lowering effect of MUFA alone when it replaces dietary carbohydrate at an equal amount of energy. Furthermore, MUFA increases the level of the protective high-density lipoprotein cholesterol more than polyunsaturated fatty acid(PUFA) does when these two classes of fatty acids replace carbohydrates in the diet. It has been generally recommended that optimal dietary fat should be rich in MUFA, such as oleic acid, low in saturated fatty acids and provide adequate amounts of PUFA. However, no conclusive observations have been made yet mainly due to a difficulty in controlling the proportion of oleic acid without adjusting the levels of the other fatty acids to be constant, which could also affect plasma cholesterol levels. Recent findings also suggest that dietary PUFA results in higher tendency toward lipid peroxidation whereas with MUFA the susceptibility of low density lipoprotein to oxidative stress is reduced. More studies are needed to clarify the effects of MUFA on reducing the incidence of CHD.

Five experiments were conducted to investigate the effects of antioxidants(Santoquin and Oxiban) using fresh or oxidized fat on the performance of broiler chicks. Day-old broiler chicks (except for Experiment 5 in which 6-d-ol birds were given experimental diets for 10 d) were fed diets containing fresh or oxidized fat (animal-vegetable fat blend in Experiments 1, 4, and 5 and corn oil in Experiments 2 and 3) with or without graded concentrations of Santoquin (0,250, 500 ppm in Experiments 1 and 2 and 0, in Experiment 4 and 400 ppm with 0.1% lipase in Experiment 5) of 2wk. In all experiments, birds fed fresh fat gained more weight, had better feed/gain, together with higher AME$_{n}$ and apparent fat digestibility (Experiments 1 and 2) than birds fed oxidized fat(P<0.05). There was no interaction among fat sources and antioxidants on the performance of chicks in any experiment. In Experiment 3, Santoquin more than 200 ppm resulted in a reduction in weight gain and feed intake(P<0.05). The livers of chicks fed oxidized fat in Experiments 2 and 5 had higher malondialdehyde (MDA) values (P<0.05) Chicks fed oxidized fat with 250 ppm Santoquin in Experiment 2 had lower liver MDA values, although this situation did not occur in Experiments 1, 4, and 5. These results indicate that antioxidant supplements can alleviate most deleterious effects of feeding oxidized fat and that supplementation of Santoquin more than 200 ppm has a negative effect on the performance of broiler chicks.s.

Two experiments were conducted to investigate the effects of feeding single or combined probiotics on performance and intestinal microflora of broiler chicks for five weeks. Diets based on corn and soybean meal contained 21.50, 19.0% CP and 3,100, 3,150 kcal/kg ME for starting and finishing period, respectively. Lactobacillus salvarius isolated from chicks intestine(LSC), Lactobacillus salvarius isolated from piglet(LSP) Bacillus polyfermenticus(BP) were fed with alone and mixed ones at the level of 0.21 and 0.1% in experiment 1 and 2. Three hundred eighty four chicks were randomly assigned to eight treatment with four replicates of 12 chicks each per treatment. Weight gain, feed consumption, feed conversion ratio(FCR) were weekly measured for 5 weeks. The number of intestinal microflora was examined at the end of experiment. There were no significant different weight gain of all treatment in both experiments. Feed consumption were not shown consistency. Chicks fed LSC alone showed the lowest feed conversion ratio of all treatment in experiment 1, but was not consistency in experiment 2. The number of Lactobacillus spp. tended to increase in chicks ileum fed probiotics treatments, whereas it was not consistency in cecum. The number of ileal E. coli was not decreased in BP treatment.

To investigate the influence of feeding Enviro on noxious gas of environmental controlled poultry house and performance of broiler chicks. Diets contained 21.5, 19.00 CP and 3,100, 3,200 kcal/kg ME, respectively for starting and finishing period. Enviro were supplemented with 0, 0.2, 0.4, 0.6 and 0, 0.1, 0.2, 0.3% in Expt 1and 2, respectively. CO$_2$and ammonia gas were periodically detected for finishing period in Expt 1. Weight gain, feed intake and feed conversion(FC) were measured for five weeks in Expt. 2. ND antibody titer were also measured after primary and booster vaccination at two and four weeks old. In Expt 1, chicks fed 0.2% Enviro showed 32.8ppm and 1719 ppm of ammonia gas, CO$_2$in poultry house and significantly decrease compared to that of control(P<0.05). Weight gain of chicks fed 0.1 and 0.2% Enviro was significantly increased for starting period(P<0.05) but was not statistically different for finishing period. Feed intake was no significantly different of all treatments. Chicks showed lower FC in 0.3% Enviro treatment for starting period(P<0.05) than others, but was not for finishing period. ND AB titet of chicks fed Enviro was prone to be higher than control, but was not significantly different. The results of these experiments indicated that 0.1% Enviro supplement would be maximize the performance of broiler chicks.

The Effects of Dietary Supplemental Charcoal Extract (CE) were examined on performance of 19-week-old ISA Brown hens for 12weeks. Four hundred and fifty were randolmy assigned to 0, 0.025, 0.05, 0.075, 0.1% dietary CE, respectively with five replicates of 18 hens per pen. Basal diets contained 17.5% CP and 2,800 ME. Egg production egg weight, feed conversion(FC), and egg qualities were measured in every four weeks. Egg production and FC was slightly improved in 0.05% supplemental CE group compared to that of other treatments, but was not signhificant different. Average egg weight was significantly higher in 0.025% and 0.1% than other treatments(P<0.05). Total egg mass tended to be higher in 0.05% supplementation. Daily feed intake increased in 0.1% supplementation than the others, but was not statistically different. Eggshell breaking strength and Haugh unit were tended to be higher in 0.05% supplementation. There were no significant difference in eggshell thickness and yolk color of all treatments.

Retaining migratory activity is a prerequisite for the manipulation and use of PGCs. This study was conducted to examine whether migratory activity is retained in the primordial germ cells(PGCs) from gonads at the later embryonic developmental stage. In the present study, gonads were dissected from 5-, 6- and 10-day-old quail embryos and treated with trypsin-EDTA for the degradation of gonadal tissue. Gonadal PGCs (gPGCs) were purified by Ficoll density gradient centrifugation and labeled with PKH26 fluorescent dye. The PKH26-labeled gPGCs were microinjected into the blood vessels of recipient quail embryo. After further incubation of 3 days, the manipulated recipients were embedded in paraffin and sectioned. The gPGCs were detected by their fluorescence under the fluorescent microscopy and the confocal laser microscopy. As a result, 10-day-old quail gPGCs as well as 5-and 6-day-old gPGCs, could migrate to recipient embryonic gonads and settle down. These results suggest that the 10-day-old gPGCs have the properties of circulating PGCs at early stage. Therefore the PGCs from 10-day old embryonic gonads can be used for the tools of genetic manipulation.

A new murine TGF-$\beta$ family member, myostatin(growth/differentiation factor-8) is expressed specifically in developing and adult skeletal muscle and may be a negative regulator of skeletal muscle development. This study aims at characterization and identification of genomic organization of chicken myostatin gene. In thi study, we identified the genomic organization and sequence of chicken myostatin gene. Results of RT-PCR and Northern blots from various tissues showed different mRNA expression levels in developmental stages of chick embryos and demonstrated strong expression of myostatin mRNA in skeletal muscle. These facts suggest that chicken myostatin gene would play an important role not only in skeletal muscle cell but also in other tissues.

Effects of different photoperiod regimens on the cellular and humoral immunity in broiler chickens were studied(Exp 1). Total one hundred ninety two one-day-old commercial broiler chicks(Cobb$\times$Cobb) were raised between constant lighting(CL) and intermittent lighting (1h light: 3h darkness(IL; 1l; 3D) Body weight, feed intake and feed conversion were measured for seven week. Peripheral blood and splenic lymphocyte activities were tested at 3 and 5 wk of age by performing a mitogen cellproliferation assay with a polyclonal T-cell mitogen, concanavalin A (Con A), and B-cell mitogen, lipopolysaccharide (LPS). To investigate the effect of photoperiod on the humoral immunity, chicks were immunized with sheep red blood cell(SRBC) and iinactivated Newcastle disease virus(NDV) vaccine. Total immunoglobulin G(IgG) concentration was also determined. Diurnal change of melatonin was tested in sera. In experiment 2, 0.1ml melatonin were subcutaneously injected from three to five weeks old if immunomodulation effect of lighting regimen was due to the melatonin or not. Injections of melatonin were made at 0700h and the dosage was 10ng (M2), 100ng(M3), 1$\mu\textrm{g}$(M4) per bird daily, respectively. control were quivalent injections of vehicle(M1). Lymphocyte activities were tested and humoral immunities were examined at 5 weeks of age. Blood melatonin concentration was determined at 0h, 1, h, 2h, and 3h posterior to injection at five weeks old. It was higher in CL chicks than IL chickens during the subsequent period of 3 to 5 wk of age. However, weight gain of chicks raised IL were significantly higher at 6 wk of age than CL(P<0.05). Antibody response to NDV was not affected by both photoperiod regimens and melatonin injection, whereas anti-SRMB titer and IgG concentration were enhanced. Lymphocyte activity of chickens raised under IL was sighificantly higher than those of chickens raised under CL. Melatonin injection also increased lymphocyte activity. When peripheral blood lymphocytes were used, proliferation response to LPS and Con A were significantly increased in M2 and respectively. The results of this experiments suggest that IL improved host immune response and melatonin have immunomodulatory roles.

To obtain the genetic information of Korean native livestock, the karyotyping of Korean native chick were performed by high-resolution banding technique. The chromosomes were prepared from lymphocyte culture and early embryos with 200 Korean native chick which have been raised at National Livestock Research Institute. There were no significant difference between Korean native chick and Leghorn in the number of chromosomes and chromosomal morphological pattern. Using high resolution banding technique, the yield of G-bands of prophase is much greater than that can be obtained by International System for Standardzed Avian Karyotypes(ISSAK, 1999). The G-band landmarks of Korean native chick were similar to those of ISSAK and Leghorn except some macrochromosomes. chromosome Z and 3 had C-band variants with heteromorphic patterns on distal and centromeric site. The proportion of constitutive heterochromatin, the heterochromatin ratio of Korean native chick was significantly more than that of Leghorn in all chromosomes.

Although primordial germ cells(PGCs) have been used in the production of germline chimera, efficiency has not been satisfactory. The Present study was conducted to improve efficiency of germline chimera production using the cultured gonadal PGCs(gPGCs). Germline chimeric chickens were produced by transfer of cultured gonadal primordial germ cells from Korean Ogol Chicken (KOC) to White Leghorn (5.5-day-old) and cultured in vitro for 10 days. Approximately 200 gPGCs (2-day-old) recipient embryos from which blood had been withdrawn via the dorsal aorta prior to the injection. Recipient embryos were incubated until hatching. Germline chimerism of the chickens reaching maturity was examined by mating them with Korean Ogol Chicken. Donor-derived offspring were identified as germline chimeric chickens based on their feather color. The frequency of germline transmission of donor PGCs ranged 1.9∼60.7%. There was no difference between both sexes. Therefore, it can be concluded that efficiency of germline chimerism can be improved via using cultured gPGCs.

Soybean meal(SMB) has not only been an important source of protein, but also a major source of isolfavones(IF) for poultry diet. Since the IF is one of effective phytoestrogens, evaluation of bioavailability of the phytochemicals for poultry and development of an animal model for assessment of the availability should be essential for its practical application. Present study was to develop bird model for assessing their bioavailability. No reports for such measurments with poultry could have every been found. Eight, 6-wk-old, layer-type, male birds were divided into two groups of four birds; normal (N) and colostomized(COL). Each bird was tube-fed a SMB sample at a level of 1% body weight. Samples from blood, urine and feces(COL birds) or urine+feces (N) were collected at 0, 2, 8, 15, 24 and 48 hours after the feeding. Plasma and urine samples were treated with -glucuronidase and fecal samples with 4N HCl for measurement of genistein(GE) and daidzein (DA) with HPLC set with an electrochemical detector. Maximum peaks of plasma IF appeared at 2 h after the meal for both birds groups. However the IF peak for N group was GE, while that for COL group was DA. Plasma DA levels for COL birds were always higher than those of GE, which was in opposite trend for N birds. This trend observed in the N birds is in accordance with those reported in rats fed SBM. In conclusion the results seem to suggest that colostomy as an attempt to separate urine from feces in birds affected the IF metabolism in the intestine and may not be a proper bird model to measure the IF bioavailability.

The experiment was conducted to determine the effects of dietary supplementation of enzyme(Endopower) into corn-soybean meal diet on the performance of broiler chicks. Three hundred sixty 3 day-old male broiler chicks(Ross) were divided into 4 groups with 3 replicates of 30 birds per replicate and assigned at random to each of four treatment groups for two energy levels(3100 and 2980 kcal TMEn/kg) with 0 or 0.1% Endopower in the diet. The body weight gain of birds fed the low energy diet with 0% Endopower was lower significantly than the other groups(P<0.05). There were no significant differences in feed intake and feed conversion rate among the treatments. The relative sizes(% B. wt) of the liver and leg muscle were not different significantly among the treatments. The breast muscle weights of the low energy diet birds were higher than those of the high ones, and those of the lower energy group with 0.1% Endopower were highest. The intesinal lengths(cm/B.wt) of low energy diet group without Endopower were lower than those of the others. No significant differences in the relative jejunum and ileum weights were found, but % duodenum weights of high energy group were higher than those of the low energy group. The villi of the ileum of birds fed corn-soybean diet without Endopower were shortened and thickened compared to those of the birds fed with Endopower diet regardless of energy level. The results demonstrated that dietary Endopower improved body weight gain reduced abdominal fats and developed intestinal villi. Therefore it can be concluded that dietary supplementation of Endopower improves nutritive value of corn-soybean diet in broiler chicks.

Considerable beneficial effects on osteoporosis from soy intake in postmenopausal women are being reported (Murkies et al.1998, Arjmandi et al. 1996). Isoflavones(IF), one of phytoestrogenic substances in the soybean, have been suggested for the effect. Our preliminary study showed that even the young chicks fed IF-rich diet tended to have higher bone ash content than those fed IF-poor diet. IF have been reported to decrease bone ash content than those fed IF-poor diet, IF have been reported to decrease bone loss by reducing bone resorption. Soybean meal has been one of the most important protein sources in poultry diets. We assume that the IF intake through dietary soybean meal could give meaningful influences on the birds. This study was carried out to determine effects of dietary IF from soybean sources on bone development in young chicks. Soy protein concentrate (SPC, IF-poor)and an IF concentrate(Phyto-Nutramin) were formulated together with purified-type ingredients to provide three different levels(25, 240 and 480 mg/kg) of total IF. Control diet(240 mg/kg) was prepared with isolated soyprotein(ISP, IF-rich). The diets were fed to 96, 3-day old, layer-type, male chicks, divided into 4 treatments with 3 replications for 3 weeks. Chicks fed the ISP diet had better gain/feed ratios than fed the SPC diets. Birds fed the diets with higher levels of IF tended to show higher values in serum total and ionized Ca% and tibial bone density, length % ash, stiffness and strain. This trend however, appeared less significant at the end of third week. No noticeable differences in sizes of comb and testicle and serum alkaline phosphatase activities were observed among the dietary groups. These results suggest that dietary isoflavones from soybean sources could be associated with chemical composition and physical properties of bone in sizes of comb and testicle and serum alkaline phosphatase activities were observed among the dietary groups. These results suggest that dietary isoflavones from soybean sources could be associated with chemical composition and physical properties of bone in young chicks.

These studies were conducted to investigate the effect of dietary supplemental lincomycin at different food waste supplements on performance of broiler chicks. Diets were based corn, soybean meal and contained 3,100kcal/kg ME, 21% CP for the rest two weeks. Three levels of dietary lincomycin(LM; 0,2.2, 4.4mg/kg) and food waste(FW; 0, 7.5, 15%) were respectively inclusion in both experiments. In experiment 1, weight gain of birds fed 4.4mg/kg LM was significantly higher than no LM treatments(P<0.05). It tended to increase in 7.5% food waste treatment compared to that of control, but was not significantly different. FCR of chicks fed 2.2mg/kg LM supplement was significantly improved compared to that of other treatments Chicks fed food waste showed inferior FCR to control as dietary FW level increased(P<0.05). There was no significance in blood components among treatments. In experiment 2, weight gain of chicks fed 15% FW exhibited higher weight gain than that of other treatments. As FW supplement increased, the feed intake increased significantly(P<0.05) There was no significance in blood components except serum calcium. The results of these experiments indicated that hicks fed 4.4mg/kg LM supplements maximized growth rate of all treatments, and improved FCR in 2.2mg/kg LM.

A 12-w feeding trial was conducted with 600 38-wk-old layers to evaluate the nutritive value of high oil corn(HOC) in layer diets. For the control, a commercial corn-soybean meal basal diet was used. An iso-calorie diet(HOC-ISO) was prepared replacing corn with HOC in the control diet. In addition a third diet was prepared by simply replacing corn with HOC on 1:1 basis to give a high energy diet(HOC-1:1). There were 5 replicates per treatment, and 40 birds per replicate. Birds were housed in an open-sided layer house equipped with wire cages. Feed and water were provided ad libitum, and 17L:7D lighting program was adopted. No significant difference (P>0.05) was found among dietary treatments in laying performance. Also physical qualities of eggs were not significantly affected by the feeding of HOC. Although not significant, HOC-ISO tended to improve the laying rate during the summer. The HOC feeding significantly increased the polyunsaturated fatty acids contents in egg yolk, especially the linoleic acid The AME contents of Chinese yellow corn, U.S. corn, and HOC were 3177, 3158 and 3387 kcal/kg respectively.