Hatching egg polyunsaturated fatty acids and the broiler chick

Transgenerational effects of certain nutrients such as essential fatty acids are gaining increased attention in the field of human medicine and animal sciences as a new tool to improve health and animal performance during perinatal life.Omega-3(n-3)and omega-6(n-6)fatty acids are denoted by the position of the first double bond from methyl end of the hydrocarbon chain.Alpha-linolenic acid(18:3 n-3)and linoleic acid(18:2 n-6)are essential n-3 and n-6 fatty acids and cannot be synthesized by the vertebrates including chickens.Alpha-linolenic acid and linoleic acid are the parent fatty acids of long chain(>20–22C)n-3 and n-6 polyunsaturated fatty acids(PUFA)such as eicosapentaenoic acid(20:5 n-3,EPA),docosapentaenoic acid(22:5 n-3/or 22:5 n-6,DPA),docosahexaenoic acid(22:6 n-3,DHA)and arachidonic acid(20:4 n-6).As components of cell membrane phospholipids,PUFA serves as precursors of eicosa-noids,act as ligands for membrane receptors and transcription factors that regulate gene expression and are pivotal for normal chick growth and development.Considering the role of egg lipids as the sole source of essential fatty acids to the hatchling,dietary deficiencies or inadequate in ovo supply may have repercussions in tissue PUFA incorpora-tion,lipid metabolism,chick growth and development during pre and early post-hatch period.This review focus on studies showing how maternal dietary n-3 or n-6 fatty acids can lead to remodeling of long chain n-3 and n-6 PUFA in the hatching egg and progeny chick tissue phospholipid molecular species and its impact on chick growth and PUFA metabolism during early life.

Comparison of Chick Quality, Health, and Inflammation from Two Hatchery Environments

Hatchery contamination can result in ingested or inhaled microbes that may modify colonization of the intestinal and respiratory tract, with potential to influence early growth, inflammation, and overall health. Six experiments were completed to compare chick quality, inflammation, and health between two hatcheries (H1 and H2). On embryonic d0, 45 eggs from the same breeder flock were set at each hatchery. On d0, length, abdominal height, navel and leg abnormalities, and self-righting were measured for 36 chicks/hatchery, yolk sacs were weighed, and crop/cloaca swabs were cultured from 12 chicks/hatchery. On d7, mid-ileum and ceca were cultured from 12 chicks/hatchery. On d0 and d7, body weight (BW) and intestinal weight were measured, lung/air sac swabs and liver were cultured, and liver and air sacs were scored for health. Blood was collected on d0 and d7 for serum alpha-1-acid glycoprotein concentrations in Exp 1 and 2. Data was analyzed using Student’s t-test or χ2, significance p < 0.05. On d0, BW, length, yolk free BW, and intestinal weight were greater for H2 chicks (p < 0.05). Liver bacterial recovery was decreased in H2 on d0 (p < 0.05) and there were fewer average leg and righting abnormalities in H2 (p < 0.05). Decreased lactase positive Enterobacteriaceae were noted in H2 in crop/cloaca and lung/air sac swabs (p < 0.05), and of alpha and beta hemolysis in crop/cloaca swabs, and alpha and gamma hemolysis in lung/air sac swabs (p < 0.05) on d0. By d7, only alpha hemolytic bacteria were increased in lung/air sac swabs of H2. Based on factors measured, chicks from H2 showed favorable microbial colonization, starting quality, and improved health on d0. While not sustained through d7, differences in d0 microbial recovery may have shifted microbial development and potentially influenced immune response development. These experiments elucidated the importance of hatchery environment on early chick quality, microbial colonization, overall inflammation, and chick health.

Effects of Combined Application of NRTUAs and ABP on Growth and Humoral Immunity of Chicks

[Objectives]The paper was to study the effects of combined application of nonreplicating Toxoplasma uracil auxotrophs(NRTUAs)and Agaricus blazei Murill polysaccharide(ABP)on growth and humoral immunity of chicks.[Methods]A total of 120 one-day old female Hyline brown laying hens were randomly divided into 4 groups,30 hens for each group.The chicks in group 1 were subcutaneously injected with NRTUAs and fed on the diet containing with ABP;the chicks in group 2 were subcutaneously injected with NRTUAs;the chicks in group 3 were subcutaneously injected with equal volume of PBS,and fed on the diet containing with ABP;the chicks in group 4 were subcutaneously injected with equal volume of PBS.The body weight of chicks in each group was counted at the 21^(st),42^(nd),84^(th)and 112^(th)week.During this period,blood samples were collected from chicks in each group at 0,7,14,21,28 and 35 d post immunization against Newcastle disease(ND),and serum was separated to detect the antibody titer of ND.[Results]The combined application of NRTUAs and ABP had no effect on growth of chicks,but promoted the humoral immune response of chicks,significantly improved the ND antibody level of chicks,and could maintain high levels of antibodies in the body for a long time.[Conclusions]The study lays a theoretical foundation for further developing the clinical application of NRTUAs and ABP.

“Chick Flicks”影视热的原因探析

近年来,"Chick Lit"作为女性流行读物的代名词,在国外甚为风行并逐渐渗透和影响到国内文学界。该类题材的文学作品不断地被搬上银幕,在影视圈受到广泛的关注,掀起了"Chick Flicks"影视热。"Chick Lit"作品的热销与"Chick Flicks"作品热播的良性互动、原生态职场现状的呈现与现实生存状态的吻合、时尚的影像化与当前流行趋势的吻合,以及女性主义与传统价值的冲突与当前时代风格的吻合是其影视热的根本原因。

Research on the appropriate way to transfer exogenous substances into chicken embryos

In biological research, chicken embryos are a classic experimental model for the exploration of the embryonic development and cell differentiation. Transferring exogenous substances into chicken embryos for producing medical antibodies has been widely used in the production practice. However, there are few studies about the effect of the different injection site and dosage on chicken embryos. The aim of this study was to explore the effects of different injection sites and dosages on chicken embryo hatching rate and development, so as to provide a basis for further studies using the chicken embryo model. Freshly laid eggs （Rugao yellow chicken） were injected with different doses of saline at the tip, equatorial plane and the blunt end of the egg shell, respectively. Egg hatching rate was recorded and compared among injection sites and different doses. A trypan blue stain was also injected at the aforementioned sites and the growth of chicken embryos was observed. The SPSS （statistical package for the social science） software was used to analyze the relationship between the chicken eggs hatching rate and the different injection sites or the different dosages. The experimental results showed that there were significant differences on egg hatching rates among the different injection sites and doses （P〈0.05）. The hatchability of the blunt end injection group was significantly higher than that of the other two sites. The egg hatching rate decreased with increased saline doses. The egg hatching rate of the 100 pL saline injection group was higher than the 200 and 300 μL dosage groups. Ultimately, we suggest that the optimal chicken embryo injection process is during early development, at the blunt end site with a dose less than 100 μL to minimize damage to the egg.

Dynamic alterations in early intestinal development,microbiota and metabolome induced by in ovo feeding of L-arginine in a layer chick model

Background:Prenatal nutrition is crucial for embryonic development and neonatal growth,and has the potential to be a main determinant of life-long health.In the present study,we used a layer chick model to investigate the effects of in ovo feeding(IOF)of L-arginine(Arg)on growth,intestinal development,intestinal microbiota and metabolism.The treatments included the non-injected control,saline-injected control,and saline containing 2,6,or 10 mg Arg groups.Results:IOF Arg increased early intestinal index and villus height,and enhanced uptake of residual yolk lipid,contributing to subsequent improvement in the early growth performance of chicks.Prenatal Arg supplementation also increased the early microbialα-diversity,the relative abundance of Lactobacillales and Clostridiales,and decreased the relative abundance of Proteobacteria of cecum in chicks.Furthermore,the shift of cecal microbiota composition and the colonization of potential probiotics were accelerated by IOF of Arg.Simultaneously,metabolomics showed that metabolisms of galactose,taurine-conjugated bile acids and lipids were modulated to direct more energy and nutrients towards rapid growth of intestine at the beginning of post-hatch when embryos received IOF of Arg.Conclusions:Prenatal Arg supplementation showed beneficial effects on the early intestinal development,cecal microbiota and host metabolism of layer chicks,contributing to subsequent improvement in the early growth performance.These findings provide new insight into the role of IOF of Arg in the establishment of the gut microbiota of newly-hatched layer chicks,and can expand our fundamental knowledge about prenatal nutrition,early bacterial colonization and intestinal development in neonate.

Influence of different levels of humic acid and esterified glucomannan on growth performance and intestinal morphology of broiler chickens

A study was under taken to investigate the effect of dietary supplementations of humic acid and esterified glucomannan) on broiler performance and the morphological measurements of small intestine. Two hundred and ten day old broiler chicks were weighed and randomly assigned to seven treatment groups in triplicate. The dietary treatments included T1) control (basal diet without any additives), T2) basal diets supplemented with 0.1% humic acid, T3) basal diets supplemented with 0.2% humic acid, T4) basal diets supplemented with 0.3% humic acid, T5) basal diets supplemented with 0.1% esterified glucomannan, T6) basal diets supplemented with 0.2% esterified glucomannan and T7) basal diets supplemented with 0.3% esterified glucomannan. Different parameters including body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR) and morphology of small intestine were evaluated during six weeks of experimental period. According to the results, at the end of experimental period, the highest average BWG were recorded in T4 group (fed with 0.3% humic acid), compared to control (T1) and other experimental groups (p < 0.05). Where as, the highest body weight gain were observed during starter period in treatment 7 (fed with 0.3% esterified glucomannan) as compare to other experimental groups (p < 0.05). Statistically, feed intake remained unaffected during the experimental period in all the treatment groups. However, the lowest and the highest feed intake were observed numerically within treatments T4 and T1 with 4229.70 g and 4362.30 g, respectively. Addition of dietary supplements used in the study appeared to have significant effect on the morphology of the small intestine (jejunum mucosal development) of the broilers in different treatment groups. Compared to control group, the inclusion of either humic acid or esterified glucomannon decreased (p < 0.01) the crypt depth and increased villus height respectively (p < 0.05). More ever, the diet supplements with humic acid 0.3% (T4) decreased crypt depth compared to esterified glucomannan and control. The dietary supplementations resulted in an increase in the villus height of intestinal mucosa of broilers. The increase in the villus height was associated with improvement of growth performance for both humic acid and esterified glucomannan. Based on our results it appeared that humic acid and esterified glucomannan can be used as a growth promoter in broiler diets and they can improve the gut health too.

Introduction of DT40 cells into chick embryos

Aim: To examine the transfection of exogenous genes into chick embryos, applying the characteristics of avianleukosis vires (ALV)-induced chicken B cell line DT40 to the production of chimeric birds. Methods: The DT40cells incorporated with exogenous gene (lacZ constructs encoding Escherichia coli β-galactosidase: β-gal) were intro-duced into chick embryos by the injection of cells into stage X blastoderm. Manipulated eggs were incubated for 3 (trial1) or 6 (trial 2) days, and the expression of lacZ DNA was detected by a histochemical staining method of β-galactosi-dase and polymerase chain reaction (PCR) analysis. Results: The survival rates of the manipulated embryos incu-bated for 3 days (stage 18-20: trial 1) and 6 days (stage 28, 30: trial 2) were about 42% and 38%, respectively.The expression rates of the lacZ gene in the embryos in the trials 1 and 2 were about 60% and 23%, respectively, forthe survived embryos. Conclusion: The rate of embryonic viability and expression rate of introduced genes were notso high, but it suggested the possibility of utilizing the DT40 cells as a vector for carrying exogenous genes into chickembryos. (Asian J Androl 2001; 3: 49-53)

Proliferation of exogenously injected primordial germ cells (PGCs) into busulfan-treated chicken embryos

Aim: This study was designed to investigate the effect of busulfan treatment on the proliferation of chicken primordialgerm cells (PGCs) in vivo, focusing on the preferential settlement of PGCs onto the germinal ridges of chicken em-bryos. Methods: Busulfan (250 ng/egg) was injected into the egg white of freshly oviposited fertilized eggs, whichwere then incubated. Embryonic development and viability were examined, and exogenous PGCs collected from embry-onic blood vessels were injected into the germinal crescent region of recipient embryos. The number of PGCs residedonto germinal ridges of the right and left sides were compared. Results: Busulfan had a slight harmful effect on theembryo viability and the PGCs proliferation. The number of PGCs resided onto the left side of germinal ridges wasslightly higher as compared with the right side. Conclusion: Busulfan suppressed the viability of embryos and the pro-liferation of endogenous PGCs in the recipient embryos. However, the number of exogenous PGCs proliferated washigher in embryos treated with busulfan than those without busulfan. Data also suggest the possibility of a preferentialresidence of PGCs toward the left side of the germinal crescent region as compared with the fight, which may be due toa more advanced functional development of the left gonad than the right. (Asian J Androl 1999 Dec; 1: 187-190)

Effect of Nano Red Elemental Selenium on GPx Activity of Broiler Chick Kidney Cells in vitro

A new selenium source, Nano red elemental selenium (Nano-Se) was used to study the effect on the GPx activity of broiler chick kidney cells (BCKC) in vitro, Sodium selenite (Na_ 2 SeO_ 3 ) and seleno-1-methionine (Se-Met) were used as the controls. The results showed that the effects of three kinds of Se forms on the GPx activity of BCKC were accordant(p>0.05) compared with each other at 0.01,0.05 and 0.10 μmol/L Se concentrations treatments. In the range of 0.00-0.10 μmol/L Se concentrations, the GPx activity increased with elevation of Se concentrations in medium. For the three kinds of Se forms, the GPx activity reached the climax at 0.10 μmol/L Se concentration. At 0.20 and 0.30 μmol/L Se concentrations, the influnces of three kinds of Se forms were not accordant with one another. For Nano-Se, the GPx activity at 0.20 and 0.30 μmol/L Se concentrations remained the same as that at 0.10 μmol/L Se concentration treatment. For Se-Met, the GPx activity at 0.20 μmol/L Se concentration treatment remained the same with 0.10 μmol/L treatment; the GPx activity at 0.30 μmol/L Se concentration treatment was declined significantly(p<0.05) compared with 0.10 or 0.20 μmol/L treatment. For Na_ 2 SeO_ 3 , the GPx activity falled gradually with Se concentration increasing from 0.10 μmol/L to 0.30 μmol/L, and at 0.30 μmol/L Se concentration treatment, the GPx activity was less than the original of BCKC. The results implicated, on the GPx activity of BCKC in vitro, the ranking of width range of the most suitable Se concentration for nutrition curve of the three Se formes is Nano-Se>Se-Met>Na_ 2 SeO_ 3 .

Effects of “Bioactive” amino acids leucine, glutamate, arginine and tryptophan on feed intake and mRNA expression of relative neuropeptides in broiler chicks

Feed intake control is vital to ensuring optimal nutrition and achieving full potential for growth and development in poultry. The aim of the present study was to investigate the effects of L-leucine, L-glutamate, L-tryptophan and L-arginine on feed intake and the mRNA expression levels of hypothalamic Neuropeptide involved in feed intake regulation in broiler chicks. Leucine, glutamate, tryptophan or arginine was intra-cerebroventricularly （ICV） administrated to 4d-old broiler chicks respectively and the feed intake were recorded at various time points. Quantitative PCR was performed to determine the hypothalamic mRNA expression levels of Neuropeptide Y （NPY）, agouti related protein （AgRP）, pro-opiomelanocortin （POMC）, melanocortin receptor 4 （MC4R） and corticotrophin releasing factor （CRF）. Our results showed that ICV administration of L-leucine （0.15 or 1.5 μmol） significantly （P〈0.05） increased feed intake up to 2 h post-administration period and elevated both hypothalamic NPY and AgRP mRNA expression levels. In contrast, ICV administration of L-glutamate （1.6 μmol） significantly （P 〈 0.05） decreased feed intake 0.25, 0.5 and 2 h post-injection, and increased hypothalamic CRF and MC4R mRNA expression levels. Meanwhile, both L-tryptophan （10 or 100 μg） and L-arginine （20 or 200 μg） had no significant effect on feed intake. These findings suggested that L-leucine and L-glutamate could act within the hypothalamus to influence food intake, and that both orexigenic and anorexigenic Neuropeptide genes might contribute directly to these effects.

Energy and Protein Requirements for 0-to 4-Week-Age Gushi Chicks

In this experiment, 540 male and female chicks of 1-day-age were selected respectively and reared separately. 3×3 factorial experiment was designed. Gushi chicks were fed with nine diets under different metabolizable energy (ME) and crude protein (CP). Effects of different diets on the performances and carcass ingredients of 0-to 4-week-age Gushi chicks were studied by rearing, comparative slaughter and metabolism experiments. Based on the results of three experiments, ME intake per kilogram metabolic weight was regarded as dependent variable (Y) ,and its corresponding net energy (NE) deposition per kilogram metabolic weight was regarded as independent variable (X) , respectively. Lineal regressive analysis was made according to the mathematic model: Y=a+bX. Maintenance ME( MEm) and the converted coefficient from net energy for gain( NEg) to ME for gain( MEg) were found out, then ME requirement was divided into MEm+ MEg, which is ME=359.14 W0.75+ 10.47△W; CP intake and corresponding metabolic weight were regarded as dependent variable and independent variable respectively, and then regressive analysis was made. The result was CP=0. 57 + 8. 21 W0.7S. Consequently, average daily gain (ADG), average daily feed intake and metabolic weight were put into the regressive equations, and then ME and CP requirements for 0- to 4-week-age Gushi chicks were obtained, 12.38 MJ kg-1 and 20.13%, respectively, the ratio of CP to ME was 16. 26 g MJ-1.

Effects of 17beta-estradiol on cell migration in male chicks distribution of primordial germ

Aim： To assess whether exogenous estradiol has any effect on migration of primordial germ cells （PGCs） in the chick. Methods： Fertilized eggs were treated with 17beta-estradiol （E2） （80 lag/egg） at stage X （day 0 of incubation）, stages 8-10 （incubation 30 h） and 13-15 （incubation 55 h）. Controls received vehicle （emulsion） only. Changes in PGC number were measured on different days according to developmental stages. Results： In male right gonads, but not in female left gonads, at stages 28-30 （incubation 132 h） significant decreases in the mean number of PGCs aggregating were observed compared with the controls （P 〈 0.05） while the total PGC number in the right and left gonads at each stage did not change （P 〉 0.05）. Conclusion： The present study provides evidence that E2 has significant effects on the localization of PGCs in male right, but not female left, gonads of chicken embryos at stages 28-30, compared with controls. （Asian J Andro12008 Mar; 10： 243-248）

Manganese enhances the expression of the manganese superoxide dismutase in cultured primary chick embryonic myocardial cells

In the present study, the effect of manganese（Mn） on antioxidant status and the expression of the manganese superoxide dismutase（MnSOD） gene in cultured primary myocardial cells collected from the chick embryos was investigated. The hypothesis that Mn supplementation would enhance the expression of MnSOD in cultured primary myocardial cells of chick embryos was tested. Eggs collected from Mn-depleted Arbor Acres laying breeder hens were incubated for 10 days and then myocardial cells were isolated and cultivated for 8 days. The embryonic myocardial cells on day 6 were treated with Mn in the cell culture medium at different time points when the proportion of cells showing spontaneous contraction was over 95% after the 3-day primary culture. A completely randomized design involving a 3 Mn levels（0, 0.5 and 1.0 mmol L^（-1））×3 incubation time points（12, 24 and 48 h） factorial arrangement of treatments（n=6） was used in the current experiment. The results showed that MnSOD activity and m RNA expression level were induced by Mn and increased with incubation time, which supported the hypothesis that Mn would enhance the expression of the MnSOD gene, and thus might protect myocardial cells from oxidative stress during the chick embryonic development.

Effects of Pleurotus eryngii Residue on Weight Gain of Chick and Duck

In the present study, Pleurotus eryngii residue was added into conventional feed of Chai chicks and meat-type ducks at different ratios to measure its effects on the production performance of chicks and ducks. The results revealed that the growth performance of chicks and ducks was the best when 20% Pleurotus eryngii residue was added into the feed. Under such condition, the daily weight gain of 8 - 11 and 12 - 15-week-old Chai chicks was increased by 6.8% and 13.5%, and that of 8 - 11 and 12 - 15-week-old ducks was increased by 11.5% and 19.3%, respectively.

Performance of chick pea under the influence of gibberellic acid and oxygenated peptone during germination

The experiments were carried out at the Post Graduate Research Center, to study the influence of Gibberellic Acid (50 ppm) and Oxygenated Peptone (1% aqueous solution) on chick pea (Cicer arietinum L. cv. Vijay) during germination by giving pre-sowing soaking treatment for 6 hours using petriplate method. Both the treatments enhanced the germination process. GA treatment was useful to increase shoot length, mobilization efficiency, emergence index, speed of germination and co-efficient of germination while oxygenated peptone showed an upper hand in root length, shoot/root ratio, biomass and vigour index. GA led to comparatively more synthesis of nucleic acids while oxygenated peptone showed more increase in total carbohydrates and soluble protein content. However, the activity of enzymes like amylase, catalase and protease showed upper hand with oxygenated peptone as compared to GA. In fact GA is costlier and can not be used in organic farming as it enters metabolic pathways of plant and alters them. Hence the use of oxygenated peptone is recommended being less expensive and usable under organic farming condition as it does not enter the plant metabolic pathways and yet brings about significant positive effect.

The Influence of Feed Intake and Conditioned Reflex on Exocrine Pancreatic Function in Broiler Chicks

The data of an experimental study of the influence of feeding and the conditional stimulus on digestive function in birds is presented. It is stated that feed consumption is a powerful stimulator of pancreatic secretion in broiler chicks. The secretory response of the pancreas was the highest in the morning when secretion of pancreatic juice was 1.8 times higher, amylase activity 3.2 times, proteases activity 3.3 times, lipase activity 2.1 times higher than before feeding (basal levels). The regulation of pancreatic activity is known to be complex-reflex with conditioned-reflex component being very important since it provides 25% higher juice secretion and 42% - 74% higher enzyme secretion compared to the basal levels during few minutes after the conditional signal.

Anti-leukemic and anti-angiogenic effects of D-Limonene on K562-implanted C57BL/6 mice and the chick chorioallantoic membrane model

Background: D-Limonene, a monoterpene from citrus fruit has been found to have chemopreventive and chemotherapeutic activities in various types of cancers. In this study, we evaluated the in vivo effect of D-Limonene on a K562-induced model of chronic myeloid leukemia(CML) in C57 BL/6 mice.Method: The tail vein injection model of K562 cells in immunocompromised C57 BL/6 mice was developed and evaluated for characteristics of the disease. The mice were treated with D-Limonene and evaluated for haematological parameters. We also evaluated the effect of D-Limonene on angiogenesis using the chick chorioallantoic membrane(CAM) assay.Results: In a complete blood count, a significant dose-dependent reduction in white blood cell, neutrophil and lymphocyte counts, but an elevation in red blood cell count and haemoglobin content was observed with D-Limonene treatment compared to the disease control or untreated group. In the CAM assay, D-Limonene produced a significant dose-dependent reduction in number of blood vessels in treatment groups compared to the vehicle-treated group.Conclusion: These studies suggest promising anti-leukemic and anti-angiogenic effects of D-Limonene in the treatment of CML.

A multiplatform metabolomic approach to characterize fecal signatures of negative postnatal events in chicks: a pilot study

Background: Negative experiences in early life can induce long-lasting effects on the welfare, health, and performance of farm animals. A delayed placement of chicks in rearing houses has negative effects on their performance, and results in fecal-specific odors detectable by rats. Based on this observation, the volatile organic compounds(VOCs) and metabolites from the feces of 12-day-old chickens were screened for early markers of response to negative events using gas-chromatography and liquid-chromatography coupled with mass spectrometry(GC-MS, LC-HRMS).Results: The low reproducibility of solid-phase micro-extraction of the VOCs followed by GC-MS was not suitable for marker discovery, in contrast to liquid extraction of metabolites from freeze-dried feces followed by GC-MS or LC-HRMS analysis. Therefore, the fecal metabolome from 12-day-old chicks having experienced a normal or delayed placement were recorded by GC-MS and LC-HRMS in two genotypes from two experiments. From both experiments, 25 and 35 metabolites, respectively explaining 81% and 45% of the difference between delayed and control chickens, were identified by orthogonal partial least-squares discriminant analysis from LC-HRMS and GC-MS profiling.Conclusion: The sets of molecules identified will be useful to better understand the chicks’ response to negative events over time and will contribute to define stress or welfare biomarkers.

INVASION OF SPHEROID OF MURINE LUNG ADENOCARCINOMA (LA_(795)) CELLS INTO EMBRYONIC CHICK HEART FRAGMENTS

An in vitro spheriod invasion model of tumor cell was established by using murine lung adenocarcinoma cell line (LA795) and precultured embryonic chick heart fragment (PHF). The spheroid of LA795 cells were prepared by incubating a suspension of trypsinized LA795 cells on a gyratory shaker. Spheroid aggregates of LA795 cells in diameter of 0. 2 mm were selected and confronted with PHF (diameter of 0. 4 mm) on semi- solid medium for 3 - 4 hours, then, individual confronting pain were transferred into fluid medium for further co-culture on gyratory shaker. After 1, 3, 5 and 7 days, multiple confronting pairs were processed for histological and ultrastructural study. The Invasive capacity and the invasion process of LA795 cells were examined and observed. The results demonstrated that LA795 cell line has a high capacity of invasion and high malignancy in vitro. This spheroid Invasion model is very useful for studying mechanism of Invasiveness of tumor cells in vitro.