Forward-and reverse- subtractive cDNA libraries between Longissimus Dorsi of Largewhite and F1 of Meishan×Largewhite pigs have been successfully generated by means of suppression subtractive hybridization(SSH), and both of them were subject to the determination of subtraction efficiency that proved to be approximately 2¹⁵-and 2¹⁰-fold indicated by β-actin as an index. PCR analysis of the total of 700 and 623 positive clones obtained from the corresponding plasmid libraries demonstrated that the cDNA inserts range in size largely from 150 to 600bp. It is safe to say that the construction of forward- and reverse- subtractive cDNA libraries between muscle tissue of parents and progenies lays groundwork for isolating and identifying genes with respect to heterosis.

OBR (obese receptor) gene plays an important role in leptin functioning signal transduction. The polymorphism of the OBR-exon 20 was detected, and a novel SNP was found by the technique of single strand conformation polymorphism (SSCP) and finally confirmed by sequencing. The frequencies of different genotypes in cross combinations of local chickens were calculated and the relationship between three genotypes and fattiness traits of these chickens were analyzed based on liner model. The results showed that the novel SNP was at 860th locus (T/C) in OBR-exon 20, genotype frequencies of AA, AB, BB were 0.641, 0.292 and 0.067, respectively, in trial group. The effect of various genotypes on abdominal fat percentage, subcutaneous fat thickness, intramuscular fat width and intramuscular fat percentage were not significant (P＞0.05). It could be a reference for future research on polymorphism of OBR and supply more information for gene mapping.

The ten STR loci as a system of genetic markers were used to analyze genetic diversity and parentage relationship in Northeast fine-wool sheep group. On average, the number of alleles per locus is 8.2, heterozygosity is 0.794, polymorphism information content (PIC) is 0.768. Northeast fine-wool sheep has abundant genetic diversity. To exclusion probability and Paternity identify, in mother-son-father set, ten markers will exclude the alleged parent with a probability of >0.999 9, and RCP is 99.999%; In the sets without mother sample, these markers will exclude the alleged parent with a probability of >0.996 2, and RCP is 99.993%. On the basis of STR loci selected in this study, it can set up a method for estimating genetic diversity and identifying parentage relationships of Northeast fine-wool sheep, and give a scientific direction to protect the resource of Northeast fine-wool sheep and select economical traits. In addition, it can also provide a method for troubleshooting Northeast fine-wool adscription.

Based the allele frequencies of 19 microsatellite loci,the accuracy of Nei’s standard genetic distance among 4 Chinese native goats were analysed at 3,6,9,12 and 15 microsatellite locus levels.The results indicated that :with the numbers of the loci increased,the accuracy of genetic distance estimation increased too.The result of “t” test was that there was remarkable difference between every two levels except 6 and 3.When the experiment was designed to analyse genetic relationship between different breed ,small number should not be used.

Expression of phosphodiesterase (PDE) isoenzymes was detected in the skeletal muscle tissue in China experimental minature pig in order to seek predominant phosphodiesterase isoenzymes, which is related to development of muscle tissue, and to screen out the selective PDE inhibitors from Chinese herbal medicines, which can improve animal growth and productivity. In this experiment, total RNA was isolated from muscle tissue, the expression of PDE isoenzymes gene was then analyzed by reverse transcript polymerase chain reaction (RT-PCR). 16 PDE isoenzymes mRNA were detected in muscle tissues of China experimental minature pig, i.e. PDE1A, 1C, 2A, 3A, 3B, 4A, 4B, 4C, 4D, 5A, 7A, 7B, 8A, 8B, 9A and 11A except PDE1B and 10A. Among them expression of PDE1A，1C，2A，3A，4B，4C，8A and 8B mRNA have not been reported in the muscle tissue of human and other animals. The different expression extent of the 16 PDE genes were discovered from the electrophoresis bands and need to be elucidated by quantitative detection.

ICR mouse blastocysts and morulas were cultured in rat heart conditioned medium (RH-CM).As far as the following indexes attaching ratio，ICM growth ratio and ES clone formation ratio are concerned，the choice of blastocysts is much better than morulas (P＜0.05)，therefore mouse blastocysts were more suitable than morulas to get ES cells. Interval between two passages (38 h) of expriment groups was significant higher than control group (P＜0.05). It was showed that RH-CM not only could maintain ES cells in the undifferentiated state, inhibiting the spontaneous differentiation effectively, but also promote adherence and proliferation of mouse ES cells. The effect of the three culture systems on formation of ES colonies at primary passage was not remarkable but significant in ES colonies formation after passage and the highest times of passage. The combination of RH-CM with mitotically inactive MEF feeder layer was the best culture system.

The current study was conducted to determine the effects of Salmonella Typhimurium lipopolysaccharide (LPS) challenge on egg production performance, inflammatory response, tissues metallothionein (MT) synthesis and tissue zinc distribution in laying hens fed two zinc sources. The experimental Hyline brown hens were fed with three different diets (a corn-soybean meal based diet without additional zinc supplementation and basal diet supplemented 60 mg/kg zinc from ZnSO₄ or ZnAA) respectively from 3-week old. At the age of 58-week-old, twelve hens of each dietary treatment were selected and randomly allotted in a 2×3 factorial design. On day 1, 3, 5, 7 of 58-week, six hens of each dietary treatment were injected intraperitoneally with Salmonella Typhimurium LPS or an equivalent amount of sterile saline. There was neither zinc source×immune challenge interaction nor zinc source effect on egg production, egg weight and percentage of cracked eggs during 7 d study period (P＞0.05). However, LPS-challenged birds have decreased egg production (P＜0.05) and increased percentage of cracked eggs (P＜0.01) compared to saline treated birds. When challenged with LPS, the fever response of hens fed ZnAA peaked and subsidized early relative to those fed ZnSO4 or basal diet. Among LPS-challenged birds, serum IL-1β was higher in hens fed ZnAA than those fed ZnSO₄ at 3 h post-injection (P＜0.01), however, birds fed ZnAA had the lowest serum IL-1β concentration among dietary treatments at 12 h postchallenge with LPS (P＜0.001). Among saline-treated birds, serum IL-1β was higher in hens fed ZnAA diet than those fed the basal diet at 3 h post-challenge(P＜0.01). Zinc concentration of liver and spleen tended to be higher in LPS-challenged hens fed ZnAA than those fed ZnSO4 (P＜0.09). MT concentration in liver of birds fed ZnAA diet was higher than those fed ZnSO₄ diet (P＜0.05). When challenged with LPS, birds fed ZnAA diet have a higher concentration of MT in both liver and spleen than those fed ZnSO₄ (P＜0.05). Supplementation of ZnAA increased MT concentration by 266% and 225% in liver and spleen respectively, whereas supplementation of ZnSO₄ increased MT concentration only by 158% and 151% in liver and spleen respectively. The results suggested that supplementation of zinc from ZnAA may increase tissue MT synthesis and zinc sequester in liver and spleen, then elevated the sensitivity to LPS challenge and shortened acute phase response which may be beneficial to immune defense.

Eight lactating Holstein dairy cows were divided into two groups (n=4) and used in a double reversal trial with three periods of 14 days each, to evaluate the effects of rumen protected fatty acids and amino acids(Lys and Met) blend(RPLMF) on rumen fermentation, blood metabolism, milk production and composition. The control group cows were fed normal diet, which contained 57% roughage (20% Sudan grass hay, 20% cubed alfalfa hay, 17% Italian rygrass silage ) and 43% concentrate mixture. The experimental group cows were fed 160 g/d RPLMF in addition to normal feed. The RPLMF mainly contains 60%fatty acids, 8% Lys, 4% Met, and 28% others. Rumen fermentation was not affected by the addition of RPLMF. There were no significant differences for the concentration of urea nitrogen, total free amino acid, total essential free amino acid, Lys and Met in blood plasma between the two groups (P＞0.1). The concentration of glucose in blood plasma tended to decrease (P＜0.1), and concentration of His in blood plasma significantly decreased (P＜0.05) with cows fed RPLMF. Dry matter intake was similar between the two groups. Yields of milk and 4% FCM production were 25.6 kg/d and 24.1 kg/d in the experimental group respectively; of that were 24.2 kg/d and 22.3 kg/d in the control group respectively, and compared with the control group, they increased by 1.4 kg/d (5.8%) and 1.8 kg/d (8.1%) respectively (P＜0.1). The percentage of milk fat tended to increase (P＜0.1) for cows fed RPLMF, but percentages of other milk components did not show significant differences between the two groups. Compared with the control group, the quantity of milk fat, increased by 9.5% (80 g/d, P＜0.05), and that of milk protein and SNF increased by 6.9% (50 g/d, P＜0.1) and 6.4% (130 g/d P＜0.1) respectively, and ratio of C18∶0 in milk fat significantly increased (P＜0.05) for cows fed RPLMF. The efficiency of conversion of feed protein to milk protein was increased from 23.9% to 25.3% by the addition of RPLMF. When dairy cows in mid lactation was fed with the RPLMF, its milk production was increased and milk composition was improved in a hot season.

A one-factorial trial arrangement including five lysine levels(0.60%,0.80%,1.00%,1.20%,1.40%) was conducted to study the effect of lysine intake on growth performance and pancreatic endocrine function of early weanling piglets. Fifty-five 21-day-old male early weanling piglets were allotted randomly to five groups, each of which was fed one of five experimental diets containing different lysine levels for twenty-one days. At the end of the trial, five piglets from each group were infused with glucose solution and blood samples were collected at different time after the infusion. The results of this experiment demonstrated that there was significant positive correlation between lysine intake and daily weight gain in early weanling piglets(P＜0.05); according to the growth performance, the lysine requirement of weanling piglet from 21-day to 42-day of age was no less than 3.16 g/day or 1.4% of the diet; the levels of insulin in serum decreased significantly when piglets were fed lysine-deficient diet(P＜0.05).

Experiments were conducted to investigate the effects of early feed restriction on the lipid peroxidation，enzymatic antioxidant activity and ascites incidence of broiler under normal or low ambient temperature. Broilers were exposed to low ambient temperature to induce ascites syndrome. In experiment 1, the restricted chicks were fed 8 hours per day either from day 7 to day 14 or from day 7 to day 21, while the controlled chicks were fed ad libitum. In experiment 2, the restricted chicks were fed 80% or 60% of previous 24 hour feed consumption of full-fed controls for 7 days from day 7 to day 14, while the full-fed controls were fed ad libitum all through the experiment. Plasma malonilaldehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) concentration and ascites heart index (RV/TV ratio) were continuously surveyed. The results showed that low temperature significantly increased the plasma MDA concentration and decreased the plasma SOD and GSH-Px activity. The RV/TV ratio at week 5~6 and the ascites morbidity were significantly increased in low temperature treated broiler. Early feed restriction markedly decreased the plasma MDA concentration. The plasma SOD and GSH-Px activity of feed restricted broiler was markedly higher than that of the fed ad libitum broiler during late experimental period. All early feed restriction treating reduced ascites morbidity. The RV/TV ratio of feed restricted chicks was lower than that of the uncontrolled chicks on day 42. The results indicated that early feed restriction alleviated the lipid peroxidation, enhanced the enzymatic antioxidant activity and finally reduced the ascites morbidity of broiler.

Eighty 25dayold male AA broilers were divided randomly into two groups (40×2): the control group (21～24℃, 50%±5% relative humidity) and thermostress group ((37±0.5) ℃,70%±5%relative humidity). The blood gas analysis, respiration rate, rectal temperature and production performance of broiler chickens were examined continuously.In thermostress group, 24 hours treatment induced a compensated respiratory alkalosis， which was characterized by the decreased partial pressure of CO2 （PaCO2）and the increased pH in artery; about 6 days later there was a decompensated metabolic acidosis, which was characterized by the dropped arterial blood bicarbonate ion (HCO-3) and the decreased pH value (P＜0.05); 12 days after thermostress acidbase balance was almost resumed. Body weight gain and feed intake of thermostressed chickens were decreased significantly (P＜ 0.01), and feed/gain was increased significantly (P＜0.01). The respiration rate and rectal temperature of heat-stressed broiler chickens were increased significantly (P＜0.01) at 1, 5, 7, 9 and 12 days after thermostress. The oxygen partial pressure （PaO2） had a significantly negative correlation with respiration rate (P＜0.01) and rectal temperature (P＜0.05). The arterial blood oxygen saturation（SaO2）had a significantly negative correlation with rectal temperature (P＜0.01). These results showed that there are the significant acidbase balance disturbance, the severely affected physiological function and decreased production performance in the broiler chickens under 37℃ constant heat-stress.

Complete chicken IL-18 gene were amplified firstly by RT-PCR from spleen cells of chicken embryo inoculated with Newcastle disease virus. The gene were inserted into pcDNA₃ vector, resulting in the construction of pcDNA₃-IL18 plasmid. Immunoenhancement effects of the pcDNA₃-IL18 plasmids on Newcastle disease vaccine were observed by the test of HI antibody, proliferation response of the T lymphocytes from thymus and the B lymphocytes from bursa of Fabricius. The results indicated that chicken IL-18 have obvious immunoenhancement effect on Newcastle disease vaccine. It can not only enhance the cell mediated immune response obviously，but also enhance the humoral response，thus improve the protective rate of ND vaccine.

The detection of tetracyclines-resistance of 16 Samonella isolates showed the resistance rate was 100%. The tetC gene of 16 salmonella strains was amplified by polymerase chain reaction. 12 strains with this gene were located on plasmids. Compared with the result of the drug-susceptibility tests, the method of PCR showed 75% concordance in positive rate. The probe of tetC gene was labelled with photobiotin，and 16 pathogenic Salmonella strains from swine were detected by colony hybridization in situ. The result indicated that 13 strains were positive, 3 strains were negative. Compared with the result of PCR, the method of the tetC probe showed 93.75% concordance in positive rate. In this study, two methods for detecting tetC gene were established by using PCR and nucleic acid probe, and they could be applied to the molecular epidemiology surveillance of tetracyclines-resistance.

In order to study the morphogenesis and distribution of duck enteritis virus(DEV),tissues of ducks infected experimentally with DEV virulent strain were collected and observed by electron microscopy.The investigation showed that a few typical herpesvirus virions and nucleocapsids were observed in the spleen and bursa of Fabricius 12 hours post inoculation,then,in the liver,small intestine,spleen, thymus,bursa of Fabricius 24 hours post inoculation.Nucleocapsids are divided into four types according to their morphology. Nucleocapsids assembled both in nucleus and cytoplasm.There are two types of maturation according to our observation.One is nucleocapsids obtained its tegument in the nucleus and enveloped from the inner nuclear membrane.Another is nucleocapsids entered cytoplasm through nuclear membrane,then obtained their tegument in the cytoplasm,enveloped from the plasma membrane,finally released by necrosis,exocytosis or other ways.With the replication,assembly and maturation of viruses,inclusion bodies,compact particles, microtubes,hollow tubes and coated electron dense bodies are observed.

The lesions of goat pox in Guizhou Province were observed using transmission electronic microscopy. Numerous typical goat poxvirus in different mature stages were found in the cytoplasma of the affected epithelial cells in skin and lung, and some also could be found in the cytoplasma of macrophages, fibroblastic cells and vascular endothelial cells with a few within the blood vessels. Besides the virus diffused or restricted as a virus inclusion body in the cytoplasm, the affected cells are usually swelling with enlarged cell organs such as mitochondrion, endoplasmic reticulum and Golgi complex. An interesting and important finding is that myelinated nerve fibers were also involved by the virus and affected macrophages and segmental demyelination with degeneration of axon and Schwann cells were noted. The typical matured or maturing virus particles were also found in the epithelial cells and the fibroblastic cells in the affected chorioallantoic membrane of chick embryo.

After administrating DES (diethylstilbestrol) by subcutaneous injections for 7 days, the changes in the morphology, distribution and number of mast cells in adult hamster epididymis caput and caudal were studied by using modified toluidine blue (MTB) staining, and cytochemical subsets of mast cells were identified by alcian blue-safranin O (AB-S) staining. The relationship of the number of epididymis mast cells between the morphology changes of epididymis caudal during DES-treated were explored. The results showed: Epididymis mast cells were belong to connective mast cells (CTMC), which distributed in the capsule and interstitium of epididymis caput and caudal. Some mast cells localized nearby epididymis tubular, and degranule mast cells could be seen in the epididymis caput and caudal in DES-treated hamster. Although mast cells area have no obvious difference in both DES-treated and control groups, but the number of epididymis caudal mast cells were significant increased in DES-treated (P＜0.01), particularly in epididymis caudal.

In order to study the effects of Chaiqikeli (CQKL) on liver protection, antibacterial action and immunity function, hepatic injury models were established by injecting carbon tetrachloride (CCl₄)and D-galactosamine (D-GalN)into mouse and then the different dose of CQKL were given respectively. The activity of ALT and AST in the serum, the contents of glutathione (GSH) in liver homogenate from all mouse were determined. It is suggested that CQKL could significantly protect liver from CCl₄ and D-GalN injury, lower the activity of enzyme ALT, AST in serum, shorten the sleep duration induced by embuter in CCl₄ damaged mice,improve the phagocytic function of reticuloendothelial system in mice and inhibit bacterial in vitro. CQKL have the antibacterial,liver protection and immunological enhancement effects.

In order to study the effects of Chaiqikeli (CQKL) on liver protection, antibacterial action and immunity function, hepatic injury models were established by injecting carbon tetrachloride (CCl₄)and D-galactosamine (D-GalN)into mouse and then the different dose of CQKL were given respectively. The activity of ALT and AST in the serum, the contents of glutathione (GSH) in liver homogenate from all mouse were determined. It is suggested that CQKL could significantly protect liver from CCl₄ and D-GalN injury, lower the activity of enzyme ALT, AST in serum, shorten the sleep duration induced by embuter in CCl₄ damaged mice,improve the phagocytic function of reticuloendothelial system in mice and inhibit bacterial in vitro. CQKL have the antibacterial,liver protection and immunological enhancement effects.

It has been almost five years since the first report of live pig produced by somatic cell nuclear transfer (SCNT) technology. Though it is more difficult, lower efficiency, compared to embryonic cell nuclear (ECNT) technology, the cloning pigs with SCNT technology has been further studied. Some progress has taken in the fields of mechanism and approaches. In this paper, we mainly focus on the key technology and its difficulties of SCNT in cloning pigs, including its applications and approach of increasing the efficiency of SCNT.

Taking Small Tail Han Sheeps ear margin as the study materials, we succeeded in establishing a fibroblast cell bank which content of samples was 52 by the method of explant culture directly and cryopreservation technique. The biological analysis results showed that population doubling time (PDT) of cells was approximately 24 h, diploid account for 90%～96% in chromosome. Confirmed by isoenzyme analysis,this cell line had no cross-contamination.The test results of the bacterium, fungi, virus, mycoplasma were negative. The transfection rate was high, and the extro-gene can be effectively expressed. Every indexes of the cell bank met all the standard quality controls of ATCC. It had not only preserved the germplasm resources of this important Small Tail Han Sheep on the cell level but also provided valuable material for the research of genome, postgenome and somacloning. Meanwhile, the setting-up of this technological platform will offer technology and theory for storing the cell genetic resources of other animals and poultry.

Lipopolysaccharide (LPS) was injected via the tail vein (0.1 μg per mouse) to induce abortion (embryo resorption) in Kunming mice. The interleukin 10 (IL-10) contents in the uterus was assayed by ELISA. The results revealed that the IL-10 level was significantly decreased in the LPS-induced abortion group of mice compared with the controls. Use of pentoxifylline, or a combination of Radix scutellariae and Rhizoma atractylodis reversed the LPS effects: bringing down the fetal resorption rate, and enhancing the IL-10 level significantly. The study indicates that the anti-abortive effects of PXF and the combination of Radix scutellariae and Rhizoma atractylodis are closely related to up-regulation of the Th2 cytokine IL-10 at the maternal fetal interface.