According to the conservative sequences of announced obese gene in human ，mouse and pig, a pair of primers were designed. The obese gene of the duck was amplified by RT-PCR. The product was cloned into pGEM-T vector. Sequence analysis revealed that it has a length of 438 nucleotides which encods a 146-amino peptide. When nucleotid sequence and deduced amino acid sequence were compared with homologous sequence of human, pig and rat, it displayed a fairly high degree of conservation. The homologue of the nucleotide sequence are 83%，84%，98% and 94% respectively; the homologue of the amino acid sequence are 86%，83%，99% and 96% respectively. With the aim of analyzing the characteristic of the expression, the cDNA fragment was inserted into expression vector pET-28a and the resulted plasmids were expressed in E.coli BL21(DE3) by IPTG induction. The results of SDS-PAGE analysis indicated that protein was specifically expressed in the E.coli BL21(DE3).The weight of the fusion protein was about 20 ku,which included the 16 ku protein expressed from duck obese gene. The cloning and expression of the duck obese gene established the foundation of the further research about the function and application of the duck leptin.

Genetic variation of the 5′ region of the IGF-Ⅰgene in 200 Shouguang chickens were detected by PCR-RELP. Three genotypes AA，AB and BB were identified after the PCR products were cut by PstⅠrestriction enzyme and their frequencies were 0.335，0.485 and 0.180, respectively. They were in Hardy-Weinberg equilibrium at the gene locus by χ² test（P＞0.05）. The associations were observed between genotypes and carcass traits including semieviscerated weight and breast muscle weight (P＜0.05). The results of the least squares means showed that a significant different effect between genotype BB and AB or AA was found in semieviscerated weight of Shouguang chickens (P＜0.05), while the significant difference was found only in breast muscle weight of the male chickens and only in liver weight of female chickens (P＜0.05). In addition, genotype BB tended to express a higher body weight in 10 weeks, semi-eviscerated weight and breast muscle weight than the other genotypes in Shouguang chickens. These results may be applied to marker assisted selection.

Technique of polymerase chain reaction(PCR) and method of restriction fragment length polymorphism(RFLP) were performed to analyse Cytochrome b(Cyt b) gene of mtDNA in 9 indigenous sheep breeds and 3 imported sheep breeds.The results indicated that 22 restriction sites and 15 restriction morphs were detected with the digestion of 6 endonucleases in all individuals,and StuⅠ, EcoRⅠ and MboⅡ were polymorphic.Fifteen restriction morphs were sorted into 4 haplotypes.The haplotype I was the main haplotype.The averaged polymorphic degree(π value=0.014 2%) of mtDNA Cyt b gene showed that the genetic diversity of mtDNA of Chinese indigenous sheep breeds was very poor.

Ninety-six 56-day-old Chinese native chickens were selected and randomly divided into 16 dietary treatments of 60 chickens each to determine the effects of dietary vitamin A and E supplemented on the performance of chickens. Diet were formulated to contain four graded levels of supplemental Vitamin A (0,5 000,10 000,20 000 IU/kg) and four graded levels of supplemental Vitamin E (0,30,60,120 IU/kg)by a 4×4 factorial design. The results showed that: Within the supplement range of 0~10 000 IU/kg for vitamin A and 0~60 IU/kg for vitamin E, ADG and F/G increased gradually .Plasma vitamin E tended to decrease when dietary vitamin A supplementation exceeded 10 000 IU/kg.Supplementation of high levels of vitamin A could increase plasma TBARS significantly, and high levels of Vatamin E could improve the oxidative stability of lipid. Deposition of pigment was inhibitated when supplementation of vitamin A was over 20 000 IU/kg.With increase of vitamin E supplementation ,the skin color was enhanced.Dietary vitamin A and E and the interaction had significant affected on serum antibody titer of Newcastle disease.In conclusion, the optimum level of dietary supplemental vitamin A, E for Chinese native chickens was respectively 5 000~10 000 IU/kg, 30~60 IU/kg.

The effects of polyunsaturated fatty acid from soybean oil and cottenseed oil on the accumulation of Trans vaccenic acid (TVA) -biohydrogenation of ruminal microbes and rumen fermentation were researched with artificial rumen.Results indicated that TVA was accumulated with treatments of soybean oil and cottenseed oil, especially 4% treatments were abstractly higher than control(P<0.05).The concentrations of total volatile fatty acid (TVFA) of all treatments were higher than control, cottenseed oil treatments were obviously higher than control(P<0.05).The concentrations of NH₃-N were also higher than control,treatments of 2%soybean oil ,2%cottenseed oil and 4%cottenseed oil were obviously higher than control(P<0.05).

The purpose of this study was to investigate the effects of cysteamine compound (Lactonin) on milk production and immune function of dairy cows during week (W) 20 through 42 of lactation. 96 Holstein lactating cows at mid- and late-lactation stage were assigned to 4 groups (n=24) on the basis of their daily milk yield (M) prior to the experiment. In each group the cows were divided randomly into Lactonin treatment (LT, n=49) and Control (n=47). In LT， Lactonin was administered to cow progressively from 2 000 to 6 000 U/d·head through the experimental period.In G1 cows received LT (n=12) produced 18% more milk (P<0.05) than did Control during the entire 23 weeks of treatment period. But in G2, G3 and G4 the milk yield of cows treated LT did not differ from that of Control, suggesting that the effect of Lactonin on milk production was influenced by the basic milk yield of cows in the period prior to Lactonin treatment. In LT groups（n=49） the milk fat (3.64%±0.05% vs 3.78%±0.05%, P<0.05) and protein percentage (2.94%±0.04% vs 3.02%±0.03%, 0.05<P<0.15) were greater than those in Control(n=47). In LT of G4 (n=13) milk fat and protein increased by 11% (P<0.05) than that of in Control, respectively. LT treatment tended to increase FCM（0.05<P<0.15）in G1 and G4. The immune activities, determined by lymphocyte transformation rate, IL-2 and IL-6, were enhanced (P<0.05) in LT treatment group (n=32) in the W 24 of lactation. Results from this study indicate that LT improved the milk yield and milk composition in the mid and late-lactation stages. These effects of Lactonin on milk production are related to its promoting effects on dairy cows in digestion, absorption and partition of the nutrients to the tissues, and its stimulating effects on immune function.

The cycling of skin and hair follicles of Arbas and Liaoning cashmere goats has been researched. The results show that the epidermis stratum basale cell starts rooting in March, the secondary hair follicles begin reconstructing at the same time. The hair follicles enter anagen from August to September, most of them enter catagen in December. Their telagen period is from February to March. The time, in which the hair follicles of the two goats enter anagen, and its duration, are different. Moreover, except for width of the primary hair follicles bulb, other characteristics of the Arbas cashmere goat are much more obvious than those of the Liaoning cashmere goat, but all characteristics of the secondary hair follicles are contrary. The differention is remarkable in most months. The depth, density, S/P and breadth of hair follicles and the period of growth are factors that have an effect on the production of cashmere.

Chicken embryos from stage 15 to stage 45 were studied by means of serial section and light microscopy in order to learn the relationship between the spermatogonium and the testicular development in the early chicken embryo. The results showed that: At the stage 22~28 (3.5~5^th hatching day), the glycogen in the PGCs cytoplasm reduced gradually. On the stage 29(6^th hatching day), the gonad of the embryo appeared the feature of testis, and the glycogen in the PGCs cytoplasm reduced further. On the stage 31 (7^th hatching day), the differentiation of ovary or testis was obvious and the glycogen in the PGCs cytoplasm later disappeared. On the stage 34(8^th hatching day), the testicular cord had been begin to differentiating. The every cord had been solid tube with the spermatogonium. On the stage 35~37 (9~11^th hatching day), the number of testicular cord had been increased with the ages of embryonic development. The spermatogonium were monlayer located in cord. In this stage, the fewer sustentacular cells had been differentiated, while difficult to distinguish. On the stage 38~40 (12~14^th hatching day), the seminiferous had been formed typically, the number of spermatogonium increased as well as sustentacular cells, and the interstitial cells in seminiferous distributed in groups. On the stage 40~45 (16~19^th hatching day), the testis on the right was a little bigger than that on the left, the number of spermatogonium increased obviously and showed likely clusters of grape in the middle of seminiferous.

Acid phosphatase(ACPase) from the sperm of PIC pigs(PIC344) could be activated by these ions of K⁺,Mg ²⁺ ,Ca ²⁺ ,Ni ²⁺ ,Mn ²⁺ , while inhibited by Cu²⁺ ,Cd ²⁺, Fe ²⁺ ,Zn ²⁺ . The concentrations of these ions rang from 1 mmol/L to 5 mmol/L. ACPase was inactivated by EDTA . The ability of metal ions activate the ACPase one by one in order for Mg ²⁺ > Ni ²⁺ > Mn ²⁺ > K⁺ > Ca ²⁺ . The ability of metal ions inactivate the ACPase one by one in order for Cu ²⁺ > Cd ²⁺ > Fe ²⁺ > Zn ²⁺ .Cu ²⁺ and Cd ²⁺ were selected for determining types of inhibition. The results show that Cu ²⁺ and Cd ²⁺ were noncompetitive inhibitors by using LineweaverBurk method.Their Ki values were determined by Dixon method,which respectively were 0.58×10^-3 mol/L， 9.44×10^-3 mol/L.The Fluorescent spectras of Mg ²⁺ ，Ca ²⁺ ，Cd ²⁺ ，Cu ²⁺ indicate that the fluorescent spectrum strength to decrease, their maximum exit wavelengths were constant. The results explain that these metal ions influence the conformation of ACPase.

In present study, atherosclerotic animal model were replicated with high cholesterol feedstuff , and the expressions of estrogen receptor α and low-density lipoprotein receptor mRNA in heart and liver were studied by half quantitive RT-PCR, the rabbits oophorectomized and fed with normal feedstuff were used as control．The results showed：the two sorts of receptors expressed in heart and liver；in control group, the relative expression of ERα mRNA in the heart and liver were 0.43±0.12, 0.39±0.20，the relative expression of low-density lipoprotein receptor mRNA in the heart and liver were 0.27±0.05, 0.86±0.12； The relative expression of estrogen receptor and low-density lipoprotein receptor mRNA in the heart and liver of model rabbits were 0.29±0.03, 0.27±0.06 and 0.04±0.01, 0.17±0.02 respectively．

Three structure protein genes of strain TS of transmissible gastroenteritis virus(TGEV), sM(small membrane protein),M(integral membrane protein) and N(nucleocapsid protein) genes were obtained by RT-PCR using primers designed according to their published nucleotide sequence in GenBank, and they are 346 bp,932 bp,1 217 bp, respectively. After splicing, the respective lengths of the sM, M and N genes of strain TS of TGEV is 248 bp,789 bp and 1 149 bp and their predicted corresponding protein has 82, 262 and 382 amino acids(aa), respectively. The homology at the nucleotide levels for the sM gene between strain TS and Purdue,TFI,96-1933 was found to be 95.2%,92.7%,90.2% respectively, and that of the deduced aa sequence was 95.9%,97.2%,98.8% correspondingly. The nucleotide sequence homology of M gene of strains TS shared 95.2%,98.0%,99.6%,95.0% nucleotide identity and 97.0%,97.3%,98.5%,93.5% deduced amino acid with that of strains Purdue, TFI,TGEV H,96-1933. The nucleotide sequence homology of N gene between strain TS and Purdue, TFI, FS722/70, Korea,TO14,TGEV H, 96-1933 is 98.1%,97.7%,99.0%,98.3%,99.2%,99.0%,95.9% and putative amino acid homology is 97.9%,98.4%,99.0%,97.7%,99.5%,96.2%,96.6%, respectively. Sequence analysis indicated that sM and N genotypes of TGEV are conservative, there are two kinds sub-genes of TGEV in China and their origins are probably from abroad.

Using the isolated strain of 030224HB and a set of specific primers, the ompH gene of P. multocida was amplified by PCR. The primers were designed based on the published sequences of the ompH gene. The 1 114 bp amplified DNA fragment was cloned into pMD18-T. The sequencing result indicated that this gene was quite conservative. The ompH gene in pMD18-T was ligated into pET28b to get the expressing vector of pET28b-ompH which was then transformed into E.coli BL21. The result of SDS-PAGE shows the expressed protein is about 35 ku, resembled to the published researches. Western-blot results indicates that this protein possesses biological activity. Using the expressed protein, ELISA to detect pasteurellosis of pigs is expected to develop.

The ORF sequence of micronem protein-2(MIC2) gene from Eimeria necatrix(GD) was cloned by PCR amplification using specific primers designed according to the sequence of EnMIC2(GD), and ligated to vector pYA3342 to construct recombinant plasmid pYA3342-EnMIC2 for transforming E.coli x6212. Then the positive recombinant plasmid identified by PCR amplification and endonuclease digestion was electroporated into attenuated S. typhimurium X4550. The recombinant EnMIC2 expressed in Salmonella by inducing of 1 mmol/L IPTG was approximately 35 ku in size and accounting for 8.6% in total bacterial proteins and could be detected in western blotting using hyperimmune serum against E.necatrix. The specific serum IgG against EnMIC2 in chickens post-immunized(PI) with recombinant Salmonella at the dosage of 10⁸ or 10⁹ CFU per bird was probed, and reached to the peak 3 weeks PI. Specific IgA in intestine was also detected 3 weeks PI. These immunized chicken were challenged with 500 E. necatrix sporulated oocysts per bird 3 weeks PI and can reduce the oocyst production by 26.62% and 48.92%, respectively in low or high vaccinating dosage compared to the control groups.

The calmodulin-domain protein kinases（CDPK）gene was cloned by RT-PCR from total RNA which was extracted from sporozoite of Eimeria tenella Gansu strain. Using the CDPK gene, the pGEX-CDPK recombinant plasmid was constructed. The recombinant plasmid was transformed into E.coli BL21 and highly expressed. The acquired fusion protein was purified by glutathione resin volume.The amount of fusion protein in total bacteria protein were 35.4%. The CDPK gene of Eimeria tenella Gansu strain was consisted of 1 470 nucleotides, encoding 490 amino acids. Compared with the CDPK gene of Eimeria tenella that reported in GenBank there are five mutation nucleotides and the homology of nucleotides is 99.6%, and there are five mutation amino acids and the homology of CDPK amino acids is 98%.

210 one-day-old Tianfu meet ducklings were divided into three groups, and fed on diets as follow: control (Cu 12.16 mg/kg)， copper toxic I (Cu 850 mg/kg) and copper toxic Ⅱ ( Cu 1 050 mg/kg) for studying effects of copper toxicity on organs and serum enzyme activities in duckling by the methods of experimental pathology. At pathological level, there were similar lesions in both two copper toxic groups compared with control group. At necropsy, the cuticle of gizzard was thickened. The digestive tract was full of the black-brown, red-brown or light-green substance and intestinal mucosa was swelled. Lymphoid organs were smaller in both copper toxic groups than that in control group. At histopathological level, the hepatocytes, epithelial cells of renal tubule and cardiac muscle cells mainly showed granular and vacuolar degeneration. The epithelial cells of intestinal mucosa were degenerated and necrotic. The intestinal villi were broken. Lymphocytes of lymphoid organs were depleted, degenerated and necrotic.At ultrastructural level, the mitochondria of hepatocytes were swelled, and its crista were broken or / and disappeared. The deposited substance with high electron density appeared in the cytoplasma and nucleus of hepatocyte. The serum caeruloplasmin activity was much lower, and serum glutamicpyruvic transminase and glutamic-oxaloacetic transminase activities were much higher in copper toxic groups than that in control group. The above mentioned results demonstrated that the target organs impaired by copper toxicity were liver, kidney, heart, gastrointestines and lymphoid organs. The death of affected duckling due to the injury, disfunction of organs.

The plasma pharmacokinetics of doramectin (DRM) after intravenous (i.v.) and intramuscular (i.m.) administration at a single dose of 300 μg/kg b.w. were determinined over a 45-day period in pigs. Ten crossbreed pigs, clinical healthy, parasite free, weighing 36~50 kg were selected for study. Pigs were located into 2 groups of 5 animals and were treated with 300 μg/kg b.w. DRM with i.v. and i.m. injection, respectively. Blood samples were collected from jugular vein at different time points in 45 days after drug administration. The separated plasma were derivatized after solid phase extraction and analysed by high performance liquid chromatography (HPLC). Pharmacokinetics parameters were calculated by a computerized kinetic program MCPKP. The mean plasma concentration of DRM after i.v. and i.m. administration were detected until 30 and 25 days, respectively. Both drug concentration-time data of DRM with i.v. and i.m. administration accorded with two compartment open model in pig. The main pharmacokinetics parameters were: T_1/2α (1.092±0.66) d，T_1/2β (6.11±2.73) d, AUC （274.19±119.89） μg ·L-1·d-1 for i.v., and T_1/2α (0.056±0.022) d，T_1/2β (3.20±1.34) d，AUC (223.51±65.20) μg·L-1·d-1， C_MAX (28.99±10.69) μg/L，Tp (1.24±0.87) d for i.m.，respectively. The general bioavailability of DRM with i.m. injection was 81.5%. The results indicated that DRM was rapidly absorbed and distributed, slowly eliminated and possessed large volume of distribution, high bioavailability in pig with i.v. and i.m. administration. It suggested that the long activity of DRM in pig was likely to resulted from the intrinsic characteristic of DRM rather than different routes of drug administration or the kind of solvent used. Therefore, the results are helpful for understanding the pharmacokinetics characteristics and correct using of DRM in pig in clinic.

Fifteen healthy piglets were distributed into three groups randomly: healthy group, spleen deficiency group, sijunzi decoction antisyndrome group, five piglets each. The study on “pharmacokinetics of syndrome differentiation” was carried out after a single oral administration of levofloxacin(20 mg/kg B.W.) in piglets. The levofloxacin concertration in plasma was detected with HPLC, calculation of pharmacokinetics parameters was performed using 3p97 PK programe, further pharmacokinetics analysis was performed using SPSS(12.0) statistic software. The datas of the drug concentration-time in the two groups of the healthy group, spleen deficiency group were fitted to a one-compartment model with first-order absorption, the counterparters of sijunzi decoction antisyndrome group were in line with a two-compartment with first-order absorption. The results indicated that the spleen deficiency condition of the piglets influenced the PK of levofloxacin; sijunzi decoction could resume the characteristics of the PK parameters in spleen deficiency condition, which also provided scientific evidence for the hypothesis of “pharmacokinetics of syndrome differentiation”, also for the better combination between the west animal medicine and Chinese traditional animal medicine.

Cerebrospinal fluid pressure (CSFP), respiration and palpitation of ten healthy miniature dogs respectively recorded on the condition of anesthesia and injecting contrast media (OMNIPAQUE(r) iohexol, 300 mg I/mL) into subarachnoid space. CSFP variations were according to respiration and palpitation. In addition, it was primarily affected by respiration, and take on a cycle in one respiration. CSFP was remarkably improved during injecting contrast media into subarachnoid space, and the range of CSFP variations were enlarged.

In this study, five immune traits including immunoglobulin G (IgG), delayed-type hypersensitivity (DTH), leukocyte counts (WBC), total erythrocytes (RBC) and total protein in serum (TP) were measured in Tongcheng pigs, Swedish Landrace, British Large White and two three-way crossbreds of Landrace× (Large White×Tongcheng), Large White×(Swedish Landrace×Tongcheng). Tongcheng pigs had the highest values of IgG (45.04 mg/mＬ)，DTH (8.87 mm)，RBC (7.05×10¹²/L) and TP (66.69 g/L) among these five pig populations. RBC had positive heterosis in these studied pigs and other four immune traits had negative heterosis. There were significantly positive correlation between IgG and DTH (r=0.33, P＜0.01), IgG and TP (r=0.27, P＜0.01)， DTH and TP (r=0.25, P＜0.01).

Avian influenza virus (AIV) is a highly variable pathogen. The M2 gene of AIV is a transmembrane protein. It has highly conservative antigenic epitopes and is a potential antigen for cross-protection. In this study, the recombinants containing the fulllength M2 and the transmembrane segment deleted M2 were constructed respectively. When measuring the expression of the two constructs, we found that the full-length M2 failed to express in the prokaryotic expression system, whereas transmembrane segment deleted M2 was highly expressed as fusion protein in a soluble form. The fusion protein reacted with SPF chicken serum specific for AIV A/goose / Guangdong /1996（H5N1）. The protein was purified by GST purification system and the purified protein was used to prepare anti-M2 serum in mice. Immunofluorescence test demonstrated the binding of the antiserum with AIV (H5N1) infected MDCK cells. The results suggest that the recombinant transmembrane segment deleted M2 could provide good antigenicity.

By mating transgenic mice, transgenic mice model of high expression of foreign gene was screened. Making use of conventional way of breeding to mate 2(A♀,B♂)transgenic mice integrated Hepatitis B virus(HBV) gene, 2A(♀♂) and 2B(♀♂)transgenic homozygote mice, and 6 bi-heterozygote mice(4♀2♂) by mating A and B homozygote mice were taken. Blood serum of these transgenic mice and their off-springs’ were collected, and HBV DNA expressing in blood serum of transgenic mice was tested by polymerase chain reaction and ELISA (PCR-ELISA). The results were as follows: HBV DNA expression in the blood of bi-heterozygote mice was much more than that of homozygote and heterozygote mice. Breeding bi-heterzygote mice is likely to be a good way of high expression of foreign gene in transgenic animals.

Water extract of Cortex toosendan (1∶1) was given by oral admistration to the pregnant mice on day 7 in order to study its toxicity. Embryo livability was examined. The natural killer cells in the uterine decidua were detected by immunohistochemistry. The Th1 cytokines IFN-γ and TNF-α in the uterine lysates were analyzed by ELISA. The results showed that Cortex toosendan is toxic to embryo, and that the toxicity is related to the enhancement of Th1 responses at the maternal-fetal interface, with the increase of NK cell counts, IFN-γ and TNF-α concentrations in pregnant uterus.