Effect of in ovo zinc injection on the embryonic development, tissue zinc contents, antioxidation, and related gene expressions of broiler breeder eggs

Two experiments were conducted to investigate the effect of in ovo zinc （Zn） injection on the embryonic development, tissue Zn contents, antioxidation and related gene expressions of fertilized eggs of Arbor Acres broiler breeders. Experiment 1 was conducted to determine an optimal embryonic age for early in ovo injection. A total of 720 fertilized eggs with similar weights were randomly allotted to 4 treatments with 6 replicates per treatment and 30 eggs per replicate in a completely randomized design. The eggs were injected with 0.1 mL sterilized water at 3, 6 and 9 embryonic days of incubation （E3, E6 and E9） or non-injection （the control）, respectively. The results from experiment 1 showed that E3 and E6 injections increased （P〈0.05） the embryonic mortalities, and decreased （P〈0.05） hatchabilities compared to the non-injected control, but no differences （P〉0.05） between E9 injection and the non-injected control were observed in either embryonic mortality or hatchability. The findings suggest that the E9 is the optimal embryonic age for early in ovo injection. In experiment 2, a total of 672 fertilized eggs with similar weights were randomly allocated to 7 treatments with 6 replicates per treatment and 16 eggs per replicate in a completely randomized design. The eggs were injected with 0 （the negative control）, 50, 100, 150, 200, or 250 μg Zn/egg as reagent grade ZnSO4.7H20 in a 0.1-mL solution, or non-injection （the positive control）, respectively at E9-10. The results from the experiment 2 demonstrated that no differences （P〉0.05） among 50 and 100 μg Zn/egg groups and the negative control were observed in the embryonic mortality and hatchability, however, the injection of 200 μg Zn/egg increased （P〈0.05） the embryonic mortality, and injections of 150 and 200 μg Zn/egg decreased （P〈0.05） hatchabilities compared with the controls. The embryonic tibia Zn contents at E20 were increased （P〈0.05） by injections of 150, 200 and 250μg Zn/egg. Zinc injection did not affect （P〉0.05） malonaldehyde （MDA） contents, copper- and Zn- containing superoxide dismutase （CuZnSOD） activities and mRNA expression levels in the liver and heart of chick embryos at E15 and E20. Compared with the negative control, injections of 50, 150 and 200 μg Zn/egg up-regulated （P〈0.05） themetallothionein （MT） mRNA expression levels in the embryonic liver at E20. These results indicated that in ovo Zn injections increased Zn contents in the embryonic tibia and MT mRNA expression levels in the embryonic liver at E20, however, injections of 150-200 μg Zn/egg were harmful to the embryonic development.

Bioavailability and Immunity Response in Broiler Breeders on Organically Complexed Zinc Supplementation

Two hundred and sixty four broiler breeder hens of 32 weeks of age were distributed randomly in four dietary treatments. The dietary treatments were T0: Broiler breeder ration containing 40 ppm zinc (basal 29.8 ppm + 10.2 ppm inorganic zinc), T1: T0 + organic zinc (zinc methionine) @ 20 ppm, T2: T0 + organic zinc @ 40 ppm and T3: T0 + organic zinc @ 60 ppm. The experiment was continued from 32 to 48 weeks of age. At 48 weeks, the weight of lymphoid organs, zinc levels in organs and immunity response were determined. The faecal zinc level was determined at monthly interval. The weight lymphoid organs of different treatment groups (both organic and inorganic zinc fed groups) of the broiler breeders did not differ significantly (P > 0.05). The cellular immune response of breeder birds to PHA-P was significantly (P 0.05) higher in group T3 than the rest of treated groups. The antibody titre to SRBC differed among the treated groups. The zinc content of serum of broiler breeders of all the groups did not differ significantly (P > 0.05) in all the periods of study. Zinc content in liver and tibia of broiler breeders in different dietary treatments of zinc differed significantly (P 0.05) with higher levels were obtained on increasing zinc concentration in the diet. The zinc level in the spleen and kidney of the broiler breeders in different dietary treatments did not differ significantly (P > 0.05). The average zinc content in the faeces of broiler breeder during 35 to 43 week of age did not differ significantly (P > 0.05) among the treated groups. At 48 weeks of age, zinc content of the faeces of T3 was found to be significantly (P 0.05) higher than the rest of treated groups. Similarly, during the overall experimental period analysis, it was found that zinc levels in the faeces of T2 and T3 were significantly (P 0.05) higher than T1 and T0.

Effects of Different Dietary Crude Protein Levels on Reproductive Performance in Breeder Roosters

[Objective] To investigate effects of different dietary crude protein levels on reproductive performance and find out the optimal additive proportion of crude protein. [Method] A total of 45 New Yangzhou breeder roosters at 21 weeks old were sampled and divided into three groups, namely, low-protein diet group, medium-protein diet group and high-protein diet group. They were fed with diets respectively at crude protein levels of 17.23%, 13.04% and 11.32%. The sperm volume, testicular traits and levels of reproductive hormones were analyzed during the whole repro- ductive period. [Result] The sperm volume, sperm motility and sperm density of the medium-protein diet group were higher than that of the other two groups, and the sperm deformity rate of the medium-protein diet group was lowest. The rooster＇s testicular traits including weight, volume and testis indexes were not significantly affected by different protein levels, but the testis shrank slowly with aging （ P 〈 0.05）. The levels of testosterone （T）, luteinizing hormone （LH） and follicule stimulating hormone （FSH） in plasma were respectively 6.34%, 19.64% and 3.88% higher in the lowprotein diet group than in the medium-protein diet group, and these indexes were respectively 7.20%, 17.54% and 9.84% higher in the low-protein diet group than in the high-protein diet group. But all these differences were not significant. [ Conclusion] The breeder roosters fed with the diet at the crude protein level of 13.04% show better reproductive performance and economic efficiency.

Effect of dietary canthaxanthin and 25-hydroxycholecalciferol supplementation on the performance of duck breeders under two different vitamin regimens

Background： Dietary canthaxanthin（CX）, 25-hydroxycholecalciferol（25-OH-D3） and vitamins have been widely reported to be involved in productive and reproductive performance of broiler breeders. However, limited information is available for duck breeders. In this study, a total of 1,560 Cherry Valley SM3 duck breeder females and 312 males were used to assess if the addition of CX and 25-OH-D3 could increase the performance of duck breeders under two different dietary vitamin regimens. Four diets were used under a 2 × 2 factorial arrangement with 2 kinds of vitamin premixes（REGULAR and HIGH; HIGH premix had higher levels of all vitamins except K3 than REGULAR premix）, and with or without the supplementation of the mixture of CX（6 mg/kg） and 25-OH-D3（0.069 mg/kg）. The ducks were fed ad libitum with pelleted diets based on corn-soybean meal from 38 to 77 wk of age.Results： HIGH vitamin premix decreased malondialdehyde（MDA） level（P 〈 0.001） of egg yolk, increased hatchability of fertile eggs（P = 0.029）, increased hatchability of total eggs（P = 0.029）, and decreased serum protein carbonyl level（P = 0.037） of breeder males. The mixture of CX and 25-OH-D3 increased serum calcium of breeder females（P = 0.010）, decreased the cracked egg rate（P = 0.001）, increased the pigmentation of egg yolk（P 〈 0.001）and male bill（P 〈 0.001）, and decreased MDA level of egg yolk（P 〈 0.001） and male serum（P = 0.034）. Interactive effects were observed in cracked egg rate（P = 0.038）, shell thickness（P = 0.011） and serum phosphorus（P = 0.026）of breeder females. HIGH vitamin premix together with the mixture of CX and 25-OH-D3 decreased cracked egg rate and increased shell thickness of duck breeders. Serum phosphorus was decreased in duck breeder females fed REGULAR vitamin premix without the addition of the CX and 25-OH-D3 mixture.Conclusions： Dietary HIGH vitamin premix increased antioxidant status of eggs and breeder males, and increased hatchability. The mixture of CX and 25-OH-D3 enhanced egg shell quality, and promoted pigmentation and antioxidant status of eggs and breeder males.

Microstructure Analysis for Chemical Interaction between Cesium and SUS316 Steel in Fast Breeder Reactor Application

The objective of this study is to presume cesium corrosion process and its dominant factors in SUS316 steel, a fuel cladding material for fast breeder reactor application, based on both experimental results of cesium corrosion out-pile test and thermodynamic consideration. The cesium corrosion test was performed in simulated environment of high burn-up fuel pin. And main corrosion products in the specimen after the corrosion test were specified by TEM （transition electron microscopy） and SEM （scanning electron microscopy） in order to formulate a hypothesis of the cesium corrosion process. At the end of this study, it was found that the dominant factors of the corrosion process are the amount of cesium on the surface of the specimen, chromium content in the alloy, the supply rate of oxygen and temperature.

Design optimization of first wall and breeder unit module size for the Indian HCCB blanket module

The Indian test blanket module（TBM） program in ITER is one of the major steps in the Indian fusion reactor program for carrying out the R＆D activities in the critical areas like design of tritium breeding blankets relevant to future Indian fusion devices（ITER relevant and DEMO）.The Indian Lead–Lithium Cooled Ceramic Breeder（LLCB） blanket concept is one of the Indian DEMO relevant TBM,to be tested in ITER as a part of the TBM program.Helium-Cooled Ceramic Breeder（HCCB） is an alternative blanket concept that consists of lithium titanate（Li_2TiO_3） as ceramic breeder（CB） material in the form of packed pebble beds and beryllium as the neutron multiplier.Specifically,attentions are given to the optimization of first wall coolant channel design and size of breeder unit module considering coolant pressure and thermal loads for the proposed Indian HCCB blanket based on ITER relevant TBM and loading conditions.These analyses will help proceeding further in designing blankets for loads relevant to the future fusion device.

竞雄玉米育种学校(Jingxiong Maize Breeder School)开班启事

为提高玉米育种工作者的理论水平和实践能力,促进我国玉米产业的发展,中国作物学会玉米专业委员会和国家玉米改良中心联合国内外重要科研单位和企业发起成立玉米育种学校。学校命名为竞雄玉米育种学校,以纪念李竞雄先生为代表的老一辈玉米专家对我国玉米事业所做出的突出贡献。

Detection of bacterial biofilm in uterine of repeat breeder dairy cows

Objective:To determine the possibility of presence of bacterial biofilm in the uterus of repeat breeder cows and to evaluate the effect of mucolytic agent in cleanup of uterus from biofilm. Methods: Twenty repeat breeder cows were selected from a large commercial dairy farm near Shiraz, Fars province, southern Iran. Uterine secretion samples were collected before and after uterine lavage with dimethyl sulfoxide (DMSO) 10% solution and periodic acid Schiff (PAS) staining was used to detect bacterial biofilm in uterine samples. After sampling, all cows were treated with two doses of PGF2 and intrauterine infusion of Cefquinome sulphate. Artificial insemination (AI) was performed after that.Results: Bacterial biofilms were found in 12 out of 20 animals (60%) in the first sampling with sterile saline lavage (before DMSO) and in 7 cows (35%) after DMSO lavage. Fourteen cows (70%) became pregnant after AI. This evidence showed the presence of bacterial biofilm in the uterus of dairy cows for the first time. Although non-significant, decrease in biofilm detection after DMSO lavage may suggest the potential ability of mucolytic agent for cleaning the uterus from bacterial biofilm. Also, high pregnancy rate after antibiotic treatment in the present study might be attributed to improved effect of antibiotic following lavage of uterine by DMSO.Conclusions:These findings should be investigated in future researches with more sample size.

Identification of pathogenic microorganisms of repeat breeder dairy cows and a hyperimmune treatment approach

Objective:To investigate the bacterial infections in repeat breeder dairy cows and to evaluate the treatment effects of hyperimmune serum against two main endometritis bacteria,Escherichia(E.)coli and Trueperella pyogenes.Methods:A total of 29 Holstein multiparous cows with three or more unsuccessful artificial inseminations were carried out and examined to confirm the absence of reproductive tract abnormality and vaginal discharges.Uterine lavage was performed to collect uterine samples for bacterial and fungal cultures.In addition,polymerase chain reaction(PCR)was done to detect Trueperella pyogenes,E.coli,Fusobacterium necrophorum,and Prevotella melaninogenicus.The cytological study was done on cervical mucus.The hyperimmune serums produced against Trueperella pyogenes and E.coli were infused into the uterus of repeat breeder cows and two doses of prostaglandin F2αwere administrated intramuscularly within 14 days'interval.Results:There were 10 positive samples in the bacterial culture with 19 isolations and no growth of the main causative bacteria of endometritis.In the PCR method,no Trueperella pyogenes,Fusobacterium necrophorum,and Prevotella melaninogenicus were found.However,11 positive samples of E.coli were identified by PCR.Cladosporium was detected in one case of repeat breeder cows.The median(interquartile range)of neutrophils in vaginal discharge was 12(22.5).Eighteen from twenty-nine(62.1%)repeat breeder and eight from eleven(72%)cows with E.coli infections in PCR were made pregnant in the first artificial insemination after treatment by intrauterine infusion of hyperimmune serum and prostaglandin F2α.Conclusions:Intrauterine administration of hyperimmune serum could be an alternative to antibiotics for the treatment of repeat breeder cows.

Combination of a <i>Lactobacillus</i>-Based Probiotic and Organic Acids Decrease Egg to Chick Weight Loss and Reduce <i>Salmonella</i>spp. Counts in the Litter of Commercial Broiler Breeders

The effects of supplementing a blend of organic acids (OA) and a lactic acid bacteria (LAB) based-probiotic on egg to chick weight loss (%) and Salmonella spp. recovery counts in the litter of commercial broiler breeders were examined in three independent trials during the years 2013, 2014 and 2015. In each trial, ten thousand birds were divided into two groups of 5000 birds (4500 females and 500 males in each group): Control non-treated group, receiving regular water or treated group, receiving OA and probiotic in the drinking water from 25 to 35 weeks of age. During the ten weeks of evaluation, one thousand fertile eggs or hatched chickens in each trial respectively, were evaluated to obtained, hatching set weight, transferred egg weight, and hatching chick weight, to estimate the difference between egg to chick weight loss (%). Besides, in trial 2 (2014) and trial 3 (2015), litter samples were collected to evaluate Salmonella spp. counts. The supplementation of OA and probiotic during ten consecutive weeks significantly decreased the egg to chick weight loss (%) when compared with the control non-treated groups in all three trials evaluated. Interestingly, at the end of the trials 2 and 3, no counts of Salmonella spp. in the litter were detected. In contrast, control-non treated groups resulted in 4.30 and 4.24 Log10 of Salmonella spp. in trials two and three respectively. The results of the present study suggest that supplementation of OA and a LAB-probiotic for ten consecutive weeks decrease the egg to chick weight loss (%) and reduce Salmonella spp. counts in the litter of commercial broiler breeders. Higher initial body weight in broiler chickens and reduction of Salmonella spp., clearly justify the use of the combination of these products, as alternatives to antibiotics.

Follicular fluid composition of ovulatory follicles in repeat breeder Holstein dairy cows

Objective: To examine differences in the metabolite, steroid and lipopolysaccharide of follicular fluid collected from the ovulatory follicle of Holstein repeat breeding cows, lactating cows, and virgin fertile heifers. Methods: Estrus was induced in animals possessing functional corpus luteum by intramuscular administration of prostaglandin F2α. Six to twelve hours after detection of the standing estrus, cervical samples were collected to detect subclinical endometritis via counting neutrophils on stained smears of cervical swabs. Then, follicular fluid of ovulatory follicles and serum samples were collected from repeat breeding cows (n=11), lactating cows (n=8) and virgin fertile heifers (n=10). Sodium and potassium were measured with a flame photometer method. Urea, total protein, glucose, cholesterol andβ-hydroxybutyric acid were assayed with commercial spectrophotometry kits. Chloride concentration was also measured with titration of samples against silver nitrate. Progesterone, estradiol-17βand lipopolysaccharide concentrations were measured using enzyme-linked immuno sorbent assay kits. Results: All analysis of follicular fluid samples showed that repeat breeding and lactating cows had a mean higher lipopolysaccharide concentration than that of the virgin fertile heifers (P<0.05). But concentration of serum estradiol-17βin repeat breeding and lactating cows was lower than that of virgin fertile heifers (P<0.05). In addition, the mean percentage of neutrophils in the cervical secretion of repeat breeding cows was higher than that of lactating cows (P<0.05). Conclusions: High follicular fluid concentration of lipopolysaccharide in ovulatory follicles results in the occurrence of repeat breeding syndrome in dairy cows. Further, a lower serum estradiol-17βconcentration and a higher percentage of neutrophil in the cervical secretion on the day of artificial insemination may have resulted in the occurrence of repeat breeding syndrome in dairy cows.

Methicillin Resistant Staphylococcus aureus in Pigs and Pig Breeders in Three Regions of Cameroon

The spread of antibiotic resistance, whether in the community or in the hospital, has recently become a major public health problem. Moreover, livestock seems to be a reservoir of resistant microorganisms such as porcine methicillin resistant Staphylococcus aureus (P-MRSA) whose carriage and transmission was mainly demonstrated in persons with occupational exposure to pigs. Much uncertainty remains about the public health implications of P-MRSA. To address concerns that exist regarding the zoonotic risk that pig carriers pose to breeders, the prevalence of P-MRSA in pigs and pig breeders was determined among 152 pig breeders in three regions of Cameroon. Materials and Method: Participants in this study came from Adamawa, Far North and Littoral regions of Cameroon. A total of 152 pig breeders or farm workers participated in this study. After having collected some social and cultural data with the aid of a questionnaire, nasal swabs were collected from pigs (n = 275) and their breeders using the standard collection procedures and placed in cooler containing cold accumulators. For each sample, microbiological assays were done as well as antibiotic susceptibility tests. Results: MRSA was isolated from 25 out of 275 pigs sampled (9.09%) and from 32 out of 152 (21.05%) pig breeders sampled;33 breeders (21.71%) were carriers of S. aureus including 32 MRSA and one MSSA. The prevalence of MRSA nasal carriage was 21.05% ± 6.48. A significant negative association between body protection and nasal carriage of MRSA (OR = 0.29, 95% CI [0.093;0.93];p = 0.04) was observed. In each region, similar strains of MRSA were isolated both in pigs and their breeders with the same antibiotic resistant profile. Conclusion: The prevalence of MRSA though not high compared to European countries warrants further research as data on this zoonosis is scarce in our context. As such, transmission of MRSA from pigs to pig breeders or vice-versa constitutes a real danger, and this relationship may be a starting point for MRSA contamination in the community. Moreover, proper use of body protections and antibiotic medications as recommended will be a better protective measure against nasal MRSA carriage.

Effect of Dietary Nitrogen Corrected-True Metabolism Energy and Digestible Amino Acids on Broiler Breeder Reproductive Performance

A study was conducted to determine the effects of dietary digestible amino acids of feedstuffs and true metabolizable energy corrected for nitrogen on broiler breeder performance in 50 weeks to 64 weeks of age. 140 females and 20 males broiler breeders in 4 treatments with 5 replicates （7 females with a male） were used in the form of a completely randomized trial design 2 ~ 2 factorial. Four experimental diets were formulation based on two factors, first factor was included, two types of Apparent and True Metabolizable Energy corrected for Nitrogen （AMEn and TMEn） and the second factor was included, two types of Total Amino Acids （TAA） and Digestible （DAA） of feedstuffs. The result showed that egg weight, egg production （%） and egg mass （g/hen/day） was significantly different which was affected by diets formulation based on energy and interaction between energy and amino acids （P 〈 0.01）. Treatment 2 （AMEn ＋ DAA） was at the highest level significantly different （P 〈 0.01） in egg weight 68.97 g, egg production 62.45%, and egg mass 43. i g/hen/day. Hatching eggs were significantly different which was affected by diet formulation based on amino acids. Fertility, hatchability and number of chicks per hen were significant different, that were affected by diet formulation based on energy （P 〈 0.05）. Interaction between two factors, were significantly different in two reproductive traits fertility and hatchability （P 〈 0.05）. This experiment showed that diet formulation based on AMEn and DAA for broiler breeder was better and significant on performance.

Effect of Bee Pollen on Reproductive Performance of Broiler Breeders

[Objective]The paper was to verify whether chestnut bee pollen can be used as feed for breeding chickens and its appropriate addition proportion.[Method]A total of 92444-week-old Ross 308 broiler breeders of parent generation with a male to female ratio of 1∶10 were randomly divided into 4 groups,with 3 replicates in each group and 7 cocks and 70 hens in each replicate.The broiler breeders in the control group were fed with the basal diet,and those in experimental groups were fed with the diets supplemented with 0.5%,1.0%and 1.5%chestnut bee pollen.The feeding trial lasted 35 d.[Result]Addition of chestnut bee pollen at different proportions improved the laying rate of breeder hens in different degrees.The experimental group supplemented with 1.5%chestnut bee pollen increased the laying rate by 9.1%,reduced the rate of unqualified eggs(broken eggs,cracked eggs,thin shelled eggs and hard shelled eggs)by 71.4%,increased the fertilization rate of hatching eggs and healthy chick rate by 4.4%and 5.2%,and improved the concentrations of testosterone(T),follicle stimulating hormone(FSH)and luteinizing hormone(LH)in breeder cocks by 60.8%,32.3%and 61.4%,respectively.Statistical analysis showed that the results were significantly different.[Conclusion]Addition of chestnut bee pollen at certain concentration can improve the reproductive performance of breeder cocks and breeder hens,and improve the body immunity.

Characterization of Lay Phase in Three Genetic Types of Heavy Broilers Breeder in Tropical Conditions

The objective of the present work is characterizing some parameters in the lay phase in the lines of heavy broilers breeder Cobb Avian 48, Arbor Acres Plus and Ross 208, reared under the same commercial conditions in the tropics. Monitored three batches of approximately 18,000 females each （one for each genetic type）, from weeks 24 to 64, according to the conditions of handling and power described by the generic lines distribution companies. Although no differences were found for feed intake, Cobb Avian was presented a lower rate of feed conversion, being also that presented the highest percentage of implementation and production of incubables eggs, which meant that it was in line with the highest cumulative production of chickens by bird and week for tropical conditions studied. To adjust the lay data to a Gorssman model, in order to predict the parameters that characterize the lay modeling, estimated the best behavior for Cobb Avian 48 females, because while it takes more time to reach the level of putting constant （5.30 weeks） and maintain it for less time （2.4 weeks）, they manage to put constant high （79.11%） level, considering that the largest number of eggs per bird （171.19 vs. 164.54 and 160.11 in Arbor Acres and Ross 208, respectively）.

Subtle sexual plumage color dimorphism and size dimorphism in a South American colonial breeder, the Monk Parakeet(Myiopsitta monachus)

Background:Parrots(Psittacidae Family)are one of the most colorful groups of birds in the world,their colors pro-duced both structurally and via unusual pigments(psittacofulvins).Most species are considered to be monogamous,and many have been viewed historically as sexually monomorphic and monochromatic.However,studies using morphometric analysis and spectrophotometric techniques have revealed sexual size dimorphism and also sexual plumage color dimorphism among some species.The Monk Parakeet(Myiopsitta monachus),a native parrot of South America,is an interesting species for the study of plumage coloration and size since it is considered sexually mono-chromatic and monomorphic.Furthermore,recent studies show that the Monk Parakeet has extra-bond paternity behavior and even breeding trios,which suggests that sexual selection may play an important role in this species,and that it might have sexually dimorphic plumage(albeit imperceptible by humans)and be dimorphic in size.Methods:For the determination of plumage color we used spectrophotometry in the range of avian vision(300-700 nm)and performed a morphological analysis.Results:Our spectrophotometric results indicate that the Monk Parakeet shows subtle sexual plumage color dimor-phism in three(crown,nape and wing)out of twelve body regions.Similarly,our morphometric analysis showed that there are subtle sex differences in body size(bill and weight).Conclusions:Although the Monk Parakeet shows extra-bond paternity and breeding trio behaviors which could increase sexual dimorphism,these behaviors occur among highly related individuals;perhaps the high rate of inbreeding is responsible for the attenuation of sexual plumage color dimorphism and sex differences in body size observed.

Detection of Mycoplasma synoviae Infection in Broiler Breeder Farms of Morocco Using Serological Assays and Real Time PCR

Mycoplasma synoviae （MS） is an economically important pathogenic agent of chickens, causing air sacculitis and synovitis. The diagnosis and monitoring of M. synoviae infection is usually made using serological assays, while confirmative diagnosis is made by isolation and identifcation of the organism, because of the cross reaction between M. gallisepticum and M. synoviae. This study was conducted from 2011 to 2013 during which l l broiler breeder flocks were sampled. These farms were located in all regions of morocco, The sampling was conducted as follows： Farms were visited on day one old chicks ＂day of importation from Europe＂. 20 to 60 ＂chicks＂ were randomly sampled. At the age of 8, 16, 32 and 56 weeks, 60 blood samples and 60 tracheal swabs were collected at each sampling. The serological screening was performed using Rapid Slide Agglutination （RSA） according the OIE protocol and Indirect EL1SA （IDEXX） according the manufacturer＇s instructions. The molecular diagnosis was performed using a commercial kit of a duplex real time PCR （Life Biotechnology）. The results revealed that one day old chicks were negative to MS by RSA and PCR, however they have a variable stock of maternal antibodies （Ig-Y） detected by iELISA. The seroprevalence found by RSA is variable and increase with the age （Sth week： 55%, 16th week： 91%, 32tb and 56th week： 100%）, the same profile was traced by PCR （Sth week： 36%, 16th week： 64%, 32th week： 82%, 56th week： 100%）, however, all farms were positive by iELISA, from the first day to 56th weeks. These results show that MS infections are very frequent and very widespread among poultry breeder flocks, and showed a perfect agreement between serological tests and Real time PCR starting from 32th week of age.

A Successful Breeder of Economic Animals

Mr.Liu Jianjun,a farmer forty years of age from Daqiaotou Village,Xiaoxian County,in Hunan Province,has become well-off by raising turtles.Liu's parents had six children and consequently lived a poor life.He was well aware that tbe family's hard time resulted from having too many children.In 1984,Mr.Liu gave birth to a boy and then choose a long-acting contraceptive method In 1985,he accepted the"single-child certificate".

Live and Inactivated Salmonella Enteritidis Vaccines:Immune Mechanisms in Broiler Breeders

Salmonella is a ubiquitous pathogen which, in addition to causing poultry diseases, has a growing zoonotic impact. It has demanded the implementation of diverse control strategies, in which vaccines play a major role. The understanding of the immune pathways elicited by the different vaccines is important, contributing for the establishment of strong immune correlates of protection, for instance. With the purpose of determining the dynamics of the humoral and cellular immune responses to vaccination, broiler breeders (Cobb Slow) were immunized with live or inactivated vaccines against Salmonella Enteritidis. Lymphocyte and macrophage subsets were analyzed in the peripheral blood by flow cytometry and antigen-specific circulating IgY and mucosal IgA were quantified. The markers analyzed by flow cytometry were CD8/CD28, CD4/TCRVβ1, Kul/ MHC II and Bu-1. Both live and inactivated vaccines induced an increase in the proportion of circulating monocytes (Kul+MHCII+) in some time points compared to non-vaccinated controls. However, whereas the live vaccine leads to an increase in CD8-CD28+ and Bu-1+ lymphocytescompared to the control group, the inactivated vaccine prompteda reduction in the percentage of severalleucocyte subsets (Kul-MHCII+, Bu-1+, CD8+CD28+, CD8-CD28+, CD4+TCRVβ1-, CD4+TCRVβ1+, CD4-TCRVβ1+) after the boost dose. Both vaccines induced specific serum IgY and mucosal IgA production;however, the inactivated vaccine stimulated higher titers in a shorter period. These results contribute to the understanding of mechanisms of action of live and inactivated Salmonella vaccines in chickens.

江苏省肉种鸡场禽多杀性巴氏杆菌流行病学调查

为了解江苏省禽多杀性巴氏杆菌流行情况,促进肉种鸡场的禽多杀性巴氏杆菌病防控,研究通过细菌鉴定方法、PCR检测、荚膜血清学分型、致病性分析以及药物敏感性试验,对分离自江苏省17个肉种鸡场的禽多杀性巴氏杆菌进行菌落形态、培养特性、生化发酵、荚膜型、菌落荧光型、药敏性等生物学特性研究,并对部分种鸡场进行血清学检测。结果显示:共鉴定13株禽多杀性巴氏杆菌,所有分离株荚膜分型均为A型,菌落荧光观察均属于强毒株;分离株对氨基糖苷类药物和氯霉素类药物具有一定的耐药性,而对β-内酰胺类药物高度敏感;确诊种鸡场阳性率显著高于未确诊种鸡场(P<0.01)。研究表明,江苏省部分地区肉种鸡场存在荚膜A型多杀性巴氏杆菌流行,强毒株比例较高,但耐药性较弱。