Prevalence and Distribution of Tick-Borne Hemoparasites in Cattle from the Noun and Ndé Divisions of the West Region, Cameroon

Background and Objective: Tick-borne hemoparasitic illnesses pose a serious threat to the well-being and productivity of cattle. This study aimed to investigate the prevalence of tick-borne hemoparasites in Cameroon, with a specific focus on the Noun and Nde Divisions of the West Region. Methodology: A total of 423 cattle from 10 villages in both divisions were included in the study. Blood smears were prepared and subjected to microscopic screening for Babesia and Anaplasma parasites. Results: The prevalence of Anaplasma was found to be 23.4%, while Babesia exhibited a seroprevalence of 17.3%. Samples from Institute of Agricultural Research for Development (IRAD) and Koupa Ngangnou demonstrated significantly higher prevalence rates, potentially influenced by climate variations affecting tick populations. Additionally, 17.3% of the animals exhibited low hematocrit levels, indicative of anemia. No significant associations were observed between the presence of hemoparasite infection and cattle characteristics. Conclusion: This study provides fundamental data on the extensive distribution and impact of tick-borne hemoparasites in a significant cattle-producing region of Cameroon.

Generation of double knockout cattle via CRISPR-Cas9 ribonucleoprotein(RNP)electroporation

Background Genome editing has been considered as powerful tool in agricultural fields.However,genome editing progress in cattle has not been fast as in other mammal species,for some disadvantages including long gestational periods,single pregnancy,and high raising cost.Furthermore,technically demanding methods such as microinjection and somatic cell nuclear transfer(SCNT)are needed for gene editing in cattle.In this point of view,electroporation in embryos has been risen as an alternative.Results First,editing efficiency of our electroporation methods were tested for embryos.Presence of mutation on embryo was confirmed by T7E1 assay.With first combination,mutation rates for MSTN and PRNP were 57.6%±13.7%and 54.6%±13.5%,respectively.In case of MSTN/BLG,mutation rates were 83.9%±23.6%for MSTN,84.5%±18.0%for BLG.Afterwards,the double-KO embryos were transferred to surrogates and mutation rate was identified in resultant calves by targeted deep sequencing.Thirteen recipients were transferred for MSTN/PRNP,4 calves were delivered,and one calf underwent an induction for double KO.Ten surrogates were given double-KO embryos for MSTN/BLG,and four of the six calves that were born had mutations in both genes.Conclusions These data demonstrated that production of genome edited cattle via electroporation of RNP could be effectively applied.Finally,MSTN and PRNP from beef cattle and MSTN and BLG from dairy cattle have been born and they will be valuable resources for future precision breeding.

Identification of key genes and metabolites involved in meat quality performance in Qinchuan cattle by WGCNA

Understanding the genetic and metabolic elements that impact meat quality is crucial to improving production and meeting consumer demands in the beef sector.Differences in meat quality among various muscle areas in beef cattle can impact pricing in the market.Despite progress in genomics,the specific genes and metabolites that affect meat quality characteristics in Qinchuan cattle remain inadequately understood.Therefore,this study aims to evaluate the meat quality characteristics of four specific muscle locations(tenderloin,striploin,high rib,and ribeye muscles)in Qinchuan bulls,including 10 traits(total protein content(TPC),intramuscular fat(IMF),non-esterified fatty acid(NEFA),meat color(L*,a*,and b*),shear force(SF),cooking loss(CL),pH0,and pH24).This experiment uses transcriptome,metabolome sequencing,and sophisticated analytical methodologies such as weighted gene co-expression network analysis(WGCNA)and protein–protein interaction networks(PPI)to identify the key genes and metabolites associated with specific traits.The findings highlight three notable genes(NDUFAB1,NDUFA12,and NDUFB7)linked to intramuscular fat(IMF),three key genes(CSRP3,ACAA3,and ACADVL)correlated with non-esterified fatty acids(NEFA),and one crucial gene(CREBBP)influencing meat color.In conclusion,this investigation offers a new perspective on the differences in bovine muscle locations and contributes to the molecular understanding of bovine meat quality.Future research endeavors could delve deeper into the identified genes and pathways to enhance beef cattle’s quality and yield.

Diet and monensin influence the temporal dynamics of the rumen microbiome in stocker and finishing cattle

Background Stocker cattle diet and management influence beef cattle performance during the finishing stage,but knowledge of the dynamics of the rumen microbiome associated with the host are lacking.A longitudinal study was conducted to determine how the feeding strategy from the stocker to the finishing stages of production affects the temporal dynamics of rumen microbiota.During the stocker phase,either dry hay or wheat pasture were provided,and three levels of monensin were administrated.All calves were then transported to a feedlot and received similar finishing diets with or without monensin.Rumen microbial samples were collected on d 0,28,85 during the stocker stage(S0,S28 and S85)and d 0,14,28,56,30 d before slaughter and the end of the trial during the finishing stage(F0,F14,F28,F56,Pre-Ba,and Final).The V4 region of the bacterial 16S rRNA gene of 263 rumen samples was sequenced.Results Higher alpha diversity,including the number of observed bacterial features and the Shannon index,was observed in the stocker phase compared to the finishing phase.The bacterial amplicon sequence variants(ASVs)differentiating different sampling time points were identified.Dietary treatments during the stocker stage temporally impact the dynamics of rumen microbiota.For example,shared bacteria,including Bacteroidales(ASV19)and Streptococcus infantarius(ASV94),were significantly higher in hay rumen on S28,S85,and F0,while Bacteroidaceae(ASV11)and Limivicinus(ASV15)were more abundant in wheat.Monensin affected rumen microbial composition at a specific time.Transportation to feedlot significantly influenced microbiome structure and diversity in hay-fed calves.Bacterial taxa associated with body weight were classified,and core microbiotas interacted with each other during the trial.Conclusions In summary,the temporal dynamics of the rumen microbiome in cattle at the stocker and finishing stage are influenced by multiple factors of the feeding strategy.Diet at the stocker phase may temporarily affect the microbial composition during this stage.Modulating the rumen microbiome in the steers at the stocker stage affects the microbial interactions and performance in the finishing stage.

Re-identifying beef cattle using improved AlignedReID++

Accurate and continuous identification of individual cattle is crucial to precision farming in recent years.It is also the prerequisite to monitor the individual feed intake and feeding time of beef cattle at medium to long distances over different cameras.However,beef cattle can tend to frequently move and change their feeding position during feeding.Furthermore,the great variations in their head direction and complex environments(light,occlusion,and background)can also lead to some difficulties in the recognition,particularly for the bio-similarities among individual cattle.Among them,AlignedReID++model is characterized by both global and local information for image matching.In particular,the dynamically matching local information(DMLI)algorithm has been introduced into the local branch to automatically align the horizontal local information.In this research,the AlignedReID++model was utilized and improved to achieve the better performance in cattle re-identification(ReID).Initially,triplet attention(TA)modules were integrated into the BottleNecks of ResNet50 Backbone.The feature extraction was then enhanced through cross-dimensional interactions with the minimal computational overhead.Since the TA modules in AlignedReID++baseline model increased the model size and floating point operations(FLOPs)by 0.005 M and 0.05 G,the rank-1 accuracy and mean average precision(mAP)were improved by 1.0 percentage points and 2.94 percentage points,respectively.Specifically,the rank-1 accuracies were outperformed by 0.86 percentage points and 0.12 percentage points,respectively,compared with the convolution block attention module(CBAM)and efficient channel attention(ECA)modules,although 0.94 percentage points were lower than that of squeeze-and-excitation(SE)modules.The mAP metric values were exceeded by 0.22,0.86 and 0.12 percentage points,respectively,compared with the SE,CBAM,and ECA modules.Additionally,the Cross-Entropy Loss function was replaced with the CosFace Loss function in the global branch of baseline model.CosFace Loss and Hard Triplet Loss were jointly employed to train the baseline model for the better identification on the similar individuals.AlignedReID++with CosFace Loss was outperformed the baseline model by 0.24 and 0.92 percentage points in the rank-1 accuracy and mAP,respectively,whereas,AlignedReID++with ArcFace Loss was exceeded by 0.36 and 0.56 percentage points,respectively.The improved model with the TA modules and CosFace Loss was achieved in a rank-1 accuracy of 94.42%,rank-5 accuracy of 98.78%,rank-10 accuracy of 99.34%,mAP of 63.90%,FLOPs of 5.45 G,frames per second(FPS)of 5.64,and model size of 23.78 M.The rank-1 accuracies were exceeded by 1.84,4.72,0.76 and 5.36 percentage points,respectively,compared with the baseline model,part-based convolutional baseline(PCB),multiple granularity network(MGN),and relation-aware global attention(RGA),while the mAP metrics were surpassed 6.42,5.86,4.30 and 7.38 percentage points,respectively.Meanwhile,the rank-1 accuracy was 0.98 percentage points lower than TransReID,but the mAP metric was exceeded by 3.90 percentage points.Moreover,the FLOPs of improved model were only 0.05 G larger than that of baseline model,while smaller than those of PCB,MGN,RGA,and TransReID by 0.68,6.51,25.4,and 16.55 G,respectively.The model size of improved model was 23.78 M,which was smaller than those of the baseline model,PCB,MGN,RGA,and TransReID by 0.03,2.33,45.06,14.53 and 62.85 M,respectively.The inference speed of improved model on a CPU was lower than those of PCB,MGN,and baseline model,but higher than TransReID and RGA.The t-SNE feature embedding visualization demonstrated that the global and local features were achieve in the better intra-class compactness and inter-class variability.Therefore,the improved model can be expected to effectively re-identify the beef cattle in natural environments of breeding farm,in order to monitor the individual feed intake and feeding time.

Comparison of methods for deriving phenotypes from incomplete observation data with an application to age at puberty in dairy cattle

Background Many phenotypes in animal breeding are derived from incomplete measures,especially if they are challenging or expensive to measure precisely.Examples include time-dependent traits such as reproductive status,or lifespan.Incomplete measures for these traits result in phenotypes that are subject to left-,interval-and rightcensoring,where phenotypes are only known to fall below an upper bound,between a lower and upper bound,or above a lower bound respectively.Here we compare three methods for deriving phenotypes from incomplete data using age at first elevation(>1 ng/mL)in blood plasma progesterone(AGEP4),which generally coincides with onset of puberty,as an example trait.Methods We produced AGEP4 phenotypes from three blood samples collected at about 30-day intervals from approximately 5,000 Holstein–Friesian or Holstein–Friesian×Jersey cross-bred dairy heifers managed in 54 seasonal-calving,pasture-based herds in New Zealand.We used these actual data to simulate 7 different visit scenarios,increasing the extent of censoring by disregarding data from one or two of the three visits.Three methods for deriving phenotypes from these data were explored:1)ordinal categorical variables which were analysed using categorical threshold analysis;2)continuous variables,with a penalty of 31 d assigned to right-censored phenotypes;and 3)continuous variables,sampled from within a lower and upper bound using a data augmentation approach.Results Credibility intervals for heritability estimations overlapped across all methods and visit scenarios,but estimated heritabilities tended to be higher when left censoring was reduced.For sires with at least 5 daughters,the correlations between estimated breeding values(EBVs)from our three-visit scenario and each reduced data scenario varied by method,ranging from 0.65 to 0.95.The estimated breed effects also varied by method,but breed differences were smaller as phenotype censoring increased.Conclusion Our results indicate that using some methods,phenotypes derived from one observation per offspring for a time-dependent trait such as AGEP4 may provide comparable sire rankings to three observations per offspring.This has implications for the design of large-scale phenotyping initiatives where animal breeders aim to estimate variance parameters and estimated breeding values(EBVs)for phenotypes that are challenging to measure or prohibitively expensive.

Analysis on the Impact of Cattle Fattening Technology on Farmer Households in Atabae Timor-Leste

Agriculture is one of the priority sectors in Timor-Leste. Introducing new agriculture technology is crucial to enhance agricultural production. Practicing cattle fattening can increase beef cattle body weight and generate income to the beef cattle farmers. As farmers face problems including agricultural production decline, lack of forages and information and weather unfavourable. The study’s purpose was to examine the impact of adoption of cattle fattening technology on farmer households in Atabae administrative post, Bobonaro municipality in Timor-Leste. There were 200 beef cattle farmers households where randomly selected in four villages in Atabae. It consisted of 65 farmers practicing cattle fattening and 135 farmers non-practicing cattle fattening. Face to face interviews used structured questionnaire. Statistical analysis such as t-test and descriptive analysis were used to examine impact adoption of cattle fattening technology by farmers and factor constraints of cattle production and the solutions of it. The results indicated the average value of cattle and profit were significant different from zero and it is associated with practicing of cattle fattening. The average of labour used on cattle activities, the average of cattle sold, and total cost spent on cattle were not significant different from zero. The percentage of farmers said that factors constraints cattle production were shortage of water and forage (53%) and spend time on culture ceremony and lack of capital (33%). The number of farmers said that they collected water from river, feed cattle with sago and forage (55.3%) and cultivated forage (23.4%). This finding contributes information to the farmers, traders, and Timorese government to continue implementing cattle fattening activities as it enhances farmers’ income and developing cattle production.

Cattle Production and Lumpy Skin Disease of Smallholder Farmers in Svay Rieng Province

The cattle production in Romeas Haek district,Svay Rieng province,was developed remarkably,since there were some households raising cattle in large number,more than 20 heads.The grazing method of cattle was tethering and free grassing in the commune grass,since the natural grass and rice straw were the main source of cattle feed,however some of them supplemented their cattle with crop-byproducts,planting grass or concentrated feed.For the majority,BCS(Body Condition Scoring)of the cattle in those areas was 3 accounting for 52%-73.33%,but it was found the thin cattle has low BCS of 2 accounting for 11.11%to 40.00%and also fat cattle has BCS of 4 up to 27.78%.However,the average BCS varied with village which ranged from 2.68 to 3.17,but is not different in term of commune and sex of cattle.Besides facing with shortage of feed,the experience with diseases was also another concern,since 85.71%to 95.83%of the households faced this problem last year.Among the clinical signs found,lumpy skin was 100%,i.e.no one escaped from this problem,thus making them aware of vaccinating their cattle against some diseases such as FMD(Foot and Mouth Disease),HS(Hemorrhagic Septicemia)and LSD(Lumpy Skin Disease),but mostly vaccination was used against FMD.Because the LSD has occurred in these areas since 2020,then the seroprevalence was found in high positive up to 72.62%by Enzyme-Linked Immunosorbent Assay(ELISA)test.This positive rate was also varying by villages,ranging from 53.3%to 94.44%.But there was no association between positive cattle with commune,BCS,sex and age of cattle.In conclusion,the cattle production in Romeas Haek district,Svay Rieng province had developed markedly,however the shortage of feed and disease occurrence are the main challenges for farmer cattle producers,especially LSD outbreak last year.However,most of the farmers have been aware of the benefit of vaccination and had vaccinated their cattle against those main disease,such as FMD,HS and LSD.

Beyond statistical significance:Embracing minimal clinically important difference for better patient care

The minimal clinically important difference(MCID)represents a pivotal metric in bridging the gap between statistical significance and clinical relevance,addressing the direct impact of medical interventions from the patient's perspective.This comprehensive review analyzes the evolution,applications,and challenges of MCID across medical specialties,emphasizing its necessity in ensuring that clinical outcomes not only demonstrate statistical significance but also offer genuine clinical utility that aligns with patient expectations and needs.We discuss the evolution of MCID since its inception in the 1980s,its current applications across various medical specialties,and the methodologies used in its calculation,highlighting both anchor-based and distribution-based approaches.Furthermore,the paper delves into the challenges associated with the application of MCID,such as methodological variability and the interpretation difficulties that arise in clinical settings.Recommendations for the future include standardizing MCID calculation methods,enhancing patient involvement in setting MCID thresholds,and extending research to incorporate diverse global perspectives.These steps are critical to refining the role of MCID in patient-centered healthcare,addressing existing gaps in methodology and interpretation,and ensuring that medical interventions lead to significant,patient-perceived improvements.

Sterilization Effects of Bacterial Inhibitor on Escherichia coli in Cattle Manure Compost

[Objective] The aim of this study was to explore the sterilization effects on Escherichia coli by adding bacterial inhibitor(CaCN2)during the process of cattle manure composting so as to provide a theoretical basis for cattle manure harmless treatment.[Method] Both experimental groups supplemented with 2.0% bacterial inhibitor and control groups without bacterial inhibitor were cultured under different temperatures(20,30,37,50,60 ℃)to determine the optimal composing temperature.Under 30 ℃,different bacterial inhibitor doses(0,2.0%,2.5%,3.0%)were added into the compost to obtain the optimal bacterial inhibitor addition dose.[Result] 30,50 and 60 ℃ were ideal temperatures for sterilization of E.coli.Under 30 ℃,E.coli couldn't be detected in 2.5% dose group and 3.0% dose group after culture for 48 h,demonstrating no less than 2.5% bacterial inhibitor should be added.[Conclusion] It has an important significance to enhance the sterilization effects on E.coli by adding CaCN2 into cattle manure compost especially in winter.

Genetic Variation of Mitochondrial D-loop Region and Evolution Analysis in Some Chinese Cattle Breeds

The complete mitochondrial D-loop region from 123 individuals in 12 Chinese cattle breeds and two individuals in Germany Yellow cattle breed was sequenced and analyzed. The results were shown as follows： 93 variations and 57 haplotypes were detected, and the average number of nucleotide difference was 22.708, nucleotide diversity （π） was 0.0251 ± 0.00479, and haplotype diversity （Hd） was 0.888 ± 0.026, indicating very high genetic diversity in Chinese cattle breeds. In the Neighbor-Joining tree, 13 cattle breeds were divided into two main clades, Bos taurus and Bos indicus; new Clade Ill had only one sequence from Apeijiaza cattle breed in Tibet, which was similar to that of yak at a higher level than other cattle breeds, proving the introgression of genes from the yak. The proportions of Bos taurus and Bos indicus were 64.3 % and 35.7 % respectively in Xigaze Humped cattle breed, and 50.0% and 50.0% respectively in Apeijiaza cattle breed, which revealed that Tibet cattle included Bos indicus haplotypes. The importance of Yunnan cattle in the origin of Chinese cattle was also confirmed based on their abundant haplotypes. Then, a very special haplotype il discovered in 27 Chinese cattle breeds, including 11 breeds in this study and 16 breeds in the GenBank, played the role of a nucleus in Chinese zebu and was further discussed. At the same time, the construction of Chinese zebu core group based on haplotype il validated the distinct origin of Bos indicus in Tibet, which was different from that of the other cattle breeds with zebu haplotypes in China.

Association of Polymorphisms of Leptin Gene with Body Weight and Body Sizes Indexes in Chinese Indigenous Cattle

PCR-SSCP was used to analyze the polymorphism of leptin gene in 539 samples of six cattle breeds, namely Nanyang （NY）, Qinchuan （QC）, Jiaxianred （JXR）, Xizhen （XZ）, Luxi （LX）, and Holstein cow （HOL） breeds. PCR products with a 330 bp were amplified and sequenced. The results showed that the frequencies of alleles A/B of NY, QC, JXR, XZ, LX, and HOL breeds were 0.558/0.442, 0.492/0.508, 0.571/0.429, 0.658/0.342, 0.591/0.409, and 0.615/0.385, respectively. The association of variations of leptin gene with growth traits in NY, QC, JXR breeds was analyzed. Some indexes of the individuals with genotype BB were higher than that with genotype AA and AB in NY breed, such as the indexes of body length, heart length, body weight, hucklebone width, body height, and average day gain. The height at hip cross of the individuals with genotype BB was higher than that of those with genotype AA and AB in QC breed （P 〈 0.05）. So leptin gene may be one of the candidate genes for growth traits with height at hip cross, but not for body weight, heart length, and body length trait. However, the height at hip cross and hucklebone width of the individuals with genotype AB and BB were higher than that of those with genotype AA in JXR breed （P 〈 0.05）, but the difference was not statistically significant in body weight and body sizes （body height, body length, and heart length）. And the polymorphisms in leptin gene were caused by G→T transversion at the 66th bp position, A→C transversion at the 67th bp position and G→T transversion at the 299th bp position. These results may be applied to marker-assisted selection of Chinese cattle breeds.

Effect of Yizhikang Powder on Hemorheological Indexes in Dairy Cattle with Retained Placenta

[ Objective ] The aim of the research was to reveal the mechanism of Yizhikang powder treatment on dairy cattle with retained placenta from the hemorheological perspective. [ Method] Dairy cattle with retained placenta were treated with oral administration of Yizhikang powder. And their hemorheological indexes were measured and compared with the corresponding indicators of pre-administration group, healthy group, and control group （sick but untreated）.[ Result] There was large decrease amplitude in the indexes （whole blood viscosity, plasma viscosity, whole blood viscosity reduction viscosity, ESR, ESR equation K value, fibrinogen content, platelet aggregation rate, RBC deformability IF value） of treated dairy cattle with retained placenta. By t test, the indexes, except hematocrit, decreased significantly after treatment （P〈0.05） and reached the status of post partum healthy cows. The hemorheological indexes didn＇t change significantly in the control group before and after treatment. [ Conclusion] Yizhikang powder could significantly improve blood flow state and reduced the occurrence of qi stagnation and blood stasis in perinatal period.

HISTOCHEMICAL TECHNIQUES IDENTIFYING MAST CELLS IN PIG,CATTLE AND SHEEP

Carnoy′s fluid and neutral buffered formalin(NBF)have been proved to be good fixatives for preservation of mast cells in pig,cattle and sheep except NBF blocked staining of most porcine mast cells,especially those located in intestinal mucosa(MMC)and in thymus medulla(TMMC). Both toluidine blue and Alcian blue were the excellent stains generally,but Alcian blue stained more porcine mast cells than did toluidine blue( P <0 01). Staining with toluidine blue of a wide pH range(from 0 1 to 7 0)showed that porcine mast cells were not very pH dependent,but the dye at pH 0 5 seemed to have the strongest affinity for all mast cells in pigs and it was also suitable for bovine and ovine mast cell staining. In the three species,unlike in rodents,the Alcian blue method did not distinguish between mast cells in the intestinal mucosa(MMC)and those in the connective tissue of the intestinal submucosa,tongue and skin(CTMC). Porcine CTMC,but not MMC,fluoresced strongly when stained with berberine sulphate or with a mixture of berberine sulphate and acridine orange. It suggested that porcine CTMC contained heparin proteoglycan.

Study on Compound Substrate Properties with Spent Mushroom Compost and Cattle Manure Compost and Effects on the Growth of Seedlings

[Objective] The purpose was to study the optimum composition ratio of compound substrate with spent mushroom compound （SMC） and cattle manure com- post （CMC） for the seedling growth of tomato, cucumber and watermelon. [Method] With internationally best formula substrate （turf：vermiculite=2：1） used for CK, SMC and CMC were matched according to different proportions to get different substrate whose physical and chemical nutrient properties and their effects on the growth of tomato, cucumber and watermelon were studied by means of plug seeding technolo- gy. [Result] The results showed that the bulk density, porosity and the pH of the compound substrates are all in the ideal condition. However, CMC increased the EC value and the pH of the compound substrates. Compound substrates with high ratio of CMC are not suitable for seedlings. [Conclusion] Tomato and watermelon seedlings grew well in the compost substrate with SMC：CMC=3：1 with no river sand. And the cucumber seedlings grew well in the compost substrate with SMC：CMC=2：1 with 5% volume river sand.

Mitochondrial DNA D-loop Variation and Genetic Background of Brahman Cattle

The complete mitochondrial DNA D-loop sequences from 10 stud Brahman cattle were sequenced and analyzed. The results showed that the genetic diversity of Brahman cattle was rich ; the rate of nucleotide variation, haplotype diversity and nucleotide diversity were 6.25%, 0.978± 0.054 and 0.014 30± 0.008 68, respectively. Nine haplotypes were defined and fell into two distinct lineages, suggesting that Brahman cattle have both Bos indicus （Zebu） and B. taurus genetic background. The taurine haplotypes were predominant at 90% and only Brah-6 belonged to the Asian zebu mthaplotype. This indicates that Brahman cattle was one of the zebu breeds and inherited the excellent characteristics of both the Asian zebu and European beef cattle, such as easy calf delivery, high quality beef, heat tolerance and resistance to various parasites. Breeders introduced Brahman cattle to improve the productivity and adaptability of native cattle. The Zebu has evidently frequently introgressed into the modem taurine breeds. As for modem zebu breeds, B. taurus also highly contributed to their formation, except for the Asian zebu. Furthermore our results also confirm the hypothesis that B. indicus has undergone a separate domestication event and originated from the Indian subcontinent.

Exploration of Methods for Preparation of Cattle Eyeball Paraffin Sections

[Objective] This study aimed to establish a new method for preparing paraffin sections of cattle eyebal s. [Method] The conventional method was used to prepare paraffin sections for cattle eyebal s in the control and a new method termed＆quot;opening a window on cornea and refixation＆quot; was used to prepare paraffin sections for cattle eyebal s in the treatment group. [Result] After the prepared specimens in the treatment group were fixed, it could be macroscopical y observed that retina and choroid were closely connected, with detachment occurring at a smal portion be-tween the two. According to the paraffin sections, it was microscopical y observed that the continuity of trabecular meshwork was intact, as wel as the continuity be-tween different layers of eyebal wal , without detachment between them, no retinal detachment, no shrinkage of each layer of tissue cells. [Conclusion] This study pro-vides a foundation for the basic research and pathological study of eyebal s.

Analysis on Polymorphisms of GHR Gene in Improved Hybrid Yellow Cattle Groups from Liupan Mountain Area in Ningxia

[Objective] The paper aimed to analyze the polymorphism of the growth hormone receptor （GHR） in improved hybrid yellow cattle group from Liupan Mountain area in Ningxia Autonomous Region,so as to provide technological basis for hybrid improvement. [Method] Polymerase chain reaction-restriction fragment length polymorphisms （PCR-RFLP） technology was carried out to examine polymorphisms of GHR gene of 70 individuals. [Result] The target fragment of 338 bp was amplified. The PCR product digested by restriction enzyme Alu I showed polymorphisms. The frequencies of the two genotypes （AA,BB） were 75.71% （53 individuals） and 24.29% （17 individuals）,respectively. [Conclusion] Two genotypes of GHR gene were detected in improved hybrid yellow cattle groups from Liupan Mountain area in Ningxia.

Drug Screening Experiment in vitro of Mycoplasma wenyonii in Cattle

RPMI-1640 was used as the basic culture medium and 30% calf serum was added. Using Berenil, tetracycline,dipterex,tiamulin,imidocarb,florfenicol,ethacri-dine,primaquine phosphate and other drug powder,the drug screening experiment in vitro of Mycoplasma wenyoni was made under the conditions of 37 ℃, 5% CO2. The results showed that the effects of ethacridine was the best ,and that of dipterex and primaquine phosphate were next. The toxicity of dipterex was greater. Berenil, imidocarb and florfenicol were efficient.

On Genetic Parameter Estimation of Xinjiang Brown Cattle's Main Economic Characters

The study aimed to determine the Xinjiang brown cattle＇s genetic param- eters of main growth and economic characters by using animal models and multiple traits derivative free restricted maximum likelihood （MTDFREML）. Results showed that： the heritability values of Xinjiang brown cattle＇s growth characters, including birth weight, 6-month-age weight, one full year weight and 2-year-old weight, were 0.45, 0.37, 0.38 and 0.34, respectively, which were medium level. The heritability values of body measurement indexes of different ages were different, indexes such as one-year-old weight, 2-year-old weight, body slanting length and body height had comparatively strong phenotypic correlation and genetic correlation. It was suggested that the breeding work of Xinjiang brown cattle should focus on selecting major breeding objectives like body height and body slanting length.