Prevalence and risk factors of Coxiella burnetii seropositivity in Danish beef and dairy cattle at slaughter adjusted for test uncertainty

Antibodies to Coxiella burnetii have been found in the Danish dairy cattle population with high levels of herd and within herd seroprevalences. However, the prevalence of antibodies to C. burnetii in Danish beef cattle remains unknown. The objectives of this study were to (1) estimate the prevalence and (2) identify risk factors associated with C. burnetii seropositivity in Danish beef and dairy cattle based on sampling at slaughter.     

Prevalence and molecular characterization of Cryptosporidium spp. and Enterocytozoon bieneusi from large-scale cattle farms in Anhui Province, China

To investigate the prevalence of Cryptosporidium spp. and Enterocytozoon bieneusi from large-scale cattle farms in Anhui Province, 955 fecal samples were collected from 16 cattle farms from March to October 2018, which included six dairy farms (526), seven yellow cattle farms (323), and three water buffalo farms (106) in different regions of Anhui Province. PCR was conducted on all fecal samples using the 18S ribosomal RNA of Cryptosporidium spp. and internal transcribed spacer gene of E. bieneusi to detect these two pathogens, and the positive samples were sequenced and analyzed. The results showed that 23 (2.4%) and 40 (4.2%) out of the 955 samples were positive for Cryptosporidium spp. and E. bieneusi, respectively. There were 11 (2.1%), 10 (3.1%), and 2 (1.9%) positive samples of Cryptosporidium spp. and 16 (3.0%), 23 (7.1%), and 1 (0.9%) positive samples of E. bieneusi collected from dairy cattle, yellow cattle, and water buffalo, respectively, and no co-infection was identified in this study. All positive samples of Cryptosporidium spp. were C. andersoni with some variations. Ten E. bieneusi genotypes were obtained, including two known genotypes, J and CHN11, and eight new genotypes, named AHDC1 and AHYC1-7. The genotype CHN11 belonged to zoonotic Group 1, and the other nine genotypes belonged to Group 2, which is mainly documented in ruminants. These results indicated that Cryptosporidium spp. and E. bieneusi infections were present in large-scale cattle farms in Anhui Province. Therefore, attention should be paid to the development of containment strategies of these two pathogens in cattle.     

Bovine cysticercosis in cattle slaughtered at Awassa municipal abattoir, Ethiopia: prevalence, cyst viability, distribution and its public health implication

A cross-sectional study was conducted from October 2005 to April 2006 on bovine cysticercosis in cattle slaughtered at Awassa municipal abattoir with the objective of determining the prevalence of Taenia saginata cysticercosis, cyst viability, distribution and its public health implication. Questionnaire survey involving 120 respondents was also conducted on human taeniasis. A total of 400 carcasses were examined during the study period, of which 105 (26.25%) were infected with T. saginata metacestodes. From a total of 3200 samples inspected, 500 cysticerci were detected in 141 samples, of which 221 (44.2%) were alive. The anatomical distribution of cysticerci were 65 (29.2%) heart, 56 (25.3%) shoulder muscle, 59 (26.7%) masseter, 23 (10.4%) tongue, 12 (5.4%) diaphragm, three (1.4%) liver, two (0.9%) lung and one (0.5%) kidney samples. The prevalence varied significantly between local and crossbred animals (OR = 3.15, P < 0.05), but not varied between sex, age groups and origin of the animals. T. saginata taeniasis was a widespread public health problem in the town with an overall prevalence of 64.2% (77 of 120). The potential risk factors for disease contraction were raw meat consumption, religion and occupational risks. In conclusion, the study revealed high prevalence of T. saginata metacestodes throughout the edible organs together with existence of deep-rooted tradition of raw meat consumption. This may magnify the public health hazards of T. saginata in the study area. As a result, the disease deserves due attention to safeguard the public health and further promote beef industry in the country.     

Prevalence,geographic distribution,and impact on lifespan of a dilated cardiomyopathy-associated RNA-binding motif protein 20 variant in genotyped dogs

IntroductionThe study objectives were to determine the prevalence and geographic distribution of a dilated cardiomyopathy (DCM)-associated RNA-binding motif protein 20 (RBM20) variant in canine DNA samples submitted for testing and to evaluate the influence of the genotype on cardiac phenotype and lifespan.AnimalsSamples from 2136 dogs including 1834 Standard Schnauzers (SSNZ), 266 Giant Schnauzers (GSNZ), and 36 dogs of other breeds.MethodsThe University of Missouri Canine Genetics Laboratory's sample-accession spreadsheet and Orthopedic Foundation for Animals' database were retrospectively reviewed for samples submitted for RBM20 genotyping from November, 2013, through May, 2018. Data analyzed included breed, date of birth, RBM20 genotype (homozygous wild-type, heterozygous variant [HET], or homozygous variant [HOM]), geographic origin of submission, pedigree, cardiac phenotype, and date of death or current age if alive.Results and DiscussionThe RBM20 variant was only detected in SSNZ and GSNZ. A total of 389 SSNZ were variant-positive (prevalence = 21.2%), with 361 HET (19.7%) and 28 HOM (1.5%). Of the HOM SSNZ, DCM was confirmed in 26 of 28 (92.9%), with the remainder lost to follow-up. The median lifespan of HOM SSNZ (3.06 years) was significantly shorter than that for HET (15.11 years) and wild-type (15.18 years) SSNZ. Twenty-six GSNZ were variant-positive (prevalence = 9.8%), with 23 HET (8.6%) and three HOM (1.1%). Nine GSNZ belonged to one family, including the three HOM GSNZ that all had DCM.ConclusionsThe HOM genotype is associated with DCM and premature death in SSNZ and GSNZ.     

Prevalence of Cryptosporidium spp. oocysts in cattle and wildlife in Morogoro region, Tanzania

Prevalences of Cryptosporidium spp. oocysts in cattle (n = 486) on five selected farms in Morogoro municipality and three species of herbivorous wildlife (n = 87) from Mikumi National Park, Morogoro, Tanzania, were determined using the modified Ziehl-Neelsen staining technique. Of 486 bovine faecal samples, 5.3% were positive for Cryptosporidium spp. The prevalence of Cryptosporidium was higher in calves less than 3 months of age compared to weaned calves and adults. Cryptosporidium spp. oocysts were detected in both diarrhoeic and non-diarrhoeic animals, but there was a significantly higher prevalence (P < 0.001) of oocyst shedding in diarrhoeic than in non-diarrhoeic animals. Of the 87 faecal specimens from the wildlife species, 36 were from the African buffaloes (Syncerus caffer), 25 from zebra (Equus zebra) and 26 from the wildebeest (Connochaetes gnou). Cryptosporidium spp. oocysts were detected in eight (22%) buffaloes, seven (28%) zebras and seven (27%) wildebeests. Confirmation of the diagnosis was performed using anti-Cryptosporidium monoclonal antibody specific for Cryptosporidium muris, Cryptosporidium parvum and Cryptosporidium baileyi (Pathasure Cryptosporidium test kit).     

Prevalence,quantitative load and genetic diversity of Campylobacter spp. in dairy cattle herds in Lithuania

Background

Campylobacteriosis is a zoonotic disease, and animals such as poultry, pigs and cattle may act as reservoirs for Campylobacter spp. Cattle shed Campylobacter spp. into the environment and they can act as a reservoir for human infection directly via contact with cattle or their faeces or indirectly by consumption of contaminated food. The aim of this study was to determine the prevalence, the quantitative load and the genetic strain diversity of Campylobacter spp. in dairy cattle of different age groups.

Results

Faecal samples of 200 dairy cattle from three farms in the central part of Lithuania were collected and examined for Campylobacter. Cattle herds of all three farms were Campylobacter spp. positive, with a prevalence ranging from 75% (farm I), 77.5% (farm II) to 83.3% (farm III). Overall, the highest prevalence was detected in calves (86.5%) and heifers (86.2%). In contrast, the lowest Campylobacter prevalence was detectable in dairy cows (60.6%). C. jejuni, C. coli, C. lari and C. fetus subsp. fetus were identified in faecal samples of dairy cattle. C. upsaliensis was not detectable in any sample. The high counts of Campylobacter spp. were observed in faecal material of dairy cattle (average 4.5 log₁₀ cfu/g). The highest numbers of Campylobacter spp. were found in faecal samples from calves (average 5.3 log₁₀ cfu/g), whereas, faecal samples from cows harboured the lowest number of Campylobacter spp. (average 3.7 log₁₀ cfu/g). Genotyping by flaA PCR-RFLP analysis of selected C. jejuni isolates showed that some genotypes were present in all farms and all age groups. However, farm or age specific genotypes were also identified.

Conclusions

Future studies are needed to investigate risk factors related to the degree of colonisation in cattle. Based on that, possible measures to reduce the colonisation and subsequent shedding of Campylobacter in cattle could be established. It is important to further investigate the epidemiology of Campylobacter in the cattle population in order to assess associated risks to public health.     

Prevalence and molecular characterization of Giardia duodenalis and Cryptosporidium spp. in dairy cattle in Ontario, Canada

Giardia duodenalis and Cryptosporidium spp. are intestinal protozoan parasites that infect a wide range of host species, including humans. Molecular characterization of these parasites has demonstrated that a number of genotypes and species are common to both humans and animals, and that zoonotic transmission may occur. Numerous studies have reported a high prevalence of G. duodenalis and Cryptosporidium spp. in cattle, particularly calves, and these animals are frequently associated with zoonotic transmission. In the present study, a total of 143 faecal samples from adults, heifers and calves were collected from two dairy cattle farms in eastern Ontario, Canada. The prevalence and molecular characteristics of G. duodenalis and Cryptosporidium spp. in these animals were determined in order to investigate the potential for transmission between cattle and humans in this region. Following DNA extractions from faecal samples, nested-PCR protocols were used to amplify fragments of the 16S rRNA gene and the heat-shock protein 70 (HSP-70) gene for determining the prevalence of G. duodenalis and Cryptosporidium spp. infections, respectively. Genotypes of G. duodenalis, and species of Cryptosporidium, were determined by means of DNA sequencing of amplicons, and subsequent sequence alignment. Cattle on both farms showed a high prevalence of G. duodenalis (42.0%) and Cryptosporidium spp. (27.3%). G. duodenalis infections were more prevalent in calves and heifers than in adults, and Cryptosporidium spp. infections were only observed in calves and heifers. The zoonotic genotype, G. duodenalis Assemblage B was isolated from 24.5% of the cattle tested, while G. duodenalis Assemblage E was found in 17.5% of the cattle tested. The overall prevalence of the zoonotic species Cryptosporidium parvum in the animals tested was found to be 21.7%, while only 1.4% were infected with C. bovis. These findings suggest that there is a potential risk of zoonotic and/or zooanthroponotic transmission of G. duodenalis and C. parvum infections between cattle and humans in eastern Ontario, likely by means of contaminated water or food, or through direct faecal-oral transmission in the case of farmers and veterinary staff.     

活牛、牛肉与生产原料比价关系分析

【目的】为掌握肉牛生产及其产品市场价格波动规律,了解牛产业各环节收益和波动情况,及时为生产指导提供科学依据。 【方法】选择在张掖市辖区内设置10个畜产品价格监测点,按日汇总,以最近一个监测周期（410天）数据为总体,选择近3个月和去年同期3个月数据为样本,按统计学原理分析其均值、标准差、误差区间、变异系数、波动趋势概率（P）和增幅等,进行总比、同比分析。【结果】本监测期玉米价格2.890.03、活牛32.772.26、牛肉72.271.97、M 11.410.65 、R 2.210.11;确定以活牛/玉米（M值）为参数,将原料与产品结合起来作活牛成本分析;用牛肉/活牛比价（R值）分析养殖与屠宰消费环节营销利益分配关系。根据M、DP（屠宰率）均值11.41、55.81%确定3个盈亏平衡点为：活牛成本32.97元,牛肉成本59.08元,活牛屠宰到消费端营销成本R值为1.8;根据 R均值2.21确定活牛屠宰到消费端营销临界利润率为 22.7%,当R≧2.21时营销利润率≧22.7%,效益增加,R≦2.21时营销利润率≦22.7%效益降低。【结论】与肉牛生产息息相关的4个临界点分别为M值为11.41,基于M值的活牛成本32.97元、牛肉成本59.08元、活牛屠宰到消费端营销成本R值2.21利润率22.7%。近期M值连续下降溢出正常区间下限值10.65达66天,R值上升溢出正常区间上限2.32达52天,养殖环节收益缩减呈现亏损状态,屠宰消费环节营销利率高达30%。 M、R值变化呈不同步状态, R滞后。     

Escherichia coli O157:H7 and non-O157 Shiga toxin-producing E. coli in healthy cattle, sheep and swine herds in Northern Spain

Three-hundred and forty-five herds (17 swine, 122 dairy sheep, 124 beef and 82 dairy cattle) were investigated for prevalence of Shiga toxin-producing Escherichia coli (STEC). Rectal faecal samples were selectively enriched and then examined by immunodetection techniques (Immunomagnetic Separation with anti-E. coli O157 Dynabeads, ImmunoMagnetic cell Separation (IMS) and automated enzyme-linked fluorescent immunoassay using VIDAS) and polymerase chain reaction (PCR) (rfbE and fliC genes) to assess the prevalence of E. coli O157:H7. Prevalence of non-O157 STEC was estimated by PCR screening for stx genes of 10 lactose-positive colonies grown on MacConkey agar after enrichment. PCR was used on all STEC isolates to detect stx(1), stx(2), eaeA and E-hlyA genes. Both immunodetection methods showed a moderate-good level of agreement (kappa = 0.649) but IMS showed 87.5% complementary sensitivity. Prevalence of positive herds for E. coli O157:H7 was estimated at 8.7% for sheep and 3.8% for cattle, whereas all the porcine herds tested negative. Non-O157 STEC were also absent from swine, but were isolated more frequently from ovine (50.8%) than bovine herds (35.9%). Within-herd prevalences of excretion of E. coli O157:H7 established by individual testing of 279 sheep (six herds) and 30 beef cattle (one herd) were 7.3% and 6.7% respectively. PCR analysis of 49 E. coli O157:H7 and 209 non-O157 isolates showed a different distribution of virulence genes. All E. coli O157:H7 were stx(2) gene-positive, eaeA was detected in 95.9%, and the toxigenic profile stx(2)/eaeA/E-hlyA was present in 75.5% of the isolates. Among the non-O157 STEC, prevalence of eaeA was significantly lower (5.3%) and E-hlyA was present in 50.2% of the isolates but only sporadically associated with eaeA. stx(2) was predominant in non-O157 isolates from cattle, whereas in sheep the combination stx(1)/stx(2) was more prevalent. This study demonstrated the wide distribution of STEC in ruminant herds, which represent an important reservoir for strains that pose a potential risk for human infections.     

Improving the quality of rice straw by urea and calcium hydroxide on rumen ecology,microbial protein synthesis in beef cattle

Four rumen‐fistulated beef cattle were randomly assigned to four treatments according to a 4 × 4 Latin square design to study the influence of urea and calcium hydroxide [Ca(OH)₂] treatment of rice straw to improve the nutritive value of rice straw. Four dietary treatments were as follows: untreated rice straw, 50 g/kg urea‐treated rice straw, 20 g/kg urea + 20 g/kg calcium hydroxide‐treated rice straw and 30 g/kg urea + 20 g/kg calcium hydroxide‐treated rice straw. All animals were kept in individual pens and fed with concentrate at 0.5 g/kg of BW (DM), rice straw was fed ad libitum. The experiment was conducted for four periods, and each period lasted for 21 days. During the first 14 days, DM feed intake measurements were made while during the last 7 days, all cattle were moved to metabolism crates for total faeces and urine collections. The results revealed that 20 g/kg urea + 20 g/kg calcium hydroxide‐treated rice straw improved the nutritive value of rice straw, in terms of dry matter intake, digestibility, ruminal volatile fatty acids, population of bacteria and fungi, nitrogen retention and microbial protein synthesis. Based on this study, it could be concluded that using urea plus calcium hydroxide was one alternative method to improve the nutritive value of rice straw, rumen ecology and fermentation and thus a reduction of treatment cost.     

A long‐term study of the effects of SLC12A1 homozygous mutation (g.62382825G>A,p.Pro372Leu) in Japanese Black cattle

Recessive missense mutation in the solute carrier family 12, member 1 (SLC12A1) gene (g.62382825G>A) is associated with hydrallantois, which is the accumulation of fluid in the allantoic cavity of a pregnant animal, and usually causes fetal death in Japanese Black cattle. However, the symptoms of a homozygote with this mutation that do not result in fetal death have not previously been tracked and evaluated. In the present study, we observed a homozygote with the SLC12A1 risk allele over a long‐term period. The calf did not show any obvious clinical symptoms, although it did exhibit a slight growth retardation that accompanied mild calciuria. At 28 months of age, the homozygote showed renal dysfunction, which in turn resulted in hydronephrosis. The time course of the symptoms was consistent with the phenotype of Bartter syndrome in humans. Additionally, the risk heterozygous genotype did not any effects on carcass traits, which indicates that eliminating the risk allele would not have any unfavorable effects. Therefore, we emphasize that both the fetal‐ and late‐stage symptoms associated with the SLC12A1 risk allele compromise animal welfare, and consequently may result in severe economic losses for individual farmers if the SLC12A1 risk allele is not eliminated from the population.     

奶牛乳和血中大肠杆菌和轮状病毒抗体检测比较

用轮状病毒和大肠杆菌给妊娠后期奶牛免疫,使之产生抗这两种病原的抗体,定期采血和乳,分别用试管凝集反应和反向间接血凝抑制试验检测大肠杆菌和轮状病毒抗体,并比较血和乳中抗体相互关系,试验结果说明：奶牛在未免疫情况下,只在初乳中才能检出抗体;在人工免疫情况下,在初乳和近２个月的常乳中均可检测到抗体,但乳中抗体比血中抗体低２个滴度左右。     

Lactobacillus hayakitensis, L. equigenerosi and L. equi, predominant lactobacilli in the intestinal flora of healthy thoroughbreds

To detect the predominant lactobacilli in the intestinal flora of healthy thoroughbreds, we isolated lactobacilli from the feces of nine thoroughbreds (five males and four females; 0–15-year-old). The isolated lactobacilli comprise 17 species (37 strains), and they were classified into five groups: Lactobacillus salivarius (6 species), L. reuteri (6 species), Lactobacillus delbrueckii (3 species), L. buchneri (1 species) and L. vitulinus (1 species). On the basis of 16S rRNA gene sequences, we identified 3 other phylogenetic relatives belonging to the genus Lactobacillus . These results suggest that the intestinal flora of thoroughbreds may comprise many species of the genus Lactobacillus . Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analyses of the 340-bp fragments of the 16S rRNA genes from the same nine fecal samples showed that L. hayakitensis , L. equigenerosi and L. equi are contained in all the samples, suggesting that these species are predominant lactobacilli in the intestinal flora of thoroughbreds.     

L-硝基精氨酸对阿尔茨海默症小鼠脑海马nNOS阳性神经元分布、NOS活性及NO含量变化的影响

为了研究D-半乳糖联合铝诱导的小鼠阿尔茨海默症(AD)脑海马一氧化氮合酶(NOS)活性和一氧化氮(NO)含量的变化及L-NNA和盐酸多奈哌齐对其变化的影响,探讨NO在阿尔茨海默症中的作用机制及2种药物对脑神经元的保护作用。选取2月龄健康昆明小鼠160只,体质量(20±2)g,随机分为正常对照组、模型组、盐酸多奈哌齐治疗组及L-NNA治疗组,利用D-半乳糖联合三氯化铝建立小鼠AD模型,应用生化检测技术测定各组脑海马在造模后每周NOS活性及NO含量。结果表明,模型组海马内NOS活性开始呈缓慢升高,从第4周开始呈显著升高,保持较高含量至12w造模结束;两治疗组脑海马NOS活性在各时间点极显著或显著低于模型组(P0.01或P0.05),并且L-NNA在4~8周时降低脑海马NOS活性的程度好于盐酸多奈哌齐治疗组(P0.05);NO含量的变化随着NOS活性的变化而变化;利用SABC免疫组织化学方法检测各组脑海马神经型NOS(nNOS)阳性神经元,发现模型组脑海马nNOS阳性神经元密度降低,细胞着色变淡,胞体截面积和最长突起长度变小,经过治疗后神经元密度增加,胞体截面积和最长突起长度显著改善(P0.05)。结果提示NO参与了AD形成过程,高浓度的NO能发挥神经毒性作用损害脑组织;L-NNA通过抑制NOS的活性,降低了脑海马NO的含量,对阿尔茨海默症中海马神经元具有明显的保护作用。     

东川银合欢POD、EST和SOD同工酶分析

采用聚丙烯酰胺凝胶电泳(PAGE)法,对云南省5个银合欢品种和1个金合欢品种种质资源的过氧化物酶(POD)、酯酶(EST)和超氧化物歧化酶(SOD)同工酶酶谱进行了分析,并依据不同种质材料间酶带特征的不同,利用酶带迁移率和酶谱相似系数分析研究了6个品种种质间的亲源关系及遗传多样性.结果表明:6个品种种质资源酶谱带数目、迁移率、酶活性及分布特征均有不同程度的差异.     

Effect of Fagopyrum dibotrys (D.Don) Hara on Growth Performance,Immune Function and Intestinal Structure of Broilers

This experiment was conducted to investigate the effects of Fagopyrum dibotrys (D.Don) Hara on growth performance,immune function and intestinal structure of broilers. A total of 270 one-day-old healthy Tiejiaoma broilers were chosen and randomly divided into 3 groups with 6 replicates per group and 15 broilers per replicate.Control group was fed with the basal diet,group Ⅱ was fed with basal diet adding 8% flavomycin 60 mg/kg +15% aureomycin 270 mg/kg and group Ⅲ was fed with basal diet adding 1% Fagopyrum dibotrys (D.Don) Hara. The trial period lasted for 21 days. The results showed as follow:① At 21 days of age,the average daily feed intake of group Ⅲ was significantly lower than that of groups Ⅰ and Ⅱ (P<0.05).However,there was no significant difference in the average daily gain and F/G among the three groups (P>0.05).②At 21 days of age,the thymus and bursa of Fabricius indexes of groups Ⅱ and Ⅲ were significantly higher than that of group Ⅰ (P<0.05);But the spleen index were not significantly different among the three groups (P>0.05).③ At 21 days of age,the content of IgA and IgM in serum of groups Ⅲ were significantly higher than that of group Ⅰ (P<0.05),and the content of IgG in serum of groups Ⅱ and Ⅲ were significantly higher than that of group Ⅰ (P<0.05).④At 21 days of age,the content of IL-2,TNF-α and sIgA in intestinal mucosa of groups Ⅱ and Ⅲ were significantly higher than that of group Ⅰ (P<0.05),and the content of IL-6 in intestinal mucosa of group Ⅲ were significantly higher than that of groups Ⅰ and Ⅱ (P<0.05).⑤At 21 days of age,the villus height of jejunum in groups Ⅱ and Ⅲ were significantly higher than that of group Ⅰ (P<0.05),the villus height/crypt depth of jejunum in group Ⅱ was significantly higher than that of groups Ⅰ and Ⅲ (P<0.05). However,the crypt depth was not significantly different among the three groups (P>0.05).In conclusion,that Fagopyrum dibotrys (D.Don) Hara could not affect the growth performance of broilers,but it could improve the development of immune organs,increase the secretion of serum immunoglobulin, promote the immune function of intestinal mucosa and intestinal morphology of jejunum.     

金荞麦对肉仔鸡生长性能、免疫功能和肠道形态结构的影响

本试验旨在研究日粮中添加金荞麦对肉仔鸡生长性能、免疫功能和肠道形态结构的影响。选择1日龄铁脚麻肉仔鸡270只,随机分为3组（Ⅰ、Ⅱ、Ⅲ组）,每组6个重复,每个重复15只鸡。Ⅰ组为对照组,饲喂基础日粮,不添加任何抗生素;Ⅱ组在基础日粮中添加8%黄霉素60 mg/kg和15%金霉素270 mg/kg;Ⅲ组在基础日粮中添加1%金荞麦。试验期为21 d。结果显示,①21日龄时,Ⅲ组肉仔鸡平均日采食量显著低于Ⅰ、Ⅱ组（P<0.05）,3组间平均日增重、料重比均差异不显著（P>0.05）。②21日龄时,Ⅱ、Ⅲ组胸腺指数、法氏囊指数均显著高于Ⅰ组（P<0.05）,3组间脾脏指数差异不显著（P>0.05）。③21日龄时,Ⅲ组血清免疫球蛋白A（IgA）、免疫球蛋白M（IgM）均显著高于Ⅰ组（P<0.05）,Ⅱ、Ⅲ组血清免疫球蛋白G（IgG）显著高于Ⅰ组（P<0.05）。④21日龄时,Ⅱ、Ⅲ组空肠黏膜白细胞介素-2（IL-2）、肿瘤坏死因子-α（TNF-α）、分泌型免疫球蛋白A（sIgA）含量均显著高于Ⅰ组（P<0.05）,Ⅲ组肠道黏膜白细胞介素-6（IL-6）显著高于Ⅰ、Ⅱ组（P<0.05）。⑤21日龄时,Ⅱ、Ⅲ组空肠绒毛高度显著高于Ⅰ组（P<0.05）,Ⅱ组绒毛高度/隐窝深度显著高于Ⅰ、Ⅲ组（P<0.05）,3组间隐窝深度差异不显著（P>0.05）。综上所述,日粮中添加适量的金荞麦对肉仔鸡生长性能无显著影响,但可促进肉仔鸡免疫器官发育,提高血清免疫球蛋白及空肠黏膜免疫因子分泌,同时可促进肠道绒毛生长,改善肠道形态结构。     

Carrier rate of the c.235G>C mutation in the bovine isoleucyl-tRNA synthetase (IARS) gene of Japanese Black cows at Kagoshima prefecture, Japan,and analysis of the metabolic profiling and reproductive performance of heterozygous cows

Bovine isoleucyl-tRNA synthetase (IARS) disorder, a major cause of weak calf syndrome, is caused by a homozygous missense (c.235G>C) mutation in the bovine IARS gene of Japanese Black (JB) cattle, which was identified in 2013. However, the extent to which the carrier rate has changed at Kagoshima prefecture, Japan, and whether the carrier status is associated with any clinical or reproductive problems, have yet to be ascertained. In this study, using a real-time polymerase chain reaction-based genotyping assay, we determined the carrier rate in a regional JB cow population at Kagoshima prefecture. Comparative analyses were performed on the metabolic profile test (MPT) results and reproductive performance data obtained for heterozygous carrier and homozygous wild-type cows. In 2009 and 2018, DNA samples were collected from 130 and 462 clinically healthy JB cows, respectively, in Kagoshima prefecture. MPT results and reproductive performance data were evaluated for 62 cows, comprising four heterozygous carriers and 58 wild-type cows. Genotyping revealed that the carrier rate was 6.9% in 2009 and 1.5% in 2018, the difference of which was statistically significant (P<0.005). There were no statistically significant differences between the carrier and wild-type cows with respect to either MPT results or reproductive performance, indicating that the carrier cows have necessary IARS activity to maintain minimal health and reproductive potential.