Distribution of the mutant allele of the DMRT3 gene associated with ambling gaits in Japanese native horse populations

There are currently eight native horse populations in Japan, namely, Hokkaido, Kiso, Noma, Taishu, Misaki, Tokara, Miyako, and Yonaguni horses. Since locomotion traits, including gaitedness, are important for riding and packing horses, the genetic properties associated with these traits could be informative for understanding the characteristics and history of these horses. In this study, we investigated the distribution of the mutant allele of DMRT3 gene (DMRT3:p.Ser301Ter) associated with ambling gaits in the Japanese native horse. We also examined haplotypes of SNPs in the 83‐kb region including DMRT3 gene by genotyping four SNPs in this region. The results revealed the presence of DMRT3:p.Ser301Ter in the Hokkaido and Yonaguni populations at allele frequencies of 0.18 and 0.02, respectively, and the observed haplotype associated with DMRT3:p.Ser301Ter was estimated as the most common haplotype in the horses in the world. Since DMRT3:p.Ser301Ter has been hypothesized to spread across Eurasian continent from Medieval England after 850 to 900 CE, our findings of the presence of DMRT3:p.Ser301Ter with the common haplotype in the Japanese native horses will provide a new insight into the history of the Japanese native horse, such as considerable level of gene flow from Eurasian continent after 850 to 900 CE.     

Effects of fallen snow on the voluntary intake and grazing behavior of Hokkaido native horses in winter woodland with underlying Sasa senanensis

The intake, digestibility, and grazing behavior of Hokkaido native horses were investigated in winter woodland with underlying Sasa senanensis. Twenty Hokkaido native horses were grazed in a woodland (8.52 ha) for 14 days in December (snowy; 20 cm of snow fall) and in November (non‐snowy) of the next year. Three mares (360 kg of average bodyweight) were used in each experiment. The fecal collection, used to investigate the intake and digestibility by the double‐indicator method, and behavioral observations were carried out for 24 h on the 6th day in each experiment. During the snowy and non‐snowy periods, the dry matter intakes of sasa foliage were 7.3 and 9.6 kg/d, respectively, which is 2.1 and 2.7% when expressed as a percentage of bodyweight. The apparent digestibility of nutrients and energy released during the snowy and non‐snowy periods were similar. The proportions of digestible energy intakes to maintenance requirement in the mares were 119 and 164% during the snowy and non‐snowy periods, respectively. Their bodyweight remained constant during the non‐snowy period; however, a slight loss in their bodyweight was observed during the snowy period. The duration of grazing on sasa foliage was 416 and 544 min/d during the snowy and non‐snowy periods, respectively, the daily grazing area of the mares during these periods was 2.0 and 5.1 ha, respectively. In other words, the area during the snowy period was smaller than that during the non‐snowy period (P < 0.05). Fallen snow, even with a depth of approximately 20 cm, inhibited the grazing behavior and intake of sasa foliage by Hokkaido native horses grazing in winter woodland pasture.     

Effect of allele frequencies,effect sizes and number of markers on prediction of quantitative traits in chickens

The objective was to assess goodness of fit and predictive ability of subsets of single nucleotide polymorphism (SNP) markers constructed based on minor allele frequency (MAF), effect sizes and varying marker density. Target traits were body weight (BW), ultrasound measurement of breast muscle (BM) and hen house egg production (HHP) in broiler chickens. We used a 600 K Affymetrix platform with 1352 birds genotyped. The prediction method was genomic best linear unbiased prediction (GBLUP) with 354 564 single nucleotide polymorphisms (SNPs) used to derive a genomic relationship matrix ( G ). Predictive ability was assessed as the correlation between predicted genomic values and corrected phenotypes from a threefold cross‐validation. Predictive ability was 0.27 ± 0.002 for BW, 0.33 ± 0.001 for BM and 0.20 ± 0.002 for HHP. For the three traits studied, predictive ability decreased when SNPs with a higher MAF were used to construct G . Selection of the 20% SNPs with the largest absolute effect sizes induced a predictive ability equal to that from fitting all markers together. When density of markers increased from 5 K to 20 K, predictive ability enhanced slightly. These results provide evidence that designing a low‐density chip using low‐frequency markers with large effect sizes may be useful for commercial usage.     

Allelic frequencies and association with carcass traits of six genes in local subpopulations of Japanese Black cattle

Marker‐assisted selection (MAS) is expected to accelerate the genetic improvement of Japanese Black cattle. However, verification of the effects of the genes for MAS in different subpopulations is required prior to the application of MAS. In this study, we investigated the allelic frequencies and genotypic effects for carcass traits of six genes, which can be used in MAS, in eight local subpopulations. These genes are SCD, FASN and SREBP1, which are associated with the fatty acid composition of meat, and NCAPG, MC1R and F11, which are associated with carcass weight, coat color and blood coagulation abnormality, respectively. The frequencies of desirable alleles of SCD and FASN were relatively high and that of NCAPG was relatively low, and NCAPG was significantly associated with several carcass traits, including carcass weight. The proportions of genotypic variance explained by NCAPG to phenotypic variance were 4.83 for carcass weight. We thus confirmed that NCAPG is a useful marker for selection of carcass traits in these subpopulations. In addition, we found that the desirable alleles of six genes showed no negative effects on carcass traits. Therefore, selection using these genes to improve target traits should not have negative impacts on carcass traits.     

Comparison of the effects explained by variations in the bovine PLAG1 and NCAPG genes on daily body weight gain,linear skeletal measurements and carcass traits in Japanese Black steers from a progeny testing program

The c.1326T>G single nucleotide polymorphism (SNP) in the NCAPG gene, which leads to an amino acid change of Ile442 to Met442, was previously identified as a candidate causative variation for a bovine carcass weight quantitative trait loci (QTL) on chromosome 6, which was associated with linear skeletal measurement gains and daily body weight gain at puberty. Recently, we identified the stature quantitative trait nucleotides (QTNs) in the PLAG1‐CHCHD7 intergenic region as the causative variations for another carcass weight QTL on chromosome 14. This study aimed to compare the effects of the two QTL on growth and carcass traits using 768 Japanese Black steers from a progeny testing program and to determine whether a genetic interaction was present between them. The FJX_250879 SNP representing the stature QTL was associated with linear skeletal measurements and average daily body weight gain at early and late periods during adolescence. A genetic interaction between FJX_250879 and NCAPG c.1326T>G was detected only for body and rump lengths. Both were associated with increased carcass weight and Longissimus muscle area, and NCAPG c.1326T>G was also associated with reduced subcutaneous fat thickness and increased carcass yield estimate. These results will provide useful information to improve carcass weight in Japanese Black cattle.     

The T allele at the g.1471620G>T in the EDG1 gene associated with high marbling in Japanese Black cattle is at a low frequency in breeds not selected for marbling

Our previous study detected a single nucleotide polymorphism (SNP), g.1471620G > T , in the 5' flanking region of the endothelial differentiation sphingolipid G-protein-coupled receptor 1 ( EDG1 ) gene, which has been considered as a positional functional candidate for the gene responsible for marbling, and showed association of the g.1471620G > T SNP with marbling in Japanese Black beef cattle. In the present study, we investigated the allele frequency distribution of the g.1471620G > T SNP among the 5 cattle breeds, Japanese Black, Japanese Brown, Japanese Short Horn, Holstein, and Brown Swiss breeds. The T allele at the g.1471620G > T SNP associated with high marbling was found at high frequency in Japanese Black breed that has been subjected to a strong selection for high marbling, while the allele was absent or at very low frequencies in the other breeds that have not been strongly selected for high marbling. Based on this finding, we hypothesized that the pressure of the strong selection for high marbling in Japanese Black breed has increased the frequency of the T allele at the g.1471620G > T SNP in the EDG1 .     

东北民猪荷包猪抗性基因多态性及其与免疫指标的相关性研究

研究目的是检测荷包猪FUT 1和Mx1基因位点多态性及其与免疫指标的相关关系。采用PCR-RFLP技术分析基因多态性,采用ELISA方法检测免疫指标白介素-4(IL-4)、分泌型免疫球蛋白A(sIgA)、α-干扰素(IFN-α)的表达量。结果表明,荷包猪FUT 1基因和Mx1基因Hin6I点酶切位点上显示多态性,优势基因型分别为GG和AA型,在Mx1基因其他两位点处未发现多态性;荷包猪免疫指标IL-4、sIgA、IFN-α的表达量明显高于大白猪(P<0.05),但抗性基因型与免疫指标间的相关性表现不明显。     

太湖流域地方猪种遗传结构评估和体重体尺性状差异相关选择位点鉴定

旨在解析太湖流域地方猪品种内部遗传结构,鉴定梅山猪亚群间、二花脸群体间和米猪群体间体重体尺性状差异的候选基因。试验采集440头猪样本(代表太湖流域地方猪最全面血统)进行基因芯片分型,并使用该基因分型数据集进行多种群体遗传学分析,明确太湖流域地方猪品种内部的遗传结构,并鉴定梅山猪亚群间、以及二花脸和米猪群体间体重体尺性状差异的候选SNP位点和候选基因。结果显示:在太湖流域地方猪种内部,二花脸猪与米猪间的亲缘关系最接近,其遗传距离小于梅山猪两个亚群间的遗传距离,并且拥有最为一致的进化路线。太湖流域地方猪各品种及梅山猪品种内两个亚群间都达到高度分化水平,Fst值均大于0.25,ADMIXTURE分析表明,包括梅山猪两个亚群在内的8个群体的群体结构不完全一致,在K=8时,各自展现出完全不同的祖先血统组成。通过梅山猪亚群间Fst分析、以及米猪和二花脸猪间Fst分析,在猪1、3和6号等染色体上,共鉴定到24个位点在两个分析中都表现出受选择状态,并在这些位点上下游50 kb范围注释到20个基因,其中有8个基因被报道与体重体尺性状相关。此外,受选择位点形成的选择区域与多个猪体重体尺相关QTLs重叠。试...     

Identification of leptin gene polymorphisms associated with carcass traits and fatty acid composition in Japanese Black cattle

Previous studies have indicated that some leptin gene polymorphisms were associated with economically important traits in cattle breeds. However, polymorphisms in the leptin gene have not been reported thus far in Japanese Black cattle. Here, we aimed to identify the leptin gene polymorphisms which are associated with carcass traits and fatty acid composition in Japanese Black cattle. We sequenced the full‐length coding sequence of leptin gene for eight Japanese Black cattle. Sequence comparison revealed eight single nucleotide polymorphisms (SNPs). Three of these were predicted to cause amino acid substitutions: Y7F, R25C and A80V. Then, we genotyped these SNPs in two populations (JB1 with 560 animals and JB2 with 450 animals) and investigated the effects on the traits. Y7F in JB1 and A80V in JB2 were excluded from statistical analysis because the minor allele frequencies were low (< 0.1). Association analysis revealed that Y7F had a significant effect on the dressed carcass weight in JB2; R25C had a significant effect on C18:0 and C14:1 in JB1 and JB2, respectively; and A80V had a significant effect on C16:0, C16:1, C18:1, monounsaturated fatty acid and saturated fatty acid in JB1. The results suggested that these SNPs could be used as an effective marker for the improvement of Japanese Black cattle.     

The interrelations of good welfare indicators assessed in working horses and their relationships with the type of work

This paper presents a different approach to the welfare of working horses through the indicators of good welfare, their interrelations and their relationships with the type of work performed by the horses. 697 working horses were assessed by using observation, behavioural tests, clinical exams and questionnaires. The correlated results highlight the complex and multiple interrelations between the good welfare indicators, showing once again that animal welfare is under the influence of all its three dimensions (physical and emotional wellbeing and naturalness). In working horses, the heavier the work they perform is, the more important it is for horse owners/breeders/farmers to fulfil their inherent needs so as to help them cope with the multiple specific risks imposed by their work.     

Detomidine and the combination of detomidine and MK‐467, a peripheral alpha‐2 adrenoceptor antagonist,as premedication in horses anaesthetized with isoflurane

ObjectiveTo investigate MK-467 as part of premedication in horses anaesthetized with isoflurane.Study designExperimental, crossover study with a 14 day wash-out period.AnimalsSeven healthy horses.MethodsThe horses received either detomidine (20 μg kg⁻¹ IV) and butorphanol (20 μg kg⁻¹ IV) alone (DET) or with MK-467 (200 μg kg⁻¹ IV; DET + MK) as premedication. Anaesthesia was induced with ketamine (2.2 mg kg⁻¹) and midazolam (0.06 mg kg⁻¹) IV and maintained with isoflurane. Heart rate (HR), mean arterial pressure (MAP), end-tidal isoflurane concentration, end-tidal carbon dioxide tension, central venous pressure, fraction of inspired oxygen (FiO₂) and cardiac output were recorded. Blood samples were taken for blood gas analysis and to determine plasma drug concentrations. The cardiac index (CI), systemic vascular resistance (SVR), ratio of arterial oxygen tension to inspired oxygen (P_aO₂/FiO₂) and tissue oxygen delivery (DO₂) were calculated. Repeated measures anova was applied for HR, CI, MAP, SVR, lactate and blood gas variables. The Student's t-test was used for pairwise comparisons of drug concentrations, induction times and the amount of dobutamine administered. Significance was set at p < 0.05.ResultsThe induction time was shorter, reduction in MAP was detected, more dobutamine was given and HR and CI were higher after DET+MK, while SVR was higher with DET. Arterial oxygen tension and P_aO₂/FiO₂ (40 minutes after induction), DO₂ and venous partial pressure of oxygen (40 and 60 minutes after induction) were higher with DET+MK. Plasma detomidine concentrations were reduced in the group receiving MK-467. After DET+MK, the area under the plasma concentration time curve of butorphanol was smaller.Conclusions and clinical relevanceMK-467 enhances cardiac function and tissue oxygen delivery in horses sedated with detomidine before isoflurane anaesthesia. This finding could improve patient safety in the perioperative period. The dosage of MK-467 needs to be investigated to minimise the effect of MK-467 on MAP.     

Genetics of hyperpigmentation associated with the Fibromelanosis gene (Fm) and analysis of growth and meat quality traits in crosses of native Indian Kadaknath chickens and non-indigenous breeds

1. The study investigated the extent of hyperpigmentation (a trait fixed in native Indian Kadaknath chickens), bodyweight, carcase quality and leanness at 12 weeks of age in F(1) and back-crosses of Kadaknath with White Leghorn, White Plymouth Rock and Aseel Peela chickens. 2. The objective of the study was to determine if hyperpigmentation was affected by the major gene Fibromelanosis (Fm) and to evaluate the effects of different proportions of Kadaknath genes on growth and carcase quality. 3. The pigmentation pattern of skin indicated that Fm behaved as the primary locus affecting dermal-hyperpigmentation and that the sex-linked Id locus produced an epistatic effect. 4. The results suggested that variable allelic forms of Id were acting in different crosses, which resulted in variation in melanosis of the host. However, no conclusive pattern for shank pigmentation could be explained through genotyping of the Id and Fm loci. 5. Analysis of quantitative traits indicated the positive impact of a Kadaknath genomic proportion of 50% or more on meat texture and carcase leanness. Improvement in leanness occurred in White Rock crosses but not in White Leghorn and Aseel Peela crosses. 6. Thigh-meat texture was influenced more by enhanced Kadaknath genomic proportions than the breast-meat. It was concluded that introgression of Kadaknath genomic proportion beyond 50% in a cross with meat-type chickens, irrespective of the impact Fm, brought improvement in meat quality whereas no such advantage was obtained for growth traits. 7. The beneficial impact of the Kadaknath genome on meat quality calls for further studies to identify causative genes for their selective use to improve meat quality in Kadaknath crossbred chickens.     

A gene co‐expression network analysis of the candidate genes and molecular pathways associated with feather follicle traits of chicken skin

Back and thigh skin of chickens showed significant differences in the thickness and the feather follicle density and size, which are important traits for slaughtered chickens' appearance. In the present study, global gene expression profiling was conducted in the back and thigh skin of chickens using Microarray technology. The results showed that 676 genes were differentially expressed between back and thigh skin. The expression of the differentially expressed genes (DEGs), including PPP1R3C, IGF1, PTCHD1, HOXB6, FGF9, CAMK4, SHH, BMP8B, FOXN1 and PTGER2, was validated by real‐time quantitative polymerase chain reaction (RT‐qPCR), and the results were consistent with microarray results. Functional analysis revealed that the DEGs were significantly involved in cell proliferation, differentiation, apoptosis, adhesion and transport process, and the pathways were significantly mapped into the ECM‐receptor interaction, peroxisome, focal adhesion, Hedgehog and PPAR signalling pathways. Protein–protein interaction network analysis suggested that signalling pathways related to feathers morphogenesis and development, such as Wnt, FGF, MAPK, SHH and BMP signalling pathways, occupied important positions in the network. Genes involved in these signalling pathways and adhesion molecules might play a vital role in skin and feather follicle development. Further single nucleotide polymorphism (SNP) association analysis of Wnt3A showed that the AC genotype of SNP g.255361 C>A significantly increased the feather follicle density of thigh skin. Our findings may provide new insights on candidate genes and pathways related to skin and feather follicle formation of chickens.     

Identification of polymorphisms and association analysis with meat quality traits in the porcine KIAA1717 and HUMMLC2B genes

Skeletal muscle genes are potential candidates for production and meat quality. Screening a subtracted cDNA library constructed with mRNA obtained from longissimus dorsi muscles of F1 hybrids Landrace × Yorkshire and their female parents Yorkshire, we isolated two partial sequences coding for the H3-K4-specific methyltransferase (KIAA1717) and skeletal muscle myosin regulatory light chain (HUMMLC2B) genes. Database search revealed KIAA1717 and HUMMLC2B encoded proteins with SET domain and EF-hand calcium binding motif, respectively. In the present work we identified their partial polymorphisms and two SNPs, one (C1354T) at the 3′ untranslated region (UTR) of KIAA1717 and one (A345G) at the SINE (PRE-1) element of HUMMLC2B, both created/disrupted a restriction site for endonuclease Msp I. The selected pigs were genotyped at the KIAA1717 C1354T and HUMMLC2B A345G sites by means of a PCR-RFLP protocol. Significant associations were observed for the KIAA1717 C1354T polymorphic site with meat marbling (longissimus doris (p < 0.05), biceps femoris (p < 0.01)) and intramuscular fat (p < 0.01). HUMMLC2B A345G were significantly associated with meat pH (longissimus doris (p < 0.05), biceps femoris (p < 0.01)), drip loss (p < 0.01), water holding capacity (p < 0.01) and meat color value (longissimus doris (p < 0.01), biceps femoris (p < 0.05)). Further studies are needed to confirm these preliminary results.     

A novel 86-bp indel of the motilin receptor gene is significantly associated with growth and carcass traits in Gushi-Anka F2 reciprocal cross chickens

ABSTRACT

1. A previous whole-genome association analysis has identified the motilin receptor gene (MLNR), which regulates gastrointestinal motility and gastric emptying, as a candidate gene related to chicken growth.

2. MLNR mRNA was expressed in all tissues tested, and the expression level in digestive tissues was greater than in other tissues. Expression levels in the pancreas, duodenum and glandular stomach at day old and one, two and three weeks of age indicated a possible correlation with the digestive system. This suggested that the MLNR gene plays a central role in gastrointestinal tract function and affects the growth and development of chickens. Moreover, there was a significant difference in expression in the glandular stomach tissue between Ross 308 and Gushi chickens at six weeks of age.

3. Re-sequencing revealed an 86-bp insertion/deletion polymorphism in the downstream region of the MLNR gene. The mutation locus was genotyped in 2,261 individuals from nine different chicken breeds. MLNR expression levels in the glandular stomach of chickens with DD genotypes were greater than those in chickens with the ID and II genotypes. The DD genotype was the most dominant genotype in commercial broiler's (Ross 308 and Arbor Acres broilers), and the D allele frequency in these breeds exceeded 91%. The deletion mutation tended towards fixation in commercial broilers.

4. Association with growth and carcass traits analysed in a Gushi-Anka F₂ intercrossed population, showed that the DD genotype was significantly associated with the greatest growth and carcass trait values, whereas values associated with the II genotype were the lowest in the F₂ reciprocal cross chickens.

5. The results suggest that the mutation is strongly associated with growth related traits and it is likely to be useful for marker-assisted selection of chickens.     

Regional distribution of collagen and haemosiderin in the lungs of horses with exercise‐induced pulmonary haemorrhage

Reasons for performing study: Regional veno‐occlusive remodelling of pulmonary veins in EIPH‐affected horses, suggests that pulmonary veins may be central to pathogenesis. The current study quantified site‐specific changes in vein walls, collagen and haemosiderin accumulation, and pleural vascular profiles in the lungs of horses suffering EIPH. Hypothesis: In the caudodorsal lung regions of EIPH‐affected horses, there is veno‐occlusive remodelling with haemosiderosis, angiogenesis and fibrosis of the interstitium, interlobular septa and pleura. Methods: Morphometric methods were used to analyse the distribution and accumulation of pulmonary collagen and haemosiderin, and to count pleural vascular profiles in the lungs of 5 EIPH‐affected and 2 control horses. Results: Vein wall thickness was greatest in the dorsocaudal lung and significantly correlated with haemosiderin accumulation. Increased venous, interstitial, pleural and septal collagen; lung haemosiderin; and pleural vascular profiles occurred together and changes were most pronounced in the dorsocaudal lung. Further, haemosiderin accumulation colocalised with decreased pulmonary vein lumen size. Vein wall thickening, haemosiderin accumulation and histological score were highly correlated and these changes occurred only in the caudodorsal part of the lung. Conclusion: The colocalisation of these changes suggests that regional (caudodorsal) venous remodelling plays an important role in the pathogenesis of EIPH. Potential relevance: The results support the hypothesis that repeated bouts of venous hypertension during strenuous exercise cause regional vein wall remodelling and collagen accumulation, venous occlusion and pulmonary capillary hypertension. Subjected to these high pressures, there is capillary stress failure, bleeding, haemosiderin accumulation and, subsequently, lung fibrosis.     

Exploring polymorphisms and their effects on reproductive traits of the INHA and INHβA genes in three goat breeds

In this study, we report the analysis of INHA and INHβA gene polymorphisms in 786 goats of three breeds: Xinong Saanen (SN), Guanzhong (GZ) and Boer (BG). We identified three new allelic variants: P1–C80G and/126G (GenBank accession no. HQ202573) in the three goat breeds and P2–C936T (GenBank accession no. HQ202572) in SN and GZ goat breeds. At P1 locus, AA, AB and BB genotypes were found in the three goat breeds. At P2 locus, CC and CT genotypes were found in SN and GZ goat breeds. After comparing genotype distribution within the three goat breeds, BG had conspicuous differences from SN and GZ (P < 0.001) at P2 locus. The SNP locus was in Hardy–Weinberg disequilibrium at P1 locus in the three goat breeds (P < 0.05). At P2 locus, the SNP locus was in Hardy–Weinberg disequilibrium in SN and GZ goat breeds (P < 0.05). Association of polymorphisms with litter size was done at P1 locus in the three goat breeds. The result showed that AA genotype had remarkable litter size at P1 locus in the three goat breeds (P < 0.05). Therefore, these results suggest that INHA gene is a strong candidate gene that affects litter size in goats.     

The outcomes of epidural anaesthesia in horses with perineal and tail melanomas: Complications associated with ataxia and the risks of rope recovery

Melanoma is a common neoplasm in horses, with a high rate of incidence in the perineum and ventral tail. Surgical excision is often recommended to remove such masses and can be achieved in the standing horse either via local infiltration of local anaesthetic, or via epidural administration of a local anaesthetic and/or an adrenergic α₂ receptor agonist. The clinical records of all horses with tail and/or perineal melanomas that received epidural anaesthesia at a single equine hospital, over a 7-year period, were reviewed to determine the drugs administered and complications associated with the epidural injection. Twenty-five cases were identified, five of which received epidural anaesthesia on two occasions. Epidural anaesthesia was insufficient to allow surgical melanoma excision in two horses; repeated epidural injection allowed sufficient loss of sensation in one of these horses and additional regional infiltration of local anaesthetic allowed completion of surgery in the other. Three horses developed significant ataxia associated with epidural anaesthesia, two of which became recumbent. Both recumbent horses were placed under general anaesthesia, and in one of these, rope-assisted anaesthetic recovery resulted in additional complications associated with facial nerve paresis, fractured ribs and a fracture of the first coccygeal vertebra, with associated neurological dysfunction of the rectum, anus, tail and surrounding skin.     

Molecular characterisation of Theileria equi and risk factors associated with the occurrence of theileriosis in horses of Punjab (Pakistan)

Theileria equi (T. equi) is an obligate intra- and extra-erythrocytic parasite that causes equine theileriosis (ET) in equids. Equine theileriosis is considered a notifiable disease of global significance, a major constraint to the international movement of horses, and endemic in many countries. This disease may be difficult to diagnose, as it can produce variable and nonspecific clinical signs. A cross-sectional study was designed for the molecular characterisation of T. equi and to investigate the associated risk factors of ET accompanied by its consequences on haematological and sero-biochemical parameters. A convenience sampling of 500 blood samples were collected from ET suspect horses from January to December 2017. PCR was performed on all blood samples targeting the 18S rRNA gene of T. equi followed by sequencing; 9% animals tested positive with confirmed sequences. The isolates of this study showed high homology with Cuban, Russian and Brazilian isolates of T. equi (accession numbers KY111762.2 , MG551915.1 and KY952237.1 , respectively). Based on multivariate analysis, the principal risk factors consisted of absence of dogs on the premises and presence of tick infestation. The haemato-biochemical parameters showed a decrease in granulocytes and erythrocytes, and an increase in lymphocytes, monocytes, mean corpuscular volume, mean corpuscular haemoglobin, mean platelet volume, glucose, phosphorus and aspartate aminotransferase in positive horses. This is the first study which identified ET in Punjab (Pakistan) using molecular techniques and risk factors together with the haemato-biochemical variations in horses.