Factors affecting the efficiency of equine embryo transfer (EET) in polo mares under subtropical conditions of Pakistan

Equine embryo transfer (EET) is a prominent technology in the equine breeding industry, and its efficacy is affected by a number of factors. The current study aimed to determine the effects of the breed of donor/recipient mares, estrus/ovulation induction treatment, cooled transportation of embryos, and synchrony between donor and recipient mares on the efficiency of the EET under subtropical conditions of Pakistan. A total of eighty-four (n = 84) Polo-playing donor mares (Argentino-polo = 41 and Anglo-Arab = 43) and seventy (n = 70) recipient mares (light breed = 26 and heavy breed = 44) were used for EET. The donor mares exhibiting natural estrus (n = 28) were detected by teaser a stallion, and corpus luteum (CL) having mares (n = 56) were treated with prostaglandin (150 μg of Cloprostenol) for estrus induction. The mares' follicular growth was monitored through ultrasonography until the dominant follicle's size reached 35 mm or more with a moderate to obvious uterine edema score. Afterward, the mares were treated either with GnRH, i.e., 50 μg of Lecirelin acetate (n = 41) or Ovusyn, i.e., 1500 IU hCG (n = 43). Insemination with chilled semen was performed 24 hours later. The embryos were collected non-surgically, 7 or 8 days after ovulation, from the donor mares. The collected embryos were transferred into the well-synchronized recipient mares as fresh (n = 44) or chilled (n = 26) embryos. The pregnancy after ET was checked through ultrasonography. Statistical analysis revealed that the embryo recovery rate (ERR) remained significantly higher (P<0.05) for the Prostaglandin (PG) treated group of donors as compared to the natural heat group of donors. The breed of donor mares, type of ovulatory treatment given, and day of embryo collection did not significantly (P>0.05) affect the ERR. There was no significant effect of the type (fresh vs chilled), classification, and stage of development of embryo on pregnancy outcomes (P>0.05). ET pregnancy rate was significantly affected by the breed of recipient mares and ovulation synchrony between donor and recipient mares (P<0.05). In conclusion, under the subtropical conditions of Pakistan, PG-based estrus induction of donor mares, breed of recipient mares, and ovulation synchrony between the donor and recipient mares had a substantial effect on the efficiency of EET.

Evaluation of haematological, serum biochemical and oxidative stress parameters in cattle naturally infected with lumpy skin disease virus

Lumpy skin disease (LSD) is a vector-borne viral transboundary disease of cattle caused by the LSD virus (LSDV). Despite investigations on clinical and outbreak features of LSDV, information on disease pathogenesis and alternative changes in blood parameters are scarce. Keeping this in view, the current study was designed to determine haematological, serum biochemical, and oxidative stress parameters in naturally infected cattle with LSDV during the recent surge of outbreaks in Punjab, Pakistan. A total of 35 blood samples was collected from polymerase chain reaction-confirmed LSDV-infected cattle for assessment of all parameters. The haematological examination of blood samples showed a significant reduction (p < 0.05) in different variables of erythrogram and leucogram. On the other hand, differences between levels of various serum biochemical parameters with the significant increase in levels of alkaline phosphatase, serum alanine aminotransferase, aspartate aminotransferase, and blood urea nitrogen were observed in LSDV naturally infected cattle. Moreover, malondialdehyde levels for lipid peroxidation and nitrate concentration were markedly elevated whereas glutathione S-transferase fluorescent and serum superoxide dismutase enzymes showed a decrease in levels. The current study suggests that alternations in haematological and serum biochemical parameters following LSDV infection stimulate oxidative stress and such findings may be useful for early and rapid diagnosis and improvement in the treatment strategy of the disease.

Prevalence of avian influenza H5, H7, and H9 viruses in commercial layers in Karachi, Pakistan

BACKGROUND

Avian influenza viruses (AIVs) cause significant harm to the poultry industry due to mortality as well as high morbidity along with the risk of potential zoonotic transmission to humans.

AIMS

The study aimed to investigate the prevalence of influenza H5, H7, and H9 viruses and their co-infections in layers having respiratory distress such as sneezing, coughing, and tracheal rales.

METHODS

Totally, 960 tracheal swabs (240 swabs in each season) were collected from 120 poultry flocks, including 10 farms per month and 8 samples per flock, located in Karachi where the outbreaks were reported. The samples were confirmed through antigen ELISA and subtyped by RT-PCR.

RESULTS

Antigen ELISA revealed that the prevalence of avian influenza viruses was 26.45%; however, seasonal differences were not significant (P<0.05). RT-PCR subtyping of hemagglutinin (HA) gene revealed the higher prevalence of H9 virus (40.16%) as compared to H7 virus (5.51%) and H5 virus (4.73%). The co-infections comprised H5/H7/H9 (37.0%) and H5/H9 (12.6%).

CONCLUSION

This study shows that AI is endemic in layer farms in Karachi where the H9 subtype is predominant along with co-infections of H5/H7/H9 subtypes.

Genetic diversity of Newcastle disease virus in Pakistan: a countrywide perspective

Background

Newcastle disease (ND) is one of the most deadly diseases of poultry around the globe. The disease is endemic in Pakistan and recurrent outbreaks are being reported regularly in wild captive, rural and commercial poultry flocks. Though, efforts have been made to characterize the causative agent in some of parts of the country, the genetic nature of strains circulating throughout Pakistan is currently lacking.

Material and methods

To ascertain the genetics of NDV, 452 blood samples were collected from 113 flocks, originating from all the provinces of Pakistan, showing high mortality (30–80%). The samples represented domesticated poultry (broiler, layer and rural) as well as wild captive birds (pigeons, turkeys, pheasants and peacock). Samples were screened with real-time PCR for both matrix and fusion genes (1792 bp), positive samples were subjected to amplification of full fusion gene and subsequent sequencing and phylogenetic analysis.

Results

The deduced amino acid sequence of the fusion protein cleavage site indicated the presence of motif (¹¹²RK/RQRR↓F¹¹⁷) typical for velogenic strains of NDV. Phylogenetic analysis of hypervariable region of the fusion gene indicated that all the isolates belong to lineage 5 of NDV except isolates collected from Khyber Pakhtunkhwa (KPK) province. A higher resolution of the phylogenetic analysis of lineage 5 showed the distribution of Pakistani NDV strains to 5b. However, the isolates from KPK belonged to lineage 4c; the first report of such lineage from this province.

Conclusions

Taken together, data indicated the prevalence of multiple lineages of NDV in different poultry population including wild captive birds. Such understanding is crucial to underpin the nature of circulating strains of NDV, their potential for interspecies transmission and disease diagnosis and control strategies.

Effect of oestrus synchronization methods on oestrus behaviour, timing of ovulation and pregnancy rate during the breeding and low breeding seasons in Nili-Ravi buffaloes

The objective of this study was to determine the effect of oestrous synchronization methods on oestrous behaviour, timing of ovulation and pregnancy rate during the breeding and low breeding seasons in Nili-Ravi buffaloes. In Experiment 1, oestrous behaviour and timing of ovulation were determined from (n=34) oestruses. The mean (+/- S.E.M.) time of ovulation after the onset of standing oestrus was greater (P<0.05) in PGF(2alpha)-induced luteolysis (30.6+/-1.5h) compared to Ovsynch buffaloes (15.0+/-0.8h). In Experiment 2, pregnancy rates were compared between two methods of synchronization (detected oestrus and Ovsynch protocol) during the breeding and low breeding seasons. Pregnancy rates of buffaloes bred at detected oestrus (62.5%) or by the Ovsynch protocol (36.3%) during the breeding season did not differ significantly (P>0.05) from those which were inseminated during the low breeding season (55.5%) and (30.4%), respectively. This study demonstrates clearly that (1) timing of ovulation in Nili-Ravi buffalo is about 30h after the onset of standing oestrus and (2) buffaloes can be successfully synchronized with optimum fertility using either PGF(2alpha) alone (detected oestrus) or using (Ovsynch protocol) during low breeding season, to calve during the period when milk availability is short.