Search bioRxiv⌕ Search

bioRxiv · 10.1101/2020.04.20.050872

Abortion and various associated risk factors in dairy cow and sheep in Ili, China

Abstract

We studied livestock abortion and various associated risk factors in the Ili region of northwest China. Livestock abortion prevalence was estimated and correlated with infections (Brucellosis, Salmonellosis, Mycoplasma and Chlamydia seropositivity) and management (farming type and contact with other herds/flocks) risk factors. The prevalence of cow and sheep abortion induced by Brucella was 76.8% (P<0.0001) and 84.1% (P<0.0001), and Mycoplasma caused an estimated 15.5% (P=0.025) and 17.6% (P<0.001) abortions, respectively. Abortion-related risk factors included mixed farming (cow P=0.001, sheep P<0.001), contact with other flocks (cow P=0.007, sheep P=0.003), brucellosis positivity (cow P<0.001, sheep P<0.001) and Mycoplasma positivity (cow P=0.031, sheep P<0.001). A total of 2996 serum samples (1402 cow, 1594 sheep) were identified by RBPT (Rose Bengal Plate Test), and they showed the seroprevalence of brucellosis in X county was cow 7.1%, sheep 9.1%; in H county was cow 11.7%, sheep 10.7%; and in Q county was cow 4.2%, sheep 9.1%. The seroprevalence of Mycoplasma in X county was cow 3.4%, sheep 7.9%; in H county was cow 5.3%, sheep 9.9%; and in Q county was cow 2.1%, sheep 4.3%. A total of 54 samples, including aborted cow (22), sheep (30) fetuses and milk samples (2), were identified as Brucella melitensis (B. melitensis) positive. A total of 38 Brucella were isolated from 16 aborted cow, 20 sheep fetuses and 2 milk samples. All of these isolates were identified, and confirmed, as B. melitensis. A phylogenetic tree showed that the Brucella isolates closely matched the B. melitensis biovar 3 isolated in Inner Mongolia, China, and B. melitensis isolated from Norway and India. These results suggest that B. melitensis biovar 3 is the main pathogen responsible for cow and sheep abortion and also pose a human health risk. Additionally, livestock reproduction can also be influenced by Mycoplasma infection and managerial factors (farming type and contact with other herds/flocks), especially in remote areas.View Full Text

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Deng, X., Zhang, H., Shao, Z., Zhao, X., Yang, Q., Song, S., Wang, Z., Wang, Y., Sheng, J., chen, c.. 2020-04-20. Abortion and various associated risk factors in dairy cow and sheep in Ili, China. https://doi.org/10.1101/2020.04.20.050872

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Wild juvenile Arctic char (Salvelinus alpinus) show seasonal acclimatization of cardiac and whole-animal heat tolerance

Arctic fishes experience extreme seasonality, yet how seasonal acclimatization shapes their ability to cope with thermal variation remains poorly understood. The Arctic char (Salvelinus alpinus) is one Arctic fish of immense cultural, subsistence, and economic value and encounters temperatures ranging from below 0{degrees}C to above 21{degrees}C. Thermal physiology commonly varies across life stages, but has been largely unexamined in wild juvenile Arctic char. We performed winter and summer field-based assessments of wild juvenile Arctic char thermal habitat use, whole-animal and cardiac heat tolerance, and mechanisms shaping the acute thermal sensitivity of heart rate ([f]H). Average body temperature increased from 1.2{degrees}C in winter to 8.9{degrees}C in summer, and critical thermal maximum (CTmax) increased correspondingly from 21.4 to 25.9{degrees}C. We assessed the intrinsic and maximum [f]H ([f]Hint and [f]Hmax) of anaesthetized fish during acute warming using cholinergic blockade (atropine) and either {beta}-adrenergic blockade (sotalol; [f]Hint) or stimulation (isoproterenol; [f]Hmax). [f]H increased with acute warming in both seasons and treatments. However, in summer, [f]H was more responsive to warming (Q10 from 5 to 15{degrees}C: 2.4 vs. 2.0 in winter), reached a higher peak, and continued to increase while maintaining rhythmicity up to higher temperatures, with the onset of heat-induced cardiac arrhythmia (Tarr) occurring at 23.6{degrees}C vs. 18.7{degrees}C in winter. Contrary to expectations, {beta}-adrenergic blockade had little effect on these cardiac parameters. During acute warming, winter-acclimatized fish exhibited slower atrioventricular conduction (longer PR interval) and slower ventricular depolarization (longer QRS duration), which may underlie their lower cardiac heat tolerance and the reduced responsiveness of [f]H to warming. Combined, our results show that wild Arctic char exhibit strong seasonal plasticity of acute thermal performance, demonstrating the value of field-based physiological assessments and the need to consider plasticity in evaluating responses to environmental change.

zoology↗

Sex-linked genomic variation reveals reproductive skew and male-biased dispersal in polygynous sea lions

Sex-biased dispersal and the resulting asymmetry in gene flow are important factors in evolution. However, their quantification in natural populations remains challenging, not least because sex-specific reproductive skew, as reflected in the mating system, further influences the relative contributions of males and females to the genetic pool of subsequent generations. Incorporating information from mitochondria (MT) and sex chromosomes (X, Y) alongside the more commonly used autosomal markers (AUT) provides a promising framework to partly disentangle confounding processes. Here, we exemplify this approach in two closely related, polygynous species with observational evidence for male-biased dispersal, the Galapagos sea lion (GSL) and the Steller sea lion (SSL). Using whole-genome resequencing data, we leveraged genetic variation among all four genomic compartments, representing genetic variation with female-only (MT), mixed (X, AUT) and male-only (Y) inheritance, to obtain information on the mating system and test for sex-specific migration across geographic and environmental boundaries. For GSL, genomic signatures were consistent with mild polygyny and a moderately elevated rate of male migration, particularly across habitat boundaries. In SSL, male reproductive skew was substantially greater, and male-biased migration was more pronounced and less habitat-dependent. Our results align with the species' life history and support a link between mating system and dispersal, but were also impacted by confounding biological processes and bioinformatic choices. This study highlights the value and challenges of population genomic approaches integrating multiple genomic compartments to infer variation in individual behaviours.

zoology↗

Impact of iron-enriched diets on the nutritional composition and microbiome diversity of house crickets (Acheta domesticus)

Iron deficiency (ID) and iron-deficiency anaemia (IDA) pose significant global health challenges. ID and IDA are particularly widespread in Sub-Saharan Africa and South Asian countries, where reliance on plant-based foods is high. Edible insects provide an alternative nutritious food source, rich in both protein and essential minerals and trace elements. Little is known about how dietary iron manipulation affects the trace element bioaccumulation and microbiome community composition of edible insects. This study examined the impact of dietary iron supplementation on the growth, survival, nutrient profile, and microbiome of Acheta domesticus. Experimental diets were formulated using iron (II) sulphate heptahydrate, resulting in final iron concentrations ranging from 333.45 mg Fe/kg (control diet) to 6923.39 mg Fe/kg (100 mM Fe diet). Iron supplementation significantly altered the cricket trace element profile, with iron levels increasing fivefold from basal 21.38 mg/kg to 118.34 mg/kg in the highest iron treatment group. Concurrently, manganese levels showed a strong negative correlation with dietary iron, while zinc and cadmium displayed non-significant downward trends. High-iron diets statistically altered dry matter, chitin, and TBARS, whereas carbohydrates, protein, glycogen, and lipids remained stable. Amino acid profiles shifted progressively, with branched-chain, sulphur-containing, and aromatic amino acids peaking in the 25 mM Fe group. In contrast, the diversity and overall structure of the microbial community remained unaffected across all treatments. In conclusion, tailoring dietary iron can significantly boost the iron content of Acheta domesticus without compromising host survival or altering core microbial structures. To optimize insect rearing strategies aimed at alleviating human micronutrient deficiencies, a feeding dose of 10-25 mmol Fe/kg is recommended.

zoology↗