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

Abstract

12 We studied livestock abortion and various associated risk factors in the Ili region of 13 northwest China. Livestock abortion prevalence was estimated and correlated with 14 infections (Brucellosis, Salmonellosis, Mycoplasma and Chlamydia seropositivity) and 15 management (farming type and contact with other herds/flocks) risk factors. The 16 prevalence of cow and sheep abortion induced by Brucella was 76.8% (P<0.0001) and 17 84.1% (P<0.0001), and Mycoplasma caused an estimated 15.5% (P=0.025) and 17.6% 18 (P<0.001) abortions, respectively. Abortion-related risk factors included mixed 19 farming (cow P=0.001, sheep P<0.001), contact with other flocks (cow P=0.007, sheep 20 P=0.003), brucellosis positivity (cow P<0.001, sheep P<0.001) and Mycoplasma 21 positivity (cow P=0.031, sheep P<0.001). A total of 2996 serum samples (1402 cow, 22 1594 sheep) were identified by RBPT (Rose Bengal Plate Test), and they showed the 23 seroprevalence of brucellosis in X county was cow 7.1%, sheep 9.1%; in H county was 24 cow 11.7%, sheep 10.7%; and in Q county was cow 4.2%, sheep 9.1%. The 25 seroprevalence of Mycoplasma in X county was cow 3.4%, sheep 7.9%; in H county 26 was cow 5.3%, sheep 9.9%; and in Q county was cow 2.1%, sheep 4.3%. A total of 54 27 samples, including aborted cow (22), sheep (30) fetuses and milk samples (2), were 28 identified as Brucella melitensis (B. melitensis) positive. A total of 38 Brucella were 29 isolated from 16 aborted cow, 20 sheep fetuses and 2 milk samples. All of these isolates 30 were identified, and confirmed, as B. melitensis. A phylogenetic tree showed that the 31 Brucella isolates closely matched the B. melitensis biovar 3 isolated in Inner Mongolia, 32 China, and B. melitensis isolated from Norway and India. These results suggest that B.33 melitensis biovar 3 is the main pathogen responsible for cow and sheep abortion and 34 also pose a human health risk. Additionally, livestock reproduction can also be 35 influenced by Mycoplasma infection and managerial factors (farming type and contact 36 with other herds/flocks), especially in remote areas. 37 38 Introduction 39 Ruminants are a major source of meat production in China and are important for food 40 security. Xinjiang Uygur Autonomous Region (XUAR) is located in northwest China 41 and is a major ruminant production province. In 2017, beef production (0.43 million 42 tons) and mutton production (0.58 million tons) in Xinjiang, respectively, accounted 43 for the 6.8% and 12.4% in the total beef and mutton production in China. Ili is located 44 in the western part of XUAR, where the economy is highly dependent on animal 45 production [1, 2]. The combined number of cattle and sheep is approximately 5.76 46 million in this region. The sheep and cattle are reared under traditional systems, and 47 confined sheep or cattle ranches are the two main feeding systems.48Diseases and poor animal health are major risk factors for animal production in Ili.49 The viability of sheep and cattle production is largely determined by their reproductive ...

Investigation of the outbreaks of abortions and orchitis in livestock in Namibia during 2016–2018

“…B. melitensis is an important cause, not only of abortions but also of orchitis and epididymitis in sheep and goats; it can also be an important cause of abortion in cattle in mixed farming practices. In a study investigating the causes of abortion in cows that were mixed and fed together with sheep and/or goats, PCR of 34 (28%) specimens out of 120 abortion samples including fetuses and milk tested positive for B. melitensis biovar 3(Deng et al 2020). This was the rst study to demonstrate B. melitensis as the main etiological agent for cows mixed with sheep and/or goats.…”