Probiotic potential and safety assessment of Lactobacillus isolated from yaks.

Current problem of antibiotic resistance and the high incidence of bacterial diseases has brought huge losses to the yak breeding industry in Tibet. Therefore, the purpose of this study was to isolate Lactobacillus with safety and beneficial probiotic potential for the prophylaxis of intestinal diseases in yaks. After 16S rDNA sequence, four strains i.e. Lactobacillus sakei (named L4), Enterococcus hirae (named E5), Pediococcus acidilactici (named P7), Weissella confusa (named W8) were isolated from feces of yaks. The results of tolerance to acid, bile salt, enzyme and temperature showed that P7 was highly tolerant to acid, bile salt and digestive enzyme, while E5 was more resistant to temperature. The antibacterial assay showed L4 had a strong inhibitory effect against Staphylococcus aureus (BNCC186335), and E5, P7, W8 had effective antibacterial ability against Escherichia coli (C83902). In addition, L4, E5, P7 and W8 mainly produced organic acids and bacteriocin production to inhibit common intestinal pathogens. The results of antibiotic susceptibility assay indicated that L4, E5, P7 and W8 were highly sensitive to most clinically used antibiotics and didn't contain the VanA and VanB genes on the basis of PCR amplification, and L4, E5, P7 and W8 didn't exhibit hemolytic activity. The animal toxicity experiment results showed that no obvious pathological change was found in intestinal tissue sections, and L4, E5 and W8 strains also promoted the growth performance of mice, consequently, the L4, E5, P7 and W8 had no toxic effect on mice. In conclusion, lactobacillus isolated from feces of yaks not only have potential probiotics and strong antibacterial ability in vitro, but also are safe. Therefore, they have the potential to reduce the occurrence of bacterial diseases as new feed additives.

Socio-economic burden of parasitic infections in yaks from 1984 to 2017 on Qinghai Tibetan Plateau of China-A review.

Yak is an important animal for the Tibetans at Qinghai-Tibetan Plateau of China. The burden of parasitic diseases has been a major threat to the health of yaks at this region presenting a considerable socio-economic losses and impact to yak production and local nomads. Keeping in view, we collected the published papers from 1984 to 2017 on major parasitic infections in yaks by electronic literature search from five databases including CNKI, Google, PubMed, Science Direct and Web of Science. The prevalence of Eimeria, Babesia, Theileria, Hypodermosis, Cystic echinococcosis, Alveolar echinococcosis, Toxoplasma gondii, Neospora caninum, Cryptosporidium, Giardia duodenalis, Enterocytozoon bieneusi, Toxocara vitulorum, and Fascioliasis infection in yaks was found to be 48.02%, 13.06%, 36.11%, 59.85%, 16.93%, 0.99%, 20.50%, 5.14%, 10.00%, 3.68%, 4.07%, 22.23% and 28.7% respectively. Data presented are contemplated to enhance our current understanding on the major parasitic diseases of yaks at Qinghai Tibetan plateau, China. The main aim of this effort is to ameliorate the effects of the parasitic burden in this specie; so that, the attempts are made to minimize the incidence of these infections in future to raise the socio-economic levels of local community.

A review on epidemiology, global prevalence and economical losses of fasciolosis in ruminants.

Fasciolosis is an important plant borne trematode zoonosis in ruminants caused by the Fasciola hepatica and Fasciola gigentica, It is classified as a neglected tropical disease and found in more than 50 countries especially where sheep and cattle are reared. Fasciolosis is a serious animal health problems in many rural and urban areas of world, causing significant financial losses due to decrease in production and viscera condemnation in animals. Accurate diagnosis of fasciolosis is always remained a challenging task for the field practitioners. There is no comprehensive summary on the occurrence and distribution of the infection at international level. Therefore, we intended to provide a complete overview on the prevalence and epidemiology of fasciolosis in farm animals from a global prospective. It includes to map the global distribution of fasciolosis in different areas of the world to identify the endemic regions which may be a source of potential disease outbreak. The financial liability related to fasciolosis on the livestock production has also been addressed. For this purpose, the published data during 2000-2015 (15 years) on fasciolosis was reviewed and collected by electronic literature search of four databases including Google, PubMed, Science Direct, and Web of Science. Data presented are contemplated to enhance our current understanding of the parasite's geographical distribution, host range, and economic losses. Information provided would be useful for the application of more effective control strategies against fasciolosis in different geo-economics regions of the world.

Prevalence of Circulating Antibodies to Bovine Herpesvirus 1 in Yaks (Bos grunniens) on the Qinghai-Tibetan Plateau, China.

Bovine Herpesvirus 1 (BoHV-1) causes infections with many clinical signs, including rhinotracheitis, encephalitis, and genital lesions. The virus occurs worldwide in bovines, and in recent years, it has been reported in yaks (Bos grunniens) inhabiting the Tibetan Plateau in China. However, there is little epidemiologic data describing BoHV-1 infections in China's yak herds. We conducted a cross-sectional study on the Qinghai-Tibetan Plateau (QTP) in China July 2011-July 2012 to estimate the prevalence of BoHV-1 antibody in yak herds. We collected 1,840 serum samples from yaks on the QTP, in Tibet (988 yaks), Qinghai (475 yaks), and Sichuan (377 yaks) Provinces. Using an enzyme-linked immunosorbent assay, we found that 381 (38.6%) of the Tibetan samples, 212 (44.6%) of the Qinghai samples, and 105 (27.9%) of the Sichuan samples had detectable antibodies to BoHV-1. Given that this high prevalence of infection in yaks could result in heavy economic losses, we suggest that an effective management program, including vaccination and strategies for infection control, be developed.

Assessment of Serum Trace Elements in Diarrheic Yaks (Bos grunniens) in Hongyuan, China.

Diarrhea is one of the main causes of animal deaths especially in neonatal calves. The objective of this study was to investigate the blood serum for cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), Molybdenum (Mo), selenium (Se), and zinc (Zn) concentrations in yak serum samples by inductively coupled plasma mass spectrometry (ICP-MS) from 35 yaks consisting of 10 healthy and 25 diarrheic ones. Our observations indicated that the concentrations of Mn, Zn, and Fe in yak affected with diarrhea had statistically significant reduced levels as compared to the control group (P < 0.05). The mean concentration of Cu in blood serum of diarrheic yaks was found significantly higher than the normal ones (P < 0.05). The Mn and Zn in the serum of diarrheic groups were observed significantly different (P < 0.05) with different ages. These findings can provide for some valuable information for the investigation on relationship between trace elements in the serum of normal and diarrheic yaks.