•The first report on the characterization of STEC isolated from cattle in Mongolia.•A variety of STEC with various O-genotypes and H-genotypes were isolated.•STEC with a higher risk of causing severe ...human disease exists in Mongolian cattle.
Shiga toxin-producing Escherichia coli (STEC) are associated with severe infections including hemorrhagic colitis and hemolytic uremic syndrome in humans. Ruminants are known as reservoirs of STEC; however, no data are available on STEC in ruminants in Mongolia, where more than 5 million cattle and 25 million sheep are raised. To disclose the existence and characteristics of STEC in Mongolia, in this study, we isolated and characterized STEC from cattle in Mongolia. We collected 350 rectal swabs of cattle from 30 farms near Ulaanbaatar city and isolated 45 STEC from 21 farms. Rectal swabs were precultured with modified Escherichia coli broth and then inoculated to Cefixime-Tellurite Sorbitol MacConkey agar plate and/or CHROMagar STEC agar plate for the isolation of STEC. The isolation ratios in each farm were from 0% to 40%. Multiplex PCR for the estimation of O- and H-serotypes identified 12 O-genotypes (Og-types) and 11 H-genotypes (Hg-types) from 45 isolates; however, Og-types of 19 isolates could not be determined. Stx gene subtyping by PCR identified 2 stx1 subtypes (1a and 1c) and 4 stx2 subtypes (2a, 2c, 2d, and 2g). Forty-five isolates were divided into 21 different groups based on the Og- and Hg-types, stx gene subtypes and the existence of virulence factors, ehxA, eae, and saa, which includes several major serotypes associated with human illness such as O26:H11 and O157:H7. The most dominant isolate, OgUT:H19 stx1a (+), stx2a (+), ehxA (+) and saa (+), was isolated from eight farms. This is the first report on the characterization of STEC in cattle in Mongolia, and the results suggest the importance of further monitoring of STEC contamination in the food chains as well as STEC infection in humans.
Information regarding the lactational performance of mares in relation to metabolic parameters can help practitioners to manipulate animal rearing management for sustainable mare milk production. The ...aim of this study was to characterize the lactational performance of Mongolian native mares grazing on natural pastureland by revealing the seasonal effects on metabolic parameters. In this study, 8 multiparous mares were used. Milk yield and composition and serum metabolic parameters, such as alanine aminotransferase, aspartate aminotransferase (AST), glucose (GLU), triacylglycerol, total cholesterol (TCH), non-esterified fatty acid (NEFA), albumin, urea, total protein, cortisol (Cort), and insulin, were determined at 30, 60, 90, 120, 150, 180, 210, 240, and 270 days of lactation. During the lactation period, milk yield peaked at around the 90th day and declined sharply in the following period. While the milk fat and protein contents decreased gradually from the early stages of lactation to the late stages, the lactose content was highest at mid-lactation and stayed constant until the end of the lactation period. Meanwhile, changes were observed between the stages of lactation, and the differences in metabolic parameters were significant (P<0.05), except for AST and GLU. The strongest correlation was found with NEFA (P<0.01), followed by the Cort (P<0.05) concentration, with both parameters showing negative correlation, and strong positive correlation was detected between the milk yield and TCH (P<0.05) concentration.
Current research was performed to determine the yield and composition of milk during entire lactation period, which lasts June to February of following year and describe fit of lactation curve using ...different mathematical models. Total 8 mares, aged from 5 to 12 years were used in the study. The total milk yield, calculated by Fleischmann's method, as well as the models were various and shape of curves for Linear, Quadratic, Cubic, and Quartic equations, and Wood's curve were different. The determination index (R2) of the milk yield and composition curve models ranged from 0.474-0.987, and R2 of Quartic curve model for milk yield (0.987) was the highest. Study result showed that the above models were able to describe the lactation curve of the milk yield and composition, and the Quartic model best fit to data collected from Mongolian mare and allowed a suitable description of the shape and dynamics of curve.
Бэлчээрийн маллагаатай Монгол гүүний лактацын муруйн загварчлал
Монгол гүүний саалийн нийт хугацаанд буюу VI сараас дараа жилийн III сар хүртэл саамны гарц, найрлагын хэмжээг үндэслэн математик загваруудаар лактацын муруй байгуулах, монгол гүүний лактацын муруйд хамгийн нийцэл сайтай загварыг сонгон тодорхойлох зорилгоор энэхүү ажлыг хийж гүйцэтгэлээ. Судалгаанд 5-12 насны 8 гүүг ашиглав. Сүүний нийт гарц, найрлагын хэмжээг Вүүд (Wood’s)-ын загвар болон шугаман, шугаман бус регрессын тэгшитгэлээр загварчлахад лактацын муруйн загварууд харилцан адилгүй байв. Саамны гарц, найрлагын муруйн загваруудын детерминацийн индекс (R2) нь 0.474-0.987-ийн хооронд хэлбэлзэж, биквадрат загварын хувьд хамгийн нийцэл өндөр буюу 0.987 байв. Судалгааны үр дүнд дээрх аргуудаар саамны гарц, найрлагын лактацын муруйг загварчлах боломжтой нь харагдаж байсан ба эдгээрээс биквадрат тэгшитгэлийн загвар нь бэлчээрийн маллагаатай монгол гүүний саамны өгөгдөлтэй хамгийн сайн нийцэж, лактацын муруйн хэлбэр, хөдлөлзүйн хувьд тохирч байв.
Түлхүүр үг: саамны гарц, саамны найрлага, лактацын муруй
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