Browsing by Author "Ondiek, JO."

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    Implications of mycotoxin contamination of dairy feeds and products
    (KARI publication unit, 2014) Lanyasunya, TP.; Lokwaleput, IK.; Mutunga, TK.; Siamba, Donald N.; Ondiek, JO.
    The complex diet of ruminants, consisting of forages, concentrates, and preserved feeds, can be a source of very diverse mycotoxins that contaminate individual feed components. A number of mycotoxins are successfully inactivated by the rumen flora, whereas others pass unchanged or are converted into metabolites that retain biological activity. Hence, the barrier function of the rumen largely determines the susceptibility of dairy cows and other ruminant species towards individual mycotoxins. An impairment of this barrier function due to diseases or the direct antimicrobial effect of certain mycotoxins may increase absorption rates. The rate of absorption determines not only the internal dose and risk for adverse health effects, but also the excretion of mycotoxins and the biologically active metabolites into milk.
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    Rapid and conventional testing methods for microorganisms in milk
    (KARI publication unit, 2014) Lanyasunya, TP.; Lokwaleput, IK.; Mutunga, TK.; Siamba, DN.; Ondiek, JO.; Bwire, JM.
    mmunomagnetic bead separation coupled with bead beating and real-time PCR was found to be a very effective procedure for the isolation, separation, and detection of Mycobacterium avium subsp. paratuberculosis from milk and/or fecal samples from cattle and American bison. Samples were spiked with M. avium subsp. paratuberculosis organisms, which bound to immunomagnetic beads and were subsequently lysed by bead beating; then protein and cellular contaminants were removed by phenol-chloroform–isopropanol extraction prior to DNA precipitation. DNA purified by this sequence of procedures was then analyzed by conventional and real-time IS900-based PCR in order to detect M. avium subsp. paratuberculosis in feces and milk. By use of this simple and rapid technique, 10 or fewer M. avium subsp. paratuberculosis organisms were consistently detected in milk (2-ml) and fecal (200-mg) samples, making this sensitive procedure very useful and costeffective for the diagnosis of clinical and subclinical Johne’s disease (paratuberculosis) compared to bacteriological culture, which is constrained by time, labor, and expense under diagnostic laboratory conditions.