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Probiootikumide kasutamise traditsioonid on pikad. Probiootikume sisaldavaid fermeteeritud toiduaineid on inimtoitumisel kasutatud aastasadu, enamus sellest ajast siiski alateadlikult. Seoses mikrobioloogiateaduse arenguga, alates eelmise sajandi algusest, on aktiivselt selgitatud probiootikumide toimet nii inimtoitumise, kui loomade toitumise juures. Loomakasvatuses on probiootikumide toimet eriti aktiivselt uuritud paar viimast aastakümmet, kui Euroopa Liidus keelustati antibiootikumide kasutamine noorloomade kõhulahtisuse preventatiivseks raviks. Täna loomakasvatuses kasutatavad täispiimaasendajad ja startersöödad sisaldavad enamuses erinevaid probiootikume. Suur osa probiootilistest bakteritest on isoleeritud noorloomade seedetraktist, kuid uuritud on ka mitmeid teisi probiootilisi baktereid. Antud magistritöös uuriti Tervisliku Piima Biotehnoloogiate Arenduskeskuse poolt registreeritud L. plantarum E-98 tüve, mis on isoleeritud heintaimedelt. Uuriti nimetatud bakteri koloniseerumist vasikate soolkanalis. Vasikatele joodeti koos täispiimaga L. plantarum E-98 tüvi alates teisest joogist pärast sündi. Seda joodeti viie päeva jooksul. Kõikidel jootmise päevadel ja kolm päeva pärast bakteri jootmist võeti vasikate pärasoolest roojaproovid. Bakterioloogilised uuringud teostati Arenduskeskuse laboris. During the last decade in Estonia, cattle breeding has vigorously been invested in. More than half of dairy cows are located in modern, new or renovated facilities. Also, the productivity of cows has grown rapidly. Because of the high cost of milk and dairy products, the area of the dairy used for feeding calves has significantly been reduced, moreover, calves are weaned significantly earlier, which is at the age of two months instead of six months. Another major change in rearing calves has occurred in the prevention of diarrhoea. In previous years a variety of antibiotics were used as a preventative measure; however, now this has now been stopped, in agreement with the European Union. The reason is the emergence of antibiotic resistance among both animals and humans. Therefore, the use of antibiotics is accepted merely for medical purposes. One possible measure against diarrhoea is the use of probiotics at a very early age, as the aim of probiotic bacteria is to introduce them into the calf’s alimentary canal before pathogenic bacteria are able to colonize it. The current research is a part of the Bio-Competence Centre of Healthy Dairy pilot project, which aims to study the survival of bacteria in the digestive tract of calves. However, the research is largely a review, based on current scientific literature, since several of the findings are filed to be patented. In the present research, a general overview of the history of the use of probiotic bacteria is given as well as an insight into the probiotic bacteria species commonly used in livestock farming. A large part of the literature review is based on the results of tests carried out with calves. The literature review is concerned with information about the effects of probiotics on calves as well as their performance characteristics, health and the ability of colonization of probiotic bacteria in their digestive tract. The experimental part of the research is concerned with the TAK-98 strain of lactic acid bacteria survival, and its study carried out among calves intestine tract registered by Bio- Competence Centre of Healthy Dairy Products. In the experiment, probiotic treatment was introduced by drenching calves from the second drench event. The L. plantarum E- 98 strain was given to calves in quantities of 1010 colony-forming units per day. The probiotic bacteria investigated was previously mixed with a carrier substance, which facilitated the preservation and dosing of bacteria. In order to examine the survival ability of probiotic bacteria, samples of faeces from the rectum of calves were collected. This procedure started on the second day of life of the calves under test and continued through the third, fourth and fifth day of life – during which time probiotics were fed to the calves. Three days after the test, new samples of faeces were taken from the calves to determine whether the probiotic had colonized the gastrointestinal tract of the calves, and also if it was viable after administration. The results showed that the level of bacterium L. plantarum E-98 in the faeces of an group of calves rose to a peak on the third day of the test. In the faeces of one of the test calves, the bacteria investigated was no longer found on the fourth day of the test. The reason for this could have been that the calf had not drunk any dairy products containing probiotics on the second and fourth day. In the faeces of the other test calves the concentration of the tested bacteria remained consistently high until the fifth day of the test, when drenching the calves with probiotic bacterium finished. As a conclusion, the results are in good accordance with the data found in the literature. The strain of bacteria investigated, L. plantarum E-98, maintains viability in the abomasum and is able to actively reproduce in the intestinal tract of calves, but will not continue to survive there after the cessation of treatment. Further studies will show how aggressive the strain of L. plantarum E-98 is against pathogenic bacteria. |
