• Home
• English
• Mitarbeiter/innen
• Kontakt
• Impressum

Titel

Untersuchungen zum Einfluß eines Oreganoöl-Zusatzes zum Futter auf die Rohnährstoffverdaulichkeit, N-Bilanz sowie auf Parameter des mikrobiellen Stoffwechsels im Verdauungstrakt von Absetzferkeln

Titel(englisch)

Studies on the effect of an oregano-oil-addition to feed towards nutrient digestibilities, Nbalance as well as towards the parameters of microbial activity in the alimentary tract of weaned piglets.

Name:

Möller, Thomas

Ort und Jahr der Promotion

Hannover, Tierärztl. Hochsch., Diss., 2001

Abstract

In the last years, several antimicrobial growth promoters used in animal nutrition have been banned from the feeding of pigs. Further restrictions on the use of antibiotics in the field of disease prevention can be expected. Owing to this fact the efforts have been increased to discover alternatives to the growth promoting and gut flora stabilizing effect of these additives. Aside from organic acids, pre- and probiotics, enzymes and other substances the effects of several spices as well as of their etheric oil components have been discussed in that context. The purpose of this dissertation was to ascertain, if - by adding an oregano oil to feed- there will be an effect on nutrient digestibilities, N-balance as well as on parameters of microbial activity in the gastrointestinal tract of weaned piglets.These studies were conducted with fifty weaned piglets in total, fed with pelleted diet (17.3 18,9 % crude protein, 2.50 - 3.43 % crude fat, 3.33 - 4.32 crude fiber).In the first three experiments, 0.2 % of a specific oregano oil product (Wg-Ropa; Ropafarm, Westerstede) were added to the diet of the experimental group while the controls were fed without any feed additives. The applied oregano oil component in this product showed an etheric oil content of 5 % (concentration of Carvacrol in this oil: 81 %, of Thymol: 2 %). In order to verify possible ergotropic effects, the apparent digestibility of crude nutrients was scrutinized and a N-balance was carried out by feeding eight weaned piglets restrictively. Each piglet had to absolve a control phase for a period of ten days as well as an experimental phase for a period of ten days (cross-over-design). In addition, the daily feed intake, daily weight gains as well as the feed conversion rate were proved. The hereto required tests for analysing feed and faeces were conducted according to the Weender analysis.In the second experiment daily feed intake, daily weight gains as well as the feed conversion rate of 12 weaned piglets fed ad libitum were tested, too. In addition, the quality of faeces (dry matter content and pH-value) were examined. After 9 to 11 days the piglets where sacrificed six hours postprandial to obtain the stomach and gut fill. The chyme quality was characterized by dry matter content and pH-value. A special point of interest was the possible influence of the oregano oil on the gastrointestinal flora. Therefore, the concentration of l-lactate (enzymatic determination), of volatile fatty acids (gas chromatography) and the content of ammonia (ionic-sensitive) have been analysed in chyme as parameters for microbial digestion. Furthermore, the lipopolysaccharide content in chyme (LAL test) was measured, to estimate the mass of grain negative bacteria indirectly.In the third experiment he identification of these parameters after experimental infection with E. coli (ham. E. coli 139X82 F107+) followed. Thereto, 10 piglets where infected orally by adding 10 mI of a liquid broth containing 2.7 x 10 00000c.f.u./ml to feed in the first run. In the second test 10 piglets were infected by a liquid broth containing 1.2 x 10 000000000 c.f u./ml The pigs where sacrificed after the outbreak of oedema disease or on the 1 & day after infection the latest.In the fourth experiment 10 weaned piglets where infected also with E. coli (as stated above; 1.0 x 10 000000000 c.f.u./mI liquid broth), to ascertain the effect of a combination of oregano oil and calcium formate. The experimental group was fed with addition of an oreganooilcalciumformate-combination (1.0 %) to feed (product: LATIBON-O, Bayer, Leverkusen; etheric oil component: 0.375 %). The controls were fed with an additon of calciumformate (1.0 %) to diet only (product: LATIBON"; Bayer, Leverkusen). The percentage of formate in both products was at least 68 %, that of calcium at least 30 %.Besides the self-conducted experiments GÖSSLING (2001) characterized the gut flora in the framework of her thesis (conducted at the same time) by direct microbiological investigations, in order to determine the number of bacteria of selected bacteria species.In the experiment without any infection she analysed the total number of aerobe and anaerobe microbial counts as well as some selected indicator counts (a.o. lactobacilli, streptococci/ enterococci, Escherichia coli, gram negative anaerobic bacteria). In the experiment with infection she determined the bred isolated microbial counts of the inoculated E. coli stock culture in faeces and chyme.The own results of the use of this oregano-oil-product as feed additive can be summarized as follows:1 . In comparison o untreated controls, no positive effects on daily feed intake, daily weight gains and feed conversion rate could be shown by feeding piglets restrictively. By feeding pigs ad libitum using the oregano oil the daily weight gains where tendencially higher, the feed conversion rate tendencially lower compared to untreated controls.2. The apparent digestibility of crude nutrients (exe. crude fibre) and the N-balance of the weaned piglets was not influenced by feeding piglets restrictively with this feed additive.3. A specific tendency towards the faeces and chyme quality could not be identified.4. The concentration of the most important organic acids (l-lactate and volatile fatty acids), the ammonia and the lipopolysaccharide content in the chyme, did not show strict dependency on the addition of this oregano-oil to feed.5. Towards untreated controls there where no significant differences in the frequency of the outbreak of disease after experimental infection. Nonetheless, it is worth to be stated that in the control group of 15 infected piglets 7 of them fell ill with disease (466 %) whereas only 20 % of the piglets, i.e. 3 out of 15 piglets developed symptoms of enterotoxemia when fed with that specific feed additive.6. The combination of oregano oil and calciumformate did not evoke any effect on the gut flora during the infection process.The in vitro antimicrobial properties of oregano could not be confirmed accordingly. The positive effects of this spice on the feeding of piglets in vivo stated by GÜNTHER and BOSSOW (1998), could only be proven partially when feeding ad libitum. Also by direct micobiological methods applied by GÖSSLING (2001) no influence of the additive on the gut flora could be found. Her conclusions support the self-conducted facts.The results after experimental infection are stimulating to examine this new feed additive with more piglets (same procedure in principal, i.e. by experimental studies) or in practice on farms which have to cope particularly with oedema disease.