Tannins and their Effect on Production Efficiency of Ruminants

Abstract

In the recent years, numerous publications have analysed the efficiency of phytogenic feed additives, plant-based supplements, in animal nutrition for improving livestock productivity and the quality of products. Regarding ruminant nutrition, the publications very often focus on the fate of proteins and on productivity as a result of the use of tannins rich plant extracts and plant parts. Most tannin-related studies are concerned with forages, mostly legumes, less is know about tannins extracts. Tannins are phenolic secondary compounds naturally occurring in plants and helping to protect them against herbivores, defend them against pathogens and are participating in energy and nitrogen conservation. Tannins were for a long time considered to be antinutritive compounds to ruminants. Several new systematic studies, associated with analyses of tannins have revealed beneficial roles in animal nutrition and health. New studies more precisely distinguish different groups of tannin. As a result, feed containing tannins, hydrolysable or condensed, has the effect of slowing down the protein digestion, increasing microbial protein synthesis in rumen and reducing methanogenesis. Positive effects onanimal health such as the prevention of bloating and multiplication of parasites have also been reported. When fed in proper amounts, tannins may promote higher level of productivity such as higher growth rate, higher milk yield and improved milk quality. Due to their positive role, they are being gradually considered as important nutritive additives in many ruminant feeds.Tanini in njihov vpliv na učinkovitost proizvodnih lastnosti pri prežvekovalcih. V zadnjih letih so v številnih publikacijah proučevali učinkovitost fitogenih krmnih dodatkov, rastlinskih krmnih dodatkov, v živalski prehrani za izboljšanje produktivnosti živali in kakovosti njihovih proizvodov. Pri prehrani prežvekovalcev se raziskave zelo pogosto osredotočajo na usodo beljakovin in produktivnost kot posledico uporabe s tanini bogatih rastlinskih ektraktov in rastlinskih delov. Večina študij, povezanih s tanini, se ukvarja s preučevanjem krme, predvsem metuljnic, manj je znanega o taninskih ektraktih. Tanini so fenolne sekundarne spojine, ki se naravno pojavljajo v rastlinah kot njihova zaščita pred rastlinojedi, obramba pred patogeni ter za ohranjanje energije in dušika. Tanini so pri prežvekovalcih dolgo časa veljali za antinutritivne spojine, vendar pa nove sistematične študije povezujejo tanine s koristnimi vlogami pri prehrani in zdravju živali. Nove študije natančneje razlikujejo različne skupine taninov. Krma, ki vsebuje hidrolizirajoče ali kondenzirane tanine, posledično učinkuje na upočasnitev prebave beljakovin, povečavo sinteze mikrobnih beljakovin v vampu in zmanjšanje metanogeneze. Poročali so o pozitivnih učinkih na zdravje živali, kot je preprečevanje napenjanja in pojava parazitov. Kadar tanine krmimo v ustrezni količini, lahko le-ti posledično vplivajo na izboljšane proizvodne lastosti, kot so večji prirasti, večja prireja mleka ter boljša sestava mleka. Njihova vloga se šteje za vse bolj pomembno v uporabi kot krmni dodatek pri številnih krmnih mešanicah za prežvekovalce.