Effect of the Rearing System on the Establishment of Different Functional Groups of Microorganism in the Rumen of Kid Goats / Uticaj Sistema Uzgoja Na Uspostavljanje Različitih Funkcionalnih Grupa Mikroorganizama U Buragu Jaradi

Abstract

This study was aimed to determine the effect of the rearing system on the establishment and development of different functional groups of microorganisms in the rumen of kid goats. Fifty kids were fed on goat milk until weaning at 45 (TR, traditional rearing system, n = 25) and 30 days of age (alternative rearing system, AR, n = 25). In addition, only AR group was offered with rumen starter from birth. Both groups consumed alfalfa hay and ground corn between 30 and 90 days of age. Five kids from each group were slaughtered at 21, 30, 45, 70 and 90 days old. It was determined the total number of protozoa, anaerobic, amylolytic and cellulolytic bacteria present in the rumen. Kids of AR were lighter in weight than TR kids between 42 and 56 days old. In both rearing systems, anaerobic and amylolytic bacteria were found at 21 days of age, while cellulolytic and protozoa were not found until 45 days of age. Kids of AR had higher quantities of anaerobic and amylolytic bacteria until 30 and 45 days of age, respectively. These results demonstrate the rearing system does not affect the sequence and time in which the functional groups of microorganisms are established in the rumen. However, the alternative rearing system with early intake of solid food allowed the establishment of greater amount of bacteria and protozoa. Nevertheless, the effect of weaning on growth rate was more marked in kids from alternative rearing system, despite its greater microbiological rumen development.Key words: kid goats, rearing system, rumen microbiology INTRODUCTIONIn the fi rst weeks of life ruminants depend exclusively on nutrients obtained from milk because the rumen is undeveloped. The establishment of microbiota and beginning of ruminal fermentation triggered rumen development [1]. At birth, the intestinal tract of animals is sterile. The establishment of ruminal microbiota is infl uenced primarily by diet and by contact with other adult ruminants that already have a developedBrought to you by | MIT Libraries Authenticated Download Date | 5/11/18 5:43 AM Acta Veterinaria-Beograd 2015, 65 (2), 175-190 176 microbiota [2]. The ruminal ecosystem of an adult animal is composed mainly of anaerobic microorganisms, including bacteria, fungi and protozoa, characterized by high population density and wide diversity [3]. Ruminal bacteria can be classifi ed according to the substrates that they ferment. Thus, bacteria that ferment starch, cellulose and hemicellulose are classifi ed within the group of amylolytic, cellulolytic and hemicellulolytic, respectively [4,5]. Taken together these groups represent the population of total anaerobic rumen bacteria. Diet is one of the main factors that affect the type and proportion of functional groups of bacteria present in the rumen of an adult ruminant. Forage diets stimulate the development of fi brolytic fl ora, while high energy concentrate diets stimulate the growth of amylolytic bacteria [6]. Newborn ruminants have no protozoa in their rumen environment, and it is well known that young ruminants inc...