ABSTRACT
This research aimed to evaluate the effectiveness of transferring rumen microbes from Kaligesing goats on changes in digestive characteristics and growth of Merino sheep fed with high-tannin forage, specifically Calliandra (Calliandra calothyrsus Meissn.). The study was based on previous research indicating that the rumen of Kaligesing goats harbours bacteria tolerant to tannins, demonstrated by their good performance when consuming Calliandra leaves containing high tannin. The experiment involved 18 Merino sheep (microbial recipients) and 2 Kaligesing goats as donors of tannin-tolerant rumen microbes. The study employed a randomized complete block design to test three treatments (transfer frequencies) with six replications for each treatment. The treatments consisted of T1 (no transfer of Kaligesing rumen microbes), T2 (one-time transfer of Kaligesing rumen microbes), and T3 (two-time transfer of Kaligesing rumen microbes) to recipient Merino sheep. The transfer of rumen microbes from Kaligesing goats was conducted by collecting rumen fluid through the goat's mouth. The diet used was 100% fresh Calliandra. Measured research parameters included nutrient intake (dry matter, organic matter, nitrogen intake), nitrogen retention, daily body weight gain, nutrient digestibility (dry matter, organic matter, and crude protein), total bacterial population, proteolytic bacteria, tannin-tolerant bacteria, total VFA content, rumen N-ammonia, and pH. The results indicated that the frequency of transferring rumen microbes from Kaligesing goats did not significantly affect consumption parameters, diet digestibility, daily weight gain, total VFA content, rumen N-ammonia, pH values, total bacterial population, and proteolytic bacteria of recipient Merino sheep. However, the tannin-tolerant bacteria population at 0 hours in Merino sheep treated with T2 (one-time transfer) and T3 (two-time transfer) was higher compared to Merino sheep without Kaligesing rumen microbe transfer (T1). In conclusion, transferring rumen microbes from Kaligesing goats twice resulted in better performance of tannin-tolerant bacteria populations in recipient Merino sheep. Meanwhile, growth performance, nutrient digestibility, fermentation characteristics, and microbial populations were relatively normal, indicating that Merino sheep in the study adapted well to consuming high-tannin Calliandra forage. Considering these findings, using Kaliandra as the sole diet component is not advisable, and alternative strategies to enhance microbial effectiveness should be explored.
