SUKUNYA KERNKLANG, CHOKE MIKLED, THERDCHAI VEARASILP, UDO TER MEULEN
Chiang Mai University, Department of Animal Science, Thailand
Georg-August-Universität Göttingen, Institute of Animal Physiology and Nutrition, Germany
The study was conducted to determine the chemical composition, rumen degradability and in vitro digestibility of soybean hulls. Soybean hulls were incorporated at 0, 20, 40 and 60% of the total rations and offered to four rumen fistulated crossbred Thai Indigenous x Holstein Friesian dairy cows of average 416 54kg in a Latin Square Design study. Rumen degradation of soybean hulls was determined using the nylon bag technique and the digestibility using Menke in vitro gas technique. The soybean hulls contained 88.71% DM. The composition of the soybean hulls as percentage of DM was 95.42% OM, 11.42% CP, 3.57% EE, 24.75% CF, 39.03% NDF and 27.78% ADF. The results from nylon bag technique showed that the potential DM degradability of soybean hulls was very high (99.35%) and the effective degradation at 0.05 hr was 56.25%. When supplemented at 60% in the diet, the effective degradation of DM, OM and CP were relative higher than at 0, 20 and 40%. The estimated DMI, DDMI, growth rate and index value also followed the same trend. The prediction values of OMD were 73.27, 73.04, 70.80 and 69.13 %, respectively, ME values were 11.98, 12.20, 12.00 and [11.59]MJkg DM, respectively and NEL values were 7.45, 7.64, 7.49 and [7.20]MJkg DM, respectively at 0, 20, 40 and 60% inclusion. The values tended to decrease at higher levels of soybean hulls supplementation. Ammonia nitrogen level in the rumen at 1h after feeding was significantly higher () at 0% soybean hulls diets than at 30%. However, at 3h after feeding the ammonia nitrogen level in the rumen at 30% soybean hulls was significantly higher () than at 20% soybean hulls diet.Total volatile fatty acid tended to decrease at the higher levels of soybean hulls in the diets. It is concluded that soybean hulls can be supplemented at 3% of the ration of dairy cattle.
Keywords: Dairy performance, nutrient digestibility, rumen degradability, soybean hulls