면양에 있어서 옥수수의 입자도가 사료의 반추위내 통과속도 , 단백질과 건물의 분해 및 소화율에 미치는 영향 = Effects of Particle Size of Corn on the Out - Flow Rate , Protein and Dry Matter Degradation , and Digestibility in Sheep

다국어 초록 (Multilingual Abstract)

The effect of different particle sizes of corn on the rate of outflow, degradations of dietary protein and dry matter, and digestibility in sheep was studied, Six adult sheep weighing about 50㎏ were used. The animals were fitted with rumen canula and individually maintained in metabolism cages. All the animals were fed, at a maintenance level, a basal diet of 70% concentrates and 30% rice-straw pellets twice daily at approximately 12-hour intervals and had free access to water. Two different particle sizes of corn (1. 68-2. 38㎜ and 0. 8411.19㎜) were labelled with sodium dichromate and a 50g of the mordanted corn was introduced as a single dose via rumen canula. The rate constants (k) and retention time were calculated. Nylon bag techniques were conducted to measure degradations of protein and dry matter of the particles, and digestion coefficients were measured using the total collection method. The results obtained are summarized as follows: The stability of the corn mordanted with sodium dichromate as an indicator was inconclusive bemuse of the various DM losses (3.32% to 8.54%) according to the particle and incubation conditions. The rate of outflow (k) of the small particles (0.0359h^(-1)) was higher than that of the large particles (0.0251h^(-1)) and retention time was shorter for the small particles (27.8 hrs) than that for the large particles (44.6 hrs). When both small and large particles were incubated at 0,3,6,12,24,36 and 48 hours, DM disappearance of the small particles at 0,3,6 and 48 hours was higher, showing 8.4, 13.5, 16.0 and 64.0?%, respectively, than those of the large particles, 5.8, 9.6, 11.7 and 54.2%, respectively. No significant differences were observed at the other incubation times. There was no significant difference in protein disappearance between the small and large particles, but at 0 time incubation, the protein disappearance of the small particles (13.4%) was significantly higher than that of the large particles (7.6%). Digestion coefficients and ruminal pH were not affected by the different particle sizes.