S-Space College of Agriculture and Life Sciences (농업생명과학대학) Dept. of Food and Animal Biotechnology (식품·동물생명공학부) Theses (Master's Degree_식품·동물생명공학부)
Effects of supplemental zinc on the rumen fermentation, nutrients digestibility, milk yield and composition of dairy cows
- Issue Date
- 서울대학교 대학원
- 아연; Zinc; 반추위; Rumen; 발효; Fermentation; 영양소 소화율; Nutrient digestibility; 우유; Milk; 젖소; Dairy cow
- Thesis (master`s)--서울대학교 대학원 :농생명공학부,2003.
- Three experiments were conducted to investigate effects of
supplemental zinc on protein degradation, rumen fermentation
characteristics and lactation performance of dairy cows.
Experiment 1 was designed to investigate effects of different
type and particle size of zinc supplementation on in situ nutrient
degradation. In DM degradation, zinc supplementation decreased
potentially degradable fraction (P<0.01). In addition, the potentially
degradable fraction and effective degradability (ED) were decreased
by particle size (P<0.01 and P<0.001, respectively). While, in CP
degradation, zinc supplementation did not affect immediately and
potentially degradable fractions, degradable rate per hour of fraction
and ED, but particle size influenced ED (P<0.01). Therefore, larger
particle size beneficially decreased protein degradation in the rumen,
but the effect of zinc was not clear for ruminal protein degradation.
In experiment 2, zinc was mixed with heat treated soybean
meal and Aspergillus oryzae. Therefore, three treatments were used,
which were soybean meal as a control, zinc with heat treated
soybean meal (Zn-SBM), and zinc with heat treated soybean meal
and Aspergillus oryzae, to assay in vitro fermentation. Generally, the
medium pH was higher in control and Zn-SBM compared with ZnAo-SBM during the incubation. Until 16 h, gas production was
highest in ZnAo-SBM among the treatments. However there was no
significantly different among the treatments from 24 to 48 h. The
NH3-N concentration was not affected by treatments, except for 8
and 16 h. On 8 and 16 h, NH3-N concentration was lowest in
ZnAo-SBM among the treatments (P<0.01). There was a tendency of
decreased DM and CP degradation in ZnAo-SBM compared with
other treatments during the incubation.
- Files in This Item: There are no files associated with this item.