Chen C Y, Hsu J T
Department of Animal Science, National Taiwan University, Taipei, R.O.C.
Proc Natl Sci Counc Repub China B. 1998 Oct;22(4):159-65.
Six continuous culture fermenters were used in three experiments to study the effects of dietary starch and protein degradability combination, hay sources, and feeding frequency on fermentation by rumen microorganisms. Experiments 1 and 2 used a 3 x 2 factorial design in which six diets were formulated to contain low (LS), medium (MS), or high starch degradability (HS) in combination with low (LP) or high protein degradability (HP). The dietary combinations were (1) LS + HP, (2) LS + LP, (3) MS + HP, (4) MS + LP, (5) HS + HP, and (6) HS + LP. In experiment 1, pangola was used as the hay source, and in experiment 2, alfalfa hay was used. In experiment 3, two starch degradabilities (LS, MS) and two hay sources (alfalfa, A; pangola, P) were combined with two feeding frequencies (2 X/d, 12 X/d). The dietary combinations were (1) LS + A + 12 X/d, (2) MS + A + 12 X/d, (3) LS + A + 2 X/d, (4) MS + A + 2 X/d, (5) LS + P + 12 X/d, and (6) MS + P + 12 X/d. A CRD design was used for experiment 3. Two rumen-cannulated Holstein cows fed alfalfa hay ad lib were used as donors of rumen fluid for all experiments. Each period was 6 d in length, with 5 d for adaptation and 1 d for sampling. In experiments 1 and 2, the effects of starch degradability on the composition of rumen microorganisms were significant. The MS or HS with HP had the highest total bacterial and protozoal density (P < 0.05). As for VFA, pH and nitrogen products, the effects of starch and protein degradability were not significant. There was no interaction between starch and protein degradability on most of microbial composition (ammonia-N, microbial nitrogen). In experiment 3, 12 X/d feeding frequency (MS + A + 12 X/d vs. MS + A + 12 X/d) resulted in higher pH, which tended to increase bacterial and protozoal density and starch and protein digestibilities. Different hay sources altered the starch and protein synchronization effect on the ammonia-N concentration (mg/dl) and non-ammonia N content (% DM) in the continuous culture system.
在三项试验中使用了六个连续培养发酵罐，以研究日粮淀粉和蛋白质降解率组合、干草来源以及饲喂频率对瘤胃微生物发酵的影响。试验1和试验2采用3×2析因设计，配制了六种日粮，分别含有低（LS）、中（MS）或高淀粉降解率（HS），并分别与低（LP）或高蛋白质降解率（HP）组合。日粮组合分别为：（1）LS + HP，（2）LS + LP，（3）MS + HP，（4）MS + LP，（5）HS + HP，以及（6）HS + LP。在试验1中，俯仰马唐用作干草来源，试验2中使用苜蓿干草。在试验3中，将两种淀粉降解率（LS、MS）和两种干草来源（苜蓿，A；俯仰马唐，P）与两种饲喂频率（每天2次，每天12次）进行组合。日粮组合分别为：（1）LS + A + 每天12次，（2）MS + A + 每天12次，（3）LS + A + 每天2次，（4）MS + A + 每天2次，（5）LS + P + 每天12次，以及（6）MS + P + 每天12次。试验3采用完全随机设计。选用两头安装了瘤胃瘘管的荷斯坦奶牛，以苜蓿干草为自由采食日粮，为所有试验提供瘤胃液供体。每个试验期为6天，其中5天用于适应，1天用于采样。在试验1和试验2中，淀粉降解率对瘤胃微生物组成的影响显著。MS或HS与HP组合时，细菌和原生动物的总密度最高（P < 0.05）。至于挥发性脂肪酸、pH值和氮产物，淀粉和蛋白质降解率的影响不显著。在大多数微生物组成（氨氮、微生物氮）方面，淀粉和蛋白质降解率之间没有交互作用。在试验3中，每天12次的饲喂频率（MS + A + 每天12次与MS + A + 每天2次相比）导致pH值较高，这往往会增加细菌和原生动物的密度以及淀粉和蛋白质的消化率。不同的干草来源改变了连续培养系统中淀粉和蛋白质同步对氨氮浓度（mg/dl）和非氨氮含量（%干物质）的影响。
