Effects of Rumen Microorganisms on Degradation Characteristics and Ultrastructure of Alfalfa Stem

XU Jun; HOU Yujie; ZHAO Guoqi; HUO Yongjiu; WU Caixia

doi:10.3969/j.issn.1006-267x.2014.03.030

Chinese Journal of Animal Nutrition >

2014 , Vol. 26 >Issue 3: 776 - 782

DOI: https://doi.org/10.3969/j.issn.1006-267x.2014.03.030

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Effects of Rumen Microorganisms on Degradation Characteristics and Ultrastructure of Alfalfa Stem

XU Jun ,
HOU Yujie ,
ZHAO Guoqi ,
HUO Yongjiu ,
WU Caixia

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College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China

Received date: 2013-09-25

Online published: 2014-03-04

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Abstract

This study was conducted to investigate the effects of rumen microorganisms on degradation characteristics and ultrastructure of alfalfa stem. Alfalfa stems with similar growth profile and plant height were harvested at early flowering to carried out a degradation rate experiment using nylon bags, at the same time, the second internode was longitudinally cut to six equal parts for samples which were incubated for 6, 12, 24, 48 and 72 h in the rumen, repectively. The changes of ultrastructure of alfalfa stem were observed under scanning and transmission electron microscopes. The results showed as follows: 1) dry matter and neutral detergent fiber were mostly degraded within 24 h of fermentation in rumen, and only a small part of neutral detergent fiber was degraded after 48 h. 2) The non-lignified epidermis, collencyma, chlorenchyma, cambium and primary xylem parenchyma were all quickly degraded, and completely degraded within 24 h of fermentation in rumen, but the lignified secondary xylem fiber and vessels remained undegraded. 3) Encapsulated cocci and irregularly shaped bacteria were the majorities of fiber digesters, and the degradation regularity was various with different structure of tissues. In conclusion, alfalfa stem can be rapidly degraded under the effects of rumen microorganisms, but the rate and content of degradation are related to the structure and composition of alfalfa stem, in addition, the highly lignified structures are difficult to be degraded in the rumen. Therefore, reducing the content of lignification composition is an effective method to improve degradation rate of alfalfa stem.

Key words： alfalfa stem; scanning electron microscopy; transmission electron microscopy; ultrastructure

Cite this article

XU Jun , HOU Yujie , ZHAO Guoqi , HUO Yongjiu , WU Caixia . Effects of Rumen Microorganisms on Degradation Characteristics and Ultrastructure of Alfalfa Stem[J]. Chinese Journal of Animal Nutrition, 2014 , 26(3) : 776 -782 . DOI: 10.3969/j.issn.1006-267x.2014.03.030

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