This study was conducted to observe the effect of fiber digestion enhancement and inhibition factors on fibrolytic bacterial colony growth and fiber digestion in the rumen fermentation environment. In order to promote the fiber digestion, 0.2% NaOH of rice straw was used as a substrate in rumen in vitro fermentation. A 0.1% methylcellulose (MC) was added rumen in vitro culture with untreated rice straw to inhibit fiber digestion. When in vitro culture was performed using untreated rice straw as a substrate, all substrate adherent colonies and rumen suspended colonies of Fibrobacter succinogenes, Ruminococcus flavefaciens and Ruminococcus albus showed an increasing growth as incubation time progressed; however there were significantly more substrate-adherent colonies than rumen fluid floating colonies at all incubation times (p<0.05). Fiber substrate digestibility in in vitro rumen fermentation was significantly higher 0.2% NaOH treated rice straw than untreated substrate (p<0.05). In addition, substrate-adherent colonies of fibrolytic bacteria were significantly more in the NaOH-treated group than in the untreated group for F. succinogenes, R. flavefaciens, and R. albus (p<0.05). When untreated rice straw was added to an in vitro culture, with or without 0.1% MC, to create a rumen environment for inhibiting fiber digestion, substrate digestibility was significantly suppressed compared to that in the untreated group (p<0.05). Additionally, substrate-adherent colonies were significantly fewer in the addition of MC than in the untreated control group for F. succinogenes, R. flavefaciens and R. albus (p<0.05). The results indicate that surface-adherent colonies of bacteria decomposing fiber substrate are far more than rumen fluid floating colonies in the rumen fermentation environment, and the environmental factors of rumen fermentation give same associative effect on the fibrinolytic function of fiber bacteria and its ecological communities.
This study was conducted to investigate the effect of the power ranking of mares on their offspring’s stereotypies and response behaviors against a restraining of their desire to eat. Nine horses (2-4 years old) - three offspring born from three Haflinger mares over 3 years - were assigned to three experimental groups (High, Middle, Low) divided by the power ranking of mares. Three mares had no oral or locomotor stereotypic behaviors, but the higher the power ranking of mares, the more diverse and longer the duration of the oral stereotypies of their offspring (p<0.05). Although the offspring born from the high-ranking mare vigorously continued oral stereotypies until 3-4 years of age, there were no individuals that progressed to chronic locomotor stereotypies such as crib-biting, weaving, and box-walking. With an increase in the power ranking of the mare, the response of her offspring to the restraining of the eating desire (measured in terms of the frequency of the oral and locomotor stereotypies) increased (p<0.05). In conclusion, the oral stereotypies shown in this study are characteristic behaviors that occur during the growth process. However, in the case of riding horses, the offspring of a high-power ranking mare and/or one that reacted excessively against restrains, may be better observed and treated in a stall to manage stereotypic behaviors and correct the behaviors at their initial stage.