Effect of dietary factors on digestive capacity of ruminal digesta of dairy cows estimated through nylon-bag technique

Using Total Mixed Rations (TMRs) for high yielding dairy cattle prevent ruminal fermentation peaks that would have negative effect on intake level and milk fat concentration. In this framework, the use of TMR is beneficial, because it provides an optimal balance of nutrients to ruminal microorganisms to stabilize ruminal diurnal fluctuation of short chain fatty acids concentration and pH. This work aimed to study the effects of feeding TMR and the amount of concentrate on TMRs on digestive capacity of ruminal digesta through nylon-bag technique. The digestive capacity of cows' digesta fed TMRs and separate ingredients with two different concentrate level (22% and 43%) for concentrate mixture and maize silage was tested by incubating samples of them for 24 hours into the rumen of three fistulated dairy cows. The differences on ruminal degradability of dry matter and neutral detergent fibres of concentrate and maize silage were not tested to be consequence of different feeding strategies or different levels of concentrate in the diet. However, among cows fed 43% concentrate, those who fed TMR tend to have higher fermentation rate of dry matter and neutral detergent fibres with origin from maize silage that can be result of more stabilized ruminal conditions created by mixed ration.