Effect of supplemental XXXX on nutrient digestibilities and ruminal pH measured continuously.

@entity4388 @entity742 @entity5993 @entity1460 @entity62
A technique was used to monitor continuously ruminal pH using a strip-chart recording pH meter. Ruminal pH measurements were made in four ruminal-cannulated crossbred wether @entity742 (ag initial weight, 42.5 kg). For l.5 h daily, @entity742 were given ad libitum access to 50% concentrate-50% chopped orchardgrass hay diets supplements with 0, l.5, 3.0 and 4.5% @entity4388 ( @entity5993 ). A split-plot Latin-square design was used to evaluate @entity5993 level and day of adaptation on the percentage of time (%T) that ruminal pH was less than 6.6, 6.2, 5.8, 5.4 and 5.0. No effect due to day of adaptation existed for ruminal pH measurements (P more than .10), while the effect of dietary @entity5993 level was quadratic (P more than .01) for the %T that ruminal pH was less than 5.4. To evaluate the effects of @entity5993 on nutrient digestion, the same diets were fed to eight wether @entity742 (avg initial weight, 38 kg) at 85% of their ad libitum intake in a replicated 4 x 4 Latin-square digestion trial. Digestibilities of @entity62 ( @entity62 ), organic matter, N and fiber fractions were not different due to level of @entity5993 (P greater than .10). Ash digestibility increased with increasing levels of dietary @entity5993 (P less than .01). Four ruminal-cannulated mature Hereford steers were also given ad libitum access to the diets in a split-plot Latin-square trial to evaluate effects of dietary @entity5993 level on ruminal pH and in situ digestion of @entity1460 meal N and orchardgrass @entity62 . During incubation of the dacron bags for 3, 6, 9, 12, 24 and 36 h also increased linearly with increasing level of @entity5993 . Ruminal solid and liquid dilution rates were not affected by level of supplemental @entity5993 (P greater than .10). The results of these trials suggest that increasing level of dietary @entity5993 greatly increases the proportion of time ruminal pH is above critical levels for ruminal protein and @entity62 digestion, but does not affect total tract nutrient digestion when 50% concentrate diets are fed.
