Effect of Subacute Ruminal Acidosis on TMR Preference in Lactating Dairy Cows
Open Access
- Author:
- McIntyre, Kolby K
- Area of Honors:
- Animal Sciences
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Arlyn Judson Heinrichs, Thesis Supervisor
Arlyn Judson Heinrichs, Thesis Supervisor
William Staniar, Thesis Honors Advisor - Keywords:
- Subacute ruminal acidosis
particle size
dairy cow
diet selection - Abstract:
- Subacute ruminal acidosis (SARA) is a condition where the pH of the rumen becomes abnormally acidic, because of increased and altered production of volatile fatty acids (VFA). A common cause of acidosis is overeating large amounts of readily available nutrients, specifically carbohydrates. Acidic by-products of fermentation are responsible for the change in the rumen environment. Salivary bicarbonate neutralizes acids during normal rumination, which is initiated by forage, specifically long fiber particles. Ruminal acidosis can lead to cows going off-feed, compromising the health of the animal. In this study, 8 multiparous rumen-cannulated Holstein dairy cows were each given a choice between a long, slow-fermenting and a short, fast-fermenting ration. Feed intake was monitored beginning after adaptation on d 8. Rumen parameters (pH, VFA concentration) were monitored beginning d 11. On d 12, cows were restricted to 75% ad libitum intake; rumen environments were monitored to demonstrate changes created by the feed restriction. Following this, on d 13 cows were given 4 kg wheat grain followed by ad libitum long and short rations. Rumen pH was decreased by the grain feeding, and was accompanied by an increase in percent of total DMI consumed as long and slow fermenting TMR. The cows can increase their intake of long particle size and slower fermenting grain when experiencing this bout of SARA.