Graduate Thesis Or Dissertation

 

Ruminant and microbial physio-chemical response to abrupt ration changes as influenced by chemical and/or biological means Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/m039k8410

Descriptions

Attribute NameValues
Creator
Abstract
  • Three trials with wethers and four trials with steers were conducted to determine some of the effects of sodium bicarbonate, calcium hydroxide and/or transfer of ruminal contents on ruminant adjustment to abrupt changes to concentrate rations. Lambs fed a basal concentrate diet plus sodium bicarbonate had the highest average feed intake, the highest pH and Lowest lactic acid level for the first ten days, but went off-feed after buffer removal (Trial I). The lambs receiving buffer plus rumen fluid had the highest overall average feed intake for the trial. Basal fed lambs went off-feed the second day of the trial at which time rumen and urine pH decreased and lactic acid levels increased. Lambs given rumen fluid developed diarrhea, went off-feed, had low rumen pH and total VFA values and elevated lactic acid levels in the rumen. Significant correlations occurred between rumen pH and acetic to propionic acid (P < .05) and acetic to butyric (P < .10) acid ratios. Also, lactic acid and feed intake were correlated (P < .05). A negative correlation (P < .01) between rumen pH and lactic acid levels also existed. Lambs fed buffered rations had the highest average intake, ADG, rumen pH at the second collection and final total VFA levels (Trial II). Lambs given buffer plus rumen fluid and those fed basal rations performed similarly overall, but basal fed lambs went off-feed. A negative correlation (P < .05) was found between rumen pH and total VFA. Rumen pH and acetic to propionic acid (P < .01) and acetic to butyric (P < .05) acid ratios were correlated. Calcium hydroxide added to the ration reduced feed intake and ADG in Trial III. Calcium hydroxide plus rumen fluid resulted in improved gains and feed efficiency. Average pH at the second collection was increased by this treatment. The sodium bicarbonate group had the highest overall feed intake but rumen pH decreased after buffer withdrawal. Correlations between rumen pH and acetic to propionic were the same as in Trial I. Steers fed a buffered ration and given rumen fluid had lower rumen pH values, but higher feed intake and ADG than steers fed a buffered ration (Trial IV). Average pH was increased significantly (P < .05) in both groups, by the addition of sodium bicarbonate to the ration. The lactic acid level was higher in the buffer plus rumen fluid group. Negative correlations (P < .05) in this trial existed between rumen pH and lactic acid and rumen pH and total VFA levels. There were no significant differences in average feed intake, ADG or average feed conversion in Trial V. Although rumen pH was increased by addition of buffers to the diet both groups went off-feed when the buffers were removed. There were negative correlations (P< .01) between rumen pH and total VFA levels and total VFA levels and lactic acid. Also, rumen pH and lactic acid were correlated (P < .01). In Trial VI there were no significant differences in animal performance. Rumen pH in the buffer plus rumen fluid group was higher than that of the basal fed group. Average rumen pH, total VFA levels and acetic to propionic acid ratios were significantly (P < .01) lower at the end than at the beginning of the trial for both groups. Rumen pH and acetic to butyric acid ratios were correlated (P < .01). Rumen pH and total VFA were negatively correlated (P < .05). The buffer fed group had a higher average intake than the basal fed group in Trial VII. One steer in the basal fed group developed acute indigestion on the second day of the trial. Rumen pH decreased and lactic acid level increased at that time. There were negative correlations (P < .01) between rumen pH and lactic acid, between rumen pH and acetic to propionic acid ratios and between lactic acid and total VFA levels.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using ScandAll PRO 1.8.1 on a Fi-6770A in PDF format. CVista PdfCompressor 5.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items