Ruminal characteristics of feeder calves

Author

Walter Stephen Damron

Date of Award

3-1982

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Animal Science

Major Professor

J. B. McLaren

Committee Members

K. M. Barth, J. P. Hitchcock, R. R. Schrode, J. R. Savage

Abstract

Most feeder calves marketed in the Southeast are subsequently exposed to the stresses of marketing and transporting which alter rumen metabolism and delay feedlot adaptation. A review of the literature established the need of a multidisciplinary approach in studying the nutritional aspects of animals subjected to these market-transit stresses.

Rumen samples were taken and weight, body measurements, and backfat thickness were determined for 360 unweaned, 6- to 10-month-old calves at 22 farms before the calves entered the market-chain during the Falls of 1977 and 1978. Mean weight, body length, height at the wither, body depth at the fore chest, width at the point of the shoulder, back-fat at the 12th rib, rumen liquid volume, in vitro gas producing potential, total volatile fatty acids, ciliated protozoa (Spirotricha and Holotricha), and rumen pH were 202 ± 1.97 kg, 97 ± 0.37 cm, 93 ± 0.49 cm, 48.0 ± 0.19 cm, 32 ± 0.15 cm, 1.47 ± 0.05 mm, 26 ± 0.54 1, 6.3 ± 0.18 cm^{3, 63.1 ± 1.29 mmol/1, 31.25 x 104 ± 1.72 x 104/ml (28.37 x 104,sup/> ± 1.71 X 104/ml and 2.87 x 10 ± 0.20 x 104/ml), and 7.0 ± 0.02, respectively.}

One-hundred-eighty-four weanling steer calves were subjected to the stresses associated with the normal industry procedures for marketing and transporting Southeastern feeder calves from the farms where they were raised to commercial backgrounding and/or finishing facilities.

Body weight decreased during the auction barn phase, increased slightly during orderbuyer barn phase, and decreased during transit. Total market-transit weight loss was 13% of the arrival auction barn weight. Rumen liquid volume, rumen gas producing potential, rumen total VFA concentration, and rumen protozoal concentration decreased signifi cantly (25.6%, 71%, 25%, and 50%, respectively) during the auction barn phase. During the auction barn starvation period, rumen pH increased. This was followed by a decrease in pH during the orderbuyer barn phase. Vleight and all other rumen parameters increased during the orderbuyer barn phase.

Recommended Citation

Damron, Walter Stephen, "Ruminal characteristics of feeder calves. " PhD diss., University of Tennessee, 1982.
https://trace.tennessee.edu/utk_graddiss/7847