Sodium bicarbonate buffered diets for marketing and transportation stressed feeder steers

Author

Carolyn L. Orr

Date of Award

8-1979

Degree Type

Thesis

Degree Name

Master of Science

Major

Animal Science

Major Professor

J. B. McLaren

Committee Members

K. M. Barth, Paul C. Smith

Abstract

Fifty-four weanling steer calves were sxibjected to one of three pre-shipment treatments: (1) normal industry stresses (Normal Industry); (2) fed a high-energy, high-antibiotic diet in the order-buyer barn (High Energy) ; or (3) preweaned and fed a concentrate diet for 30 days before marketing (Preweaned). After being exposed to commercial auction and order-buyer barn environments for 4 days, the steers were assigned to one of three post-shipment treatments: (1) nonbuffered control (Nonbuffered); (2) 40 grams of sodium bicarbonate per steer per day (40- gram-NaHCO₃); and (3) 80 grams of sodium bicarbonate per steer per day (BO-gram-NaHCO₃) in a 3X3 factorial arrangement with pre-shipment treatments.

Ruminal pH and in vitro gas production values decreased as the steers progressed through the normal sequence of market-transit events (auction barn, order-buyer barn and trucking) and were significantly lower upon arrival at the feedlot than at the farm of origin or upon arrival at the auction barn. Pre-shipment concentrate feeding at the farm of origin or in the order-buyer barn significantly reduced ruminal pH and increased in vitro gas production. In steers subjected to normal industry market-transit stresses, increased gas production was observed in the 40- and 80-gram NaHCO₃-supplemented groups on feedlot sampling day 4, 11 and 32. However, in calves preweaned and fed a concentrate diet at the farm of origin or order-buyer barn no response to feedlot NaHCO^ supplementation was observed until feedlot day 32 and these responses were inconsistent and of lower magnitude than in the normal-industry-stressed steers. Packed cell volume, total serum protein, red blood cell count, white blood cell count and rumen protozoa concentration were not affected by feedlot sodium bicarbonate supplementation.

There was a significant pre- by post-shipment treatment interaction with respect to feedlot gain. Feeding 80 grams of NaHCO₃ to Normal-Industry stressed steers and feeding 40 grams NaHCO₃ to High- Energy steers resulted in higher cumulative ADG to feedlot day 11 than the respective Nonbuffered groups. In Normal-Industry NaHCO₃-buffered steers, feedlot time required to regain market-transit shrink was shorter, illness index was lower, and elevated early feedlot rectal temperatures returned to normal values quicker than in Nonbuffered steers. In High-Energy steers the 40 grams NaHCO₃ resulted in higher early-feedlot gains but had no effect on rectal temperatures and in Preweaned steers, the Nonbuffered steers gained faster to feedlot day 11 than the other NaHCO₃ groups. Although, NaHCO₃ increased the rate of feedlot adaptation, its beneficial effects were limited to the early feedlot period when used as a buffering agent with a high corn-silage ration.

Preweaned steers gained more weight at the farm of origin. High- Energy steers lost more weight during the auction-barn, order-buyer barn .phase and Normal Industry steers lost more on the truck than steers in the other two groups, respectively. However, total market-transit weight loss was similar for the three pre-shipment treatments.

Recommended Citation

Orr, Carolyn L., "Sodium bicarbonate buffered diets for marketing and transportation stressed feeder steers. " Master's Thesis, University of Tennessee, 1979.
https://trace.tennessee.edu/utk_gradthes/7823