Trona and Sodium Bicarbonate in Beef Cattle Diets: Effects on Site and Extent of Digestion

Abstract

Six yearling Hereford X Angus steers (avg 272 kg), each with ruminal, duodenal and ileal cannulas were used in a 6 X 6 Latin-square metabolism trial to evaluate the impact of NaHCO3 and trona (a ground, nonrefined ore with chemical composition NaHCO3-Na2CO3-2H2O) on site and extent of digestion of nutrients in the digestive tract. The diets were 50:50 or 90:10 (cracked corn-based concentrate:cottonseed hulls) with no buffer, 1% NaHCO3, or 1% trona. Intake, across all treatments, averaged 2.4% of body weight. Dry matter (DM) and starch digestibility (via indigestible acid detergent fiber) before the duodenum was decreased (P less than .10) with trona in the 50:50 diet. Digestibility of DM, crude protein and starch before the ileum were greater (P less than .05) in the 90:10 diet vs 50:50 diet. Total tract digestibility was similar across buffer treatments in the 90:10 diet. Addition of NaHCO3 increased (P less than .05) digestibility of dry matter and cell solubles in the 50:50 diet. Organic matter and crude protein digestibility were also increased (P less than .10) with NaHCO3. Apparent crude protein and cell solubles digestibility were greater (P less than .10) with trona than NaHCO3 in the 50:50 diet. This trial indicates that buffers provide overall enhancement of diet digestibility in mixed grain/roughage diets.

Trona and Sodium Bicarbonate in Beef Cattle Diets: Effects on pH and Volatile Fatty Acid Concentrations

“…A metabolism trial was conducted with six multicannulated (ruminal, duodenal and ileal) yearling (avg 272 kg) Hereford x Angus steers in a 6 X 6 Latin-square design (Boerner et al, 1987). Briefly, steers were given ad libitum access to a balanced adaptation diet (70% cracked corn and 30% cottonseed hulls) for 7 d; intake of assigned diets was then limited to 90% of ad libitum.…”

“…Ruminal samples (approximately 100 ml) were collected at 12-h intervals (Boerner et al, 1987). Ruminal fluid pH was measured on each sample immediately after collection.…”

“…Individual samples were strained through four layers of cheese cloth, frozen and later composited by steer and period. Intestinal samples and fecal grab samples were taken at prescribed times (Boerner et al, 1987) and pH was measured immediately with a portable pH meter.…”

“…Integrating the area of the pH time curve beneath the mean for the respective concentrate level control yielded pH-area, a term somewhat analogous to area below a specific pH (6.0) designated as PH6-hours (Mackie and Gilchrist, 1979). A discussion of the importance of these two measurements has been presented by Boerner et al (1987). These two measures provided more discriminating measures of buffer effectiveness in maintaining a stable pH, and in preventing substantial low-pH periods.…”