Comparison of whole, raw soybeans, extruded soybeans, or soybean meal and barley on digestive characteristics and performance of weaned beef steers consuming mature grass hay

J Anim Sci. 1993 Jan;71(1):26-32. doi: 10.2527/1993.71126x.

Abstract

Two experiments were conducted to compare whole, raw soybeans (WSB), extruded soybeans (ESB), and soybean meal+barley (SBM+BAR) as supplemental protein sources for growing beef steers consuming low-quality, mature grass hay (6.5% CP). In Exp. 1, a 23-d digestion study, four ruminally cannulated steers were assigned to the following treatments in a 4 x 4 Latin square design: 1) control, no supplement; 2) 1.5 kg.animal-1.d-1 of WSB; 3) 1.36 kg.animal-1.d-1 of ESB; and 4) 1.48 kg.animal-1.d-1 of 62%:38% SBM+BAR. Apparent DM digestibility was increased by supplementation (P < .10), but NDF digestibility was not changed (P > .10). No differences in digestibility were observed among supplement treatments (P > .10). In situ rate and extent of supplement CP disappearance in Dacron bags did not differ among supplements (P > .10), but extent of DM disappearance was greater for WSB than for ESB (P < .10). In situ rate of forage NDF disappearance was decreased by protein supplementation (P = .10). In Exp. 2, 40 Polled Hereford and Red Angus x Simmental weanling steer calves were stratified by weight (average BW, 250 kg) and allotted randomly to one of two replications of the four treatments used in Exp. 1 (eight pens, five animals per pen). Forage DMI was not affected by treatment (P > .10). Average daily gain and feed efficiency were increased by supplementation (P < .05). Supplement source had no effect on intake or ADG (P > .10), but ESB tended to exhibit better feed efficiency than WSB (P = .10). In conclusion, WSB and ESB seem to be as effective as SBM+BAR protein supplements for growing beef cattle. In addition, WSB and ESB, at the levels used in these experiments, can be incorporated into diets for cattle consuming low-quality roughage without deleterious effects on fiber digestion or subsequent performance.

Publication types

  • Comparative Study

MeSH terms

  • Ammonia / metabolism
  • Animal Feed*
  • Animals
  • Cattle / growth & development
  • Cattle / physiology*
  • Dietary Fiber / metabolism
  • Dietary Proteins / administration & dosage
  • Digestion*
  • Eating
  • Fermentation
  • Food, Fortified
  • Glycine max
  • Hordeum
  • Male
  • Poaceae
  • Random Allocation
  • Rumen / metabolism
  • Rumen / physiology
  • Valerates / metabolism
  • Weight Gain

Substances

  • Dietary Fiber
  • Dietary Proteins
  • Valerates
  • Ammonia