Effects of grain sorghum planting density and processing method on nutrient digestibility and retention by ruminants

J Anim Sci. 2001 Jan;79(1):19-25. doi: 10.2527/2001.79119x.

Abstract

Grain sorghum grown in 38-cm rows (high density [HD]) or 76-cm rows (normal density [ND]) was treated as follows: steam-flaked (SF), high-moisture-harvested followed by rolling and ensiling (HM), or dry-rolled (DR). Resulting grains were evaluated using lambs in two 5 x 5 Latin square digestion trials. Treatment diets contained either SF-HD, SF-ND, HM-HD, HM-ND, or DR-ND grain sorghum in two trials; a 90 or a 60% concentrate diet was fed in each trial. High-density planting increased (P < 0.10) the apparent absorption of P relative to ND planting for both 60 and 90% concentrate diets. Steam flaking decreased (P < 0.10) the apparent absorption of P in the 90% concentrate diet and decreased (P < 0.10) the apparent absorption of N in both the 90 and 60% concentrate diets. Despite differences in N digestibility, steam flaking and HM ensiling resulted in similar (P > 0.10) N retention as a percentage of N intake in both trials. However, changes in the distribution of N between feces and urine among processing methods could affect N content of manure and alter nutrient management strategies. These results indicate that both planting density and grain processing can alter the apparent absorption of grain sorghum P by ruminants. Furthermore, it seems that grain processing can alter the route of N excretion in ruminants without changing total N retention.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agriculture / methods*
  • Animal Feed / standards*
  • Animal Nutritional Physiological Phenomena*
  • Animals
  • Digestion
  • Edible Grain / growth & development*
  • Feces / chemistry
  • Food Handling / methods*
  • Intestinal Absorption
  • Male
  • Manure
  • Nitrogen / metabolism
  • Sheep / metabolism*

Substances

  • Manure
  • Nitrogen