Dietary Crude Protein Levels Affect Growth Performance in Hanwoo Steers

Strategic Insights -

Research conducted at Chungnam National University investigated the effects of increasing dietary crude protein (CP) concentrations on growth performance, rumen characteristics, blood metabolites, and methane emissions in finishing Hanwoo steers. The 12-week study involved 24 Hanwoo steers, with each animal assigned to one of four dietary treatments with different CP levels (15.0, 16.2, 17.5, and 18.5% on a dry matter basis). The results showed that forage and total dry matter intake linearly increased with increasing CP levels, while concentrate intake was not affected by treatments.

Key Takeaways:

  • Feed efficiency showed a trend of linear decrease (P = 0.092) with increasing CP levels.
  • Rumen parameters, including ruminal pH, total volatile fatty acid, and molar proportions of various volatile fatty acids, were not affected by treatments.
  • Blood concentrations of total protein, urea, glucose, and various enzymes were not different among treatments.
  • Concentrations of methane from respiration or eructation were not affected by dietary CP. However, methane ppm per forage NDF intake linearly decreased (P = 0.005) with increasing CP from both respiration and eructation.
  • Increasing the CP content of the concentrate mix from 15.0 to 18.5% DM may negatively affect feed efficiency.
  • This study provides no clear evidence that increasing the CP content of the concentrate mix improves growth performance and body metabolism in finishing Hanwoo steers.

Statistics:

  • 24 Hanwoo steers were utilized in a 12-week study.
  • The animals were divided into four dietary treatments with different CP levels (15.0, 16.2, 17.5, and 18.5% on a dry matter basis).
  • Forage and total dry matter intake linearly increased (P = 0.029) with increasing CP levels.
  • Feed efficiency showed a trend of linear decrease (P = 0.092) with increasing CP levels.
  • Methane ppm per forage NDF intake linearly decreased (P = 0.005) with increasing CP from both respiration and eructation.

Sources:

  • VerticalNews. "Chungnam National University Reports Findings in Animal Bioscience (Effects of dietary crude protein levels on growth performance, rumen characteristics, blood metabolites, and methane emissions in finishing Hanwoo steers)". Global Warming Focus. May 12, 2025; p 415.
  • NewsRx LLC. "Chungnam National University Reports Findings in Animal Bioscience (Effects of dietary crude protein levels on growth performance, rumen characteristics, blood metabolites, and methane emissions in finishing Hanwoo steers)". Global Warming Focus. May 12, 2025; p 415.