High-lysine corn as a source of protein and energy for finishing calves
1995
Ladely, S.R. | Stock, R.A. | Klopfenstein, T.J. | Sindt, M.H.
Three trials evaluated the protein and energy value of high-lysine corn for finishing calves. In Trial 1, 60 finishing steer calves were used to evaluate corn source (high-lysine vs control) and protein source (urea, blood meal [BM], corn gluten meal [CGM]) and level BM and CGM addition: low, medium, high). Calves were individually fed using Calan gates for 102 d, and then were pen-fed (two pens per corn treatment) the remaining 83 d. During the initial 102 d, calves fed high-lysine corn had similar gains but were 6% more efficient (P < .10) compared with calves fed control corn. Performance did not differ (P > .10) among sources or levels of protein supplementation. Over the entire feeding period (185 d), calves fed high-lysine corn were 10% more efficient (P < .10) than calves fed control corn. In the second study, in situ starch disappearance was faster (P < .10) and the proportion of CP degraded by 12 h was 27% greater (P < .10) for high-lysine corn than for control corn. In a metabolism trial, five steers fitted with ruminal, duodenal, and ileal cannulas were used in a randomized block design to evaluate the effect of corn source on site and extent of digestion. Intake and ruminal and total tract digestibility of OM and N did not differ (P > .10) between corn sources. Steers fed high-lysine corn tended to have greater ruminal (P = .23) and postruminal (P = .18) starch digestion, resulting in greater (P < .10) total tract starch digestibility. Because protein source and level had no effect on performance and starch digestibility was increased with high-lysine corn, the improved feed efficiency observed with calves fed high-lysine corn was likely a result of improved energy utilization and not due to the additional lysine content.
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