Evaluation of various nitrogen supplements in starter diets for growing Holstein steers and their effects on ruminal bacterial fermentation in continuous culture.

Hugh Chester-Jones, Marshall D Stern, A. Su, J. D. Donker, D. M. Ziegler, K. P. Miller

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

Concurrent in vivo and in vitro studies were conducted to evaluate urea (U), soybean meal (SBM), ground soybeans (RAW), extruded soybeans (ES) or extruded soybeans plus urea (ES + U) as primary supplemental N sources in starter diets for Holstein steers. Three groups of 48 Holstein steers each were fed five different starter diets to 181 kg BW in three experimental periods over 2 yr. Average daily gains were similar (P greater than .05) for steers fed ES + U (1.12 kg), ES (1.08 kg) and SBM (1.09 kg) but lower (P less than .05) for those fed U (1.00 kg) or RAW (.97 kg) diets. Feed/gain was similar (P greater than .05) for ES-fed steers vs those fed other diets except U. From 181 to 477 kg, all steers were fed the same diet. Steers fed the RAW starter diet had the lowest (P less than .05) ADG for the entire period. The starter diets were used as substrates for ruminal microbial metabolism in eight dual-flow continuous culture fermenters. True OM digestion was higher and NDF and ADF digestion was lower (P less than .05) for the ES + U diet than for the ES diet. Dietary protein degradation was lowest (P less than .05) for the ES diet (64.4%). Total bacterial N flow was higher (P less than .05) with the ES + U, SBM and U diets than with the ES diet. Lysine flow was higher (P less than .05) for the ES + U diet than for all other diets except ES. Results of these experiments indicate that ES as a protected ruminal escape N source with or without added urea did not improve steer performance above that obtained from SBM in starter diets.

Original languageEnglish (US)
Pages (from-to)2954-2964
Number of pages11
JournalJournal of animal science
Volume68
Issue number9
DOIs
StatePublished - Sep 1990

Fingerprint Dive into the research topics of 'Evaluation of various nitrogen supplements in starter diets for growing Holstein steers and their effects on ruminal bacterial fermentation in continuous culture.'. Together they form a unique fingerprint.

Cite this