Lactation responses to sulfur-containing amino acids from feather meal or rumen-protected methionine.
The objectives of this experiment were to determine: 1) if Cys in hydrolyzed feather meal (HFM) can contribute to the supply of sulfur amino acids for meeting requirements of dairy cows; 2) if the feeding value of meat and bone meal (MBM) can be enhanced by HFM or ruminally protected Met (rpMet); and 3) the value of HFM sulfur amino acids relative to rpMet. Fifteen multiparous Holstein cows were used in a replicated 5 x 5 Latin square design with 21-d periods. The control (CTRL) diet was designed to contain feeds that were low in RUP and Met and consisted of 50% alfalfa silage and 50% corn-based concentrate. Additional treatments were modifications of CTRL in which MBM (4% of DM), MBM + rpMet (Smartamine M) (4 and 0.08% of DM), MBM + HFM (4 and 2% of DM), and MBM + rpMet + HFM (4, 0.04, and 1% of DM) replaced corn grain. Feeding MBM depressed milk and 3.5% fat-corrected milk (FCM) yields. Adding rpMet to MBM enhanced dry matter intake, milk and 3.5% FCM yields, and milk crude protein percentage. Milk fat percentage and 3.5% FCM yield were increased when HFM and rpMet were added to MBM. Supplementing HFM to a diet containing MBM could not duplicate the response of adding rpMet to MBM. Results of this study indicate that feeding HFM may not alleviate Met deficiency in lactating dairy cows.
Pruekvimolphan
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S
University of Wisconsin, Madison 53706, USA.
Grummer
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RR
D000603:Amino Acids, Sulfur / Q000378:metabolism*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000378:metabolism / Q000502:physiology*; D005241:Feathers; D005260:Female; D007774:Lactation / Q000187:drug effects / Q000378:metabolism*; D008715:Methionine / Q000172:deficiency / Q000378:metabolism* / Q000494:pharmacology; D012417:Rumen / Q000378:metabolism
D000603:Amino Acids, Sulfur; D008715:Methionine