Sulfur Supplementation of Urea-containing Silages and Concentrates. I. Feed Intake and Lactation Performance

Abstract Thirty-two lactating cows were in a 2 × 2 factorial experiment; factors were corn silage treated with .5% urea or 2.8% soybean meal at ensiling time and concentrates containing 0 or .9% added sodium sulfate. In a 19-week experiment cows fed soybean corn silage consumed more dry matter per unit body weight and produced more milk than cows on urea corn silage (P In a second experiment 24 cows arranged in a 2 × 2 × 2 factorial were fed .5% urea silage or 3.5% soybean meal silage and concentrates containing 0 or .8% added urea, each with 0 or .8% added sodium sulfate. No treatment differences were detected in feed intake or milk yield during 40 weeks. Sulfur supplementation increased sulfur in ration dry matter from .13% to .22% (Experiment I) and .11 to .18% (Experiment II) and also changed the ratio of nitrogen to sulfur from 19:1 to 11:1 (Experiment I) and 21:1 to 13:1 (Experiment II).