Sulfur Requirement of Lactating Dairy Cows. I. Sulfur Balance and Dietary Supplementation

Abstract

Two experiments measured the effects of sulfur supplementation of rations for lactating cows. In Experiment 1, a basal diet (Ration 1) containing .104 sulfur was a semipurified concentrate mix and corn silage fed in a 1:l ratio on a dry basis. Sodium sulfate was added to the basal diet to produce rations containing .15% (Ration 2) and .18% sulfur (Ration 3). The sulfur content of the basal ration was also increased to .18% by supplementation with methionine hydroxy analog (Ration 4) Sulfur supplementation of the basal diet increased dry matter intake and dry matter digestibility. Methionine hyroxy analog fed at 43 g/day decreased dry matter intake to the intake of the sulfur deficient diet without affecting daily milk production. Both sodium sulfate and methionine hydroxy analog improved the sulfur balance of lactating cows with supplements of .15 and .18% sulfur in the complete diet. In Experiment 2, a basal diet containing .06% sulfur was supplemented with either sodium sulfate or a mixture of potassium and magnesium sulfate sulfur to .18 and .24% in the compIete diet. The low-sulfur diet decreased dry matter intake, dry matter digestibility, and milk production and caused the sulfur balance to be negative. Regression analysis showed that dietary .12% sulfur would approximate sulfur balance and .18% sulfur would allow for a mean positive balance of 4 g of sulfur daily in cows producing between 8 and 37 kg milk. © 1973, American Dairy Science Association. All rights reserved.