Investigations on sulfate concentration in milk replacers and dried whey products and its effect on feces composition in calves

In continuing investigations on effects of milk replacers with high ash and mineral contents (KAMPHUES et at., 1999a) on feces' quality and Compositio n in calves in the present study the sulfate concentration land its effects ) in milk replacers and whey products were prooved. In 13 samples of milk r eplacers the SO4 concentration varied between 2.4 and 6.7 g/kg dry matter, in 14 samples of dried whey products SO4- concentrations of 1.4 up to 41.8 g/kg dm were found. In general higher sulphur contents were caused by highe r concentrations of sulfate. In feeding a milk replacer (6.7 g SO4/kg dm) a bout 20 % of the consumed sulfate were excreted via feces (app. digestibili ty of about .80 %). In experiments with elevated SO4 intake (in liquid diet s: 560-1980 mg/l) the digestibility rate of sulfate decreased dose dependen tly (75 --> 65 %). By analysis of milk replacers (used in previous experime nts, TSCHENTSCHER, 1998) resulting in diarrhea in all treated carves unexpe cted SO4-concentrations were found of 16.3 and 10.2 g/kg dm. In feeding exp eriments (6 calves) by addition of Na2SO4 (85 %) and Mg SO4 (15%) sulfate c oncentration in the liquid diet was elevated from 560 mg to 1980 mg/l. Here the SO4 concentration in the diet and the dry matter content in carves' fe ces were correlated significantly (r = -0.86). Presented results on the SO4 concentration in milk replacers and the observ ed effects of sulfate intake on feces quality (i. e. dry matter content of Feces) indicate by the first. time that the SO4 content in milk replacers a nd dried whey products is an essential parameter when an estimation of milk replacers or whey products' quality is required.