Sulfate supplementation of alpine goats: effects on milk yield and composition, metabolites, nutrient digestibilities, and acid-base balance.
Effects of sulfate supplementation on milk yield and composition, ruminal and blood metabolites, acid-base status, and nutrient digestibilities were determined using 30 multiparous, lactating Alpine does. Goats were fed isonitrogenous diets containing .16 (basal), .26, or .36% S (DM basis) during a 13-wk lactation trial that coincided with wk 3 to 15 of lactation. During wk 16 to 17, four does from each treatment were placed in a metabolism crate to measure nutrient digestibility and balance. Feed intake, yield of 4% fat-corrected milk, and milk S content were not affected by added S, but the goats fed the .26% S diet had a trend of higher persistency of lactation (P < .20). During wk 10 and 15 of lactation, milk solids-not-fat percentage was higher (P < .10) for does fed the .26% S diet. Sulfur supplementation resulted in quadratic decreases in ruminal ammonia N (P < .05) in wk 15 and in plasma urea N in wk 10 and 15 (P < .05) but in linear increases (P < .05) in ruminal protein S concentrations throughout the experiment. Added S had little effect on blood acid-base status. Apparent digestibilities of DM, OM, ash, ADF, and GE were increased linearly (P < .10) by added S. The milk N:S ratio remained constant. Increasing S from .16 to .26% of diet DM was beneficial to lactating Alpine goats during early lactation.
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Agriculture Research and Extension Programs, Langston University, OK 73050.
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D000136:Acid-Base Equilibrium / Q000187:drug effects; D000821:Animal Feed; D000818:Animals; D004063:Digestion / Q000187:drug effects*; D004435:Eating / Q000187:drug effects; D004734:Energy Metabolism; D005260:Female; D005527:Food, Fortified; D006041:Goats / Q000502:physiology*; D007774:Lactation / Q000187:drug effects*; D008892:Milk / Q000737:chemistry* / Q000378:metabolism; D011897:Random Allocation; D012417:Rumen / Q000737:chemistry; D013431:Sulfates / Q000008:administration & dosage / Q000494:pharmacology*
D013431:Sulfates