Influence of Calcium Chloride Fed Prepartum on Severity of Edema and Lactational Performance of Dairy Heifers

¹ Animal Science Department, Oklahoma State University, Stillwater 74078

Twenty Holstein heifers in a completely randomized design were used to evaluate the effects of prepartum dietary CaCl₂ on the development and regression of edema and on subsequent lactational performance. Heifers were assigned to diets containing either 2.17% limestone or 1.5% CaCl₂ (DM basis) at 3 wk before expected calving date. Except for the Ca sources, diets were identical. Test diets were only fed prepartum; at calving, all heifers were offered a lactation diet for 3 wk. Severity of edema was evaluated independently by five people daily throughout the experiment; a 10-point rating system was utilized to quantify the severity of edema. Calcium chloride reduced the severity of edema, although this response was most evident during the 1st wk that this salt was fed. The beneficial effects of CaCl₂ on edema prepartum disappeared postpartum, when CaCl₂ was removed from the diet. Indeed, edema was higher for heifers fed CaCl₂ than for those fed limestone at 2 wk postpartum. Calcium chloride reduced DMI prepartum, but, following parturition, a compensatory increase in feed intake occurred. Postpartum daily DMI averaged 1.3 kg higher for heifers fed CaCl₂ than for those fed the limestone diet prepartum. Milk yield and composition were somewhat lower for heifers fed CaCl₂, although this response was most evident at 1 wk postpartum. Feeding CaCl₂ prepartum to prevent milk fever also may reduce the severity of udder edema prepartum and increase feed intake during early lactation.

Key Words: calcium chloride • heifers • udder edema • cation-anion balance

Submitted on September 9, 1991
Accepted on April 30, 1992