Prepartum high-starch diet enhances colostrum IgG concentration in dairy goats

Abstract

This study hypothesizes that feeding a high-starch (HS) diet during the last month of gestation can enhance colostrum yield and composition as well as dam and goat kid metabolism and immune status. Thirty multiparous pregnant Majorera dairy goats were randomly assigned to a prepartum dietary treatment at wk -4 relative to expected parturition. Goats were fed either a control (n=15; 100% DM of starch requirements) or HS (n=15; 134% DM of starch requirements) diet during the last month of gestation. Blood samples were collected on wk -4, -3, -2, and -1 relative to expected parturition, immediately after parturition and on d 1, 2, 3, 5, 10, 15, 30 postpartum. Colostrum yield, chemical composition and IgG concentration and serum metabolites and plasma IgG concentration were determined. Data were analysed using MIXED and ANOVA procedure of SAS (SAS 9.4). The model included the prepartum diet, time, and the interaction between both as fixed effects. The statistical significance was set as P≤0.05. No differences were obtained for colostrum yield and chemical composition, whereas the HS group showed higher colostrum IgG concentration than the control group (i.e., 85.4±8.39 and 60.5±8.30 mg/mL, respectively). Serum BHB concentration in the HS group increased progressively until parturition, whereas the control group showed a sharply increased from wk -1 to parturition (i.e., 0.24±0.02 and 0.29±0.02 mmol/L at parturition, respectively). In goat kids, no differences were observed for plasma IgG concentration although the HS group showed an increased serum total protein concentration. The present study indicates that feeding a high-starch diet prepartum does not affect either colostrum yield or chemical composition but increases colostrum IgG concentration and promotes a smoother transition from late pregnancy to early lactation without affecting the metabolic and immune status of goat kids.