Impact of deoxynivalenol in a calcium depletion and repletion nutritional strategy in piglets.

Abstract

This study evaluated the effect of dietary calcium (Ca) levels and deoxynivalenol (DON) contamination on Ca and phosphorus (P) utilization and bone mineralization in piglets. During an initial 13-day depletion phase, 64 piglets (15.7±0.7kg) received a control (DON-) or DON-contaminated treatment (DON+, 2.7mg DON/kg) with either a low Ca (Ca-, 0.39%) or normal Ca level (Ca+, 0.65%) with a constant digestible P level (0.40%). A second group of 16 piglets received DON- or DON+ treatments for 9 days for gene expression analysis. During the subsequent 14-day repletion phase, all piglets were fed a Ca+DON- diet containing 0.65% Ca and 0.35% digestible P without DON. After 5 days of the depletion phase, the absorption of P (DON × Ca; P<0.05) and Ca was increased by the Ca- (P<0.01) and DON+ (P<0.01) diet. After 13 days, feed conversion ratio (P<0.01) and average daily feed intake (P=0.06) tended to decrease with the Ca- diet. The bone mineral content (BMC) gain was decreased by Ca, especially with Ca-DON+ (DON × Ca, P< 0.05). The P absorption was increased by Ca-DON+ (DON × Ca, P<0.01), although the P retention efficiency was only increased by Ca+DON+ (DON × Ca, P<0.001). The absorption of Ca was increased by DON+ (P < 0.001), and the Ca efficiency was increased by Ca-DON- (DON × Ca, P<0.01). After 9 days, the gene expression of intestinal claudin 12 (P<0.01) and CYP24A1 (P< 0.05), femur cortical RANKL (P<0.05) and OPG (P=0.06), and renal calbindin D9K (P< 0.05) and Klotho (P=0.07) were decreased by DON+. The Ca (P=0.06) and magnesium (P<0.01) concentrations were decreased by DON+, and the Ca (P=0.06) and P digestibility (P<0.01) were increased. After the repletion phase, Ca- piglets recovered their BMC deficit, but not those receiving DON+ (DON × Ca; P=0.06). The Ca (P<0.05) and P (P=0.06) retention efficiency tended to increase with Ca-. The absorption of Ca and P were increased by Ca- and DON+ (DON × Ca, P<0.05). The results show that piglets increased their Ca and P utilization efficiency, allowing them to recover the BMC deficit caused by Ca-, but not when the piglets were exposed to DON. Pigs previously receiving Ca-deficient diet with DON still has lower body Ca and P, leading to elevated calcitriol concentrations and enhanced Ca and P intestinal absorption. The fact that DON decreased the expression of genes implicated in Ca intestinal and renal transport and P excretion after 9 days can potentially explain the reduced plasma Ca concentration.