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-d depletion phase, 64 piglets (15.7 +/- 0.7 kg) received a control (DON-) or DON-contaminated treatment (DON+, 2.7 mg 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 d for gene expression analysis. During the subsequent 14-d repletion phase, all piglets were fed a Ca+ DON- diet containing 0.65% Ca and 0.35% digestible P without DON. After 5 d of the depletion phase, the absorption of P (DON x Ca; P < 0.05) and Ca was increased by the Ca- (P < 0.01) and DON+ (P < 0.01) diet. After 13 d, 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 x Ca, P < 0.05). The P absorption was increased by Ca- DON + (DON x Ca, P < 0.01), although the P retention efficiency was only increased by Ca+ DON + (DON x 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 x Ca, P < 0.01). After 9 d, 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 x 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 was increased by Ca- and DON+ (DON x 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 have 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 d can potentially explain the reduced plasma Ca concentration. Lay Summary Calcium (Ca) deficiency can increase how efficiently pigs use Ca and phosphorus (P), but exposure to the mycotoxin deoxynivalenol (DON), often found in pig feed ingredients, can impact the digestibility and excretion of Ca and P. In our study, piglets received a diet with or without DON-contamination and either low Ca (0.39%) or normal Ca levels (0.65%) during a 13-d depletion phase, followed by a 14-d repletion phase where all piglets were fed a normal Ca diet without DON. The short Ca-depletion phase is known to improve the utilization efficiency of Ca and P in piglets by increasing the retention of these nutrients through both depletion and repletion phases and the Ca and P digestibility through the repletion phase, which allows recovery of the bone mineralization deficit that occurred during Ca deficiency. However, the diet contaminated with DON prevented pigs from recovering from their bone mineralization deficit observed during the Ca-depletion phase, even though they were better able to absorb and digest Ca and P during both phases. This was supported by the reduced expression of genes involved in Ca intestinal absorption, renal transport, osteoclastogenesis, and P excretion

Impact of Deoxynivalenol in a Calcium Depletion and Repletion Nutritional Strategy in Piglets