Bone and Cellular Immune System of Multiparous Sows are Insensitive to Ovariectomy and Nutritive Calcium Shortage

Research in osteoporosis, which is a complex systemic disease, demands suitable large ani- mal models. In pigs, most research has been done in growing minipigs, which probably are not ideal models for postmenopausal oste- oporosis. Therefore, our aim was to analyze the eff ects of ovariectomy (OVX) and nutritive calcium shortage on multiparous Large White sows. 32 animals were randomly assigned to 4 groups in a cross design with OVX vs. sham and physiological calcium supplementation (0.75 % calcium) vs. dietary calcium shortage (0.3 % cal- cium). The observation period was 10 months with blood sampling every 2 months for hema- tological, immunological, and biochemical bone marker measurements. At the termination of the experiment, animals were sacrifi ced. Samples of trabecular bone of distal radius, proximal tibia, and sixth lumbar vertebra were subjected to micro-computed tomography imaging and ashed afterwards. Dual X-ray absorptiometry scans of the proximal femora were performed with pre- pared bones being placed in a water bath for mimicking soft tissue. Analyses of bone marker and cytokine profi le kinetics, distribution of leu- kocyte subpopulations, and morphometrical and densitometrical analyses showed no evidence of any impact of OVX or calcium shortage. In con- clusion, the skeleton of adult sows of a conven- tional breed is seemingly protected from eff ects of OVX and calcium shortage.