title: Impact of parity on bone metabolism throughout the reproductive cycle in sows.
abstract: Bone metabolism fluctuates throughout the reproductive cycle of sows to enable foetal growth and milk production. Although increased bone mineralisation is conceivable in sows during reproduction, a study of mineralisation in function of parity has not been performed. This study evaluated the fluctuations of markers for bone metabolism in primiparous and multiparous sows throughout a reproductive cycle. The experiment included ten multiparous and five primiparous commercial hybrid sows from one herd. The sows were monitored for one reproductive cycle and fed according to commercial dietary standards. Blood samples were taken in the morning before feeding at fixed time intervals before (day -5) and during gestation (insemination (day 0), 21, 42, 63, 84), around parturition (day 108, 112, parturition (115), 118), and during lactation (day 122, 129, 143). Serum osteocalcin (OC) concentration increased in early and mid-gestation (P=0.002) and decreased at the end of gestation (P=0.001), whereas crosslaps (CTX) concentration decreased during early and mid-gestation (P=0.002) and increased towards the end of gestation (P=0.001). Towards the end of lactation serum levels of both markers increased (P=0.007 and 0.013, respectively). For hydroxyproline (HYP) no significant fluctuation in function of the reproductive cycle was detected. Matrix metalloproteinase 2 (MMP2) concentration increased towards parturition for both primiparous and multiparous sows (P=0.001), whereas during lactation no significant fluctuations in function of the reproductive cycle were found. A parity effect was found for OC and CTX (P<0.010), but not for the other markers. These results demonstrate that bone metabolism differed between primiparous and multiparous sows, although in both groups a similar fluctuation throughout the reproductive cycle was observed.
authors.affiliation: 1Animal Sciences Unit,Institute for Agricultural and Fisheries Research (ILVO),Scheldeweg 68,9090 Melle,Belgium.
authors.forename: M M J
authors.initials: MM
authors.lastname: van Riet
authors.affiliation: 1Animal Sciences Unit,Institute for Agricultural and Fisheries Research (ILVO),Scheldeweg 68,9090 Melle,Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Millet
authors.affiliation: 3Institute of Animal Nutrition,Vetsuisse Faculty,University of Zurich,8057 Zurich,Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Liesegang
authors.affiliation: 1Animal Sciences Unit,Institute for Agricultural and Fisheries Research (ILVO),Scheldeweg 68,9090 Melle,Belgium.
authors.forename: E
authors.initials: E
authors.lastname: Nalon
authors.affiliation: 1Animal Sciences Unit,Institute for Agricultural and Fisheries Research (ILVO),Scheldeweg 68,9090 Melle,Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Ampe
authors.affiliation: 1Animal Sciences Unit,Institute for Agricultural and Fisheries Research (ILVO),Scheldeweg 68,9090 Melle,Belgium.
authors.forename: F A M
authors.initials: FA
authors.lastname: Tuyttens
authors.affiliation: 5Department of Obstetrics, Reproduction and Herd Health,Faculty of Veterinary Medicine,Ghent University,Merelbeke,Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Maes
authors.affiliation: 2Department of Nutrition,Genetics and Ethology,Faculty of Veterinary Medicine,Ghent University,Merelbeke,Belgium.
authors.forename: G P J
authors.initials: GP
authors.lastname: Janssens
keywords: bone markers; bone mineralisation; crosslaps; osteocalcin; sow