title: Differences in peripartal plasma parameters related to calcium homeostasis of dairy sheep and goats in comparison with cows.
abstract: Recently it has been demonstrated that there are differences between sheep and goats in respect to adaptation to a calcium-restricted diet. It was the aim of the present study to evaluate whether species-specific peculiarities also occur when calcium homoeostasis is challenged by lactation. Therefore, we investigated the time courses of plasma parameters related to calcium homoeostasis (calcium, phosphate, calcitriol, the bone resorption marker CrossLaps and the bone formation marker osteocalcin) during the transition period in multiparous animals of both species and compared the results to data from a former study carried out with dairy cows. As in cows, plasma calcium and the ratio of bone formation to bone resorption decreased at parturition in goats while plasma calcitriol increased. On day 10 post partum the bone parameters of goats reached prepartum values again, which was not the case in cows. Sheep were found to experience a challenge of calcium homoeostasis already 10 d before parturition, reflected by a very low ratio of bone formation to bone resorption, which was not accompanied by an increase in plasma calcitriol. Additionally, sheep and goats which had been in milk for 3 months were sampled, dried-off and sampled again 6 weeks later. In dried-off animals there were no detectable differences in parameters of bone metabolism. In conclusion we could show that the contribution of bone mobilisation to the compensation for the enhanced calcium demand due to lactation differs between the three ruminant species.
authors.affiliation: Department of Physiology,University of Veterinary Medicine Hannover,Foundation, Hannover,Germany.
authors.forename: Mirja R
authors.initials: MR
authors.lastname: Wilkens
authors.affiliation: Institute of Animal Nutrition, Vetsuisse Faculty Zurich, University of Zurich,Zurich,Switzerland.
authors.forename: Annette
authors.initials: A
authors.lastname: Liesegang
authors.affiliation: Department of Physiology,University of Veterinary Medicine Hannover,Foundation, Hannover,Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Richter
authors.affiliation: Faculty of Veterinary Science,University of Sydney,Sydney,Australia.
authors.forename: David R
authors.initials: DR
authors.lastname: Fraser
authors.affiliation: Department of Physiology,University of Veterinary Medicine Hannover,Foundation, Hannover,Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Breves
authors.affiliation: Department of Physiology,University of Veterinary Medicine Hannover,Foundation, Hannover,Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Schröder
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000097:blood / Q000502:physiology; D002118:Calcium / Q000097:blood* / Q000378:metabolism; D002417:Cattle / Q000097:blood* / Q000502:physiology; D003094:Collagen / Q000097:blood / Q000502:physiology; D005260:Female; D006041:Goats / Q000097:blood* / Q000502:physiology; D006706:Homeostasis / Q000502:physiology; D007774:Lactation / Q000097:blood* / Q000502:physiology; D015675:Osteocalcin / Q000097:blood / Q000502:physiology; D010446:Peptide Fragments / Q000097:blood / Q000502:physiology; D010710:Phosphates / Q000097:blood / Q000502:physiology; D012756:Sheep / Q000097:blood* / Q000502:physiology
chemical_list: D010446:Peptide Fragments; D010710:Phosphates; C110762:glutamyl-lysyl-alanyl-histidyl-aspartyl-glycyl-glycyl-arginine; D015675:Osteocalcin; D003094:Collagen; D002117:Calcitriol; D002118:Calcium