title: Genetic parameters of calcium, phosphorus, magnesium, and potassium serum concentrations during the first 8 days after calving in Holstein cows.
abstract: Calcium, Mg, P, and K are of great importance for the health and productivity of dairy cows after calving. So far genetic studies have focused on clinical hypocalcemia, leaving the genetic parameters of these macroelements unstudied. Our objective was to estimate the genetic parameters of Ca, Mg, P, and K serum concentrations and their changes during the first 8d after calving. The study was conducted in 9 herds located in northern Greece, with 1,021 Holstein cows enrolled from November 2010 until November 2012. No herd used any kind of preventive measures for hypocalcemia. Pedigree information for all cows was available. A total of 35 cows were diagnosed and treated for periparturient paresis and, therefore, excluded from the study. The remaining 986 cows were included in genetic analysis. The distribution of cows across parities was 459 (parity 1), 234 (parity 2), 158 (parity 3), and 135 (parity ≥4). A sample of blood was taken from each cow on d1, 2, 4, and 8 after calving and serum concentrations of Ca, P, Mg, and K were measured in each sample. A final data set of 15,390 biochemical records was created consisting of 3,903 Ca, 3,902 P, 3,903Mg, and 3,682K measurements. Moreover, changes of these concentrations between d1 and 4 as well as 1 and 8 after calving were calculated and treated as different traits. Random regression models were used to analyze the data. Results showed that daily heritabilities of Ca, P, and Mg concentrations traits were moderate to high (0.20-0.43), whereas those of K were low to moderate (0.12-0.23). Regarding concentration changes, only Mg change between d1 and 8 after calving had a significant heritability of 0.18. Genetic correlations between Ca, P, Mg, and K concentrations and their concentration changes from d1 to 4 and 1 to 8 after calving were not significantly different from zero. Most phenotypic correlations among Ca, P, Mg, and K concentrations were positive and low (0.09-0.16), whereas the correlation between P and Mg was negative and low (-0.16). Phenotypic correlations among macromineral concentrations on d1 and their changes from d1 to 4 and 1 to 8 after calving varied for each macromineral. This study revealed that genetic selection for normal Ca, P, Mg, and K concentrations in the first week of lactation is possible and could facilitate the management of their deficiencies during the early stages of lactation.
authors.affiliation: Department of Animal Production, Faculty of Veterinary Medicine, Box 393, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece.
authors.forename: V
authors.initials: V
authors.lastname: Tsiamadis
authors.affiliation: Department of Animal Production, Faculty of Veterinary Medicine, Box 393, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece; Scotland's Rural College, Roslin Institute, Edinburgh, United Kingdom EH25 9RG.
authors.forename: G
authors.initials: G
authors.lastname: Banos
authors.affiliation: Clinic of Farm Animals, Department of Clinics, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece.
authors.forename: N
authors.initials: N
authors.lastname: Panousis
authors.affiliation: Diagnostic Laboratory, Department of Clinics, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece.
authors.forename: M
authors.initials: M
authors.lastname: Kritsepi-Konstantinou
authors.affiliation: Department of Animal Production, Faculty of Veterinary Medicine, Box 393, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Arsenos
authors.affiliation: Department of Animal Production, Faculty of Veterinary Medicine, Box 393, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece. Electronic address: geval@vet.auth.gr.
authors.forename: G E
authors.initials: GE
authors.lastname: Valergakis
mesh_terms: D000818:Animals; D002118:Calcium / Q000097:blood*; D002417:Cattle / Q000097:blood / Q000235:genetics*; D002418:Cattle Diseases / Q000097:blood / Q000235:genetics / Q000517:prevention & control; D005260:Female; D006115:Greece; D006996:Hypocalcemia / Q000235:genetics / Q000517:prevention & control / Q000662:veterinary; D007774:Lactation / Q000235:genetics; D008274:Magnesium / Q000097:blood*; D036801:Parturition; D010758:Phosphorus / Q000097:blood*; D049590:Postpartum Period / Q000097:blood*; D011188:Potassium / Q000097:blood*; D011247:Pregnancy
chemical_list: D010758:Phosphorus; D008274:Magnesium; D011188:Potassium; D002118:Calcium
keywords: genetic parameters; macrominerals