title: A phenotypical approach to the effects of production traits, parturition, puerperium and body condition on commencement of luteal activity in high yielding dairy cows.
abstract: The interval from calving to commencement of luteal activity (CLA) was determined by progesterone measurements from milk samples obtained once a week until the 14th week post-partum in 513 German Holstein cows in first to third parity. Milk samples were analyzed by an "on-farm" device (eProCheck(®), Minitüb, Germany) and simultaneously by RIA. The objective of this study was to examine the effect of milk yield, protein content and body condition of a cow on the CLA post-partum. Milk progesterone concentrations of "on-farm" measurements correlated with measurements done by the RIA-method significantly (r=0.72; P<0.001). Within the analyzed herd the interval from calving until the first rise of progesterone averaged 5.6±2.4 weeks. The 100-days milk yield was not associated with CLA. Cows with a milk protein content at 1st milk recording of ≤3.5% revealed first luteal activity 1.3±0.3 weeks later than cows that had a content of >3.75% protein (P<0.01). Furthermore cows with assisted calving or dystocia presented significantly later CLA than cows which required no help during the calving process (P<0.05). The change in back fat thickness from 1st to 2nd milk recording had a significant influence on CLA (P<0.05). In conclusion the phenotypic impact of milk yield on fertility cannot be confirmed regarding to CLA. The negative energy balance after calving, caused by the high milk yields, is more detrimental for the cyclical activity as was shown by the parameters milk protein content and change in BFT.
authors.affiliation: State Research Institute of Agriculture and Fishery Mecklenburg-Western Pomerania, Institute for Animal Production, Dummerstorf, Germany.
authors.forename: Ariane
authors.initials: A
authors.lastname: Boldt
authors.affiliation: Leibniz Institute for Farm Animal Biology, Institute for Reproductive Biology, Dummerstorf, Germany. Electronic address: becker@fbn-dummerstorf.de.
authors.forename: Frank
authors.initials: F
authors.lastname: Becker
authors.affiliation: Martin-Luther-University Halle-Wittenberg, Institute of Agricultural and Nutritional Sciences, Halle/Saale, Germany.
authors.forename: Gunter
authors.initials: G
authors.lastname: Martin
authors.affiliation: Leibniz Institute for Farm Animal Biology, Institute for Genetics and Biometry, Dummerstorf, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Nürnberg
authors.affiliation: State Research Institute of Agriculture and Fishery Mecklenburg-Western Pomerania, Institute for Animal Production, Dummerstorf, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Römer
authors.affiliation: Leibniz Institute for Farm Animal Biology, Institute for Reproductive Biology, Dummerstorf, Germany.
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Kanitz
mesh_terms: D000818:Animals; D001823:Body Composition; D002417:Cattle / Q000502:physiology*; D002418:Cattle Diseases / Q000378:metabolism; D003338:Corpus Luteum / Q000502:physiology*; D004420:Dystocia / Q000662:veterinary; D005260:Female; D007774:Lactation; D008892:Milk / Q000737:chemistry; D010298:Parity; D011247:Pregnancy; D011374:Progesterone / Q000737:chemistry / Q000378:metabolism
chemical_list: D011374:Progesterone
keywords: Body condition; Fertility; First luteal activity; Milk progesterone; Milk yield; Parturition