title: Validation of a direct time-resolved fluoroimmunoassay for progesterone in milk from dairy and beef cows.
abstract: The aim of this study was to validate a direct time-resolved fluoroimmunoassay (TR-FIA) for quantifying progesterone concentrations in milk during the bovine oestrous cycle. Holstein-Friesian and suckled and non-suckled Japanese Black cows were used to demonstrate the relationship between milk and plasma progesterone concentrations and to monitor progesterone profiles in milk and plasma during the oestrous cycle. The minimum detection level of the assay was 1.53ng/mL. Progesterone concentrations in milk and plasma changed in a similar manner throughout the oestrous cycle in dairy and beef cows, and milk and plasma progesterone profiles were significantly correlated (P<0.001). The study confirmed that a direct TR-FIA can be used to monitor the oestrous cycle in cattle and to quantify progesterone concentrations in whole milk.
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka 020-8550, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Oku
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka 020-8550, Japan. Electronic address: osawa@iwate-u.ac.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Osawa
authors.affiliation: Omyojin Experimental Station, Field Science Center, Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan.
authors.forename: Toh-Ichi
authors.initials: TI
authors.lastname: Hirata
authors.affiliation: Omyojin Experimental Station, Field Science Center, Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kon
authors.affiliation: Omyojin Experimental Station, Field Science Center, Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Akasaka
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka 020-8550, Japan; Department of Theriogenology, Faculty of Veterinary Medicine, Assiut University, Assiut 71526, Egypt.
authors.forename: Waleed S
authors.initials: WS
authors.lastname: Senosy
authors.affiliation: Reproductive Biology Research Unit, National Institute of Agrobiological Sciences, Tsukuba 305-8602, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Laboratory of Theriogenology, Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka 020-8550, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Izaike
mesh_terms: D000818:Animals; D002417:Cattle / Q000378:metabolism*; D030762:Estrous Cycle / Q000378:metabolism*; D005260:Female; D015200:Fluoroimmunoassay / Q000379:methods / Q000662:veterinary*; D057230:Limit of Detection; D008892:Milk / Q000737:chemistry*; D011374:Progesterone / Q000032:analysis / Q000378:metabolism*
chemical_list: D011374:Progesterone