title: Effect of β-carotene supply during close-up dry period on the onset of first postpartum luteal activity in dairy cows.
abstract: The aim of this study was to examine the effect of β-carotene supply during the close-up dry period on the onset of first postpartum luteal activity in dairy cows. Twelve cows were supplied with 2000 mg of β-carotene (20 g Rovimix(®) β-Carotene containing 10% β-carotene; DSM Nutrition Japan K.K., Tokyo, Japan) by oral administration daily from day 21 before expected calving date to parturition. Fourteen cows (control) did not receive β-carotene supplementation. Blood samples were obtained on days 21, 14 and 7 before expected calving date and on days 1, 7, 14, 21 postpartum. When the plasma progesterone concentration exceeded 1 ng/ml by day 21 postpartum, luteal activity was assumed to have been initiated. The result showed that serum β-carotene concentrations in the β-carotene cows were higher than in the control cows during the experimental period (p < 0.01). The number of cows with the onset of luteal activity by day 21 postpartum was 9/12 in the β-carotene cows and 4/14 in the control cows (p < 0.05). Retinol, certain metabolic parameters and metabolic hormones concentrations did not differ between β-carotene and control cows. In addition, serum retinol concentration in β-carotene cows without luteal activity was lower than in β-carotene cows with luteal activity (p < 0.05), and serum gamma-glutamyl transpeptidase concentration in β-carotene cows with luteal activity (p < 0.05) and control cows without luteal activity (p < 0.01) was higher than in control cows with luteal activity. In conclusion, β-carotene supply during the close-up dry period may support the onset of luteal activity during early lactation in dairy cows.
authors.affiliation: Field Centre of Animal Science and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan. kawasima@obihiro.ac.jp
authors.forename: C
authors.initials: C
authors.lastname: Kawashima
authors.forename: S
authors.initials: S
authors.lastname: Nagashima
authors.forename: K
authors.initials: K
authors.lastname: Sawada
authors.forename: F J
authors.initials: FJ
authors.lastname: Schweigert
authors.forename: A
authors.initials: A
authors.lastname: Miyamoto
authors.forename: K
authors.initials: K
authors.lastname: Kida
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle; D003338:Corpus Luteum / Q000187:drug effects*; D003612:Dairying; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D004734:Energy Metabolism; D005260:Female; D007774:Lactation / Q000187:drug effects*; D049590:Postpartum Period; D011374:Progesterone / Q000097:blood; D013997:Time Factors; D014801:Vitamin A / Q000097:blood / Q000378:metabolism; D019207:beta Carotene / Q000097:blood / Q000494:pharmacology*
chemical_list: D019207:beta Carotene; D014801:Vitamin A; D011374:Progesterone