title: Postpartum responses of dairy cows supplemented with n-3 fatty acids for different durations during the peripartal period.
abstract: The objective of this study was to determine the effect of different durations of n-3 supplementation during the peripartal period on production and reproduction performance of Holstein dairy cows. Thirty-two Holstein dry cows (16 multiparous and 16 primiparous) were blocked within parity for similar expected calving dates 8 wk before calving. Cows within blocks were assigned randomly to 1 of 4 treatments: (1) control without n-3 fatty acid (FA) supplementation during the dry period; (2) n-3 FA supplementation during the whole dry period (8 wk); and (3) n-3 FA supplementation during the early dry period (first 5 wk; far-off), or (4) n-3 FA supplementation during the late dry period (last 3 wk; close-up). All cows received the same diet without n-3 FA after calving for the first 6 wk of lactation. Ovaries of each cow were examined 10, 17, 24, and 34 d from calving (calving=d 0) by transrectal ultrasonography to determine follicular development. Blood samples were collected at 14-d intervals starting on the first day of the dry period (8 wk before expected calving) to determine plasma concentrations of glucose, β-hydroxybutyrate, nonesterified fatty acids, urea N, aspartate aminotransferase, and insulin. Blood samples were also collected on d 1, 10, 17, 24, 31, and 38 postpartum for determination of progesterone concentration. Milk yield was recorded daily throughout the experiment and samples were taken twice weekly (Monday and Thursday mornings) for analysis of fat, protein, and lactose. Yields of milk and 4% fat-corrected milk and milk composition were similar among treatments except for fat proportion, which tended to be lower in cows that were fed n-3 FA throughout the dry period. We observed no differences among treatments for plasma concentrations of metabolites and hormones. The cows that were fed in the 3 n-3 FA treatments had larger ovulatory follicles compared with those fed the controlled diet. Treatments did not differ significantly in terms of the number of days open, day to first service, or number of services per pregnancy. In conclusion, n-3 FA supplementation throughout the dry period or in the early or late prepartal period had no carryover reproductive postpartum benefits and no effect on the production of Holstein dairy cows.
authors: Department of Clinical Sciences, Faculty of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran.
authors: A
authors: A
authors: Badiei
authors: Department of Animal Science, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.
authors: A
authors: A
authors: Aliverdilou
authors: Department of Animal Science, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.
authors: H
authors: H
authors: Amanlou
authors: Department of Animal Science, Faculty of Agricultural Science and Engineering, University of Tehran, Karaj, Iran.
authors: M
authors: M
authors: Beheshti
authors: Department of Animal Science, Sari Agricultural Sciences and Natural Resources University, Sari, Iran.
authors: E
authors: E
authors: Dirandeh
authors: Department of Animal Science, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.
authors: R
authors: R
authors: Masoumi
authors: Department of Pathobiology, Faculty of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran. Electronic address: fmoosakhani@kiau.ac.ir.
authors: F
authors: F
authors: Moosakhani
authors: Agriculture and Agri-Food Canada, Dairy and Swine Research and Development Centre, Sherbrooke, QC, Canada.
authors: H V
authors: HV
authors: Petit
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000097:blood; D000818:Animals; D002417:Cattle / Q000502:physiology*; D003612:Dairying; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements / Q000032:analysis; D005230:Fatty Acids, Nonesterified / Q000097:blood; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D007328:Insulin / Q000097:blood; D007774:Lactation; D008892:Milk / Q000737:chemistry / Q000378:metabolism*; D010298:Parity; D049590:Postpartum Period / Q000502:physiology*; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D012098:Reproduction
chemical_list: D005230:Fatty Acids, Nonesterified; D015525:Fatty Acids, Omega-3; D007328:Insulin; D011374:Progesterone; D020155:3-Hydroxybutyric Acid
keywords: dairy cow; fatty acid; ovarian function; progesterone; uterine response