Effects of feeding fish meal and n-3 fatty acids on ovarian and uterine responses in early lactating dairy cows.
The study was designed to test the effects of dietary supplementation with fish meal or specific n-3 fatty acids on ovarian activity and uterine responses in early lactating cows. From 5 to 50 d in milk (DIM), cows were fed diets that were isonitrogenous, isoenergetic, and isolipidic containing none (control), 1.25, 2.5, or 5% menhaden fish meal (FM) or 2.3% Ca salts of fish oil fatty acids (CaFOFA). Ovarian follicular dynamics were monitored along with plasma concentrations of estradiol and progesterone. Beginning at 23 DIM, cows were induced into a synchronized ovulatory cycle. On d 15 after ovulation (49 DIM), cows were injected with oxytocin and blood samples were collected to monitor uterine release of PGF(2alpha) (measured as 13, 14-dihydro-15-keto PGF(2alpha); PGFM). Uterine endometrial biopsies were collected for fatty acid analysis and cyclooxygenase-2 (COX-2) protein measurement. Ovarian follicular activities as well as plasma estradiol and progesterone concentrations were similar across diets. Endometrial fatty acid composition of eicosapentaenoic acid (C20:5, n-3) and docosahexaenoic acid (C22:6, n-3) were increased as much as 3-fold by supplementation with fish meal and CaFOFA. Conjugated linoleic acid (C18:2 cis-9, trans-11) in the endometrium was also increased; conversely, arachidonic acid (C20:4, n-6) percentage was decreased by 5% FM. Plasma PGFM response to oxytocin injection was not different among diets and endometrial COX-2 protein abundance did not differ. Results from this experiment demonstrate that dietary supplementation with fish meal or n-3 fatty acids in early lactating dairy cows significantly increased uterine n-3 fatty acid concentrations, but had no apparent effect on endometrial COX-2 or PGF(2alpha) production in response to oxytocin challenge.
Moussavi
A R Heravi
AR
Department of Animal Science, Ferdowsi University, Mashhad 91775-1163, Iran.
Gilbert
R O
RO
Overton
T R
TR
Bauman
D E
DE
Butler
W R
WR
D000821:Animal Feed / Q000032:analysis; D000818:Animals; D002417:Cattle / Q000502:physiology*; D051546:Cyclooxygenase 2 / Q000032:analysis; D003612:Dairying; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood; D004717:Endometrium / Q000737:chemistry / Q000187:drug effects*; D005227:Fatty Acids / Q000032:analysis; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005260:Female; D005396:Fish Products; D007774:Lactation; D008099:Liver / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology; D006080:Ovarian Follicle / Q000187:drug effects*; D010121:Oxytocin / Q000008:administration & dosage / Q000494:pharmacology; D013997:Time Factors
D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D010121:Oxytocin; D015237:Dinoprost; D051546:Cyclooxygenase 2