title: The effect of aspirin administration and parity on plasma salicylate concentrations and postpartum reproductive parameters in Brahman cows.
abstract: Forty pluriparous (M) and 20 primiparous (P) suckled Brahman cows were used to evaluate the effect of aspirin and parity on plasma 13,14-dihydro-15-keto-prostaglandin F2alpha (PGFM) and progesterone (P4) concentrations and some reproductive parameters. On Day 7 after calving (PP), the cows were allocated within parity into 2 groups: the aspirin group received concentrate containing aspirin at a rate of 100 mg/kg of body weight every 12 h until Day 13 PP; and the control received concentrate every 12 h for the same interval. Blood samples were collected after first and last aspirin feeding and daily from Day 1 PP to Day 6 PP and from Day 14 PP to Day 21 PP, twice daily from Day 7 PP to Day 13 PP, and weekly until first non-return to estrus. Plasma salicylate concentrations in the aspirin group cows were affected by parity (P < 0.01) and time after feeding (P < 0.0001). P cows showed higher plasma salicylate concentrations with a later peak and slower decrease than M cows. Aspirin-treated P cows had longer PP intervals than either control P, control M, or aspirin-treated M cows. Cows receiving aspirin had a lower pregnancy rate, an increased incidence of abnormal estrous cycles, and a decline in the presence of corpora lutea after estrus. Cows that formed a corpora lutea and had received aspirin had higher P4 release between Day 6 and 14 after estrus. Aspirin-treated cows that did not form corpora lutea had lower P4 release between Days 9 and 14 after estrus. A treatment by parity interaction affected mean PGFM proportions (P < 0.01) during the treatment period. Aspirin-fed P cows increased PGFM release as measured by mean proportion of Day 6 PP values. Aspirin-fed M cows showed a decrease in mean PGFM proportions. Aspirin feeding during the early PP showed different effects on some reproductive parameters in P and M Brahman cows, indicating differences in PP physiology between parities.
authors.affiliation: Estación Experimental Agropecuaria-Instituto Nacional de Tecnologiá Agropecuaria Colonia Benitez, Argentina.
authors.forename: R C
authors.initials: RC
authors.lastname: Stahringer
authors.forename: D A
authors.initials: DA
authors.lastname: Neuendorff
authors.forename: R D
authors.initials: RD
authors.lastname: Randel
mesh_terms: D000818:Animals; D001241:Aspirin / Q000494:pharmacology*; D001835:Body Weight; D002417:Cattle; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood; D004971:Estrus / Q000187:drug effects / Q000502:physiology; D005260:Female; D010298:Parity; D049590:Postpartum Period; D011247:Pregnancy; D011270:Pregnancy, Animal; D011374:Progesterone / Q000097:blood; D012459:Salicylates / Q000097:blood*; D012737:Sex Factors
chemical_list: D012459:Salicylates; C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D011374:Progesterone; D015237:Dinoprost; D001241:Aspirin