title: Growth and estrous behavior of heifers actively immunized against prostaglandin F2 alpha.
abstract: To determine the effects of active immunization against prostaglandin F2 alpha (PGF) on estrous activity and performance traits of beef heifers, 50 14-mo-old cyclic heifers (358 +/- 3.3 kg) were assigned to two treatments (n = 25 per treatment): 1) heifers (controls) given 3.3 mg of human serum albumin (HSA) on d 0 (primary) and 27 (booster), and 2) heifers (PGF-immunized) given 3.3 mg of PGF-HSA on d 0 and 27. The adjuvant was DEAE-dextran, and the duration of the experiment was 167 d. Plasma progesterone concentrations (every 3 to 4 d) were used to monitor corpus luteum (CL) presence; PGF antibody titers were determined every 2 wk. Heifers were checked twice daily for estrous behavior and were weighed every 2 wk. Data were analyzed using ANOVA. Antibody titers for PGF-immunized heifers increased to a peak (43 +/- 2.9% binding at a plasma dilution of 1:1,250) on d 55 +/- 4.6. Antibody titers were greater (P = .02) in PGF-immunized than in control heifers by d 15 and remained elevated (P < or = .001) throughout the experiment. Twenty-four of 25 PGF-immunized heifers formed persistent CL with a mean duration of 129 +/- 6.4 d. The mean number of estrous period per heifer were less for PGF-immunized (1.5 +/- .27) than for control heifers (7.0 +/- .32). Mean daily live weight gain of the PGF-immunized heifers was decreased (P < .05; .75 +/- .024 kg) compared with that of controls (.83 +/- .014 kg), largely due to a 31.5% decrease during the 28-d period after booster.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Faculty of Veterinary Medicine, University College Dublin, Ballsbridge, Ireland.
authors.forename: M A
authors.initials: MA
authors.lastname: Crowe
authors.forename: W J
authors.initials: WJ
authors.lastname: Enright
authors.forename: P
authors.initials: P
authors.lastname: Swift
authors.forename: J F
authors.initials: JF
authors.lastname: Roche
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000917:Antibody Formation; D001522:Behavior, Animal / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D002417:Cattle / Q000254:growth & development* / Q000276:immunology / Q000502:physiology; D015237:Dinoprost / Q000276:immunology*; D004971:Estrus / Q000276:immunology* / Q000502:physiology*; D005121:Extremities / Q000254:growth & development; D005260:Female; D007117:Immunization, Secondary / Q000009:adverse effects / Q000662:veterinary; D010053:Ovary / Q000502:physiology; D011374:Progesterone / Q000097:blood; D011897:Random Allocation; D012709:Serum Albumin / Q000494:pharmacology; D014611:Vaccination / Q000662:veterinary*; D015430:Weight Gain / Q000502:physiology
chemical_list: D012709:Serum Albumin; D011374:Progesterone; D015237:Dinoprost