title: Strategic supplementation of calcium salts of polyunsaturated fatty acids to enhance reproductive performance of Bos indicus beef cows.
abstract: Five experiments evaluated the effects of supplemental Ca salts of PUFA on reproductive function of Bos indicus beef cows. In Exp. 1, nonlactating and multiparous grazing cows (n = 51) were assigned to receive (as-fed basis) 0.1 kg of a protein-mineral mix + 0.1 kg of ground corn per cow/d, in addition to 0.1 kg per cow/d of 1) Ca salts of PUFA (PF), 2) Ca salts of SFA (SF), or 3) kaolin (control). Treatments were offered from d 0 to 20 of the estrous cycle. No treatment effects were detected on serum progesterone concentrations (P = 0.83), day of luteolysis (P = 0.86), or incidence of short cycles (P = 0.84). In Exp. 2, nonlactating and multiparous grazing cows (n = 43) were assigned to receive PF, SF, or control from d 0 to 8 of the estrous cycle. On d 6, all cows received (intramuscularly) 25 mg of PGF(2α). No treatment effects were detected on serum progesterone concentrations on d 6 (P = 0.37), and incidence (P = 0.67) or estimated time of luteolysis (P = 0.44). In Exp. 3, twenty-seven lactating and multiparous grazing cows, approximately 30 to 40 d postpartum, were assigned to receive PF or control for 10 d beginning at the first postpartum ovulation. No treatment effects were detected (P = 0.85) on incidence of short cycles. In Exp. 4, lactating and multiparous grazing cows (n = 1,454), approximately 40 to 60 d postpartum, were assigned to receive 1 of the 7 treatments for 28 d after timed AI (TAI; d 0): 1) control from d 0 to 28, 2) SF from d 0 to 14 and then control, 3) PF from d 0 to 14 and then control, 4) SF from d 0 to 21 and then control, 5) PF from d 0 to 21 and then control, 6) SF from d 0 to 28, and 7) PF from d 0 to 28. Cows receiving PF for more than 21 d after TAI had greater (P < 0.01) pregnancy to TAI compared with all other treatments combined (50.4 vs. 42.4%, respectively). In Exp. 5, lactating and multiparous grazing cows (n = 501), approximately 40 to 60 d postpartum, were assigned to receive 1 of the 4 treatments for 21 d after TAI (d 0): 1) PF from d 0 to 14 and then control, 2) control from d 0 to 6 and then PF, 3) control from d 0 to 13 and then PF, and 4) PF from d 0 to 21. Cows receiving PF after d 14 of the experiment had greater (P = 0.02) pregnancy to TAI compared with cows not receiving PF during the same period (46.8 vs. 33.1%, respectively). In summary, supplemental Ca salts of PUFA during the expected time of luteolysis increased pregnancy to TAI in beef cows.
authors.affiliation: Departamento de Produção Animal, Faculdade de Medicina Veterinária e Zootecnia-UNESP, Botucatu-SP 18618-000, Brazil.
authors.forename: C N
authors.initials: CN
authors.lastname: Lopes
authors.forename: R F
authors.initials: RF
authors.lastname: Cooke
authors.forename: M M
authors.initials: MM
authors.lastname: Reis
authors.forename: R F G
authors.initials: RF
authors.lastname: Peres
authors.forename: J L M
authors.initials: JL
authors.lastname: Vasconcelos
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002118:Calcium / Q000737:chemistry*; D002417:Cattle; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D015232:Dinoprostone / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage / Q000737:chemistry* / Q000494:pharmacology*; D005260:Female; D005300:Fertility Agents, Female / Q000494:pharmacology; D007616:Kaolin; D010060:Ovulation; D011247:Pregnancy
chemical_list: D005231:Fatty Acids, Unsaturated; D005300:Fertility Agents, Female; D007616:Kaolin; D015232:Dinoprostone; D002118:Calcium