title: Effects of body condition and leptin on the reproductive performance of Lusitano mares on extensive systems.
abstract: The aim of this study was to investigate the effects of body condition (BC), BC changes, and plasma leptin concentrations on the reproductive performance of Lusitano broodmares on extensive systems. Data from 119 mares (ranging from 4 to 22 years of age) were collected over a period of four consecutive breeding seasons. Each case was considered as one foaled mare bred in 1 year. Body condition changes at conception (ΔBCScon) showed a strong effect on fertility at the first two postpartum estrous cycles and a significant interaction with body condition score at conception (BCScon) was observed (P < 0.01). The best fertility results were obtained with positive and greater ΔBCScon. The best predictive value of fertility (91%) was achieved when the BCScon was 3.0 and ΔBCScon was 0.375. Global foaling rate for the 4-year period was 74.5%. Mean foaling interval and gestation length were, respectively, 368.0 ± 2.8 and 340.3 ± 1.0 days. Gestation length was influenced by the month of foaling (P < 0.05) and decreased as mares got older (P < 0.01). The number of estimated estrous cycles per live foal was 1.78 ± 0.12, including foal heat ovulation. Leptin was correlated with BCS (0.41; P < 0.001), but in the present study, plasma leptin concentrations on late gestation and early lactation did not influence fertility results. At 90 days of age, lower growth performances were obtained in foals which dams presented negative BCS changes on the first 3 months of lactation (P < 0.05). In conclusion, BC changes at early postpartum period influence the reproductive efficiency of broodmares and the growth of their suckling foals. These findings are important to help breeders on management options concerning feeding strategies in the Lusitano production systems and others under similar conditions.
authors.affiliation: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Av. Universidade Técnica, Lisboa, Portugal.
authors.forename: M J
authors.initials: MJ
authors.lastname: Fradinho
authors.affiliation: Coudelaria de Alter, Tapada do Arneiro, Alter-do-Chão, Portugal.
authors.forename: M J
authors.initials: MJ
authors.lastname: Correia
authors.affiliation: Coudelaria de Alter, Tapada do Arneiro, Alter-do-Chão, Portugal.
authors.forename: V
authors.initials: V
authors.lastname: Grácio
authors.affiliation: Qta. da Lagoalva de Cima, Alpiarça, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Bliebernicht
authors.affiliation: Companhia das Lezírias, Porto Alto, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Farrim
authors.affiliation: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Av. Universidade Técnica, Lisboa, Portugal.
authors.forename: L
authors.initials: L
authors.lastname: Mateus
authors.affiliation: INRA, Centre de Recherche de Clermont-Ferrand/Theix, Saint Genes Champanelle, France.
authors.forename: W
authors.initials: W
authors.lastname: Martin-Rosset
authors.affiliation: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Av. Universidade Técnica, Lisboa, Portugal.
authors.forename: R J B
authors.initials: RJ
authors.lastname: Bessa
authors.affiliation: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Av. Universidade Técnica, Lisboa, Portugal.
authors.forename: R M
authors.initials: RM
authors.lastname: Caldeira
authors.affiliation: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Av. Universidade Técnica, Lisboa, Portugal. Electronic address: gmlfdias@fmv.ulisboa.pt.
authors.forename: G
authors.initials: G
authors.lastname: Ferreira-Dias
mesh_terms: D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D001823:Body Composition; D005260:Female; D005298:Fertility; D006736:Horses / Q000502:physiology*; D020738:Leptin / Q000097:blood*; D011247:Pregnancy; D011270:Pregnancy, Animal; D013997:Time Factors
chemical_list: D020738:Leptin
keywords: Body condition; Fertility; Growth of suckling foals; Leptin; Lusitano breed; Mare