title: Short-term dietary concentrate supplementation during estrus synchronization treatment in beef cows increased IGF-I serum concentration but did not affect the reproductive response.
abstract: The objective of this study was to evaluate if short-term dietary concentrate supplementation increased IGF-I serum concentration and resulted in a reproductive response during estrus synchronization treatment in non-lactating beef cows. Thirty non-lactating beef cows (Bos indicus × Bos taurus) were allocated to the same pastureland and fed native tropical grasses as a basal diet. Cows were synchronized using a 7-day CO-Synch plus controlled internal drug release (CIDR) protocol and received fixed time artificial insemination (FTAI). Cows were divided into two groups; the control group (n = 16) received 0.5 kg of concentrate/cow/day, whereas the supplemented group (n = 14) received 4.0 kg of concentrate/cow/day. The period of supplementation was 10 days from the day of CIDR insert to FTAI. The concentration of IGF-I increased (P < 0.05) in the supplemented group, while no significant changes were observed in the control group. Moreover, at the time of insemination, IGF-I serum concentrations were higher in supplemented cows compared with control cows (P < 0.05). Notably, metabolite and insulin concentrations did not differ (P > 0.05) between treatment groups or sampling day. The response to estrus induction, measured as estrus presentation, ovulation rate, and pregnancy rate, was similar between experimental groups (P > 0.05). In conclusion, our results indicated that supplementation with dietary concentrate for 10 days in non-lactating beef cows changed the endocrine milieu, specifically increasing IGF-I serum concentration. However, these endocrine changes did not affect response to estrous induction treatment.
authors.affiliation: Departamento de Producción Agrícola y Animal, Universidad Autónoma Metropolitana-Xochimilco, Calzada del Hueso 1100, 04960, Ciudad de México, Mexico.
authors.forename: A M
authors.initials: AM
authors.lastname: Rosales-Torres
authors.affiliation: Universidad Autónoma Metropolitana-Xochimilco, Ciudad de México, Mexico.
authors.forename: Z B
authors.initials: ZB
authors.lastname: López-Cedillo
authors.affiliation: Universidad Autónoma Metropolitana-Xochimilco, Ciudad de México, Mexico.
authors.forename: C G
authors.initials: CG
authors.lastname: Hernández-Coronado
authors.affiliation: Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Hueytamalco, Puebla, 73580, Mexico.
authors.forename: J V
authors.initials: JV
authors.lastname: Rosete-Fernández
authors.affiliation: Departamento de Producción Agrícola y Animal, Universidad Autónoma Metropolitana-Xochimilco, Calzada del Hueso 1100, 04960, Ciudad de México, Mexico.
authors.forename: G D
authors.initials: GD
authors.lastname: Mendoza
authors.affiliation: Departamento de Producción Agrícola y Animal, Universidad Autónoma Metropolitana-Xochimilco, Calzada del Hueso 1100, 04960, Ciudad de México, Mexico. aguzman@correo.xoc.uam.mx.
authors.forename: A
authors.initials: A
authors.lastname: Guzmán
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D001522:Behavior, Animal; D001823:Body Composition; D001835:Body Weight; D002417:Cattle; D003692:Delayed-Action Preparations; D019587:Dietary Supplements; D015237:Dinoprost / Q000494:pharmacology; D004971:Estrus / Q000187:drug effects; D004973:Estrus Synchronization / Q000187:drug effects*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000502:physiology; D007315:Insemination, Artificial / Q000662:veterinary*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D006080:Ovarian Follicle / Q000502:physiology; D010060:Ovulation / Q000187:drug effects; D011247:Pregnancy; D018873:Pregnancy Rate; D011374:Progesterone / Q000097:blood; D000069466:Red Meat; D013997:Time Factors
chemical_list: D003692:Delayed-Action Preparations; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D007334:Insulin-Like Growth Factor I; D015237:Dinoprost
keywords: Beef cows; Dietary concentrate supplementation; Estrus induction; IGF-I