Estrous cycle characteristics of postpubertal gilts approaching anestrus due to limited dietary energy intake

• Published in: Journal of animal science Vol. 71; no. 2; p. 436
• Main Authors: Rozeboom, D.W. (University of Minnesota, St. Paul), Pettigrew, J.E, Dial, G.D, Moser, R.L, Cornelius, S.G, Wheaton, J.E
• Format: Journal Article
• Language: English
• Published: United States 01.02.1993
• Subjects: ALIMENTACION RACIONADA; ALIMENTATION RATIONNEE; Animal Nutritional Physiological Phenomena; Animals; CERDAS; CICLO ESTRAL; CYCLE OESTRAL; ENERGIA; ENERGIE; Energy Intake; Estrus - physiology; Female; Food Deprivation - physiology; PROGESTERONA; PROGESTERONE; Progesterone - blood; Random Allocation; SERUM SANGUIN; Sexual Maturation; SUERO SANGUINEO; Swine - physiology; TRUIE
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/1993.712436x

Twenty-nine Duroc X (Yorkshire X Landrace) gilts, approximately 9 mo of age and each having experienced at least three estrous cycles, were allotted randomly to five dietary treatments. Each treatment provided a different daily intake of metabolizable energy: 0.25, 0.5, 0.75, 1.0 Mcal (severely restrictive [RES]; chosen to cause cessation of estrous cycles) or 3.4 Mcal (control; designed for maintenance of estrous cyclicity). Blood samples were drawn by venipuncture every 3 d and sera were assayed for progesterone (P4) concentration. Estrous cycle length was estimated by defining d 0 as the last day when serum P4 concentrations were 1 ng/mL before increasing to 1 ng/mL. Gilts were considered acyclic when serum P4 levels remained 1 ng/mL for four consecutive samples (9 d). Anestrus occurred after 78.7 +/- 6.1 d in all RES gilts (n