title: Influence of imposed feed intake patterns during lactation on reproductive performance and on circulating levels of glucose, insulin, and luteinizing hormone in primiparous sows.
abstract: Thirty-six primiparous sows were assigned to one of five treatments designed to mimic the lactation feed intake patterns observed in a previous study of commercial farms: high energy intake (HHH) or low energy intake during each week of a 3-wk lactation (LLL), or reduced intake during wk 1 (LHH), wk 2 (HLH) or wk 3 of lactation (HHL). The metabolizable energy intake of sows was either 16.5 (H) or 6.5 (L) Mcal/d. Diets were equal in lysine, providing 45 g/d. The HHH sows had a shorter (P < .05) weaning-to-estrus interval (9 +/- 3.2 d) than the sows in the LLL (23 +/- 3.5 d), HLH (22 +/- 3.5 d), and HHL (18 +/- 3.2 d) groups. The LH pulse frequencies of HHH (d 14: 1.5 pulses/8 h; d 21: 2.1 pulses/8 h) were greater (P < .05) than those of LLL (.2 pulses/8 h) and HLH (.5 pulses/8 h) on d 14 and those of LLL (0 pulses/8 h) and HHL (.9 pulses/8 h) on d 21 of lactation. No differences (P > .1) in mean serum concentrations of LH were observed among treatment groups either on d 21 of lactation or on d 1 postweaning. When fed a low-energy diet, sows had lower (P < .05) concentrations of serum insulin and plasma glucose than did sows fed a high-energy diet. Our results indicate that energy intake during lactation influences circulating insulin and glucose levels and LH pulse frequency and amplitude during midlactation and during the postweaning period.
authors.affiliation: Department of Clinical and Population Sciences, University of Minnesota, St. Paul 55108, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Koketsu
authors.forename: G D
authors.initials: GD
authors.lastname: Dial
authors.forename: J E
authors.initials: JE
authors.lastname: Pettigrew
authors.forename: W E
authors.initials: WE
authors.lastname: Marsh
authors.forename: V L
authors.initials: VL
authors.lastname: King
mesh_terms: D000821:Animal Feed / Q000592:standards; D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D001835:Body Weight / Q000502:physiology; D004435:Eating / Q000502:physiology*; D005260:Female; D005298:Fertility / Q000502:physiology; D007328:Insulin / Q000097:blood*; D007774:Lactation / Q000502:physiology*; D007986:Luteinizing Hormone / Q000097:blood*; D011897:Random Allocation; D012098:Reproduction / Q000502:physiology*; D012741:Sexual Maturation / Q000502:physiology; D013552:Swine / Q000097:blood / Q000502:physiology*; D015430:Weight Gain / Q000502:physiology
chemical_list: D001786:Blood Glucose; D007328:Insulin; D007986:Luteinizing Hormone