Effects of energy source in the diet on reproductive hormones and insulin during lactation and subsequent estrus in multiparous sows

• Published in: Journal of animal science Vol. 73; no. 10; p. 3022
• Main Authors: Kemp, B, Soede, N M, Helmond, F A, Bosch, M W
• Format: Journal Article
• Language: English
• Published: United States 01.10.1995
• Subjects: Animals; Body Weight - physiology; Dietary Carbohydrates - pharmacology; Dietary Fats - pharmacology; Eating - physiology; Energy Metabolism - physiology; Estradiol - blood; Estrus - metabolism; Estrus - physiology; Female; Fetal Death - veterinary; Insulin - blood; Lactation - metabolism; Lactation - physiology; Luteinizing Hormone - blood; Ovulation - metabolism; Ovulation - physiology; Pregnancy; Progesterone - blood; Soybean Oil - administration & dosage; Soybean Oil - pharmacology; Starch - administration & dosage; Starch - pharmacology; Swine - blood; Swine - physiology
• ISSN: 0021-8812
• DOI: 10.2527/1995.73103022x

Two experiments were performed. The first experiment was done to study the effects of dietary energy source on plasma insulin concentration using five gilts in a Latin square design with two diets over two periods. The diets contained either 200 g/kg of cornstarch (Starch) or soybean oil (Fat) as energy sources. Results indicate that insulin response was greater in the Starch-fed than in the Fat-fed gilts. A second experiment was performed in which 18 multiparous sows were fed one of the two experimental diets from farrowing until slaughter at d 35 of subsequent pregnancy. All sows nursed nine pigs. Blood samples were taken from a permanent jugular vein catheter every 12 min during a 12-h period on d 109 +/- 1 of pregnancy, on d 7 +/- 1, 14 +/- 1, and 21 +/- 1 of lactation, and on the day of weaning ( d 22 +/- 1). From 48 h after weaning, blood samples were taken every 4 h until 24 h after ovulation. After that, blood samples were taken at 12-h intervals until d 10 after ovulation. Differences between diets in insulin response were not significant. In Starch-fed sows, LH pulsatility at d 7 of lactation was greater (P < .05), the preovulatory LH surge was greater ( P < .05), and progesterone production was greater (P < .05) from 108 h until 256 h after the LH surge than in the Fat-fed sows. Results indicate that feeding Starch-rich diets to multiparous sows compared with Fat-rich diets, on an isocaloric basis, increases LH pulsatility during early lactation, the preovulatory LH surge, and progesterone production after the LH surge.