Effects of Dietary Glucose on Serum Estrogen Levels and Onset of Puberty in Gilts

摘要

Metabolic signals and the state of energy reserves have been shown to play a crucial role in the regulation of reproductive function. This study was carried out to investigate the effects of dietary glucose levels on puberty onset in gilts. Weight matched, landrace gilts (n = 36) 162 3 days old, weighing about 71.05 +/- 4.53 kg, were randomly assigned to 3 dietary treatment groups of 12 gilts each. The trial lasted until the onset of puberty. Gilts in each group were supplied with diets containing different levels of glucose as follows: i) starch group (SG) was free of glucose, contained 64% corn derived starch; ii) low-dose group (LDG) contained 19.2% glucose and 44.8% corn derived starch; iii) high-dose group (HDG) contained 30% glucose and 30% corn derived starch. Results indicated: i) The growth performance of gilts were not affected by the addition of glucose, but the age of puberty onset was advanced significantly (p0.05); ii) Compared with the SG, the concentration of insulin significantly increased before puberty in HDG (p0.05); iii) There was no difference in serum progesterone (P) levels amongst the different feed groups, however, levels of estradiol (E-2), luteinizing hormone, and follicle-stimulating hormone were significantly higher at puberty onset in HDG (p0.05). Overall, our findings indicate that glucose supplementation significantly advances puberty onset, which can have practical purposes for commercial breeding.