PHYSIOLOGICAL APPROACHES TO INCREASE THE EFFICIENCY OF PORK PRODUCTION THROUGH IMPROVED NUTRITIONAL AND REPRODUCTIVE COMPETENCE
Location: Reproduction Research
Title: Zearalenone Increases Reproductive Tract Development, but not Skeletal Muscle Signaling in Prepubertal Gilts
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: March 7, 2010
Publication Date: July 1, 2010
Citation: Oliver, W.T., Miles, J.R., Diaz, D.E., Dibner, J.J., Rottinghaus, G.E., Harrell, R.J. 2010. Zearalenone Increases Reproductive Tract Development, but not Skeletal Muscle Signaling in Prepubertal Gilts [abstract]. Journal of Animal Science, 88(E-Supplement 2):113.
Zearalenone (zea) is a potent mycotoxin that has estrogenic properties. In vitro results indicate that zea metabolites are capable of down-regulating proteins associated with protein synthesis (mammalian target of rapamycin, mTOR) and cellular proliferation (extracellular signal-regulated kinase, ERK) in muscle. The objectives were to determine the effect of zea consumption by prepubertal gilts on: 1) growth performance, 2) reproductive tract development, and 3) skeletal muscle mTOR and ERK activation. Gilts were weaned at 21 d of age and allowed to adjust for 1 wk on a commercial diet. After 1 wk (d 0), gilts were randomly assigned to consume a commercial basal diet (C, n = 9) or C + 1.5 mg/kg zea (n = 10) for 4 wk, at which time gilts were euthanized, urine collected, and tissue collected and frozen. Zearalenone, a-zearalenol, and ß-zearalenol were detected at levels of less than 4 µg/kg in urine of C gilts, but were increased (292 ± 76, 113 ± 20, and 15 ± 3 µg/kg, respectively) in pigs consuming zearalenone (P < 0.01). No differences were observed in ADG, ADFI, or G:F between treatments (P > 0.28). Reproductive tract size was increased 1.5-fold (20.9 ± 4.3 vs. 50.6 ± 3.8 g) in Zea gilts (P < 0.01). Uterine endometrial gland development was increased 50% in gilts consuming zea (P < 0.01). In uterus, estrogen receptor (ER)-a mRNA and protein were unchanged (P > 0.28), but gilts consuming zea had 2- and 3-fold higher abundance of ER-ß mRNA and protein, respectively, compared to the C group (P < 0.01). No differences were observed in mTOR and ERK protein phosphorylation or total abundance in skeletal muscle (P > 0.36). The consumption of zea had no effect on growth performance or skeletal muscle signaling in prepubertal gilts, but zea increased reproductive tract size and glandular development, possibly due to altering the expression of ER-ß.