Effect of prenatal testosterone treatment on nitrogen utilization and endocrine status of ewe lambs

• Published in: Journal of animal science Vol. 68; no. 12; pp. 4100 - 4108
• Main Authors: DeHaan, K.C, Berger, L.L, Bechtel, P.J, Kesler, D.J, McKeith, F.K, Thomas, D.L
• Format: Journal Article
• Language: English
• Published: Savoy, IL Am Soc Animal Sci 01-12-1990; American Society of Animal Science
• Subjects: Animals; Biological and medical sciences; Blood Glucose - analysis; blood plasma; Blood Urea Nitrogen; ewes; fatty acids; Fatty Acids, Nonesterified - blood; Female; Fundamental and applied biological sciences. Psychology; General aspects. Hormone interactions. Hormone actions on several organ systems. Adaptive reactions; Genitalia, Female - drug effects; glucose; Hormones - blood; insulin; Insulin - blood; insulin-like growth factor; Insulin-Like Growth Factor I - analysis; L-thyroxine; lambs; Nitrogen - metabolism; nitrogen compounds; Pregnancy; Prenatal Exposure Delayed Effects; prenatal period; Random Allocation; Sheep - metabolism; testosterone; Testosterone - pharmacology; Thyroxine - blood; urea nitrogen; Vertebrates: endocrinology; Pancreatic hormone; Somatomedin C; Glucose; Insulin; Young animal; Pregnancy; Prenatal; Testosterone; Vertebrata; Reproduction; Regulation(control); Mammalia; Nitrogen balance; Radioimmunoassay; Thyroxine; Thyroid hormone; Sheep; Artiodactyla; Sex steroid hormone; Ungulata
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/1990.68124100x

Thirty-eight pregnant Suffolk ewes were assigned randomly to a control group or implanted with approximately 2 g of testosterone propionate (TP) when they were between d 40 and 60 of gestation. Implants were removed 3 wk prior to lambing. Five ewe lambs born to implanted ewes and ten ewe lambs born to nonimplanted ewes were utilized in this experiment. Ram lambs were not used in this trial. No differences (P greater than .10) were observed for fecal, urinary and total N excretion and amount of N absorbed. Nitrogen retained (percentage of N intake and g/d) was higher (P less than .05) in prenatally androgenized ewe lambs than in control ewe lambs. Plasma insulin concentrations averaged 99% higher (P less than .05) in prenatally androgenized ewe lambs. Plasma insulin-like growth factor I (IGF-I) concentrations averaged 29% higher (P less than .06) in ewe lambs treated prenatally with testosterone. Nonesterified fatty acid (NEFA) concentrations averaged 41% higher (P less than .05) in prenatally androgenized ewe lambs. Significant (P less than .05) treatment x time effects were observed in plasma thyroxine, glucose and urea N concentrations of prenatally androgenized vs control ewe lambs. These significant modifications in the plasma metabolite and endocrine status could be an important element of the physiological mechanism(s) by which prenatal androgenization improves growth performance and leanness of ewe lambs.