Effects of prenatal androgenization and lactation on adipose tissue metabolism in finishing single-calf heifers

• Published in: Journal of animal science Vol. 75; no. 6; p. 1504
• Main Authors: Reiling, B A, Drackley, J K, Grum, L R, Berger, L L
• Format: Journal Article
• Language: English
• Published: United States 01.06.1997
• Subjects: Acetates - analysis; Acetates - metabolism; Adenosine Deaminase - analysis; Adenosine Deaminase - metabolism; Adipose Tissue - chemistry; Adipose Tissue - metabolism; Adipose Tissue - pathology; Animals; Biopsy - veterinary; Carbon Radioisotopes; Cattle - growth & development; Cattle - metabolism; Cattle - physiology; Diet - veterinary; Drug Implants; Epinephrine - pharmacology; Fatty Acids - analysis; Fatty Acids - metabolism; Fatty Acids, Nonesterified - analysis; Fatty Acids, Nonesterified - metabolism; Female; Glucose - metabolism; Glycerol - analysis; Glycerol - metabolism; Lactation - physiology; Lipid Metabolism; Lipids - analysis; Norepinephrine - pharmacology; Pregnancy; Prenatal Exposure Delayed Effects; Testosterone - administration & dosage; Testosterone - pharmacology; Theophylline - pharmacology
• ISSN: 0021-8812
• DOI: 10.2527/1997.7561504x

Twelve control (C) and 12 prenatally androgenized (PA) lactating (L) first-calf heifers and five (two C and three PA) similar, nonlactating (NL) heifers were used to assess the effects of PA and L on the metabolic activity of s.c. adipose tissue (AT). Heifers were fed an 85% concentrate diet, and their calves were weaned at 112 +/- 1 d of age. Adipose tissue was biopsied at approximately 77 d (period 1, during lactation for L heifers) and 126 d (period 2, after L heifers had calves weaned) postpartum. The NL heifers gained .22 kg/d faster (P = .20) and had greater fat deposition than L heifers during period 1. The PA heifers were fatter and gained 14.6% faster than C heifers during lactation. Epinephrine (E) and norepinephrine (NE) increased in vitro fatty acid (FA) release 25 (P < .01) and 15% (P < .06), respectively, above basal rates. Near-maximal release of FA, as estimated by stimulation with E plus theophylline plus adenosine deaminase (ETAD), was 73% (4,110 vs 2,379 +/- 161 nEq/[2 h.100 mg of tissue]; P < .01) above basal rates. Basal FA release was unaffected, but ETAD-stimulated rates were decreased (P < .04; 4,430 +/- 246 vs 3,789 +/- 209 nEq/[2 h.100 mg of tissue]) by PA. Stimulation of FA release by E (P = .22) or NE (P = .31) did not differ between C and PA. For NL heifers, PA decreased (P < .02) FA release, which corresponded with their greater fat deposition, but PA did not affect L heifers (PA x L interaction, P = .14). The content of NEFA in s.c. AT (pool size) was 34% greater (P < .01) during period 2 than during period 1. Pool size was not affected (P = .72) by NE but was increased by E (1,628 vs 1,777 +/- 92 nEq/100 mg of tissue; P < .05) and ETAD (1,628 vs 2,176 +/- 93 nEq/100 mg of tissue; P < .01). For L heifers, PA tended (P < .07) to increase incorporation of acetate into FA during period 1. Thus, PA resulted in subtle increases in lipogenesis and decreases in lipolysis during the first lactation-weaning cycle that were consistent with greater rates of gain and fat deposition.