Effect of prenatal androgenization on performance, lactation, carcass, and sensory traits of heifers in a single-calf heifer system

• Published in: Journal of animal science Vol. 73; no. 4; p. 986
• Main Authors: Reiling, B.A. (University of Illinois, Urbana.), Berger, L.L, Faulkner, D.B, McKeith, F.K, Nash, T.G
• Format: Journal Article
• Language: English
• Published: United States 01.04.1995
• Subjects: ANALISIS ORGANOLEPTICO; ANALYSE ORGANOLEPTIQUE; Animals; Body Composition - drug effects; Body Composition - physiology; BOVIN DE BOUCHERIE; CANAL ANIMAL; CARCASSE; Cattle - growth & development; Cattle - physiology; CONTENIDO DE MATERIA SECA; CRECIMIENTO; CROISSANCE; DESEMPENO; Drug Implants; EFFICACITE ALIMENTAIRE; EFICIENCIA DE CONVERSION DEL PIENSO; Female; GAIN DE POIDS; GANADO DE CARNE; GANANCIA DE PESO; GENISSE; INGESTION DE PIENSOS; LACTACION; LACTATION; Lactation - drug effects; Lactation - physiology; Maternal-Fetal Exchange - physiology; Meat - standards; Milk - metabolism; NOVILLA; PESO; PESO AL NACIMIENTO; POIDS; POIDS A LA NAISSANCE; Pregnancy; PRISE ALIMENTAIRE (ANIMAUX); RENDEMENT EN VIANDE; RENDEMENT LAITIER; RENDIMIENTO CARNICO; RENDIMIENTO LECHERO; TENEUR EN MATIERE SECHE; TERNERO; TESTOSTERONAS; TESTOSTERONE; Testosterone - administration & dosage; Testosterone - pharmacology; TRANSPLANTATION; TRASPLANTES; VACA; VACHE; VEAU; Weight Gain - drug effects; Weight Gain - physiology
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/1995.734986x

Twenty-four prenatally androgenized (PA) heifers, born to testosterone propionate-implanted cows, and 27 control (C) heifers, born to nonimplanted cows, were bred, calved, and placed in drylot pens, with calf at side, to assess the effects of PA on feedlot growth and lactational performance of heifers used in a single-calf heifer (SCH) system. Lactating heifers were fed an 85% concentrate diet, calves weaned at 117 d postpartum, and heifers slaughtered at a constant compositional end point of 1.1 cm of s.c. fat. Preweaning, PA heifers gained 22.5% faster (P 0.01) and were 17.3% more efficient (P .0.01) than controls. Prenatal androgenization of the heifer, however, did not affect calf growth performance. All calves gained more than 1.4 kg/d and had an average weaning weight of 159 kg at 117 d of age. Combining heifer-calf weights, PA and C pairs gained 2.88 and 2.53 kg/d, respectively. Correcting for DMI of calves, PA improved (P 0.01) efficiency of beef production 10.8%. Four percent fat-corrected milk yield of PA and C heifers averaged 7.96 and 7.60 kg/d, respectively, and the percentage of milk protein and fat did not differ. Accounting for average BW, milk production, and DMI, PA and C lactating heifers should have gained 1.27 kg/d; however, gains were 137 and 127% of those predicted, respectively. Overall, pre- and postweaning, PA heifers required 10 fewer (P 0.04) days on feed, gained 23% faster (P 0.01), and were 16% more efficient (P 0.02) than C heifers. At slaughter, PA and C heifers averaged 853 and 865 d of age, respectively. Bone and lean maturity scores averaged B0 and A60, respectively, although one carcass was classified as mature (C-maturity). Marbling scores exceeded Sma50, and sensory traits did not differ. Thus, PA enhanced growth and efficiency of beef production from heifers used in a SCH system but did not affect lactational or carcass traits