Effects of plane of nutrition and selenium supply during gestation on ewe and neonatal offspring performance, body composition, and serum selenium.

To investigate the effects of nutritional plane and Se supply during gestation on ewe and offspring performance and body composition, 84 Rambouillet ewe lambs (age = 240 +/- 17 d, BW = 52.1 +/- 6.2 kg) were allocated to a 2 x 3 x 2 factorial arrangement of treatments. Factors included Se [adequate Se (ASe, 11.5 microg/kg of BW) or high Se (HSe, 77.0 microg/kg of BW)] initiated at breeding, nutritional plane [60% (restricted, RES), 100% (control, CON), or 140% (high, HIH) of NRC requirements] initiated at d 40 of gestation, and physiological stage at necropsy [3 to 24 h postpartum or d 20 of lactation]. Ewes were fed and housed individually in a temperature-controlled facility. At parturition, all lambs were removed and artificially reared until necropsy on d 20.6 +/- 0.9 of age. Ewes assigned to the treatment at d 20 of lactation were transitioned to a common diet meeting lactation requirements and were mechanically milked. From d 95 of gestation through parturition and d 20 of lactation, ewe BW and BCS were least (P