Experimental Procedures
Forty-eight ewes rearing twins and 12 ewes rearing singles were used in a completely randomized experiment with a 2 X 2 factorial arrangement of treatments. Main effects were source of energy supplement (corn versus soybean hulls) and level of energy supplement (1.5 versus 3.0 lb/ewe/day). The trial was initiated in February, 2000 and each group of ewes was fed for 49 days. As ewes lambed out, they were accumulated in pens such that each pen had four ewes rearing twins and one ewe rearing a single. A total of 12 pens were used, thus there were three pens for each of the following treatment combinations (amounts presented are on a per ewe basis): 1) 1.5 lb corn + 0.5 lb SH-275 + 10 lb alfalfa haylage; 2) 1.5 lb soybean hulls + 0.5 lb SH-276 + 10 lb haylage; 3) 3.0 lb corn + 0.5 lb SH-277 + 4.5 lb alfalfa haylage; 4) 3.0 lb soybean hulls + 0.5 lb SH-278 + 4.5 lb haylage.
Compositions of the soybean hull (SH) supplements are presented in Table 1. Haylage was stored in a bottom unloading concrete silo and was 38% dry matter. Ewes averaged 3.2 years of age (range = 2 to 10 years) and 180 ± 3 lb of body weight at the beginning of the trial. Haylage was increased by 2 lb/ewe for all pens on days 28 and 35 to adjust for increased energy requirements of the ewes as lactation progressed. Lambs had access to creep feed (Table 1) from day 14 until day 49 when the trial ended. Three ewes and their lambs were removed from the trial due to problems unrelated to experimental treatment. Sore mouth occurred randomly through this flock during the trial. Ewes were housed in 5 X 16 ft pens located on an expanded metal floor. Pens were constructed of metal gates on three sides and a wooden fence-line feed bank (5 ft long) on the fourth side. Each pen had an automatic water cup to provide water ad libitum. Creeps were constructed on day 14 so that ewes did not have access to creep feed. Ewes were fed at 0800 hours daily. Intake and refusals of ewe feed and creep feed were recorded daily. Ewes and lambs were weighed and ewe body condition score (BCS) was measured on days 0, 14, 28 and 49.
Statistical analysis was performed using the GLM procedure of SAS (1988) for a completely randomized design with a 2 × 2 factorial arrangement of treatments. The model contained effects due to supplement source, supplement level, and the interaction. Pen served as the experimental unit.