8 Differential Growth Performance in Conventionally and Artificially Raised Lambs Fed High-Concentrate and High-Forage Post-Weaning Diets

Abstract Artificial rearing of lambs on milk replacer presents management challenges for producers and can impact performance. The objective this experiment was to evaluate effects pre-weaning adaptation post-weaning finishing diets. We hypothesized that fed a high-concentrate (HC) diet would exhibit more efficient body weight (BW) gain than high-forage (HF) regardless management. Thirty-two Polypay conventionally raised (CR; n = 10 rams, 6 ewes) or artificially (AR; =10 (age: 84.0 ± 0.8 d) were blocked by sex BW randomly assigned either HC (85:15 concentrate: forage) HF (50:50 concentrate:forage) (n 8 CR AR diet-1). Individually housed ad libitum remained feed through target 59.0 54.4 kg rams ewes, respectively. Feed intake measured at 7-day intervals. Data analyzed PROC GLM in SAS (v. 9.4, Inst. Inc., Cary, NC). Initial (39.0 ±.9 kg) greater (32.9 0.5 kg; P < 0.01), but there no difference between diets (P 0.72) interaction 0.54). Time average daily (ADG) did not differ (time feed: 48.1 2.8 d; ADG: 206.9 ±1.4 g∙d-1; ≥ 0.22). In contrast, time lambs, with longer (68.9 2.5 (56.2 2.4 0.01). ADG also numerically (424 ±9.8 g) (370 24.0 0.11). Dry matter (DMI) less (35.16 ±.65 g BW-1∙d-1) (41.32 0.69 g∙kg BW-1∙d-1,P 0.01) (40.58 ±.35 BW-1∙d-1; 0.99). decreased DMI resulted efficiency (0.26 0.02) compared (0.21 0.01; 0.03). not, however, (HC: 0.27 0.02; 0.64). Results study suggest better able adapt lambs. Additionally, exhibited superior utilization when comparison HF, response found Overall, these results demonstrate differential vs.