206 Efficacy of Using Ammonium Chloride Supplements During Crisis Management to Stop Growth in Various Ages of Pigs

This project aimed to develop nutritional strategies to “hold” pigs at no growth for 2-6 weeks during crisis management. Previously, growth was reduced in 25-kg pigs fed hold-growth (HG) diets formulated with reduced nutrients +2%NH4Cl (HG+2). Recovery was only monitored for 11-days. The current experiment assessed HG+2 diets fed at 25, 50, and 75kg for 28-days followed by recovery to market weight. Eighty crossbred pigs were allotted (20kg) to 16 pens. Other than during the 28-d hold, pigs were fed standard diets and marketed at a constant weight. Compared with ADG of Ctl (0.963, 1.086, and 1.094 kg/d) growth was reduced (P< 0.01) by 81.9, 77.1, and 79.9% at 25, 50, and 75 kg in pigs fed HG+2 (0.174, 0.249, and 0.220 kg/d). Pigs fed HG+2 recovered and only required 14 extra days to reach market weight (128.6 kg). During the 28-d hold phase feed intake was reduced (P< 0.01). However, feed efficiency (0.310, 0.184, and 0.132 G:F) was reduced compared with Ctl (0.689, 0.397, 0.351 G:F) pigs at 25, 50 and 75 kg, respectively. Dramatic shifts occurred in growth and feed intake during initial recovery phases. Over the entire trial, gain was only reduced by 13.0, 12.6, 12.7% and total feed intake was increased by 1.9, 5.3 and 6.0% for HG+2 pigs held at 25, 50 and 75 kg, respectively. Whole body DXA scans (n=4/treatment) revealed reduced %bone mineral of Ctl vs. HG+2 (2.06 vs. 1.84, 1.82, and 1.83%) at 25, 50, and 75 kg, respectively. No differences were detected in DXA %Fat, %Lean, or traditional carcass traits (fat depth, loin depth, % lean). No adverse effects associated with treatments were observed. Thus, HG+2 diets provided a successful strategy to hold pigs during crisis management. This empirical data will be used to generate dynamic models to guide decisions on economic consequences.