247 Hybrid Rye in Commercial Grow-Finish Production Diets: A Case Study

Abstract

Abstract An experiment was conducted to test the hypothesis that inclusion of hybrid rye in diets fed to growing-finishing pigs would not affect growth performance. A total of 1,177 pigs (initial body weight: 25.75 ± 0.04 kg) were randomly allotted to one of four dietary treatments with 40 experimental pens, 30 pigs per pen, sex split evenly within pen, and pen as the experimental unit. There were 2 experimental phases with a control diet containing corn (CON) and three diets containing increasing levels of hybrid rye replacing corn (LOW, MOD, or HIGH) formulated within each phase: 10%, 20%, or 30% in phase 1 and 20%, 40% or 50% in phase 2, respectively. Prediction equations were used to calculate net energy values of hybrid rye and diets were formulated to be isocaloric, with the addition of choice white grease (CWG) as hybrid rye was increased in the diet to compensate for predicted energy values. Pigs were provided ad libitum access to feed and water. Pig body weights and feed consumption were recorded on d 14, 28, 42, 56, 70, 84, 90, 100, and 118. Average daily gain, average daily feed intake, and gain:feed were calculated. Data were analyzed with R using linear and quadratic contrast statements to evaluate effects of increasing levels of hybrid rye in the diet, and another contrast statement to compare the control diet with the combined rye dietary treatments. Average daily feed intake was linearly reduced (P ≤ 0.05) if hybrid rye was added to the diet on d 56, 70, 84 and 90, and in the overall experimental period. Average daily gain linearly increased (P ≤ 0.05, d 90, d 100; P ≤ 0.10, d 28) or was not affected by dietary treatment throughout the experiment. Consequently, addition of hybrid rye resulted in a linear increase (P ≤ 0.05) in gain:feed on d 28 and d 90, with a tendency for a linear increase (P ≤ 0.10) also observed on d 70 and d 100. The hybrid rye treatment groups had a greater (P ≤ 0.05; overall; P ≤ 0.10; d 56) gain:feed compared with the corn-based control group, indicating improved efficiency. There were also no differences (P ≥ 0.21) among treatments in the average selling body weight on d 90, d 100, or d 118. However, it is possible that the energy value of hybrid rye was greater than predicted, and that the inclusion of CWG in the diet resulted in improvements in growth performance due to the greater energy content. Therefore, it may be concluded that hybrid rye is a suitable ingredient in swine rations with or without the addition of CWG to improve or maintain feed efficiency and market weight during the growing-finishing phase of production.