PSVII-29 Integrating hybrid rye into organic pig production to reduce feed and bedding costs

Abstract

Abstract An obstacle to profitable organic swine production is the high cost of feed and bedding. We evaluated whether growing hybrid rye for organic feed and bedding for pigs was economically viable by replacing corn with hybrid rye and evaluating pig growth performance and feed and bedding costs. Hybrid rye was grown on certified organic land at WCROC in 2022 and 2023. Rye grain and straw were used in a feeding trial with pigs raised according to the National Organic Standards. The animal trial consisted of three replicates. Each replicate included 100 pigs in two pens (Control vs. Rye, 50 pigs/pen) in a bedded hoop barn. Control pigs were fed corn soybean meal-based diets and Rye pigs were fed diets with 50% of corn in the control diets replaced by hybrid rye. Each replicate lasted for about 12 wk until pigs reached market weight (120 kg). Pigs were weighed individually at the beginning, every 4 wk thereafter, and at the conclusion of the study. Feed disappearance was recorded on a pen basis at the time of weighing pigs. Growth performance[average daily gain(ADG), average daily daily feed intake (ADFI), and Gain: Feed] was calculated for each weigh period. Carcass weight was recorded at harvest and dressing percent was calculated for each pig. Bedding usage was recorded for each pen (Control pen = wheat straw, Rye pen = rye straw) and average usage for each pig was calculated. Growth performance and bedding usage data were analyzed using the Proc Glimmix Procedures of SAS, with dietary treatment as the fixed effect, replicate as the random effect, and pen as the experimental unit. Production costs were set at $239/ha for organic rye grain and $20/ha for rye straw baling according to the FINBIN Database, and the unit costs ($/kg) were calculated based on yield for each year. Prices for organic corn, soybean meal, base mix, wheat straw, and market pigs were based on market prices (Table 1). Yield of organic hybrid rye grain at WCROC was 1,070 and 712 kg/ha in 2022 and 2023, respectively, with corresponding rye straw yield being 661 and 367 kg/ha. The reduction in rye yield in 2023 was considered due to drought. No difference was detected in growth performance, dressing percent, or bedding usage between Control and Rye pigs (all P > 0.19; Table 1). Replacing 50% of corn with hybrid rye saved $9.6/pig in 2022, but cost $7.20/pig more for feed in 2023, due to changes in hybrid rye grain yield. Savings on bedding were $15.40 and $13.20/pig for 2022 and 2023, respectively. Results indicate that replacing 50% of corn with hybrid rye in feed did not negatively affect growth performance of pigs raised organically, but the economic viability of integrating hybrid rye into organic pig production may depend on crop yield.