Evaluation of energy and nutrient digestibility of DDGS, soybean meal, and rapeseed meal in multiparous sows during the gestation, lactation, and post-weaning period1.

While the impact of physiological stage on nutrient utilization in sows is recognized, data on specific feed ingredients remain limited. Research has evaluated soybean meal (SBM) in mid-to-late gestation, but information is lacking across other stages. Furthermore, the available energy and nutrient digestibility of rapeseed meal (RSM) and dried distillers' grains with solubles (DDGS) are largely unknown during gestation, lactation, and the post-weaning period. To fill this gap and expand the database of feed ingredient values for sows, this study aimed to evaluate the available energy and nutrient utilization of DDGS, SBM, and RSM in sows across gestation, lactation, and the post-weaning period. A total of 24 multiparous sows (initial body weight: 286.58 ± 11.35 kg) were used across gestation (50 d), lactation, and the post-weaning period, using a randomized complete block design with 4 dietary treatments (basal, DDGS, SBM, and RSM), with 6 replicates per treatment. The basal diet was a corn-soybean meal basal diet, and the three test diets were formulated by replacing part of the basal diet with 30% DDGS, 20% soybean meal, or 20% rapeseed meal, respectively. The results showed that for DDGS, the digestible energy (DE) in multiparous sows during lactation was greater than that during gestation and the post-weaning period (P < 0.05). The apparent total tract digestibility (ATTD) of dry matter (DM), ether extract (EE), and gross energy (GE) during lactation was also greater than that during gestation (P < 0.05). For SBM, the DE and the ATTD of DM, crude protein (CP), and GE during gestation and the post-weaning period were greater than those during lactation (P < 0.05). Meanwhile, the ATTD of EE and organic matter (OM) during gestation was greater than that during lactation (P < 0.05). For RSM, the DE and the ATTD of OM and GE during lactation were greater than those during the post-weaning period (P < 0.05). Physiological stage significantly affected the available energy and nutrient digestibility of DDGS, SBM, and RSM in multiparous sows. Specifically, for DDGS and RSM, higher digestibility of DE and nutrients was observed during lactation, whereas for SBM, higher digestibility of nutrients and DE was observed during gestation and the post-weaning period. These findings highlight the importance of accounting for both physiological stage and feed ingredient characteristics when evaluating feed ingredients and formulating diets for multiparous sows.