Abstract: This study aimed to assess the effects of dietary supplementation of alfalfa straw and enzyme preparation on ethology and reproductive performance of sows, and to explore the feeding technique that can reduce the incidence of abnormal behavior and improve reproductive performance of sows. A total of 45 multiparous binary hybrid sows with similar mating time, parities and physical condition were randomly assigned into the following 3 groups: the experimental groupⅠ(n=15) was fed with a supplementary diet of alfalfa straw pulping of 2 kg per head per day after the concentrate feeding; the experimental groupⅡ(n=15) received the supplementation of alfalfa straw powder of 0. 5 kg per head per day in basal diet; both of the experimental groups received an addition of a commercially available enzyme preparation ('Youlimei') of 1 kg/t in their basal diet; the control group (n=15) was fed with a basal diet without addition of alfalfa straw and enzyme preparation. The experimental period lasted for 4 months. During the whole experiment, the incidence of stereotypic behavior and constipation of the sows in different groups was observed and recorded, and the indicators associated with reproductive performance were determined. The results showed that in the every single observed months of the whole experimental period, the incidence of stereotypic behavior and constipation of the sows in experimental groupⅠand Ⅱ was significantly (P<0. 05) decreased compared to that in control group; while the experimental groupⅠhad lower incidence of stereotypic behavior and constipation compared to the experimental group Ⅱ, no significant difference was observed (P>0. 05); significantly (P<0. 05) elevated average live litter size and within-litter birth weight of piglets as well as significantly (P<0. 05) shortened inter oestrual period of sows were observed in experimental groupⅠand Ⅱ compared to the control group, respectively; there were no significant differences in reproductive performance indicators between experimental groupⅠand Ⅱ (P>0. 05). The combined data suggest that dietary supplementation of alfalfa straw pulping (2 kg per head per day) or straw powder (0. 5 kg per head per day) simultaneously with enzyme preparation (1 kg/t) can significantly decrease the incidence of stereotypic behavior and constipation of the sows, and can significantly improve their reproductive performance.

Key words: alfalfa straw pulping, alfalfa straw powder, enzyme preparation, sows, ethology, reproductive performance