Effect of Dietary Neutral Detergent Fiber Intake on Improving Fecal Consistency in Gestating Gilts

Constipation is a common issue in sows, characterized by dry and hard feces or prolonged absence of defecation, which exerts adverse effects on the overall health and reproductive performance of sows. While dietary neutral detergent fiber (NDF), due to its physicochemical properties, can enhance satiety and promote gastrointestinal health. The present study aims to determine the effect of different dietary NDF intake levels on reducing constipation without impairing the reproductive capacity of gestating sows. A total of 110 primiparous crossbred gilts (Landrace × Yorkshire) were randomly assigned to five groups with different NDF levels of 19.28% (Group A), 21.36% (Group B), 22.08% (Group C), 22.67% (Group D), and 23.43% (Group E), respectively. The daily feed intake was adjusted across groups to ensure a gradual increase in NDF intake from Group A to Group E, while maintaining consistent intake of other nutrients. The results revealed that dietary higher NDF intake (Groups D and E) significantly reduced the rates of constipation and stereotypic behaviors in gilts (p < 0.05). The experiment lasted for two parities, starting from day 30 of the first parity gestation to the end of parturition in the second parity. During the second parity, all groups were fed the same diet, and only the reproductive performance of the sows was observed and recorded. Notably, NDF intake had no significant effect on gilts’ first-parity reproductive performance. This study confirms that an appropriate increase in dietary NDF intake can alleviate constipation in gilts. This finding provides critical, targeted references for optimizing nutritional strategies in primiparous gilt management, filling the void in tailored dietary guidelines for this understudied group and offering a practical solution to balance production efficiency and animal stress in commercial pig farming.