Effect of straw enriched environment on behaviors of nursery piglets reared in the farrowing pens

The aim of the present study was to study the effects of straw enriched environment on behaviors of nursery piglets reared in the farrowing pens. Fourteen litters (Large White x Landrace) weaned at 35 days of age were reared in the modified farrowing pens, flatdecks (F) or straw enriched pens (P), until 70 days of age. The behavior was observed from 7 to 10 weeks of age. Results showed that straw enriched pens significantly increased walking, total exploring and active behavior, reduced lying and exploring behavior direct to pen, but not that direct to penmates. Meanwhile, in wk8-wk10, the number of fighting piglets in P was significantly more than that in F. With increasing age, piglets exploring in total or direct to pen, and active piglets decreased gradually in F. In P, piglets exploring in total or that direct to straw decreased, and reached a trough in wk9, then rose up. Lying piglets in F increased with age while that in P increased only at 9 or 10 weeks of age. Walking piglets decreased significantly with age in both environments. The number of fighting piglets in F was a maximum in wk7 while it in P was fewer in wk7 or wk8. Furthermore, the activity of piglets in F was at peak during 08:00-10:00 hr and reached a trough during 11:00-13:00 hr. In P, refreshed straw kept piglets at a more active state during morning, shortened the activities trough at noon, and showed high activity in the afternoon. In conclusion, present straw enriched pen can prevent fighting, increase total exploring, reduce exploring direct to pen, and even affect the rhythm of behavior. It is applicable for improving welfare of nursery piglets.