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Effect of feeding system (dry vs liquid) on the behavior of wean to finish pigs
A study was undertaken to compare the behavior of wean to finish pigs that have been acclimatized to liquid and dry feeding systems. Randomly selected pigs ((n=192; Yorkshire X Large White) x Duroc); 100 ± 4 d of age) of both sexes (barows and females), were housed in groups of 8 each (12 replicates) and fed two dietary treatments (liquid and dry). Four pigs from each pen were randomly selected as focal pigs for behavioral observations. The pigs on liquid feed were fed equal meals, six times daily (liquid feeding system (Big Dutchman Pig Equipment, Vechta, Germany), whereas those on dry feed were fed ad libitum from single space feeders. Water was available for all pigs ad libitum. A time lapse video recording system (Nuvico AI1600) was used to record the behavior of the focal pigs over a period of 3 hours in the morning (8-11 am) and 3 hours in the afternoon (1-4pm) for 2 days/ week, for 2days/week, for two months. The recordings were analyzed using the Noldus Observer XT version 11.5, and data analyzed using the GLM procedure of SAS version 9.3. The data were arcsine square root transformed. Comparisons were made between the sexes, feeding systems and periods of the day. None of the behavior variables were affected by sex. The major behavior categories identified (based on % time spent) were standing (5.97 ± 1.5%), resting (51.93 ± 2.4%), locomotion (8.51 ± 1.32%), feeding (9.39 ± 1.23%), drinking (1.95 ± 0.52%), exploring the pen (11.65 ± 1.46%), agonistic behaviors (3.63 ± 0.83%), and comfort behaviors (7.35 ± 1.73%). The total activity times were not significantly different in the two systems. The pigs were significantly more active in the morning (P<0.01) than afternoon, while agonistic (P<0.001) and comfort behaviors (P<0.001) were significantly more in the afternoon. The pigs on liquid feed were found to spend significantly more time resting (P<0.05), doing agonistic activities (P=0.05), and exploring the pen (P=0.001). Pigs on dry feed spent significantly more time standing (P<0.01), and showed significantly more locomotory (P<0.05) activities in the morning when compared those on liquid feeding system. Time spent on agonistic behaviors was significantly more in liquid feeding system as the pigs have to compete for feed at the time it is dropped. In conclusion, the feed restriction in liquid feeding system affected the behavior pattern of wean to finish pigs.
Keywords: liquid feed; dry feed; pigs; behavior