Abstract
In this study we investigated the effects of feeding method on growth performance and spatial preference within the home-cages (HC) of young pigs. Pigs (n = 41 boars) were weaned at postnatal day (PND) 2, allotted to treatment controlling for litter and body weight (BW), and reared artificially over a 15-d period. Pigs were provided a nutritionally adequate milk replacer 20-h per day, dispensed in one of two ways: 1) ad libitum (continual access to milk replacer), and 2) prescribed [330 mL/kg of BW from PND 3-7 (week 1), and 357.5 mL/kg of BW from PND 8-18 (week 2)]. In addition to water in the reconstituted milk replacer, free choice access to water was provided throughout the study. Milk intake (i.e., disappearance) and BW were recorded daily, with pigs undergoing continuous video surveillance throughout the study. Video analysis of pigs (n = 6) was performed to establish time spent in each HC quadrant (Table 1). All data were analyzed via a 2-way ANOVA (feeding style vs. home-cage quadrant) using the MIXED procedure of SAS. During week 1, pigs in the ad libitum treatment had increased (P < 0.05) average daily gain (219 g/d) and average daily milk intake (1,014 g/d) compared with the prescribed treatment (183 g/d and 794 g/d, respectively). This same effect continued in week 2 for average daily milk intake, with ad libitum-fed pigs consuming more (P < 0.05) milk replacer (780 g/d) compared with prescribed-fed pigs (614 g/d). Ad libitum-fed pigs exhibited better (P < 0.05) feed efficiency [i.e., reduced G:F ratio (0.22 and 0.19, respectively)] compared with prescribed-fed pigs (0.24 and 0.21, respectively) during both weeks 1 and 2. Over the entire 15-d feeding study, average daily gain (253 g/d) and milk intake-to-BW ratio (0.59) were greater (P < 0.05) in the ad libitum treatment compared with prescribed feeding (206 g/d and 0.52, respectively). Video analysis of spatial preference within HC suggested pigs spent more (P = 0.08) time in quadrants 2 and 4 (33.6% and 35.5% of time recorded, respectively), likely due to proximity to the feeding bowl, compared with quadrant 3 (8.7% of time recorded) but this effect did not differ (P = 0.50) by feeding method. Overall, type of feeding style altered growth performance within young pigs and may impact the spatial preference of pigs within their home-cage environment.
