PSXI-13 Growth and Onset of Puberty in Replacement Gilts Fed on Ad Libitum Or Restricted Bases Using an Electronic Sow Feeder

Abstract

Abstract Replacement gilts are typically fed on an ad libitum basis until approximately 135 kg BW at approximately 200 d of age and are bred between 135 and 160 kg BW during their second estrus. The shift to group-housing of the breeding herd makes it difficult to manage animals individually. Thus, utilization of an electronic sow feeder (ESF) enables caretakers to manage animals individually in group-housing situations, by allotting predetermined amounts of feed. The objective was to determine the effect of feeding level on growth and sexual development in gilts. Crossbred gilts, assumed prepubertal, were moved at 150 d of age to an open pen measuring 44.3 m2 located in a curtain-sided building with partially slatted concrete floors and an ESF (ACCUTEAM, Osborne Industries, Osborne, KS). Gilts were acclimated to the ESF during a 10-d period, during which they received feed on an ad libitum basis. At 160 d of age, gilts were randomly assigned to receive feed on either an ad libitum (AD, n = 18) or restricted (2.73 kg/d; RS, n = 19) basis. Estrus detection was performed for 42 d. Feeding level had no effect on age at puberty (P = 0.23). The pubertal estrus length was similar between treatments (P = 0.23); however, AD gilts exhibited a longer second estrus period (P = 0.05) compared with RS gilts (37.6 vs 30.8 h, SE = 3.6). Estrous cycle length was not affected (P = 0.72) by feeding level. There were no effects of feeding level (P = 0.36) or feeding level x day (P = 0.53) on BW; however, there was an effect of day (P < 0.01), indicative of growing gilts. Feed disappearance was affected by feeding level (P < 0.01, 4.25 vs. 2.68 kg/d, SE = 0.05 for AD and RS, respectively), day (P < 0.01) and feeding level x day (P < 0.01). Total station visits were affected by feeding level x day (P = 0.05). Non-feeding visits were affected by feeding level (P < 0.01, 1.0 vs. 3.7, SE = 0.22) and day (P < 0.01) but not feeding level x day (P = 0.20). Feeding visits were affected by feeding level x day (P < 0.01). Data were then normalized to the 20-d period before second estrus. Feed disappearance was affected by feeding level x day (P < 0.01), with feed disappearance decreasing in AD, but not RS, gilts as they approached estrus. During this 20-d period, BW was affected by feeding level x day (P < 0.01), with AD gilts having improved growth compared with RS gilts. In this study, feeding level did not affect age at puberty; however, utilizing an ESF may augment current estrus detection methods by monitoring feeding behavior.