Effects of the number of animals per automated feeder and length and time of access on feed intake, growth performance, and behavior of yearling Boer goat wethers

- Meat goats were given different periods of access to automated feeding units.
- Environmental and social conditions affect behavior in confinement.
- Restricting feeder access can limit growth but improve efficiency of feed usage.
- Both aggressive and feeding behaviors impact level and efficiency of production.

Effects of the number of Boer goat wethers with initial age of 285 days (SEM = 5.1) and 34.4 kg body weight (SEM = 0.90 kg) per automated feeder and length and time of feeder access on feed intake, growth performance, and behavior were determined in a 10-wk experiment. Treatments were 6 and 12 wethers per 6 × 6 m pen and feeder with continuous access (Cont-6 and Cont-12, respectively); 2 and 4 wethers per feeder with 8 h/day access during daytime (Day-2 and Day-4, respectively); and 4 and 8 wethers per feeder with 16 h/day access at night (Night-4 and Night-8, respectively). Therefore, maximal potential feeder occupancy time per wether was 2 or 4 h/day. Dry matter intake was greater for continuous vs. restricted feeder access (P = 0.001) and for night vs. daytime access (P = 0.025) (2.04, 2.01, 1.45, 1.50, 1.92, and 1.76 kg/day), and feeder occupancy time per wether tended (P = 0.071) to be greater for continuous access (1.83, 1.55, 1.23, 1.34, 1.51, and 1.25 h/day for Cont-6, Cont-12, Day-2, Day-4, Night-4, and Night-8, respectively). Rate of dry matter intake (DMI) was similar among treatments. There were effects of continuous vs. restricted (P = 0.012) and day vs. night (P = 0.051) access on average daily gain (ADG), as well as a tendency (P = 0.078) for an interaction between time and length of restricted access (237, 252, 174, 207, 247, and 211 g for Cont-6, Cont-12, Day-2, Day-4, Night-4, and Night-8, respectively). The ratio of ADG:DMI was not affected by treatment other than a tendency for an interaction (P = 0.070) between time and length of restricted access (116, 126, 120, 138, 130, and 121 g/kg), although residual feed intake (RFI) was greater (P < 0.001) for continuous vs. restricted access (49, −25, −167, −257, −81, and −112 g for Cont-6, Cont-12, Day-2, Day-4, Night-4, and Night-8, respectively). In summary, continuous feeder access allowed high ADG, but resulted in relatively inefficient feed utilization as assessed by RFI. Restricting feeder access to daytime minimized DMI compared with continuous access, which was due to factors other than feeder occupancy time and rate of DMI; however, efficiency of feed utilization for daytime access based on RFI, particularly for Day-4, was high relative to continuous access. In conclusion, restricting feeder access influenced feed intake, growth performance, and behavior, with results impacted by time of access.