Physical castration is a current practice on commercial farms used to reduce boar taint and aggressive behavior. Immunological castration (IC) using a GnRF conjugate is an alternative to physical castration. IC males eat more, grow faster and are easier to handle than intact males. The objective of this study was to evaluate the effect of IC on gilt behavior, handling during loading and unloading, weight gain, reproductive function, and physiological responses. Gilts were given a first immunization at wk 3 of the finishing period (about 12 weeks of age) followed by a second immunization at wk 7 of the finishing period. Gilts were marketed when they were 143.6 kg on average. Behaviors of immunized gilts (IG) (n = 48) and control gilts (CG) (n = 48) were assessed 2 times through the finishing period, one before (second week of grower-finisher phase) and one after effective immunization (eleventh week of grower-finisher phase). Handling during loading and unloading a livestock trailer was also recorded during a simulated transport experience. Weight gain was assessed weekly. Physiological response was assessed via heart rate, plasma cortisol and ovarian weights. IG spent more time feeding (4.17%) (P = 0.04) than CG (3.43%). However, CG spent 1.41% more time standing (P = 0.002) and 0.17% more time drinking (P = 0.01) than IG. No difference was found in transport and handling measures between treatments. At the last week of grower-finisher phase IC were 5.15 kg heavier than CG (P = 0.04). Control gilts had 225% heavier ovaries than IG (P < 0.001). No differences were found in plasma cortisol and heart rate between CG and IG. Immunological castration does not induce a stress response or cause behavioral problems in the home pen or during handling and transport compared with intact gilts. IC is an effective tool to increased gilt feeding behavior, feed intake, and weight gain with no identified animal welfare concerns.