You are using the e-collar incorrectly. The shocks need to be very well timed to coincide exactly with when the indiscretion is initiated, not later when you happened to discover it and were pissed off. I would suggest that you lose the collar until you learn how to use it correctly. It's VERY easy to ruin a good dog with poor e-collar corrections.
The reason your dog growled at you is because it was already amped up from making a kill, then you shocked it out of nowhere, then scruffed it, and spanked it. No doubt the dog was confused and defensive and probably even afraid of you at that point. Nothing wrong with disciplining a dog, but it needs to be done properly and effectively and not out of anger.
Sorry but I disagree. I didn't shock her because I was pissed off that she had the bird. The bird was already dead. I shocked her because she refused to listen to ANY commands (sit, down, drop it).... All of which she knows. Instead she took off and tried to hide the bird. She was being corrected IN THE MOMENT when she was disobeying. And I didn't just go on a shock binge while pissed off. I didn't shock her more than twice. I WALKED up to her.... Mostly because you can't run in that area of the yard without losing a kneecap or spraining an ankle... Thanks to the moles and her digging everywhere.
Look, she's my dog. She is not and was not abused. I shocked her in the moment of her disobedience. She knew that she was doing something wrong. It was evident to her and everyone else who was there. I smacked her twice on the bottom in addition to the stern NO for her growling behavior. I feel there is NOTHING wrong with that response. In a dog pack, a superior dog would have bitten her or worse. She was disciplined. Not abused. You are entitled to your opinion but I've found that when it comes to dog training, many people have opinions. This post isn't about how I disciplined her but rather an explanation of the events that happened and looking for advice on how to TRAIN HER not to kill chickens. I even said in an earlier post that I am worried it may be too late to train her not to kill since she clearly killed and ate the Pullet last night.... But I'm still willing to try. She and my chickens deserve that much.