My ducks are like 4 1/2-5 weeks and I have given them bird grit (the smaller stuff from the pet store) as they do eat grass and stuff along with their grower crumbles. I noticed the Buff's crop looked bigger than the others is this normal? I gave them regular grit and they are some. I lost a chicken to sour impacted crop so I'm scared her's may be. Does it look normal to you for this time of the day? Maybe it was like this before and I didn't notice it.