Diarrhea in stockers

[rockroadseminole]

I've been feeding a pelletized feed from FRM for about 16 days. I started around 8# per day and am up to 12# per day. The cattle have access to pasture that's still green, but backing off in a hurry. The steers were around 550 on the low end and 625 on the high end prior to first feeding. Have been straightened out for about 100 days.
About 80% are blowing up and looking great. 10% are coming along but I suspect may be the bottom end and were behind to start.
The remaining 10% is where I need some help. They look terrible. Seem to be losing weight. Diarrhea seems to be a major contributor. I don't have any hay out. I thought they would get their roughage from the pasture. I had in mind them eating the grass down to help with my ryegrass planting next month.
Any help is appreciated.

 

[Hpacres440p]

Maybe check fecals on the bottom 10% for parasites or coccidia? Are they a mixed batch or from same source? Are the poor ones youngest or mixed?

 

[rockroadseminole]

Mixed. We put them together this summer. They were dewormed for a second time on 08/22 with pour on and oral drench. That was longer ago than I thought after referencing my notes. The thing that has me confused is they looked behind, but not bad prior to starting feed.

 

[Bigfoot]

I'd suspect cocidiosis

 

[Lucky_P]

Coccidiosis at top of my rule-out list.

 

[sandraeric]

I also think its Coccidiosis.

 

[Katchy]

I could be the parasites or coccidio or altogether something different. And there's also a possibility that it has nothing to do with the feed. There could be some other issue ailing the remaining 10%. Are these 10% huddled together ?