HELP! Steer pen

So I have a pen that is fully covered and with fans going. But with all the rain and it being slightly downhill it is getting so muddy. I have sandbags covered the side that the water drains down and it seems to help as well as trenches. But the bottom was dirt (now soupy mud) and we are thinking about clearing it and putting concrete covered in shavings. But I feel like it would still make him sore and we don't really have the money to buy the big matts. Does anyone have any ideas on how I can fix the problem of a muddy pen, or tips on if we do put concrete in it ? Also what are some inexpensive shavings that work well?

Sounds like you have a general drainage issue that probably needs addressed at the source.

1.  Bring in more dirt to raise the elevation of the bottom of the pen above your drainage ditches.
2.  Better drainage in general.
3.  Rain Gutters to take water to the low side of the structure
4.  Raise the "floor" of the entire covered area above the surrounding area so your pen and everything under the cover is an island.

I agree with GoWyo.  I had a similar problem in my 24x30 day pen.  A lot of rain last summer plus red east Texas clay and a white equaled a world of frustration.  When it dried out in September I did the following:
1.  Laid down a geotextile (heavy duty industrial weed paper) from Amazon.  Preventing my next layer from mixing with the clay.
2.  Hauled in 2 loads of SB2 rock and leveled
3.  used a vibrator plate to compact the rock
4.  laid down reclaimed astro turf from Craigslist (.25 per sq/ft for $300 total)
5.  put gutters on that end of the barn
Now it can come a flood and 5 minutes later you can be in the pen in tennis shoes setting up the calves.  You can wash them the night before a show and lock them in there and their as clean as they would have been if they stayed in the house that night.  I have pictures documenting how I did everything.  PM me if you want more details.  I also did all 3 of my 10x10 stalls and did a 10x10 section of the barn but graded the rock to drain outside and covered that with stall mats for a covered wash rack.  I looked at about every option to include concrete, asphalt, pavers and even some horse and driveway cells that you put pea gravel in.  This is the cheapest and cleanest option but you have to solve the drainage and elevation problem first.  Good luck. 

Okay thank you ! This was very helpful