https://i.ibb.co/806rGX4/D80-A383-D-EA76-416-D-919-F-EFBFC778279-E.jpg

https://i.ibb.co/TbRJ9M4/E971-CD91-DFD5-4-A7-F-BFF8-B8503-D0-C5-F2-E.png

https://i.ibb.co/rbv4Gb2/F60-C6-DDC-BEBF-4-D36-BF98-36-DB213-CC4-C5.jpg

https://i.ibb.co/b6PRpwX/4-B43522-B-DA9-A-4-D96-B40-D-D9-A4-A3404-A16.jpg

https://i.ibb.co/fN3QX2F/F6-F70-EF7-9-FCA-4-E79-946-D-854-F2-AE180-F9.jpg

https://i.ibb.co/L6m549L/5-E0-EDA3-C-6-BEF-4-D50-BCA3-00-DB87-E81718.png

https://i.ibb.co/4FDV4Vx/5146-D5-B6-7-F6-D-4-B6-D-B97-D-0054-A50-DA7-EC.png

https://i.ibb.co/X8WQXT2/973-FACF6-924-E-4-C1-D-A832-B7-C984-AB0275.jpg

https://i.ibb.co/mH2k94C/90-B9310-C-96-D4-41-B5-9463-1-C1-A8-DB757-BE.jpg

https://i.ibb.co/YjSY5sr/4678-A2-BA-FD08-437-F-9-A63-E71733953-C0-F.jpg

https://i.ibb.co/FB2zLyX/63-BC1-BDB-4-CB3-49-F9-BAB0-F37-D1031807-B.png

https://i.ibb.co/mF4cp8Y/3030-B230-E83-D-4-D75-9-BBB-911-E14-DD4082.png

https://i.ibb.co/JCyC7rx/A43-F9-B81-8973-4-B22-BCE7-7-BC2-A594262-F.png

Your grounding, from what I can see needs some work as well as your lighting

The first one especially needs some grounding work, some shadows on the hoofs/lower leg

Try some of these tutorials

https://horseeden.com/forums.php?f=17&t=14436