My cow is just lying down and it has given birth to a calf one day ago

Milk fever is the first thing to suspect here. A cow that goes down within a day after calving often has low calcium. Keep her chest-down on her sternum, not flat on one side. Give her a soft dry bed, keep the calf away for now, and do not force her to stand. If she is alert, offer clean water and a little jaggery water. Check her ears and legs; if they are cold and she is weak, this is urgent. She needs a calcium injection from a vet today. If she is bloated, breathing hard, or cannot lift her head, treat it as an emergency and arrange help at once. This can turn fatal within hours, but quick treatment usually saves the cow and protects the milk income. Book a Pashu Vet on Pashushala now, or call one nine six two if you need immediate field help.