Increase hay, reduce grain, and feed no silage. Allow the animal to exercise and graze if possible. If recently fresh, consider supplemental calcium, either IV or as an oral paste. Infertility in cows is a constant source of consternation. Icelandic kelp added to the ration provides some 54 vitamins, minerals and micro-nutrients, which can stimulate a cow's level of health and should be considered especially when reproductive performance is lagging.
Many conditions also respond well to homeopathic intervention.
All cows should be given Sepia at 21 days after calving to promote a healthy reproductive state. Cows with a creamy discharge can be given Pulsatilla, followed by Sepia. Cows not cycling, yet having normal ovarian structures, can be nudged into heat with Ovarian. A herdsperson must look for the slightest hints of heat when using natural treatments. For example, a cow not letting her milk down quite right on the expected day of heat should probably be bred, even though not obviously standing to be mounted.