What are the causes of poor milk production in cattle?

It is primarily due to either genetics or nutritional factors. Low feed quality or poor feed is quite often the primary reason that a cow is not producing adequate milk. But genetics also plays a big role. A cow with poor milking ability will produce less milk than a cow with good milking ability.

Stress is also a concern. If a cow is stressed from heat, cold, pain from an injury or illness/disease, discomfort or fear, she will produce less milk than a cow that is comfortable, relaxed and experiences no pain of any kind.