As with many symbols, the meaning of a cow in your dream can vary widely depending upon the context, but also depending upon the features of the cow that are emphasized in the dream. Cows are known for "chewing their cud", thus one possible meaning is the idea of mulling over something or continuing to bring something back up to "chew" on. Some cattle are more known for milk production while others are known for their beef, thus while a possible meaning relates to provision - in one case the meaning may refer to the "milk of the Word", while in the other it would be more likely to be "solid food".
* Symbol meanings provided by www.mydreamstories.com should not be used as a dream dictionary. They are for reference only and both dreamer and interpreter should be careful to listen to the voice of Holy Spirit as to what any particular symbol means in any specific dream.