Bava Kamma 58: Chasing Away a Lion; Valuing Damaged Property

The rabbis continue their conversation about damages paid when an animal falls into another person's garden.  Generally speaking, damages are paid for the benefit that the animal gains - the actual produce that is consumed by the animal.

To examine this further, the rabbis question why the animal fell, and whether or not that should influence the damages paid.  Examples refer to the case of "chasing away a lion".  In this scenario, a person distracts a lion from attacking another person's flock of sheep.  That person is not offered a reward because s/he has performed a mitzvah which is rewarded in the world to come.  Similarly, if an animal falls into a garden, are the vegetables that cushion its fall just like the person who chases away the lion?  Why should damages be paid for that 'mitzvah'?  

The rabbis also consider the example of an animal that falls into another person's garden and then gives birth.  If its amniotic fluid causes damage to the field, will those damages be covered?

The rabbis also consider animals who enter and damage a larger field.  How do we know that they are assessed based on the difference in value of the land before and after the damage has been caused?  The rabbis find proof texts that teach that one part is valued as sixty parts.  Thus if an animal damages one stalk of produce, that stalk is valued at the cost of sixty stalks of produce.  We see the example of a man who cuts down a date palm where that tree was one of three stalks growing from the same stalk.