The Shechitah Process

Animal and Knife Positions

1. Shechitah for birds may be done by holding the bird down and cutting by moving the knife or temporarily fastening the knife upwards or downwards and passing the bird's neck along the blade. This may not be done for animals, though, for fear of Derasa by the weight of the animal. Moreover, in order to avoid future pitfalls, there is a rabbinic decree prohibiting any animal meat shechted in this manner despite the shochet's claim that he did not violate Derasa. Some argue that holding the knife steady from below and passing the animal neck along the knife from above has the same status. On top of that, some are further concerned that shechting from below when the animal is stationary is also problematic, unless the animal's head is tied upwards. If it's standing freely or lying down, that could be an issue even Bediavad. Therefore, some argue that ideally one should only shecht the animalwhen it is lying down with the neck below or to the side of the knife and stationary as the knife moves. Alternatively, the head can be tied and pulled upwards.
2. In this context, all birds are considered the same and all animals (Behemot Gasot and Dakot and Chayot) are considered the same. There is no distinction by species.

Credibility & Dispute

1. If a dispute arises between the shochet and others regarding the kashrut of a shechita he did/they witnessed, there is much debate about the kashrut of the meat, depending on the circumstances, such as what the Shochet claims the issues were, if he made any excuses or made any marks on the animal, etc.