Goa'uld shield

The Goa´Uld were one of the few races to possessed shield Technology, although isn´t as powerfull as the shield of other races like Asgard or Ancient.

Is possible the shield that the Goa´Uld possesses are derived from Old Ancient Technology that the Ancients left in the Milky Way Galaxy.

The Goa´Uld, use shield Technology for personal defense and in their ships.

Goa´Uld Personal Defense Shield:
Many Goa´Uld, including Osiris, Cronus and Apophis, use a personal shield activated via Kara Kesh for self-defense. This shield are directly proportional to the amount of kinetic energy used, making them capable of whithstanding fire from Staff Weapons, Zats and P90, but ineffective against arrows or throwed knifes ("The Nox" "Secrets" "Double Jeopardy" "The Curse" "Chimera").

Goa´Uld Field Generator:
Another possibility is use a bigger shield to cover a field. That kind of Shield requires more energy, but is not directly proportional to the amount of kinetic energy used. It has been used by Hathor and Aris Boch ("Into the Fire" "Deadman Switch").

Goa´Uld Solar Radiation Shield:
This is a kind of shield that protects from the radiation and covers a great area ("The First Commandment").

Ships:
Firstly, the Death Gliders and the Tel´Tak are no-shielded, and the Al´Kesh and Ha´Tak the only ones that possesses shield. After, the Tel´Tak has been upgraded with shield.

Tel´Tak:
The shield of a Tel´Tak is the weakest, being capable of withstand 5 shots of another Tel´Tak and less than two shots from an Anubis-Upgraded Ha´Tak.

Al´Kesh:
The Al´Kesh has weak shield, going depleted for only 2 missiles of an F-302 ("Lost City, Part 2").

Ha´Tak:
Being the main attack ship in the Goa´Uld empire, The Ha´Ra ships are equiped with the second most powerfull shield the Goa´Uld possesses. The shield are capable of withstanding 12 shots of another Ha´Tak, 6 shots from an Anubis Upgraded Ha´Tak and only three from an Replicator-Upgraded Ha´Tak. In Adition, are capable of withstanding the radiation in the corona of a blue giant star for 9 hours ("Reckoning, Part 1" "Flesh and Blood" "Enemies" "Company of Thieves")

These shield are penetrated by Asgard Transporters,, Asgar Ion Guns for the Biliskirmir-Class ships, Tollan Ion Cannons and even Drones from a Gateship with easy.

A shielded Ha´Tak is easily destroyed by the main weapon of an Ori Mothership ("Camelot")

Ancient-Derived Goa´Uld Shields:
When Anubis ascends, he got on much more knowedge that he has before. With that knowedge, Anubis upgraded de Shields of his Ha´Tak and his Mothership.

Anubis Ha´Tak:
The power of theses shield can equate with a Bilskirmir-Class, and is capable of withstanding 24 shots of another Anubis-Upgraded Ha´Tak ("Off the Grid").