In human history to date, only a few species of large animal have been domesticated. In approximate order of their earliest domestication these are: dog, sheep, goat, pig, ox, yak, reindeer, water buffalo, horse, donkey, llama, alpaca, Bactrian camel and Arabian camel.
For instance at sea level and standard weather (29.9 Hg) a gauge vacuum of -25.9 Hg is equivalent to an absolute pressure of 4 Hg. In other words, the vacuum gauges that read, for example, -25.9 Hg at full vacuum is actually reporting 4 Hg, or 136 mbar. That is still in the low vacuum range.
Absolute pressure: The total pressure exerted on a system referenced to zero Pascals, and equal to the gauge pressure plus atmospheric pressure. Gauge Pressure: Pressure referenced to one atmosphere, and is the pressure actually shown on the dial of a gauge that registers pressure relative to atmospheric pressure.