Weird that the main source of this video bills himself as "GHGGuru Blog. Helping to establish environmentally benign livestock systems".
Which would suggest that livestock are not environmentally benign, which is also the commonly accepted answer.
In the video he claims going vegan would have no measurable impact, and yet his job creating "environmentally benign livestock systems" seems like it could only ever have less effect than that.
at around 18:21 in (https://youtu.be/sGG-A80Tl5g?t=1103), the author claims that since cows produce methane (CH4) from grass that was built by metabolizing rainwater and atmospheric CO2, and methane is subsequently washed out over the course of a decade by being broken down to H2O and CO2. True, but methane is still a potent GHG even though a less persisting one than CO2. You cannot just show that there's a chemical cycle going on and then claim there's no environmental effect; without cows' burps, there would be one less source of intermittent atmospheric methane. You'd need at least one more factor to demonstrate it's irrelevant (like it's only a tiny fraction of all methane sources, or if we were to live without that many cattle we'd inevitably produce other GHG to keep us from starving or somesuch).
Earlier in the video, it is claimed that the water footprint calculations one hears so often are calculated in a misleading way, since almost all of it is natural rainwater anyway, and secondly, it's almost completely urinated back onto the land within hours or a day anyway. I agree with that and want to add that I'm for this reason skeptical of many water footprint calculations. This site https://www.watercalculator.org/water-footprint-of-food-guid... seems to do a fairly good job at explaining the different water sources (surface, rain, tap) and detailing where the actual contention occurs. As far as cattle is concerned though, one thing the video glances over is that cow piss is not considered potable (though some cultures have been known to use it for disinfection and as a insect repellant). And while cattle and grassland is a natural thing with mutual benefits, the barren earth you see in those many, many hectares where tens of thousands of cows are corraled—that land does not look like it benefits from being incessantly being trampled on and 'fertilized'.
Which would suggest that livestock are not environmentally benign, which is also the commonly accepted answer.
In the video he claims going vegan would have no measurable impact, and yet his job creating "environmentally benign livestock systems" seems like it could only ever have less effect than that.