He was a white pig, and was always kept very clean.

Mr.Wood said that it is wrong to keep pigs dirty.

They like to be clean as well as other animals, and if they were kept so, human beings would not get so many diseases from eating their flesh.
The cow, poor unhappy creature, never, as long as she lived on Dingley Farm, lost a strange melancholy look from her eyes.

I have heard it said that animals forget past unhappiness, and perhaps some of them do.

I know that I have never forgotten my one miserable year with Jenkins, and I have been a sober, thoughtful dog in consequence of it, and not playful like some dogs who have never known what it is to be really unhappy.
It always seemed to me that the Englishman's cow was thinking of her poor dead calf, starved to death by her cruel master.