Co-operative dairies are numerous.
With a further view to uniformity it has certain powers of supervision and control over local authorities, and can make by-laws respecting construction of local sewers, sanitary conveniences, offensive trades, slaughter-houses and dairies,, and prevention of nuisances outside the jurisdiction of local authorities.
In connexion with cheese dairies pigs are largely fed on sour whey thickened with mixed meal produced from any or all of the grains or pulses, the choice depending upon the market price.
During the last forty years of the 19th century dairy-farming was greatly developed in Denmark, and brought to a high degree of perfection by the application of scientific methods and the best machinery, as well as by the establishment of joint dairies.
A definite bacillus to which the peculiarly fine flavour of certain butters is due, is said to be largely employed in pure cultures in American dairies, and in Denmark certain butters are said to keep fresh much longer owing to the use of pure cultures and the treatment employed to suppress the forms which cause rancidity.