[1] The breed was developed from the native landrace of pigs of the area, crossbred with strains from neighboring counties.
[1] The breed is unusually responsive to the halothane test, which can be used to weed out individuals with low projected survivability and meat production.
Yorkshire) and 1/4 Dutch Landrace mix, developed with "great stress on production detail", by the following breeding formula: Large White boar × (Large White boar × Dutch Landrace) sow.
[1] A 1978 study showed that Dutch Landrace pigs are especially responsive – compared, for example, to the Dutch Yorkshire crossbreed – to the halothane-induced malignant hyperthermia test (halothane test, for short), which can be used to weed out specimens with high susceptibility to stress and likely abnormal meat quality.
[4] Halothene-reactive castrated males, as opposed to un-modified boars, differed from non-reactive in "all carcass and meat quality traits", and had "significantly lower feed conversion ratios".