The Dutch Landrace pig ( nl, Nederlands Landras) is a standardized breed of

domestic pig The pig (''Sus domesticus''), often called swine, hog, or domestic pig when distinguishing from other members of the genus '' Sus'', is an omnivorous, domesticated, even-toed, hoofed mammal. It is variously considered a subspecies of ''Sus ...

originating in the

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. The breed was developed from the native

landrace A landrace is a domesticated, locally adapted, often traditional variety of a species of animal or plant that has developed over time, through adaptation to its natural and cultural environment of agriculture and pastoralism, and due to isolatio ...

of pigs of the area, crossbred with strains from neighboring counties. The Dutch Landrace is considered "a meaty and efficient breed". The breed is unusually responsive to the halothane test, which can be used to weed out individuals with low projected survivability and meat production.

Populations

The Dutch Landrace is found mostly in the south, east and north of the Netherlands. The Centraal Bureau Voor de Varkensfokkerij ('Central Bureau for Pig-breeding'), in Nijmegen, serves as the

breed registry A breed registry, also known as a herdbook, studbook or register, in animal husbandry and the hobby of animal fancy, is an official list of animals within a specific breed whose parents are known. Animals are usually registered by their breeder ...

. The breed is exported, especially to

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and Japan.

Traits

Dutch Landrace pigs are similar to those of the other "Landrace"-named breeds of Europe. They are white, and have large, drooping ears. However, they are wider-backed and have heavier hams than some other Landrace strains. These latter two traits are stronger in individuals that are heterozygous for the halothane-responsive gene . The breed has high fertitility and strong maternal abilities. At four test stations throughout the Netherlands, the Centraal Bureau tests over 1,000 Dutch Landrace litters per year, for conformation ("desirable carcass characteristics"), and for the rate and meat-to-fat ratio (''economy'') of their weight gain.

Breeding and crossbreeding

Whether a boar can be used as a

stud Stud may refer to the following terms: Animals * Stud (animal), an animal retained for breeding ** Stud farm, a property where livestock are bred Arts and entertainment * Stud (band), a British progressive rock group * The Stud (bar), a gay ba ...

for

artificial insemination Artificial insemination is the deliberate introduction of sperm into a female's cervix or uterine cavity for the purpose of achieving a pregnancy through in vivo fertilization by means other than sexual intercourse. It is a fertility treatment ...

is controlled by the Centraal Bureau, through testing of progeny, boar sire performance, and conformation. The Dutch strain of the "Landrace" pig breeds originated, as its name suggests, from the native

of pigs in the Netherlands, plus controlled

crossbreed A crossbreed is an organism with purebred parents of two different breeds, varieties, or populations. ''Crossbreeding'', sometimes called "designer crossbreeding", is the process of breeding such an organism, While crossbreeding is used to mai ...

ing with German Landrace and Danish Landrace pigs.

Dutch Yorkshire pig

Dutch Landrace sows are the bulk of the female stock for a standardized three-way cross, the Dutch Yorkshire pig, a 3/4 Large White (a.k.a. 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.

Responsiveness to the halothane test

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. Dutch Landraces are responsive 22% of the time (vs. 3% for Dutch Yorkshires), and those responsive to the test are almost ten times likelier to die during the fattening period than responsive Dutch Yorkshires. Two 1980 follow-up studies by the same team of researchers found that the Dutch Landrace's susceptibility is inherited as "a single recessive autosomal trait", and " e gene for this trait affects production traits", including carcass and meat quality. Three

genotypes The genotype of an organism is its complete set of genetic material. Genotype can also be used to refer to the alleles or variants an individual carries in a particular gene or genetic location. The number of alleles an individual can have in a ...

(genetic strains) have been identified in the breed:

Heterozygous Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism. Mo ...

for (carrying but not expressing) the gene, and

homozygous Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism. Mo ...

either for (expressing) the gene, or not possessing it at all. The heterozygous has an intermediate carcass and meat quality and a

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advantage. The homozygous for reactivity to halothane had lowest meat quality, though highest meat production of the three genotypes, and as noted in the first study, its high reactivity level can be used for screening. It also has the lowest percentage loss at slaughter. 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". Halothene reactivity seems to be more

heritable Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic informa ...

from the sire than the dam; in a population with an average 24.9% of individuals being reactive, 40.7% of those with reacting sires were themselves reactive, vs. 21.3% without.

References