Chapter 1. Introduction
Utilisation and conservation of farm animal genetic resources 17
3.2. Sheep
In countries with high input livestock systems in Europe, North America and Australia the number of sheep has declined in recent years. Sheep wool now has a lower economic
value, and this is a threat to some breeds. In North and West Europe the future use of this species seems to be nature management. his ofers a great opportunity for
in vivo conservation programmes, because large locks are required for this purpose, which is
attractive for conservation. In small scale farming systems and the semi-intense systems in Africa, Asia and East and South Europe sheep are still important for meat or milk
production. In some religions sheep have a ceremonial function. hese functions guarantee continued utilisation of the species. In general natural mating systems are
applied in sheep breeding. Artiicial reproduction techniques are developed, but only in a few countries they are used as a routine for example in sire reference schemes to
improve breeding value estimates.
3.3. Goats
he goat’s importance in small scale farming systems for milk and meat production, its stable numbers and the wide variety of conditions under which goats can be kept are
guarantees of continued utilisation. his species is not faced with real threats. In general natural mating systems are applied in goat breeding. Artiicial reproduction techniques
are developed, but only applied experimentally.
3.4. Pigs
In Europe, North America and Australia pork production is dominated by a few multinational companies. In the concentration of the breeding industry, continuously
many breeds and lines become uneconomic for market driven food production. In a number of regions including Europe, Africa and North America, relatively few local pig
breeds exist. Conversely, in East Asia many local pig breeds can be found. he speed of industrialisation and specialisation, in combination with the lack of opportunities
for the
in vivo conservation of pigs means that this species requires special attention in national and regional conservation programmes. Frozen semen is used for the
dissemination of genetic improvement and frozen semen and frozen embryos are used for exchange of genetic material within the companies between their populations
present in diferent countries.
Kor Oldenbroek
18 Utilisation and conservation of farm animal genetic resources
3.5. Chickens
he breeding and production of this species is the most specialised and industrialised of all animal species. It is showing similarities with plant breeding and production. At
a global level only a very few multinationals are active selling highly specialised hybrid layers and broilers. he number of chickens increases very fast at the global level, mainly
due to active marketing by the layer and poultry industry. In developing countries the substantial role of chickens in small-scale farming, and the preference of local people
for meat from local chicken breeds will stimulate the use of these local breeds in the future. In the developed world many people keep chickens as a hobby, which maybe an
opportunity for conservation. Artiicial reproduction techniques are well developed, but cryoconservation of embryos or primordial germ cells still has to be developed.
3.6. Horses
In the past, horses were mainly used for draught and transport. he onset of the mechanisation in transportation and later on in agriculture has meant that in many parts
of the world horses are bred almost entirely for hobby and sport purposes. It develops itself as an industry in which hobbyists play an important role. he large variety in
purposes may stimulate the maintenance of a wide genetic diversity within the species. However, in general, the genetic diversity within horse breeds is threatened by the wide
use of a few popular stallions. he “heavy” breeds, originally bred for draught purposes, are threatened. In some countries they are still kept for meat production. Artiicial
reproduction techniques including cloning and cryoconservation techniques are very well developed in this species, facilitating conservation.
3.7. The threat of genetic erosion
From the former subsections it can be concluded that the threat of genetic erosion difers between the species. At the global level the threats are of little importance in goats and
most severe in pigs. In pigs, chicken and cattle only a few breeds or lines are developed towards high-output breeds itting in high-input systems. In this process many breeds
are set aside from the food producing livestock systems. hese breeds will be faced with extinction unless new functions for these breeds are found. his is a real threat for the
genetic diversity within species. In farm animal species a substantial amount of genetic diversity exists within the breeds chapter 3. In commercial populations of cattle, pigs
and chicken this diversity may be threatened by applying high selection intensities.