low conf. because not much time to resch: may a/the nucleus population of the breed

http://www.fao.org/docrep/006/t0665e/T0665E10.htm

Livestock Production Science : Impact of biotechnology on (cross ...
It is generally believed that for pig breeding, there is no or little effect of the application of cloning on the rate of progress in the nucleus population ...
linkinghub.elsevier.com/retrieve/pii/S0301622699001803

thepig
Pig breeders from all over the country bring their animals in to the central ... Selection of pigs at both the nucleus and multiplication stages is based on ...
agtr.ilri.cgiar.org/Casestudy/dzama/thepig.htm

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Note added at 1 hr (2007-12-03 20:11:54 GMT)
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Genetic evaluation scheme in Zimbabwe

In Zimbabwe the Pig Industry Board (PIB) has the mandate for genetic evaluation of pigs. This is done in two ways;

1. nucleus testing which is done centrally at the PIB station in Arcturus 30 km east of Harare; and

2. multiplication testing which is done on farm.

In both the nucleus and multiplication tests, animals are evaluated based on their own performance. Progeny testing was once a component of the nucleus test but was stopped in the early 1980s. The board at that time viewed it as an expensive methodology, which also took a long time to yield results. The current nucleus test evaluates two traits namely - backfat thickness and feed conversion efficiency (FCE) while the multiplication test evaluates growth rate and backfat thickness.
Nucleus testing

This is conducted at the PIB station in Arcturus. Pig breeders from all over the country bring their animals in to the central station at the PIB for testing. This system necessitates the bringing together of animals from different sources, which is contrary to the basic principles of disease control. To reduce the risk of spreading diseases the animals are quarantined for three weeks at the PIB quarantine station before being moved into the main station. While the animals are in quarantine, a veterinarian inspects them on a weekly basis. Any animal that dies in the station is sent to the veterinary laboratories for post mortem.

The breeder pre-selects the animals to be sent for testing. Both boars and gilts are eligible for testing. Pigs are only taken in for testing if they are from gilt litters of not less than 9 born and 7 weaned and sow litters of not less than 10 born and 8 weaned. Control over numbers weaned per litter assists in standardising the pre-test environment. (from above link)

Livestock Production Science : Impact of biotechnology on (cross ...
It is generally believed that for pig breeding, there is no or little effect of the application of cloning on the rate of progress in the nucleus population ...
linkinghub.elsevier.com/retrieve/pii/S0301622699001803 -

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Note added at 12 hrs (2007-12-04 07:35:50 GMT)
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