The several hundred domestic pig breeds officially recognized today [ 14] vary significantly in their external morphology, reflecting differing local environmental factors, husbandry practices and selection strategies.
We made a selection of husbandry units with a minimum of 70 reindeer, a relatively conservative estimate of the number of animals needed for maintaining viable herds (Næss and Bårdsen 2010; Næss et al. 2010).
This study aimed to evaluate livestock diet composition, diet overlap, forage selection and livestock husbandry and associated land use practices in a typical traditional village landscape in the cold arid region of the trans-Himalaya, India.
The animal husbandry was consistent throughout the selection experiment, as has been previously described in detail (Dunnington and Siegel 1996; Márquez et al. 2010).
Domestic animals are mainly subject to intensified artificial selection through diverse husbandry practices (both in the past and present), with relaxation of natural selection associated with captivity and management.
As a consequence of the long juvenility phase of apple trees and of relatively high husbandry costs, the breeding and selection of novel apple rootstocks and scions is a time-consuming and costly procedure.
Whether these findings are due to differential selection based on differences in husbandry between the two sites or due to chance is not known.
The burden of mouse husbandry costs enforces the need for strict selection of lines by individual researchers, generally based on pre-existing genetic or phenotypic data, yet this is entirely absent for many of the genes now being identified in EP lethal lines.
Although domestic pigs may be affected to some degree by the same environmental factors as wild boar (climate, food availability, etc)., selection is mainly influenced by local husbandry practices, ranging from free-range extensive management of regionally specific varieties [ 15] to complex breeding schemes and confinement in modern-day industrialised units.
We suggest that despite the selection pressure mediated by plant and animal husbandry in agronomic systems, endophyte-infected grasses maintain a large genetic variability and display gene flow among distant populations of the same species and populations of related species.
