Problems of mini-pig breeding

Abstract

This article provides an overview of some problems of the breeding and reproduction of laboratory minipigs. The most obvious of these are the lack of centralized accounting of breeding groups, uniform selection standards for reproduction and evaluation of breeding animals, as well as minimizing the accumulation of fitness-reducing mutations and maintaining genetic diversity. According to the latest estimates, there are at least 30 breeding groups of mini-pigs systematically used as laboratory animals in the world. Among them, there are both breed formations represented by several colonies, and breeding groups consisting of a single herd. It was shown that the main selection strategy is selection for the live weight of adults of 50–80 kg and the adaptation of animals to a specific type of biomedical experiments. For its implementation in the breeding of foreign mini-pigs, selection by live weight is practiced at 140- and 154-day-old age. It was indicated that different herds of mini-pigs have their own breeding methods to counteract inbred depression and maintain genetic diversity. Examples are the maximization of coat color phenotypes, the cyclical system of matching parent pairs, and the structuring of herds into subpopulations. In addition, in the breeding of foreign mini-pigs, molecular genetic methods are used to monitor heterozygosity. Every effort is made to keep the number of inbred crosses in the breeding of laboratory mini-pigs to a minimum, which is not always possible due to their small number. It is estimated that to avoid close inbreeding, the number of breeding groups should be at least 28 individuals, including boars of at least 4 genealogical lines and at least 4 families of sows. The accumulation of genetic cargo in herds of mini-pigs takes place, but the harmful effect is rather the result of erroneous decisions of breeders. Despite the fact that when breeding a number of mini-pigs, the goal was to complete the herds with exclusively white animals, in most breeding groups there is a polymorphism in the phenotype of the coat color.

Pigs as Models to Test Cardiovascular Devices

“…In different countries, researchers use a variety of laboratory pigs (about 30 different breeding groups) [15]. Hence, for various breeds, different variations in the relationship Another important issue under discussion is whether the indicators of mass-growth in adult animals correlate with the size of their cardiac structures.…”

“…The authors studying the relationships between these parameters conducted experiments on pigs aged between 0 and 3–4 years old. This makes correlations between the size of internal organs and height–weight indicators apparent due to intensive growth during their early years [ 11 , 14 , 15 ]. However, the growth of internal organs stops when the animal reaches sexual maturity.…”

A Pig as a Model to Test Cardiovascular Devices

“…Every author studying the relationship between these indicators has conducted experiments on pigs aged from 0 to 3-4 years. This makes correlations between the size of internal organs and height-weight indicators obvious due to intensive growth at an early age [11,14,15]. However, the growth of internal organs stops when the animal reaches its sexual maturity.…”

“…In different countries, researchers use laboratory pigs of different breeds (about 30 breeding groups) [15]. It might be possible that for different breeds, different variations in the ratio between height-weight indicators and the size of cardiac structures can be observed.…”

“…The growth period of these animals is 6.6 years in wild boars and 3 years in sows [16], while mini-pigs reach their main size by the age of 2. The age dynamics of growth and weight in mini pigs of this breeding are described in detail in the available literature, including the growth dynamics of some internal organs of piglets in the postnatal period [15,16]. However, main morphometric parameters of the heart and main vessels of these pigs have not been described yet.…”