Temporal Trends in Performance and Hatchability Traits of Eight Strains of Hens Covered by the Gene Pool Protection Programme in Poland

Abstract

The aim of the study was to determine trends in performance and hatchability traits of eight strains of hens that have been covered by the gene pool protection programme in Poland over ten years/generations. The study involved conservation populations of laying hens: Greenleg Partridge (Z-11), Yellowleg Partridge (Ż-33), Sussex (S-66), Leghorn (H-22, G99), Rhode Island Red (R-11, K-22) and Rhode Island White (A-33), which were maintained at the Experimental Station of the National Research Institute of Animal Production in Chorzelów. The following productive traits were analysed for each population: body weight at 20 wk (g), egg weight at 33 and 53 wk, sexual maturity and number of eggs laid per hen up to 56 wk of age. Mortality and culling were also recorded during rearing and production periods. Furthermore, effective population size (Ne) and inbreeding coefficient in the population (Fx) were calculated for each strain. The analysis of the performance results of the eight strains of hens and their trends indicate that the methods of conservation breeding adopted for these populations enable effective implementation of the conservation programme. The strains were found to differ in all the performance traits subjected to evaluation. Over the 10 generations, the strains examined showed high survival and hatchability parameters during both rearing and production periods. The currently used random mating system proved effective to prevent the populations from an increase of inbreeding. However, a worrying downward trend in body weight was observed in some strains.

Influence of Genotype on Productivity and Egg Quality of Three Hen Strains Included in a Biodiversity Program

“…The main goal of the program for the conservation of laying hens' genetic resources is to preserve individual populations of laying hens from extinction, by maintaining the genetic balance at an unchanging level in each protected flock (strain), while maintaining the characteristic phenotype of birds of both sexes [6,7]. A very important point in conducting breeding work in these flocks is the system of reproduction, based on the rotation of males between different groups of hens [16]. In our study, we obtained low inbreeding rates (Fx ≤ 0.17), proving that the rotational mating system used in the reproduction of four groups of birds effectively protects the evaluated hen populations from an increase in their inbreeding, consistent with our previous observations [16,25,26].…”

“…Meanwhile, the preservation of native poultry breeds is of great importance both in highly developed countries, where it is part of the policy recommendations for sustainable agricultural development, and in underdeveloped countries, where the rearing of native poultry dominates [1,8]. Hence, in recent years, we have seen an increasing number of studies on the characteristics of native and locally adapted breeds of hens from different parts of the world [9][10][11][12][13][14][15][16]. The authors especially point out the necessity of monitoring the effective population size and the inbreeding level of small, closed populations of hens, and emphasize that the maintenance of these parameters at an appropriate level determines their good health and productivity and allows assessing the effectiveness of adopted conservation programs.…”

“…In Poland, a number of native and locally adapted hen breeds have already become extinct, including, among others, gray hens, spotted hens, naked neck hens, and some varieties of crested hens. Hence, in the 1970s, the staff of the National Research Institute of Animal Production, with the participation of other scientific centers, defined the concept of conservation and genetic reserve flocks and developed the first conservation programs for the preservation of native breeds of hens, which included, among others, methods of conservation, breed standards, and an appropriate system for mating birds [2,6,7,16]. In the 1990s, on the initiative of the FAO, a comprehensive program for the conservation of genetic resources in agriculture was developed, the main goal of which was to preserve livestock populations threatened with extinction.…”

“…Production traits such as body weight, egg weight, and laying rate in hen populations included in the biodiversity program show high variability between genetically different populations of the same species [6,15,16,25,26], so it is very important to analyze their formation over several generations. The analysis of genetic and production parameters of three laying hen strains included in the biodiversity program is in line with global research in this area and can be a valuable source of information for the scientific community dealing with animal biodiversity.…”

Discriminant Canonical Analysis as a tool to determine traces of endangered native hen breed introgression through egg hatchability phenomics

“…Fertility and hatchability, as well as other reproductive traits, characterize by low and stable heritability values (h 2 < 0.2) [2054]. However, still significant differences in fertility and hatchability traits across breeds or genotypes occur, and may base upon a widely variable physiological range of components [2155].…”