Abstract
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.
Highlights
Protection of local poultry breeds plays a significant role both in highly developed countries, where it follows the recommendations of sustainable agricultural policy, and in less developed countries, where native poultry farming predominates
K-22 and A-33 hens are characterised by a different genetic structure and genetic origin compared to the other strains kept in Poland, and when crossed with other strains they show a high level of heterosis
The analysed strains of G-99 and H-22 hens were genetically not very similar, while genetically the most distinct from the other strains under study were H-22 hens, which were selected the longest for egg laying out of all the analysed breeds, as reflected in the DNA profile. These data differ from the findings of Brodacki et al (2003), who observed the smallest genetic distance between strains G-99 and H-22, as well as high similarity among the three strains derived from Greenleg Partridge hens (Z-11, ZKF and Ż-33)
Summary
Protection of local poultry breeds plays a significant role both in highly developed countries, where it follows the recommendations of sustainable agricultural policy, and in less developed countries, where native poultry farming predominates. In the 1960s, in an effort to improve the production traits, Greenleg hens were crossed with New Hampshire cocks; the intensive selection over the few generations resulted in a new breed known as Greenleg Partridge (Ż-33) This breed was characterised by partridge-like plumage, higher body weight and laying performance, and yellow colour of the legs, carcasses and skin. K-22 and A-33 hens are characterised by a different genetic structure and genetic origin compared to the other strains kept in Poland, and when crossed with other strains they show a high level of heterosis Each of these breeds/strains, covered by the gene pool protection programme, forms a distinct genotype, which determines the presence of unique traits that are not found in the breeds selected for high productivity (Cywa-Benko, 2002; Calik, 2008; Krawczyk and Calik, 2010). The 10-year analysis (2009–2018) of the production parameters of 8 layer strains included in the conservation programme fits into the international studies in this area and may provide a source of information for scientists engaged in animal biodiversity
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
