The aim of the study was to evaluate changes in laying patterns depending on the age of different genotypes of laying hens. In the experiment, six genotypes were evaluated (brown-egg hens Bovans Brown, Bovans Sperwer and Isa Sussex, white-egg hens Dekalb White, and laying hens with tinted shells Moravia Barred and Moravia BSL) in three periods during the laying cycle (the onset of lay between 20 and 26 weeks of age, the middle from 36 to 42 weeks of age and the end of lay between 64 and 70 weeks of age). A significant interaction between genotype and age was apparent in mean sequence length (P<0.001), length of the prime sequence (P<0.001), mean number of sequences (P<0.001) and mean time of oviposition (P˂0.001). The longest lag during the course of the experiment was with Moravia BSL, which was more than 3h; the shortest lag was observed in Bovans Brown, which was less than 1h. The mean time of oviposition was also affected by genotype (P˂0.001). Bovans Brown laid their eggs approximately 3.5h after the lights came on, whereas Moravia BSL laid their eggs almost 6h after the lights came on. Egg weight increased with age (P˂0.001), and the smallest differences in egg weight were with ISA Sussex (5g), whereas the biggest differences were with Moravia BSL (10g).

• MeSH
• genotyp * MeSH
• kladení vajíček genetika   fyziologie   MeSH
• kur domácí genetika   fyziologie   MeSH
• stárnutí genetika   fyziologie   MeSH
• vejce * MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The age at which final nutria weight is achieved varies in literature between six and 14months. The aim of this study was to evaluate the growth, carcass composition and meat quality of male and female nutrias between the ages of six and eight months in intensive production system. Sexual dimorphism in growth was observed from three months of age, and in females, growth considerably decreased after six months of age. The dressing-out percentage and the meat color were not affected by the age or sex of nutrias. Dry matter, ether extract and energetic values were significantly higher in females and in older nutrias. The decreasing frequency of type IIA fibers in older nutrias was presumably associated with a conversion of type IIA fibers to type IIB fibers. Nutrias under intensive production system can be slaughtered at six months of age when they reach a high carcass yield and meat quality.

• MeSH
• chov zvířat metody   MeSH
• dieta veterinární   MeSH
• hlodavci růst a vývoj   MeSH
• kosterní svalová vlákna MeSH
• krmivo pro zvířata MeSH
• maso analýza   MeSH
• pohlavní dimorfismus MeSH
• složení těla MeSH
• tělesná hmotnost * MeSH
• věkové faktory MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH