Curvilinear inbreeding effects on some performance traits in laying hens.
Quadratic partial regression coefficients were estimated for the inbreeding level on five performance traits (body weight, average egg weight, age at first egg, percentage of fertilized eggs, and hatchability of set eggs) of two strains of laying hens. Data on 5631 of H77 layers and 3563 of N88 layers from nine consecutive generations were analysed. Only dams were accounted for. Partial regression coefficients were estimated by REML with a single-trait animal model, which included fixed effects (generation and hatching period) and random effects (additive genetic and error effects). The mean inbreeding level was 0.87% in strain H77 and 1.08% in strain N88. The inbreeding effects were analysed based on the quadratic partial regression equations. A slight inbreeding depression was found for all the traits analysed in N88. In strain H77, negative effects of inbreeding were only noted for body weight and average egg weight. The small inbreeding effects shown here resulted from a relatively low level of homozygosity in the populations studied. The strains were found to differ in the effects of inbreeding. It is worth pointing out that differences were noted both between the inbreeding depression estimated from the partial linear regression equation and the quadratic partial regression equation, as well as different inbreeding levels.
Effects of Different Levels of Licorice (Glycyrrhiza glabra) Medicinal Plant Powder on Performance, Egg Quality and some of Serum Biochemical Parameters in Laying Hens
An experiment was conducted to evaluate the effects of different levels of licorice powder (LP) in diet on performance, egg traits and some serum biochemical parameters of laying hens in the late laying period. Totally 180 Hy-Line W-36 layer hens aged 55-68 weeks with similar weight were selected and assigned to 5 treatments, 3 replicates and 12 hens in each replicate in a completely randomized...متن کامل
Effects of rosemary essential oils and zinc on performance, egg quality traits, and some serum biochemical metabolites of laying hens
This study was conducted to evaluate the effects of dietary supplement-ation of rosemary essential oils (REO) and zinc (as zinc sulfate) on performance, egg quality traits, and some serum biochemical metabolites of laying hens. A total of 144 44-weeks-old Lohmann LSL-Lite laying hens were randomly allocated into four treatments, each comprising six replicates of six birds. The first group was s...متن کامل
The Effects of Different Levels of Grass ClippingWaste on Performance, Egg Traits and Blood Parameters of Laying Hens
In this experiment 144 Hy-line (W36) laying hens, 65 to 77 weeks of age were separated into 4 treatments with 3 replicates (12 birds per replicate) in a completely randomized design experiment. The grass clipping wastes incorporated into a complete formulated layer diet, consisting on a corn and soybean based diet, were 0, 1.5, 3.0 and 4.5% in 1 to 4 experimental groups. The results showed that...متن کامل
The Effects of Different Levels of Costmary (Tanacetum balsamita) Medicinal Plant onPerformance, Egg Traits and Blood Biochemical Parametersof Laying Hens
This experiment was conducted to evaluate the effects of different levels of costmary(Tanacetum balsamita)medicinal plant on performance, egg traits, and blood biochemical parameters of laying hens. Hundred-eighty of Hi-line laying hens (W 36) from 46 until 58 weeks of age were used in a completely randomized design in five treatments and three replicates (12 birds per replicate). The treatment...متن کامل
The Effects of Different Levels of Dried Aerial Parts Powder and Extract of Pennyroyal (Mentha pulegium) Medicinal Plant on Performance, Egg Quality, Blood Biochemical and Immunity Parameters of Laying Hens
This experiment was conducted to evaluate the effects of different levels of dried aerial parts powderand extract of pennyroyal (Mentha pulegium) medicinal plant on performance, egg traits, blood biochemical and immunity parameters of laying hens. Two-hundred-fifty-two Hi-line (W36 strain) laying hens from 46 until 58 weeks of age were used in a completely randomized design in 7 treatments and...متن کامل