Crossbreeding effects on reproductive traits in two strains of duck (Anas platyrhynchos): brown Tsaiya and Pekin

Dietary methionine deficiency reduces laying performances of female common ducks and impacts traits of interest of their mule ducklings

The effects of maternal nutrition on offspring phenotypes have been mainly documented over the past years in mammals, and are now studied in poultry as well. In the present study, we investigated the effects of a reduced level of dietary Methionine (Met) on laying performances of common laying ducks and their impacts on the phenotype of their mule ducklings. A total of 60 female laying ducks were divided into 2 dietary treatments at 10 wk of age. The restricted group received Met-restricted diets (R group) containing 0.25% of Met whereas the control group received control diets (C group) containing 0.40% of Met that meets Met requirements. The restriction was applied during the growing and laying periods, from 10 to 51 wk of age and a particular focus was put on female breeder traits that might be affected by the Met restriction. Plasma parameters of hepatic and lipid metabolisms were recorded in ducklings. Total weight (P < 0.001), albumen weight (P < 0.001) and albumen percentage of dry matter (P < 0.01) were decreased for eggs laid by female breeders from the R group. Both male and female ducklings from the R group of female breeders showed a reduced BW at hatching (P < 0.001) and a tendency to an increased proportional liver weight (P = 0.07). Finally, the maternal low dietary Met level modified plasma parameters in newborn ducklings regardless of sex: alkaline phosphatase (ALP) and alanine transaminase (ALT) activities were reduced (P = 0.07 and P = 0.002, respectively), levels of glucose (P = 0.03) and triglycerides (P = 0.01) were higher whereas level of free fatty acids decreased (P = 0.01). It was concluded that feeding female laying ducks with a restricted dietary Met content during the growing and laying periods has a negative effect on egg weight and composition. The ducklings that were restricted in nutrients during their early development, have a reduced BW, and altered lipid and hepatic metabolisms.

Conservation of poultry genetic resource in the Veneto region of Italy

A conservation scheme for local poultry breeds from the Veneto region (Italy), the Co.Va. (Conservazione e Valorizzazione di Razze Avicole Locali Venete - Conservation and valorisation of local poultry genetic resources of Veneto region) project began in 2000 with finance provided by the Veneto Region. This project involved four organic farms located in different areas (mountain, hill and plain) in the region. The local chicken breeds included in the project were the Robusta Maculata, Robusta Lionata, Ermellinata di Rovigo, Pépoi and Padovana; the local duck breeds were the Germana Veneta and Mignon; the local turkey breeds were the Bronzato Comune and Ermellinato di Rovigo; and the local guinea fowl breed was the Camosciata. All breeds are dual-purpose breeds and are utilized for meat and egg production. The Department of Animal Science of the University of Padova planned a marker-assisted conservation scheme based on the maintenance and multiplication of these breeds within their production system (in situ conservation scheme). The objectives of the farmers involved in this project were to use these genotypes to generate typical regional products for local markets, to support the development of economically marginal areas through the revaluation of local breeds and to allow the preservation of animal biodiversity.

Production benefits of the crossbreeding of indigenous and non-indigenous ducks--growing and laying period body weight and production performance

To evaluate different crosses and purebreds ducks in respect to various economic traits and to estimate different crossbreeding genetic parameters, a 3 x 3 complete diallel cross involving indigenous duck (DD), Khaki Campbell (KK) and White Pekin (WW) were used to produce three purebreds (DD, KK, WW) three crossbreds (DK, DW, KW) and three reciprocals (KD, WD, WK). A total of 609 ducklings produced were reared on deep litter and the females (316 in number) were evaluated for growing and laying period body weight along with the production performance traits. Different crossbreeding genetic parameters were estimated for different traits. All the traits in respect to body weight gain during growing and laying period and different production traits including laying house mortality rate showed significant (p <or= 0.05) difference between different genetic groups. In general, crossbreds perform better than the purebreds for most of the traits studied. General combining ability (GCA), specific combining ability (SCA) and reciprocal effect (RE) were significant (p <or= 0.01) for body weight and production traits. Egg weight showed significant (p <or= 0.01) difference in respect to GCA, SCA and RE for all the ages of measurement except RE for 30th week egg weight. Laying period mortality rate was only significant (p <or= 0.05) for SCA. Most of the crossbreds recorded heterosis rate in desirable direction for majority of the traits. Overall results revealed that the crossbreds perform well in respect to different traits than the purebreds and may be used to take advantage of heterosis. DW performs well in respect to majority of the traits measured and is of importance for commercial exploitation. Further, pure line selection with development of specialised sire and dam line followed by crossing may be of importance to enhance the performances in the crosses.