Genetic parameters of body weight, egg production, and shell quality traits in the Shan Ma laying duck (Anas platyrhynchos)

Abstract

Three hundred and four female ducks of the Chinese indigenous Shan Ma breed, progeny of 11 sires and 104 dams, were used to study laying traits. Among them, 264 ducks were used to study the egg shell quality traits of eggs laid at 300 days of age. The mean age at first egg was 109 days with an average egg weight of 49.6 ± 3.7 g. Between 210 and 300 days of age, egg weight increased from 65.0 ± 3.9 g to 67.0 ± 4.2 g and the mean of the number of eggs laid up to 300 days was 161 ± 15.0. Egg length was 59.57 ± 3.01 mm and egg width was 45.02 ± 1.98 mm, leading to a shape index of 1.32 ± 0.08. Egg shell thickness was about 0.31 mm whatever the shell region, and the breaking strength was 28.80 ± 8.29 N. The heritability's estimated using restricted maximum likelihood (REML) methodology were high for egg weights (ranging from 0.43 to 0.61), intermediate for the number of eggs laid (ranging from 0.38 to 0.43), and low for the age at first egg (0.13). Heritability's for egg shell quality traits varied from 0.20 for the breaking strength to 0.44 for egg length, with in-between values of 0.28 for shell thickness and 0.34 for the shape index. The number of eggs laid was not genetically correlated with the age at first egg or egg weight, but was correlated with body weight (r g = +0.54 ± 0.23). High positive correlations were found between egg weight and body weight traits, and both of these traits (except egg weight at first egg) were highly and positively correlated with egg length and width. Breaking strength was genetically correlated with egg shell thickness (r g = +0.54 ± 0.19) and the shape index (r g = +0.71 ± 0.23). These results suggest that an efficient selection strategy could be implemented to improve the egg production of the pure Shan Ma duck line.

Nutritional requirements of meat-type and egg-type ducks: what do we know?

“…In addition, many studies have aimed to improve the main egg-type breed of ducks (Longyan laying ducks), important for several reasons, viz. : medium size (1.2–1.3 kg), early maturation (110 d), high egg yield (more than 280 eggs/yr), huge populations (more than 300 million birds), adaptation to high ambient temperature, and resistance to disease [ 2 , 5 , 6 ]. However, the recommendations of the National Research Council 1994 (NRC1994) [ 7 ] for approving the development of a new strain of meat-type ducks, however, defined their nutritional requirements based on 40-year-old data, or on results obtained in other species.…”

Ovarian transcriptomic analysis of Shan Ma ducks at peak and late stages of egg production

“…Since ovarian function in poultry exerts a direct impact on egg production [ 1 ], poultry breeding scientists usually focus on the ovary to study egg production, including examination of the main genes controlling egg production and also other related differentially expressed genes. The Shan Ma ducks ( Anas Platyrhynochos ) is an excellent egg-type duck breed in Fujian, as a famous Chinese indigenous duck mentioned in the photograph alblum of china indigenous poultry breeds, with many advantageous traits, including small size, early maturity, great egg production, strong adaptability, and a high feed-conversion rate [ 2 , 3 ]. Its excellent egg-producing performance has therefore brought greater attention from poultry-breeding scientists.…”

The comparison of quality characteristics of Pekin duck and Cherry Valley duck eggs from free-range raising system

“…This has also been shown in this study because the average weight of the Cherry Valley duck eggs was even 31.04% higher than weight of the Pekin duck eggs. Ipek and Sozcu (2017) (Lin et al, 2016) and Brown Tsaiya duck of 64.2-67.8 g (Cheng et al, 1995).…”

“…The average force need to rupture Cherry Valley duck eggs tested in this study was significantly (P˂0.01) higher (50.32 N). In comparison to Pekin duck eggs, lower forces to egg rupture are needed for Shan Ma duck eggs 28.8 N (Lin et al, 2016), Rouen duck eggs 3.43 kg cm -2 (Kralik et al, 2015), Brown Tsaiya duck eggs 3.4-3.9 kg/cm 2 (Cheng et al, 1995) and Longyan duck eggs 3.87-4.13 kg/cm 2 (Wang et al, 2014). Higher forces to egg rupture are needed for Dumyati duck eggs 5.04 kg/cm 2 and for Muscovy duck eggs 5.56 kg/cm 2 (Ahmed, The specific deformation values for eggs compressed along the Z-axis were significantly higher than for those compressed along the both X-axes.…”