Selection response and estimation of the genetic parameters for multidimensional measured breast meat yield related traits in a long-term breeding Pekin duck line

Objective This study was conducted to estimate the genetic parameters and breeding values of breast meat related traits of Pekin ducks. Selection response was also determined by using ultrasound breast muscle thickness (BMT) measurements in combination with bosom breadth (BB) and keel length (KL) values. Methods The traits analyzed were breast meat weight (BMW), body weight (BW), breast meat percentage (BMP) and the three parameters of breast meat (BB, KL, and BMT). These measurements were derived from studying 15,781 Pekin ducks selected from 10 generations based on breast meat weight. Genetic parameters and breeding value were estimated for the analysis of the breeding process. Results Estimated heritability of BMW and BMP were moderate (0.23 and 0.16, respectively), and heritability of BW was high (0.48). Other traits such as BB, KL, and BMT indicated moderate heritability ranging between 0.11 and 0.28. Significant phenotypic correlations of BMW with BW and BMP were discovered (p<0.05), and genetic correlations of BMW with BW and BMP were positive and high (0.83 and 0.66, respectively). It was noted that BMW had positive correlations with all the other traits. Generational average estimated breeding values of all traits increased substantially over the course of selection, which demonstrated that the ducks responded efficiently to increased breast meat yield after 10 generations of breeding. Conclusion The results indicated that duck BMW had the potential to be increased through genetic selection with positive effects on BW and BMP. The ultrasound BMT, in combination with the measurement of BB and KL, is shown to be essential and effective in the process of high breast meat yield duck breeding

Multi-trench fiber with four gaps for improved bend performance

A modified multi-trench fiber (MTF) design with gaps to create leakage channels is proposed and investigated numerically using the scalar finite-difference beam-propagation method algorithm. Great potential in single-mode operation, mode area enlargement, and resistance to bending is demonstrated. A high loss ratio (&gt;50) between high-order modes and the fundamental mode is possible over a wide range of high-index ring thickness, gap width, and bending orientation. This reduces the required fabrication accuracy. We obtain an effective area of 920µm2 at a wavelength of 1050 nm and a 20 cm bend radius with a high loss ratio (&gt;100). Our modified gap MTF can possibly be fabricated by drilling holes in an ordinary MTF and inserting rods into the holes