North China's Inner Mongolia Autonomous Region has launched a genomic breeding tool for dairy cattle, also known as a gene chip, enabling precise screening for key traits such as high milk yield, high fertility, disease resistance and longevity, and marking a fresh breakthrough in China's dairy cattle breeding technology, the Inner Mongolia Daily reported on Saturday.

As an iteration of the previous generation dairy cattle breeding array, which holds proprietary intellectual property rights, the new-generation "Breeding No.2" breeding array was led by the National Center of Technology Innovation for Dairy and developed by Youran Dairy Saikexing, with upgrades in loci coverage, compatibility and gene-trait prediction algorithms.

The "Breeding No.2" breeding array covers about 50,000 loci across the dairy cattle genome, with a focus on functional loci tied to milk production, reproduction, disease resistance and length of productive life. It has achieved a sample call rate of 99.65 percent and a genotyping concordance rate of 99.91 percent for duplicate samples, and is compatible with mainstream international chips, allowing historical breeding data to be shared and reused.

Drawing on a phenotype database and genome resequencing data to optimize a proprietary algorithm, advancing breeding evaluation from qualitative screening to quantitative assessment, bringing the accuracy of breeding stock selection up to advanced international levels, according to the report.

The breeding array enables more precise genomic selection of calves at an early stage, substantially shortening the generation interval in breeding bull selection and cutting spending on raising low-performing replacement heifers. Compared with imported high-density chips, the "Breeding No.2" chip carries a lower per-sample testing cost and delivers stronger input-output returns, making it highly suited to large-scale dairy cattle breeding operations in China, the report said.