Funding for this research was provided by:
National Natural Science Foundation of China (31872330, 31802041)
Earmarked Fund for Modern Agro-industry Technology Research System (CARS-36)
Beijing Dairy Industry Innovation Team (BAIC06-2018/2019)
Program for Chang jiang Scholar and Innovation Research Team in University (IRT_15R62)
Beijing Science and Technology Program (D171100002417001)
National Science and Technology Programs of China (2013AA102504)
Received: 12 December 2018
Accepted: 20 May 2019
First Online: 28 May 2019
Ethics approval and consent to participate
: All protocols for collection of the samples of experimental individuals and phenotypic observations were reviewed and approved by the Institutional Animal Care and Use Committee (IACUC) at China Agricultural University. Samples were collected specifically for this study following standard procedures with the full agreement of the Beijing Sanyuanlvhe Dairy Farming Center who owned the Holstein cows and bulls, respectively.
: Not applicable.
: The authors declare that they have no competing interests.