Estimation of genetic parameters and single-step genome-wide association studies for milk urea nitrogen in Holstein cattle

Longgang Ma; Hanpeng Luo; Luiz F. Brito; Yao Chang; Ziwei Chen; Wenqi Lou; Fan Zhang; Lei Wang; Gang Guo; Yachun Wang

Journal of Dairy Science (Jan 2023)

Estimation of genetic parameters and single-step genome-wide association studies for milk urea nitrogen in Holstein cattle

Longgang Ma,
Hanpeng Luo,
Luiz F. Brito,
Yao Chang,
Ziwei Chen,
Wenqi Lou,
Fan Zhang,
Lei Wang,
Gang Guo,
Yachun Wang

Affiliations

Longgang Ma: National Engineering Laboratory of Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China; College of Animal Science, Xinjiang Agricultural University, Urumqi, 830052, China
Hanpeng Luo: National Engineering Laboratory of Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China
Luiz F. Brito: Department of Animal Sciences, Purdue University, West Lafayette, IN 47907
Yao Chang: National Engineering Laboratory of Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China
Ziwei Chen: National Engineering Laboratory of Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China
Wenqi Lou: National Engineering Laboratory of Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China
Fan Zhang: National Engineering Laboratory of Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China; College of Animal Science, Xinjiang Agricultural University, Urumqi, 830052, China
Lei Wang: National Engineering Laboratory of Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China; College of Animal Science, Xinjiang Agricultural University, Urumqi, 830052, China
Gang Guo: Beijing Sunlon Livestock Development Company Limited, 10029, Beijing, China
Yachun Wang: National Engineering Laboratory of Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, MARA, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China; Corresponding author

Journal volume & issue: Vol. 106, no. 1
pp. 352 – 363

Abstract

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ABSTRACT: The main objectives of this study were to estimate genetic parameters for milk urea nitrogen (MUN) in Holstein cattle and to conduct a single-step (ss)GWAS to identify candidate genes associated with MUN. Phenotypic measurements from 24,435 Holstein cows were collected from March 2013 to July 2019 in 9 dairy farms located in the Beijing area, China. A total of 2,029 cows were genotyped using the Illumina 150K Bovine Bead Chip, containing 121,188 SNP. A single-trait repeatability model was used to evaluate the genetic background of MUN. We found that MUN is a trait with low heritability (0.06 ± 0.004) and repeatability (0.12). Considering similar milk production levels, a lower MUN concentration indicates higher nitrogen digestibility. The genetic correlations between MUN and milk yield, net energy concentration, fat percentage, protein percentage, and lactose percentage were positive and ranged from 0.02 to 0.26. The genetic correlation between MUN and somatic cell score (SCS) was negative (−0.18), indicating that animals with higher MUN levels tend to have lower SCS. Both ssGWAS and pathway enrichment analyses were used to explore the genetic mechanisms underlying MUN. A total of 18 SNP (located on BTA11, BTA12, BTA14, BTA17, and BTA18) were found to be significantly associated with MUN. The genes CFAP77, CAMSAP1, CACNA1B, ADGRB1, FARP1, and INTU are considered to be candidate genes for MUN. These candidate genes are associated with important biological processes such as protein and lipid metabolism and binding to specific proteins. This set of candidate genes, metabolic pathways, and their functions provide a better understanding of the genomic architecture and physiological mechanisms underlying MUN in Holstein cattle.

Published in Journal of Dairy Science

ISSN: 0022-0302 (Print); 1525-3198 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Agriculture: Animal culture: Cattle: Dairy processing. Dairy products; Agriculture: Animal culture: Cattle: Dairying
Website: https://www.journals.elsevier.com/journal-of-dairy-science

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