Phenotypic and genetic analysis of milk and serum element concentrations in dairy cows

Scott J. Denholm* (Corresponding Author), Alan A Sneddon, Shabina Bashir, Mairi C Mitchell, Tom N. McNeilly, Eileen Wall

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)
4 Downloads (Pure)


Enhancing micronutrient (i.e., mineral and vitamin) concentrations within milk and serum from dairy cows is important for both the health of the cow and the nutritive value of the milk for human consumption. However, a good understanding of the genetics underlying the micronutrient content in dairy cattle is needed to facilitate such enhancements through feeding or breeding practices. In this study, milk (n = 950) and serum (n = 766) samples were collected from Holstein-Friesian dairy cows (n = 479) on 19 occasions over a 59-mo period and analyzed for concentrations of important elements. Additionally, a subset of 256 milk samples was analyzed for concentrations of vitamin B 12. Cows belonged to 2 genetic lines (average and highest genetic merit for milk fat plus protein yield) and were assigned to 1 of 2 diets based on either a by-product or homegrown ration. Univariate models accounting for repeated records were used to analyze element and vitamin B 12 data and investigate the effect of genotype and feeding system as well as derive estimates of variance components and genetic parameters. Bivariate models were used to study correlations both within and between milk and serum. Only concentrations of Hg in milk were seen to be affected by genotype, with higher concentrations in cows with high genetic merit. In contrast, element concentrations were influenced by feeding system such that cows fed the homegrown diet had increased milk concentrations of Ca, Cu, I, Mn, Mo, P, and K and increased serum concentrations of Cd, Cu, Fe, Mo, and V. Cows on the by-product diet had increased milk concentrations of Mg, Se, and Na and increased serum concentrations of P and Se. Heritability (h 2) estimates were obtained for 6 milk and 4 serum elements, including Mg (h 2 milk = 0.30), K (h 2 serum = 0.18), Ca (h 2 milk = 0.20; h 2 serum = 0.12), Mn (h 2 milk = 0.14), Cu (h 2 serum = 0.22), Zn (h 2 milk = 0.24), Se (h 2 milk = 0.15; h 2 serum = 0.10), and Mo (h 2 milk = 0.19). Significant estimates of repeatability were observed in all milk and serum quantity elements (Na, Mg, P, K, and Ca) as well as 5 milk and 7 serum trace elements. Only K in milk and serum was found to have a significant positive genetic and phenotypic correlation (0.52 and 0.22, respectively). Significant phenotypic associations were noted between milk and serum Ca (0.17), Mo (0.19), and Na (−0.79). Additional multivariate analyses between measures within sample type (i.e., milk or serum) revealed significant positive associations, both phenotypic and genetic, between some of the elements. In milk, Se was genetically correlated with Ca (0.63), Mg (0.59), Mn (0.40), P (0.53), and Zn (0.52), whereas in serum, V showed strong genetic associations with Cd (0.71), Ca (0.53), Mn (0.63), Mo (0.57), P (0.42), K (0.45), and Hg (−0.44). These results provide evidence that element concentrations in milk and blood of dairy cows are significantly influenced by both diet and genetics and demonstrate the potential for genetic selection and dietary manipulation to alter nutrient concentration to improve both cow health and the healthfulness of milk for human consumption.

Original languageEnglish
Pages (from-to)11180-11192
Number of pages13
JournalJournal of Dairy Science
Issue number12
Early online date3 Oct 2019
Publication statusPublished - Dec 2019

Bibliographical note

This research, including the Langhill experiment at Crichton Dairy Research Centre and all authors, was funded by the Scottish Government Rural Affairs, Food and the Environment (RAFE) Strategic Research Portfolio 2016-2021. Samples collected pre-2016 were collected as part of a BBSRC project awarded to EW (grant no. BB/K002260/1) and TNM (BB/K002171/1). The authors gratefully acknowledge the high standard of work by all staff at Crichton farm (SRUC, Dumfries, Scotland) in the collection of samples and management of animals, and Ian Archibald (SRUC, Edinburgh, Scotland) for managing the Langhill database and assisting with data extraction.


  • micronutrient
  • heavy metal
  • dairy cow
  • heritability
  • correlation


Dive into the research topics of 'Phenotypic and genetic analysis of milk and serum element concentrations in dairy cows'. Together they form a unique fingerprint.

Cite this