Association of &amp;lt;i&amp;gt;TLR4&amp;lt;/i&amp;gt; and &amp;lt;i&amp;gt;CARD15/NOD2&amp;lt;/i&amp;gt; polymorphisms with SCC in Holstein–Friesian cattle

K Wojdak-Maksymiec,K Prüffer,K Mikołajczyk

doi:10.5194/aab-58-293-2015

Association of &lt;i&gt;TLR4&lt;/i&gt; and &lt;i&gt;CARD15/NOD2&lt;/i&gt; polymorphisms with SCC in Holstein–Friesian cattle

K Wojdak-Maksymiec, K Prüffer + Show 1 more

Open Access

https://doi.org/10.5194/aab-58-293-2015

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Abstract

Abstract. Mastitis is one of the most important dairy cattle diseases which results in economic losses in dairy production. Mastitis cases can be classified as subclinical or clinical. All forms of mastitis lead to changes in milk composition and induce an increase in somatic cell count (SCC). SCC is a very important and basic indicator of udder health. An increase in SCC is usually caused by the immune response to the invasion of pathogens contributing to mastitis. The aim of this study was to investigate associations between the polymorphisms of selected genes (TLR4 and CARD15/NOD2) whose products are involved in the identification of pathogen-associated molecular patterns (PAMPs) during the innate immune response to infection, and immunity to mastitis expressed as SCC. The genes under study were also examined for epistatic effects as well as effects of interactions with parity and stages of lactation. In all the studied classes, allele G of TLR4 had a favourable additive effect with negative values, contributing to a lower lnSCC. Allele A of CARD15/NOD2 had a desirable additive effect which varied with time and the changing internal environment during lactation. With regard to the dominance effect, allele A of CARD15/NOD2 was found to be significantly associated with a higher SCC in milk in the first lactation and in the third stage of each single lactation. Moreover, statistically significant epistatic effects were found, in particular additive–additive and dominance–additive interactions were favourably associated with SCC which was lower than expected in the case of no epistasis.

Highlights

Mastitis is the most devastating cattle disease in terms of economic losses occurring worldwide (Kumar et al, 2010)
When investigating the associations between somatic cell count (SCC) in milk and allele G of tolllike receptor 4 (TLR4) and allele A of caspase recruitment domain 15 (CARD15)/NOD2, it was found that single additive effects of the genes were statistically significantly associated with a lower lnSCC in all the test milkings in total (Table 3)
The following statistically significant epistatic effects with desirable negative values associated with a lower SCC were found in lactation stages: aT LR4 · aCARD15/NOD2 in the second stage of lactation and in the whole lactation; dT LR4 · aCARD15/NOD2 in the third stage of lactation and in the whole lactation

Summary

Introduction

Mastitis is the most devastating cattle disease in terms of economic losses occurring worldwide (Kumar et al, 2010). Mastitis is the consequence of the adverse effect on the mammary gland and the cow’s immune system of many factors – environmental (both external and internal), genetic and the interactions between them (Rinaldi et al, 2010; Schukken et al, 2011). Mastitis can be classified as subclinical or clinical, depending on whether clinical signs are present or not. In dairy practice, this inflammatory process in the dairy cow’s mammary gland is generally detected by measuring somatic cell count, SCC (Schukken et al, 2003). Due to the absence of readily available and reliable data on the clinical mastitis phenotype, many countries around the world have included SCC in their breeding programmes as a way to improve resistance to intramammary infections (Rupp and Boichard, 2003; Beecher et al, 2010)

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