A study based on records taken at time of hoof trimming reveals a strong association between the IQ motif-containing GTPase-activating protein 1 (IQGAP1) gene and sole hemorrhage in Holstein cattle

Abstract

Feet and leg problems have a major effect on the well-being and lifespan of the dairy cow and thus are economically important to the dairy farmer. Apart from approaches using genetic selection for classical traits from conformation scoring, attempts for genetic improvement can be based either on records of individual disease cases or on records of disorder status at time of hoof trimming. In this study, 1,962 first-lactation cows were subjected to hoof trimming with an assessment of disorder status for sole hemorrhage as a binary trait. Cows were from 7 large commercial herds in Mecklenburg-Western Pomerania (northeastern Germany) that had similar housing with cubicles, slatted flooring, little use of straw for bedding, and total mixed ration feeding. Cows were trimmed and assessed once, focusing on cows in the first half of the lactation. Herds were visited at intervals to enable recording of cohorts at a similar stage of lactation. Each cohort or herd-visit included between 31 and 165 cows. Additional measurements included body weight, back fat thickness, and body condition at time of trimming. Further data on dairy production, conformation scores, and reproductive performance were merged after collection of records had finished. The DNA extracted from blood of 1,183 cows was used for analysis with a custom-made array of 384 single nucleotide polymorphisms (SNP). The SNP were selected according to results from the literature for effects in classical conformation traits, from biochemical pathway analysis, and from comparative analysis of putative candidate genes in cattle, pigs, and sheep. Selection of cohorts of cows for SNP chip analysis was such that cohorts with extreme frequencies of disorders and cohorts with slightly deviating housing systems were excluded in this first step. The results from a mixed threshold model analysis with genotype included as a fixed effect and accounting for relationships among animals revealed that the intronic SNP rs29017173 (A/G) within the IQ motif-containing GTPase-activating protein 1 (IQGAP1, Bos taurus autosome 21) was significantly associated with disorder status. Back-transformed means of disorder status for the 3 genotypes were 0.37 (AA), 0.52 (AG), and 0.56 (GG). Using the full data set of 1,962 cows, including the less-suitable cohorts, gave back-transformed means of 0.51 (AA), 0.58 (AG), and 0.62 (GG). As SNP rs29017173 is included on the Illumina BovineSNP50 DNA Analysis BeadChip (Illumina Inc., San Diego, CA), a sample of 2,394 artificial insemination sires from the German calibration sample for genomic selection from birth years 1998 to 2003 was studied for possible correlated effects. The A/G polymorphism of SNP rs29017173 studied here was also associated with substantial effects for feet and leg traits from the classical conformation score system. Selection using this polymorphism will be facilitated by the fact that the same allele is favored for all traits with substantial effects.

Association analysis for feet and legs disorders with whole-genome sequence variants in 3 dairy cattle breeds

“…The IQ motif-containing GTPaseactivating protein 1 (IQGAP1) gene was found to have a strong association with sole hemorrhage in German Holstein cattle (Swalve et al, 2014). We did not detect any SNP on BTA21 at 22 Mb, where IQGAP1 is located.…”

“…A few studies have detected QTL for some FLD, such as hoof trimming, lameness, and claw disorders (Buitenhuis et al, 2007;Swalve et al, 2014;van der Spek et al, 2015). However, genetic studies on feet and legs traits are limited due to a lack of recording in most countries.…”

Review: Opportunities and challenges for small populations of dairy cattle in the era of genomics

“…A general consideration for the collection of health data is whether to diagnose only affected cows or to record whole cohorts of animals. Including complete contemporary groups has the benefit that affected and nonaffected cows contribute to the later analysis, which is particularly advantageous for association studies as shown by Swalve et al (2014). An example for an improved definition of an existing trait is the claw disorder dermatitis digitalis.…”

Impact of Nutrients on the Hoof Health in Cattle

“…Lameness is currently one of the most critical problems in dairy farming, affecting animal health and welfare [ 1 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. Lameness is described as a clinical symptom, which is recognizable by a change in locomotion, usually associated with lesions of the pelvic limbs.…”

“…Lameness is described as a clinical symptom, which is recognizable by a change in locomotion, usually associated with lesions of the pelvic limbs. More than 90% of diagnosed lesions affect the distal part of the limb [ 11 , 13 , 15 , 16 , 17 , 18 , 19 , 20 ]; however, the resulting lesions are not only a welfare problem, but they also affect production and profit [ 8 , 14 , 15 , 19 , 21 , 22 ]. Dairy cows that are affected by limb diseases have lower dry matter intake and milk yield [ 3 , 4 , 9 , 10 , 11 , 14 , 16 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ], reduced fertility [ 3 , 4 , 15 , 16 , 17 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ], and they have an increased risk of culling [ 3 , 4 , 11 , 14 , 16 , 17 , 18 , 19 , ...…”