Genetic parameters for claw disorders and the effect of preselecting cows for trimming

Abstract

Claw disorders are important traits relevant to dairy cattle breeding from an economical and welfare point of view. Selection for reduced claw disorders can be based on hoof trimmer records. Typically, not all cows in a herd are trimmed. Our objectives were to estimate heritabilities and genetic correlations for claw disorders and investigate the effect of selecting cows for trimming. The data set contained 50,238 cows, of which 20,474 cows had at least one claw trimming record, with a total of 29,994 records. Six claw trimmers scored 14 different claw disorders: abscess (AB), corkscrew claw (CC), (inter-)digital dermatitis or heel erosion (DER), double sole (DS), hardship groove (HG), interdigital hyperplasia (IH), interdigital phlegmon (IP), sand crack (SC), super-foul (SF), sole hemorrhage (SH), sole injury (SI), sole ulcer (SU), white line separation (WLS), yellow discoloration of the sole (YD), and a combined claw disorder trait. Frequencies of the claw disorders for trimmed cows ranged from 0.1% (CC, YD, HG) to 23.8% (DER). More than half of the cows scored had at least one claw disorder. Heritability on the observed scale ranged from 0.02 (DS, SH) to 0.14 (IH) and on the underlying scale from 0.05 to 0.43 in trimmed cows. Genetic correlations between laminitis-related claw disorders were moderate to high, and the same was found for hygiene-related claw disorders. The effect of selecting cows for trimming was first investigated by including untrimmed cows in the analyses and assuming they were not affected by claw disorders. Heritabilities on the underlying scale showed only minor changes. Second, different subsets of the data were created based on the percentage of trimmed cows in the herd. Heritabilities for IH, DER, and SU tended to decrease when a higher percentage of cows in the herd were trimmed. Finally, a bivariate model with a claw disorder and the trait "trimming status" was used, but heritabilities were similar. Heritability for trimming status was relatively high (0.09). Genetic correlations of trimming status with claw disorders were generally moderate to high. To conclude, the effect of selecting cows for trimming on the heritability for claw disorders is negligible. Selecting herds with a high fraction of cows being trimmed tended to decrease heritability. Trimming status, as such, is a heritable trait and correlated with claw disorders and is therefore an interesting trait to include in the genetic evaluation.

Genetic selection for hoof health traits and cow mobility scores can accelerate the rate of genetic gain in producer-scored lameness in dairy cows

“…Variance Components. Heritability estimates for the hoof health traits considered in the present study were generally higher than previously reported in other dairy cow populations that also used linear models and considered the same noninfectious and different infectious hoof health traits (van der Waaij et al, 2005;van der Linde et al, 2010;Johansson et al, 2011;van der Spek et al, 2013), the reason for which is likely multifactorial. First, participating herds in the present study were selected because of their reputation for prompt and correct data recording, thus helping to reduce the residual variance.…”

“…Moreover, differences in relative economic importance (Enting et al, 1997;Ettema and Østergaard, 2006) and control methods (Leach et al, 2010;Bicalho and Oikonomou, 2013) for hoof health traits exist in different environments and production systems. All herds in the present study were pasture-based, spring-calving production systems; many other studies (Chapinal et al, 2013;Oberbauer et al, 2013;van der Spek et al, 2013) have documented variance components of hoof health traits from cows in confinement, nonseasonal calving herds. Genotype × environment interactions are known to contribute to differences in the genetic variances among production systems, a phenomenon that has been reported for other performance traits in dairy cattle (Berry et al, 2003;Nauta et al, 2006;Haile-Mariam et al, 2008).…”

Estimation of heritability for claw traits in Holstein cattle using Bayesian and REML approaches

“…The production decline will usually occur during two to four months before the claw disease is diagnosed (Strapák et al, 2013). For example in Netherlands, the economic loss due to the claw disorders have been estimated at 75 $ per cow per year (Bruijnis et al, 2010;Van der Spek et al, 2013). Krupová et al (2016) estimated the marginal economic value of claw disorders incidence in dairy population of Slovak Pinzgau cattle to −€26.73 per case per cow and year.…”

“…For European dairy cattle the prevalence of 70% of the cows with at least one claw disorders have been reported (Van der Linde et al, 2010;Chapinal et al, 2013;Van der Spek et al, 2013). The risk of claw disorders incidence depends on various factors, including environment conditions (for example management practices and design of the facilities) and animals' genetic background (Cramer et al, 2009;Van der Linde et al, 2010).…”

“…The effect of herd management on claw health is high and due to the low heritabilities of claw morphometric parameters as well as disorders, the improvement of claw health can be achieved most easily in short-term by improving only the environment conditions. But, it has been showed that being able to accurately assess claw morphometric traits could be significant benefit when determining selection strategy and gauging the impact of factors, such as the environment and nutrition (Van der Spek et al, 2013;Laven et al, 2015). Thus, in long-term perspective, direct or indirect selection of both may be the best option for improving the claw health (Häggman and Juga, 2013).…”