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

Abstract

Cattle breeding programs that strive to reduce the animal-level incidence of lameness are often hindered by the availability of informative phenotypes. As a result, indicator traits of lameness (i.e., hoof health and morphological conformation scores) can be used to improve the accuracy of selection and subsequent genetic gain. Therefore, the objectives of the present study were to estimate the variance components for hoof health traits using various phenotypes collected from a representative sample of Irish dairy cows. Also of interest to the present study was the genetic relationship between both hoof health traits and conformation traits with producer-scored lameness. Producer-recorded lameness events and linear conformation scores from 307,657 and 117,859 Irish dairy cows, respectively, were used. Data on hoof health (i.e., overgrown sole, white line disease, and sole hemorrhage), mobility scores, and body condition scores were also available from a research study on up to 11,282 Irish commercial dairy cows. Linear mixed models were used to quantify variance components for each trait and to estimate genetic correlations among traits. The estimated genetic parameters for hoof health traits in the present study were greater (i.e., heritability range: 0.005 to 0.27) than previously reported in dairy cows. With the exception of analyses that considered hoof health traits in repeatability models, little difference in estimated variance components existed among the various hoof-health phenotypes. Results also suggest that producer-recorded lameness is correlated with both hoof health (i.e., genetic correlation up to 0.48) and cow mobility (i.e., genetic correlation = 0.64). Moreover, cows that genetically tend to have rear feet that appear more parallel when viewed from the rear are also genetically more predisposed to lameness (ge-netic correlation = 0.39); genetic correlations between lameness and other feet and leg type traits, as well as between lameness and frame type traits, were not different from zero. Results suggest that if the population breeding goal was to reduce lameness incidence, improve hoof health, or improve cow mobility, genetic selection for either of these traits should indirectly benefit the other traits. Results were used to quantify the genetic gains achievable for lameness when alternative phenotypes are available.

Profiling Detection and Classification of Lameness Methods in British Dairy Cattle Research: A Systematic Review and Meta-Analysis

“…Developing tools to identify lameness in pre-clinical stages would allow for early intervention providing the necessary support for preventing animals from becoming obviously lame. Genetic improvement of herds based not just on production traits such as milk yield and fertility, but also on resistance to certain health condition such as lameness could offer a way to reduce the incidence of the ailment (84)(85)(86). Apart from all the different strategies that can be adopted to alleviate lameness frequency and/or its impact it must be acknowledged that it is up for farmer to make the decisions and take action in managing the health and welfare of the animals.…”

Genomic Regions Associated With Skeletal Type Traits in Beef and Dairy Cattle Are Common to Regions Associated With Carcass Traits, Feed Intake and Calving Difficulty

“…Linear type traits have been used in both beef and dairy cattle since the early 20th century to characterize the skeletal characteristics of an animal . These type traits have previously been identified as being moderately to strongly genetically correlated with a range of performance traits in cattle including feed intake (Veerkamp and Brotherstone, 1997;Crowley et al, 2011), reproductive traits (Berry et al, 2004;Wall et al, 2005;Carthy et al, 2016), carcass merit (Mukai et al, 1995;Berry et al, 2019), animal value (Mc Hugh et al, 2010), and health (Ring et al, 2018). As type trait measurements are typically taken when an animal is young (Doyle et al, 2018), they may be useful as early predictors of the correlated traits which are often measured later in life or after the animal is slaughtered.…”

Suboptimal mobility in spring calving, pasture-based dairy systems: causes and economic consequences

“…Data for 11,472 cows from 68 pasture-based dairy herds located in the Munster region of Southern Ireland were collected as part of a larger research project. The aim of the project was to collect hoof health traits from a large sample of cows, representative of the Irish dairy population, for the estimation of variance components of hoof health for consideration in national genetic evaluations (Ring et al, 2018). The average herd size was 169 (standard deviation = 115) cows.…”

“…The average herd size was 169 (standard deviation = 115) cows. The main breed of the cows were 75% Holstein, 13% Jersey, and 9% Friesian breeds, which is representative of the national population (Ring et al, 2018). Cow parity records were only available for 6,927 of the total number of cows.…”

“…The claw disorders were identified, recorded and severity scored by one of two Teagasc technicians (not the same technicians who scored BCS and mobility). Both technicians recorded a similar number of animals and a similar prevalence for each of the claw health traits, differing by only 4% on average (Ring et al, 2018). The claw disorders were identified using the claw atlas of the International Committee for Animal Recording (ICAR), 2015.…”