Genetics of animal health and disease in cattle

Abstract

There have been considerable recent advancements in animal breeding and genetics relevant to disease control in cattle, which can now be utilised as part of an overall programme for improved cattle health. This review summarises the contribution of genetic makeup to differences in resistance to many diseases affecting cattle. Significant genetic variation in susceptibility to disease does exist among cattle suggesting that genetic selection for improved resistance to disease will be fruitful. Deficiencies in accurately recorded data on individual animal susceptibility to disease are, however, currently hindering the inclusion of health and disease resistance traits in national breeding goals. Developments in 'omics' technologies, such as genomic selection, may help overcome some of the limitations of traditional breeding programmes and will be especially beneficial in breeding for lowly heritable disease traits that only manifest themselves following exposure to pathogens or environmental stressors in adulthood. However, access to large databases of phenotypes on health and disease will still be necessary. This review clearly shows that genetics make a significant contribution to the overall health and resistance to disease in cattle. Therefore, breeding programmes for improved animal health and disease resistance should be seen as an integral part of any overall national disease control strategy.

Risk factors associated with detailed reproductive phenotypes in dairy and beef cows

“…It is now widely accepted that aggressive single-trait selection for greater milk production in dairy cattle has resulted in unfavourable genetic trends in both animal health (Berry et al, 2011) and reproductive performance (Albarrán-Portillo and Pollott, 2013). Genetic selection for terminal traits in beef cattle is also known to have unfavourable correlated responses in reproductive performance (Berry and Evans, 2013).…”

Modelling impacts of performance on the probability of reproducing, and thereby on productive lifespan, allow prediction of lifetime efficiency in dairy cows

“…It is widely accepted that single-trait selection for greater milk production in dairy cattle is associated with significant declines in animal health (Berry et al, 2011) and reproductive performance (Albarrán-Portillo and Pollott, 2013). These problems not only impair the lifetime production efficiency of dairy cows via reduced longevity by increasing involuntary culling (Seegers et al, 1998), but also increase veterinary and reproductive costs (Hogeveen et al, 2011) and environmental losses (Garnsworthy, 2004), and affect animal welfare (Oltenacu and Algers, 2005).…”

Breeding strategies to reduce environmental footprint in dairy cattle

“…However, the genetic variance of a trait is equally important in achieving genetic gain and the coefficient of genetic variation in fertility traits is similar to that for production traits (Berry et al, 2003b). For a given number of progeny, the accuracy of selection for a low heritability trait will be less than that for a high heritability trait and, therefore, genetic gain for the former will be less (Berry et al, 2011a). High accuracy of selection (i.e.…”

“…The low heritability is negated against through access to phenotypic records on a large population of animals, thereby resulting in accurate estimates of genetic merit for animals with large progeny group sizes (Berry et al, 2011a). Furthermore, phenotypic information on correlated traits, such as body condition score (Berry et al, 2003b) can be exploited to augment further the accuracy of selection for reproductive traits (Berry et al, 2003b).…”