Predicting and enhancing lifetime resilience in dairy cattle

Resilience in animals refers to their capacity to cope with short-term environmental disturbances, with a fast return to normal status and it is an acknowledged beneficial trait of farmed livestock. Resilient cows are considered those with a high probability of completing multiple lactations, with good reproductive performance, that encounter few health problems which they overcome easily, and that are efficient and consistent in their milk production. A major contributor to an individuals' ability to be robust or resilient over their life-course is the "Developmental Origins of Health and Disease" (DOHaD), whereby insults to the developing embryo/foetus (e.g. nutritional insults, inflammatory response to disease/toxins, therapeutics, elevated concentrations of hormones) at specific developmentally sensitive time points, can alter an individuals' susceptibility to disease.

Resilience in dairy cattle at both individual and herd level is therefore considered critical to optimise health, welfare, and productivity and to reduce the environmental footprint of dairy farming as the industry targets net-zero. Rather than considering health or welfare according to individual diseases, traits or syndromes, enhanced resilience allows the possibility of a wide-ranging enhancement of health and wellbeing. Therefore, enhancing resilience could provide a step change to reduce endemic disease in dairy cows. The aim of this 12-month study is to quantify in-utero environmental factors that contribute to post-partum lifetime resilience in dairy cows, using a very large set of data (>30,000 cow lifetime records).

Our hypothesis for the research is that perturbations to dairy cows during developmentally sensitive stages of early pregnancy influence lifetime resilience of their offspring. We will quantify and predict resilience using a large dataset containing detailed lifetime records for the offspring that can be mapped back to a wide of maternal-mediated stressors experienced by the offspring at specific stages of pregnancy. We will measure the effect of known on-farm stressors during specific stages of pregnancy and evaluate how these underpin lifetime resilience. During the 12 month project we will;

1) Produce an optimised, validated predictive model of lifetime resilience for dairy cows from events that occur while in utero.

2) Identify and quantify the major factors and events during pregnancy that impact on lifetime resilience and thereby evaluate the extent to which resilience can be enhanced through optimised herd management.

Outcomes:

i) A method to predict lifetime resilience for dairy cows at birth, co-developed by farmers and vets, to inform selective breeding programmes on-farm.

ii) Identification of major factors during pregnancy (and their relative importance) that impact the lifetime resilience of the offspring to inform management strategies to optimise resilience on-farm.

HOW WILL THIS HELP FARMERS?
With an accurate knowledge of lifetime resilience for dairy heifers at birth, a farmer will be able to; i) avoid breeding from replacements with low resilience (evidence indicates that in utero insults can be transmitted via genetic changes, giving transgenerational effects), ii) minimise the factors during pregnancy that have a deleterious impact on resilience (success being monitored by an overall herd resilience score), iii) in the short term, use improved management strategies for the subset of animals with low scores, to mitigate their low resilience.

Translation to farmer:

Our industry partner has developed a software platform to house the models, construct the resilience predictions real time and deliver results direct to farmers - therefore the route to translate research findings to practice is already in place.

Resilience in animals refers to a capacity to cope with short-term environmental perturbations with a fast return to normal status; it is an acknowledged beneficial trait of farmed livestock. Resilience in dairy cattle at both individual and herd level is considered critical to optimise health, welfare, and productivity and to reduce the environmental footprint of dairy farming. Enhancing resilience has the potential to provide a step change to reduce endemic disease in dairy cows.

A major contributor to an individuals' ability to be robust or resilient over their life-course is the Developmental Origins of Health and Disease (DOHaD), whereby exposure of the gametes or developing embryo/foetus to adverse conditions at specific developmentally sensitive time points in utero, can alter an individuals' susceptibility to disease.

Our hypothesis for this research is that perturbations to dairy cows during developmentally sensitive stages of early pregnancy influence lifetime resilience of their offspring. We will quantify and predict resilience using a large dataset containing detailed lifetime records for offspring (n>30,000) that can be mapped back to a wide range of maternal-mediated stressors experienced by the offspring at specific stages of pregnancy. We will measure the effect of known on-farm stressors during specific stages of pregnancy and evaluate how these underpin lifetime resilience. Project aims are; i) to produce an optimised, validated predictive model of lifetime resilience for dairy cows from events that occur while in utero and ii) to identify and quantify the major factors and events during pregnancy that impact most on lifetime resilience and thereby evaluate the extent to which resilience can be enhanced through optimised herd management.

With this knowledge, a farmer will be able to use breeding and management strategies to maximise resilience of cows in the herd.