Improvement of fertility in cows

PROLIFIC - a Pluridisciplinary study for a RObust and sustainabLe Improvement of Fertility In Cows. The project will address the problems of reproductive success in the cow using a pluridisciplinary approach to find new phenotypes, to deliver targets for genomic selection of fertility, to improve biotechnologies and to find molecular indicators of the ability of the cow to support the pregnancy.

Fertility is crucial for sustainability

Reproductive performance is central to farm sustainability as it underpins cow productivity and longevity. At the herd level, good reproductive performance is crucial for economic sustainability. At the individual level, it is a key factor that affects the cow’s health, welfare, and also the animal’s robustness. The sustainability of dairy cattle farming systems relies in large part on the ability of cows to maintain reproductive performance as they cope with the constraints imposed by environmental conditions and livestock practices. Genetic selection has been highly successful and has resulted in modern dairy cows with very high milk yields, but there has been a parallel reduction in fertility. This has created a situation where farmers are losing control of this key component of cattle system sustainability.

The aim of PROLIFIC

The aim of PROLIFIC is to unlock the potential for proactive herd management by providing the farmer with improved tools for on-farm reproductive monitoring and management. This will be achieved by a multidisciplinary approach between genomics, genetics, nutrition and herd management, and by integrating existing and obtained knowledge into predictive models that will allow development of innovative solutions for a robust and sustainable improvement of fertility in cows.

From genomics to selection

For this project progesterone and other data will be collected from research herds of the project partners, but also from commercial farms equipped with a Herd Navigator (DeLaval, FOSS) that measures progesterone in milk routinely on farms. Data from the Herd Navigator have been used to define new fertility traits for which genetic parameters have been estimated. Next steps are genome-wide screens for associations between DNA markers and these traits to identify genomic regions associated with these fertility traits. Such regions will then be fine-mapped using sequence data, which hopefully leads to the identification of causal genes. All genetic information obtained will then be taken into account to develop an optimal breeding strategy for improved fertility.

Multilevel integration and modelling of reproductive performances at different scales

This project also aims at mathematical modelling of the reproductive physiology and the chance of reproductive success on a cow level. This model is then used to predict how this is affected by nutrition and milk production. Extrapolation of this modelling to the herd level will then allow to predict on a farm level the impact of reproductive management measures on reproductive success and economic benefit.

The focus of Wageningen UR Livestock Research will be on reproductive modelling on the cow model, to find which elements of the reproductive physiology may be responsible to reproductive (dys)function. In addition these elements will be related to genes or DNA markers associated with fertility traits.