Project

Health and welfare of Irish dairy calves: a strategic approach to assessment and improvement

PhD project by John Barry. Previous studies investigating colostrum management on commercial dairy farms in Ireland have found it to be inadequate. Following the removal of milk quotas and subsequent expansion of dairy herds, this research targets calf health and welfare, with a particular emphasis on colostrum management.

The objectives of this project are to investigate:

  1. health and welfare of calves on commercial Irish dairy farms,
  2. the depletion rate of maternally derived antibodies and
  3. neonatal immunity following pooled and non-pooled colostrum feeding.

Health and welfare of production animals is of significant importance to consumers and producers, and influences the social and economic sustainability of animal production systems. Health refers to the animal’s physical condition, while welfare refers to the animal’s physical and mental well-being. Welfare is directly influenced by physical health, as well as the ability to express natural behaviours and affective state. Consumers favour animal products that are produced from animals managed in an animal-friendly way. For producers, animal health and welfare is essential if production systems are to operate efficiently and for economic and environmental sustainability to be achieved.
Morbidity and mortality rate of dairy calves provides an indication of health and welfare standards, both within herds and at a national level.

In Ireland, the current mortality rate of dairy calves is about 6%, which is lower than that of the US and UK, but significantly higher than a number of European countries. This relatively high mortality rate can be partially attributed to colostrum management. Colostrum is the first mammary secretion following parturition, and contains a high concentration of immunological components. Immunoglobulin G (IgG) is one such component and can provide the neonatal calf with passive immunity. Achieving adequate passive transfer (APT) of immunity is of
paramount importance as no immunity is transferred between the dam and the neonate in utero. The provision of immunity through colostrum feeding is influenced by colostrum management practises, such as timing of collection from the cow, determining quality before feeding, timing of
feeding, and volume fed. If colostrum is not managed correctly, failure of passive transfer (FPT) of immunity can occur, predisposing the neonatal calf to an increased risk of morbidity and mortality. Previous studies investigating colostrum management on commercial dairy farms have found it to be inadequate. These inadequacies were confirmed as 59 % of calves submitted for post-mortem examination in 2014 had FPT of immunity. Based on these findings, the need to address colostrum
management is evident. Following the removal of milk quotas and subsequent expansion of dairy herds, further research is required on calf health and welfare, with a particular emphasis on colostrum management. The development and application of a health and welfare assessment protocol, will allow for post-quota calf rearing to be evaluated. By investigating and identifying methods of improving colostrum management, the occurrence of FPT, and rates of morbidity and mortality, can be reduced. Combined, on-farm health and welfare evaluations and improved colostrum management techniques will allow for pre-existing issues surrounding colostrum management to be addressed.
This will also provide the insight necessary to pre-empt any further issues surrounding calf health and welfare, and colostrum management, which may arise in this post quota era.

This research has the potential to set a new precedent for calf rearing internationally and contribute to a reduction in calf morbidity and mortality, which is of significant importance to consumers and producers. Both consumers and producers could be satisfied that dairy calves are managed in a sustainable manner that prioritises and maintains high standards of animal health and welfare. Moreover, producers would benefit through increased economic performance and efficiency of their
production systems and possibly through an improved public perception.