Dairy cattle are an integral part of agriculture worldwide, providing many products in addition to milk for the human population. The efficient production of these products is of utmost importance and high reproductive performance is absolutely crucial to this. In September 1999, Dr Michael Diskin led a committee (Dr Joseph M. Sreenan, Prof James Roche, Prof Maurice Boland and Dr Diarmuid O’Callaghan) to organize an extremely successful and informative occasional meeting ‘Fertility in the High-Producing Dairy Cow’, jointly with the British Society of Animal Science (BSAS) in Galway, Ireland, to address the important issue of declining reproductive performance in dairy cattle. The full papers were later published in an occasional publication by BSAS (2001). As discussed by Dr John Robinson in the conference summary, ‘…delegates, after a starting point of uncertainty about how to deal with the problem [infertility], came away very well informed scientifically and, if perhaps with varying views as to the best way forward, more aware of the multi-disciplinary research and development approach now being used to investigate it’. Dr Robinson concluded his summary by stating ‘Reversing this relentless decline in dairy cow fertility, while simultaneously sustaining high yields, is not going to be easy……it is a challenge that will require great interchange of information and ideas between science, practice, research and development. The establishment of contacts and beginning of such interchange has been initiated during this [Galway, 1999] meeting and it is essential that this is sustained.’
Now, exactly 8 years later, it seemed time for those representatives from all disciplines involved in attempting to improve dairy cattle fertility to reconvene. Since 1999, the continued and well-documented decline in dairy cow fertility worldwide (Royal et al., Reference Royal, Darwash, Flint, Webb, Woolliams and Lamming2000; Lucy, Reference Lucy2001; Mayne et al., Reference Mayne, McCoy, Lennox, Mackey, Verner, Catney, McCaughey, Wylie, Kennedy and Gordon2002; Washburn et al., Reference Washburn, Silvia, Brown, McDaniel and McAllister2002; Lopez-Gatius, Reference Lopez-Gatius2003; Swedish Dairy Association, 2005) has prompted new research into diverse aspects of dairy cow reproduction. To name but a few areas and publications, these include aspects such as genetics (Royal et al., Reference Royal, Flint and Woolliams2002a and Reference Royal, Pryce, Woolliams and Flint2002b; Berry et al., Reference Berry, Buckley, Dillon, Evans, Rath and Veerkamp2003; Haile-Mariam et al., Reference Haile-Mariam, Morton and Goddard2003; Philipsson and Lindhe, Reference Philipsson and Lindhe2003; Wall et al., Reference Wall, Brotherstone, Woolliams, Banos and Coffey2003; Holmberg and Andersson-Eklund, Reference Holmberg and Andersson-Eklund2006; Weigel, Reference Weigel2006; Hayhurst et al., Reference Hayhurst, Sørensen, Royal and Løvendahl2007; Petersson et al., Reference Petersson, Berglund, Strandberg, Gustafsson, Flint, Woolliams and Royal2007; Veerkamp and Beerda, Reference Veerkamp and Beerda2007), nutrition (Kadokawa and Martin, Reference Kadokawa and Martin2006; Robinson et al., Reference Robinson, Ashworth, Rooke, Mitchell and McEvoy2006; Chagas et al., Reference Chagas, Bass, Blache, Burke, Kay, Lindsay, Lucy, Martin, Meier, Rhodes, Roche, Thatcher and Webb2007; Friggens and Newbold, Reference Friggens and Newbold2007; Wathes et al., Reference Wathes, Bourne, Cheng, Mann, Taylor and Coffey2007) Economics (Vargas et al., Reference Vargas, Groen, Herrero and Van Arendonk2002; Esslemont, Reference Esslemont2003; Santarossa et al., Reference Santarossa, Stott, Woolliams, Brotherstone, Wall and Coffey2004; McGuirk et al., Reference McGuirk, Forsyth and Dobson2007), veterinary interventions and management (Refsdal, Reference Refsdal2000; Roche et al., Reference Roche, Mackey and Diskin2000; Sheldon et al., Reference Sheldon, Noakes, Rycroft and Dobson2004; Bertoni et al., Reference Bertoni, Trevisi, Han and Bionaz2006; Diskin et al., Reference Diskin, Murphy and Sreenan2006; Drillich et al., Reference Drillich, Mahlstedt, Reichert, Tenhagen and Heuwieser2006; Mansell et al., Reference Mansell, Cameron, Taylor and Malmo2006; Mee, Reference Mee2007; Valergakis et al., Reference Valergakis, Arsenos and Banos2007). It has also prompted the development of new technology and applications in the field. The purpose of this conference and subsequent publications is to provide an update on these activities since 1999 and to provide a forum for ‘bridging the gaps’ between the different disciplines involved.
Invited and submitted theatre and poster sessions included new, up and coming presenters in addition to keynote speakers from across the globe, recognized as international experts in their field. As was the case at the 1999 meeting, the content is of direct interest to scientists, university lecturers, veterinarians, farm advisors and technical representatives working within the dairy industry as well as many dairy farmers. The following papers are a collection of research published at the conference.
Dobson et al. (Reference Dobson, Walker, Morris, Routly and Smith2008) highlight the factors predisposing to lowered fertility and disrupted oestrus in order to review ‘Why it is getting more difficult to successfully AI dairy cows’. The review by Morris and Diskin (Reference Morris and Diskin2008), considers the current knowledge on embryo growth, development and survival in the cow and how these may be influenced by changes in uterine function and the concentration of systemic progesterone. Leroy et al. (Reference Leroy, Van Soom, Opsomer and Bols2008), continues the investigations into the embryo reviewing a number of possible mechanisms linking negative energy balance to oocyte quality. Furthermore, in the event an embryo is formed after fertilization, the paper investigates whether the quality of early life is impaired. Interestingly, the pre-natal environment is known to have a large impact not only on foetal development but also health in later life and since its identification in 1986, the developmental origins of adult disease, has been applied to many areas of science. The paper by Gardner et al. (Reference Gardner, Lea and Sinclair2008) reviews specifically for the first time ‘Developmental programming of reproduction and fertility in farm animals’.
The average dairy cow survives only three lactations. This severely limits opportunities for on-farm selection of breeding cows in addition to presenting a welfare issue and causing economic loss. Wathes et al. (Reference Wathes, Brickell, Bourne, Swalia and Cheng2008) review a range of factors influencing heifer survival and fertility on commercial dairy farms. In their paper titled ‘Integration of physiological mechanisms that influence fertility in dairy cows’, Garnsworthy et al. (Reference Garnsworthy, Sinclair and Webb2008) review the potential modulating role of additional factors, such as peripheral metabolites, metabolic hormones and locally produced growth factors suggesting that progress towards restoring fertility could be made by an integrated approach that allows for interactions between physiological mechanisms that regulate metabolism and reproduction. Following parturition, contamination of the uterine lumen by bacteria is ubiquitous, and uterine health is impaired in cattle because infection persists. In their paper, Williams et al. (Reference Williams, Herath, England, Dobson, Bryant and Sheldon2008) discuss the numerous mechanisms underlying uterine disease in cattle from the whole animal to the cell. Finally, developing new research areas in the field of functional genomics, such as epigenetics, RNA interference, variable copy numbers and nutrigenomics, are discussed in the review by Beerda et al. (Reference Beerda, Wyszynska-Koko, te Pas, de Wit and Veerkamp2008), including their promising future value for dairy cow fertility.
The meeting promoted one of the major aims of the BSAS, which is to encourage fruitful exchange of information and ideas between all of those involved in the science and practice of animal production.
The organizers are very grateful for the sponsorship from BASF, Genesis Faraday, Genus ABS, Holstein UK and CIS, Merial, Pfizer, Reproduction Specialities Inc., The Stapledon Memorial Trust and World Wide Sires Ltd. We would also like to thank everyone who has contributed to bringing this excellent international conference to fruition.