Dairy herd health

Issued: Tue, 16 Dec 2014 17:49:00 GMT

Managing carbohydrate overload of the rumen

Dairy herd feedingRuminants have evolved to accommodate microorganisms that can digest fibrous feeds, which are generally low in soluble carbohydrates (starch and sugars) but high in insoluble carbohydrates (cellulose and pectins). However, the growth rate and lactational performance of ruminants can be dramatically increased by feeding concentrates with high levels of starch, a soluble carbohydrate. There is a limit to how much starch a cow can be fed before the rumen content becomes too acidic to maintain a healthy microbiome.

Prof. Nick Jonsson’s group is working on three related, industry-funded projects intended to optimise the feeding of high energy concentrates to cattle. One project is a BBSRC Industrial Partnership Award, led by University of Aberdeen, with University of Strathclyde, Harbro, Chr. Hansen, AB Vista, Quality Meat Scotland and DairyCo support. This project is a field study to characterise the pathology associated with high levels of soluble carbohydrate feeding and to identify new probiotics for cattle to prevent acidosis.

Another project, funded by AB Vista, is comparing the metabolomic, metagenomic, and transcriptomic responses to concentrate feeding of cattle and sheep, with a view to determining the extent to which sheep can substitute as a model for cattle.

A third study is a collaboration between Well Cow Ltd; Silent Herdsman and the University of Glasgow to develop a new device for monitoring rumen function.

Dairy herd health monitoring

Dairy herd health monitoring is an increasingly important component of commercial veterinary and consultancy services on dairy production units. Effectively monitoring herd performance in areas including nutrition, mastitis, fertility, lameness, infectious disease and replacement rearing allows the farmer to make improvement where necessary and maximise animal welfare and efficiency of production.

Mr Tim Geraghty and team developed a project that combines provision of routine veterinary services and herd health consultancy with active research in herd health monitoring with two large commercial dairy farms in central Scotland. The project benefits the farmers by providing service delivery and access to up to date knowledge on developments in herd health; and benefits the School of Veterinary Medicine by gaining access to commercial production units for teaching (undergraduate and post-graduate) and development of applied research projects.

Research projects completed to date include work on fertility manipulation (Viora et al., In press) and monitoring of pathogens associated with mastitis (Viora et al., 2014). Currently ongoing projects include optimising neonatal calf health and developing non-invasive methods of monitoring udder health during the last stages of pregnancy in replacement heifers. The project still has 3 years to run (with option to extend at that time); both parties are very satisfied with the outputs to date.

Evaluation of a culture-based pathogen identification kit for bacterial causes of bovine mastitis

Accurate identification of mastitis-causing bacteria supports effective management, allowing selective treatment and providing the opportunity to reduce unnecessary antimicrobial use, an important issue in food producing animals. On-farm culture-based pathogen detection kits (allowing crude identification of pathogens within 18-24h) have been used successfully for this purpose in US dairy herds, but no reports are available on UK dairy herd samples.

The culture-based mastitis pathogen detection test kit (‘VetoRapid’, Vétoquinol) results were compared with standard laboratory culture by Mr Lorenzo Viora and Mr Tim Geraghty to evaluate whether they could be used to inform a selective treatment programme. The kit has provided rapid preliminary identification of five common causes of bovine mastitis under UK field conditions, likely to be suitable for informing selective antimicrobial treatment of clinical mastitis caused by Gram-positive organisms.

A recent training day for the UK-Ireland Vétoquinol team discussed the practicality of the test kit, the main outcomes of this project, and a possible future collaboration.