The Crichton Royal Farm, close to Dumfries, was the centre of interest at a meeting of the Dairy Science Forum at a visit in November 2011. The visit was hosted by RABDF Council member Dr Dave Roberts, who is Head of SAC Dairy Research Centre at Crichton Royal Farm and a member of the Forum. During the visit the Forum members were updated on the Centre’s latest research work on dairy farming systems, including grassland and nutrition.Crichton Royal Farm has an area of over 250 ha of freely draining soils and rises from near sea level to about 45 m. There are two dairy units, Crichton and Acrehead with some 480 cows milked three times daily and yielding about 9000 litres. Forage maize is grown for maize silage and wheat is made into alkakage as alternative forages to grass silage. The majority of the land is however devoted to growing grass for grazing and silage.The main aim of the research programme at the Dairy Research Centre is to develop and test sustainable breeding and management systems for dairy cattle, with particular emphasis on improving health and welfare of the animals and on measuring the effects that these systems have on the environment. It aims to develop sustainable systems of dairy production and to support the dairy industry with expert advice and training. The genetic work on the Langhill pedigree herd which started in 1970 is well respected in the industry and has continued through study of the effect of different management systems on cows of different genetic merit. Interesting studies on welfare and behaviour research are currently underway with the aim of assessing the overall impact of continuous housing on the national herd. The outcome will influence housing design such as the purpose built loafing areas, provision of feed and “furniture” such as brushes, and importantly the development of techniques to assess welfare by measuring animals themselves rather than the quality of the housing.The programme includes development of a technical understanding of changes that can be made to land management to ameliorate climate change especially greenhouse gas emissions, improving energy use in the dairy, measuring cow methane levels in addition to the challenges faced when farming in an NVZ.
November 11th 2008
Visit to Institute of Biological, Environmental and Rural Sciences (IBERS),
Aberystwyth University
IBERS was formed on 1 April 2008 through the merger of the former BBSRC institute; the Institute of Grassland and Environmental Research (IGER), and two Aberystwyth University departments; the Institute of Rural Sciences and the Institute of Biological Sciences. Professor Wayne Powell started as the new institute director on 1 September 2008. Following its formation, IBERS now has over 300 staff, farms over 1200 ha, and teaches about 1200 undergraduate and postgraduate students.
A number of presentations were made to highlight some of the plant-orientated research taking place in the Animal and Microbial Sciences pillar of IBERS. Topics presented included:
The role of plant enzymes in rumen proteolysis, by Dr Alison Kingston-Smith. Dr Kingston-Smith explained how our understanding of plant proteases has increased in relation to their effects on the breakdown of forage proteins following consumption by the ruminant animal. Until relatively recently it has been assumed that the initial degradation of plant proteins was carried out by proteases released from colonising microbes in the rumen. However, incubation of plant material in microbe-free buffer in otherwise rumen-like conditions (dark, warm and anaerobic) results in similar patterns of protein disappearance and amino acid appearance as occurs in similar conditions in the presence of rumen microbes. Therefore, differences in the activity of plant proteases, at least in terms of their action with regards to recently ingested forage material, offers scope for manipulation by plant breeders to reduce inefficiency of use of plant proteins for ruminant (meat and milk) production.
Microbial colonisation of feed in the rumen, by Sharon Huws and Joan Edwards. Dr Huws outlined the importance of the microbial population of the rumen in terms of the ruminant animal being able to use parts of its diet not available to monogastric animals. A key element to this is the development of biofilms on the surface of feed particles, which are structured communities of bacterial cells formed on the surface of a feed particle, covered by self-produced layers of extracellular polymeric substances (EPS, or ‘slime’). Slime formation has a protective function, to prevent protozoa from engulfing bacteria, and also to help concentrate (and prevent the removal) of degradative enzymes secreted by the bacteria.
Polyphenol oxidase in red clover and potential benefits in ruminant nutrition, by Dr Ana Winters. Polyphenol oxidase (PPO) is a very common enzyme that catalyses the oxidation of phenols to quinones. This process leads to the undesirable browning reaction in damaged fruit and vegetables. In forage plants, such as red clover, PPO catalyses the formation of quinones can bind with plant proteins and reduce their availability to microbial degradation in the silo and also in the rumen. Reducing the speed and/or extent of degradation of forage proteins in silage and in the rumen means that less nitrogen may be absorbed from the rumen as ammonia, and thus excreted in urine as urea, thereby reducing the environmental footprint of ruminant agriculture. PPO activity is high in red clover, but not white clover, some important forage grasses (such as cocksfoot) also have high PPO activities. Although cocksfoot is not agronomically important in the UK, it demonstrates the potential for use of PPO in other more important forage grasses.
Effects of grass and clover mixtures on methane production, by Dr Eun Joong Kim. Ruminant livestock account for a large proportion of the methane emitted from the UK. The project that Dr Kim is working on is testing the effect of using mixtures of high water-soluble carbohydrate (WSC) varieties of ryegrass on the output of methane by sheep. A series of in vitro and in vivo measurements are being used to compare varieties with different heading dates, grown as monocultures and as mixed swards, on methane production. Preliminary data suggests that increased WSC concentration in the grass dry matter reduces the amount of methane produced, possibly because the additional WSC encourages a rumen fermentation that promotes propionate production (acting as a sink for metabolic hydrogen) rather than acetate production (in which carbon dioxide acts as a sink, producing methane).
Role of dietary fatty acids in ruminant product quality, by Dr Michael Lee. Despite the fact that fresh grass contains relatively high concentrations of polyunsaturated fatty acids (PUFA), ruminant products, in the form of meat and milk, contain a relatively high proportion of saturated fatty acids as a result of the biohydrogenation by the rumen microbial population. Work at IBERS is being carried out to determine the best ways to improve the concentrations of fatty acids in meat and milk that are linked with beneficial effects on human health, such as conjugated linoleic acid (CLA). This includes investigating the effect of genetics (e.g. dairy versus beef cattle for meat production) and nutrition (e.g. use of red clover versus ryegrass).
Visits were also made to the glasshouses to hear about plant breeding activities being carried out in the Crop Breeding and Genomics and the Plant-Based Biorenewals pillars at IBERS. The former aims to use knowledge of the plant genome to breed (mainly) forage plants that are resilient to climate changes (e.g. drought tolerance) and improve plant nutritional value for animal feeding. The latter is developing plant-based renewal energy resources for biomass, biofuel, and bio-feedstock requirements.
A tour of the metabolism unit at Trawsgoed Research Farm was also made. This has facilities for housing and measurements to be made on individual beef, sheep and dairy animals. This is equipped to measure nitrogen partitioning in the animal, to determine the effects, for example, of different diets on nitrogen use efficiency, with the aim of reducing N excretion from the animal. Equipment is also available that enables methane production from sheep offered different diets to be measured, again with the aim of reducing the environmental impact of livestock farming.