Enhancing precision within winter feeding systems for dairy cows

Project code: D-82-16

Objectives:

The overall objective of this research programme is to introduce increased precision into concentrate allocation and management strategies for dairy cows, and to increase reliance on quality forage in dairy cow diets, through 1) an enhanced focus on individual animal data, by 2) making use of individual cow precision monitoring technologies, 3) through the development of intake prediction algorithms and, 4) by exploring the role of Mid-Infra Red Reflectance milk technology to predict animal characteristics.

This overall objective will be achieved through the following specific objectives:

1. To quantify the response (especially an understanding of forage intake) at a 'herd' and 'individual cow' level when freshly calved dairy cows are offered concentrates on a 'feed-to-yield' basis, alongside either a high or moderate quality grass silage (Winter 1).
2. To examine the impact at both a 'herd' and 'individual cow' level of moving to an enhanced level of precision within individual cow feeding systems, by taking account of individual cow live weight, milk yield, milk composition, and actual intakes (seeking to precisely meet the energy requirements of each individual cow throughout the early lactation period) (Winter 1).
3. To examine the impact of 1) and 2) above on cow welfare/behaviour (Winter 1 and 2).
4. To seek to develop algorithms to predict the relative forage intakes of individual cows in a herd (as a proportion of the total forage offered), based on individual performance data, and stage of lactation, thus bringing increased precision to feed-to-yield type systems (Winter 1 and 2).
5. To assess the use of a range of precision technologies in monitoring dairy cows, and the potential to integrate information from these into feed management practices, with the ultimate objective of improving efficiency (Winter 1 and 2).
6. To examine the use of Mid Infra-red Spectroscopy as a means of developing management tools to provide early warnings of problems, and to improve efficiency of production (Winter 1 and 2).
7. To repeat objectives 3 - 6 above during a second winter feeding study (Winter 2) in a follow up study (to be defined, based on the outcomes of study conducted in Winter 1: Objectives 1 and 2), but with a likely focus on the maximising the potential of very high quality forages.

Research Provider: AFBI

Project lead: Conrad Ferris

Project Team: Conrad Ferris, Tianhai Yan, John Archer, Alan Gordon

Background

Dairying is a key component within the Northern Ireland agricultural sector. However the profitability of the dairy sector can vary greatly from year to year, with milk price and costs of inputs being two of the key factors influencing returns. With regards milk price, this is largely outside of the control of the Northern Ireland dairy farmer, with local milk prices increasingly determined by world market forces, a consequence of trade liberalisation and changes in CAP support. Similarly, the costs of feed, fuel and fertiliser (main input costs associated with dairying), are largely determined by international factors outside of the control of local farmers. These include the strength of the global economy, oil prices, together with weather conditions in the main cereal/protein crop exporting regions of the world. While farmers have little control over the costs of feed, fuel and fertiliser, they can optimise the use of these resources on their own farms, and in so doing control inputs costs within their own farm business. This is particularly true for feed costs, and especially the costs of concentrates, which currently represent approximately 60-70% of variable costs on Northern Ireland dairy farms.

CAFRE Benchmarking data indicates that average per cow concentrate inputs on benchmarked dairy farms within Northern Ireland increased from 1.1 tonnes/year in 1997/1998, to 2.6 tonnes/year in 2015/2016, while during this same time concentrate costs have almost doubled. With an increasing world population now competing for many components of concentrate feeds, feed costs are likely to continue to increase long term. During this same period 'milk produced from forage' decreased from 3200 to 1686 litres/cow/year.

Concentrate inputs have increased for a number of reasons, including historically low world cereal prices, and the rapid increase in the genetic merit of the Northern Ireland dairy herd during the last two decades (and the associated increase in milk output per cow). These higher yielding dairy cows are without doubt much more difficult to manage nutritionally, especially with poorer quality forage diets. In early lactation, these higher yielding cows experience a dramatic increase in milk production which has not been matched by a proportionate increase in energy intake (Veerkamp et al., 1995; Ingvartsen et al., 1999). The resulting energy deficit, better known as negative energy balance (NEB), is manifest in the mobilisation of body tissue reserves. Severe and prolonged periods of NEB can predispose the dairy cow to metabolic disorders, immune-suppression, reproductive failure, and behavioural abnormalities, all of which contribute to a decline in the cow's general well-being (Nielsen, 1999). The approach most often advocated to reduce NEB is to increase nutrient intake. This can be achieved by either increasing total dry matter intake or by increasing the nutrient density of the diet by either improving forage quality (high digestible grass silage/inclusion of maize silage), or by increasing concentrate feed levels. Nevertheless, this over reliance on concentrates has developed at the expense of making cost effective use of quality locally grown forage resources, the latter traditionally regarded as providing a key competitive advantage to ruminant based livestock sectors within Northern Ireland. The overall outcome has been the development of higher cost less profitable dairy systems within Northern Ireland. Indeed a recent modelling exercise of Northern Ireland milk production systems by Anderson et al. (2011) has clearly demonstrated that moving to higher concentrate input-higher milk output systems reduces the overall financial robustness of these systems across a wide range of milk price/concentrate price/fertiliser price scenarios. This research programme has clearly demonstrated that moderate input-moderate output systems are more profitable than either high or low input systems.

Project

The project seeks to increase efficiency in production systems, and will do so by addressing three key sub-areas, namely: 1) better use of home grown resources; 2) new developments in precision agriculture; 3) precision in nutrient/feed input requirements.

On many Northern Ireland dairy farms the cost effective use of quality forage resources has been replaced by an over reliance on concentrates, resulting in higher-cost, less-profitable and environmentally less sustainable dairy systems. However, concentrate feeds will continue to play a key role within local dairy systems due to the limited land base on many farms and the milk yield potential of the cows on farms. Moving forward, a two 'pronged' approach is required, and this will involve making more use of quality home produced forages, and at the same time making more effective use of concentrate feeds.

As described below in detail, previous AFBI research has demonstrated that for a group of cows with a tight calving pattern, concentrate allocation strategy has relatively little impact on performance, when cows on each strategy are offered the same total amount of concentrates over a period of time. However, within the local dairy sector there has been a general moved towards 'precision' concentrate feeding systems which seek to target concentrates to individual cows according to their milk yields. However, AFBI research has also demonstrated that due to the large number of assumptions made within these 'precision' systems, they are in-fact far from precise, and that the lack of precision may well result in either underfeeding, or perhaps more likely, overfeeding of concentrates. The overall objective of this proposal is therefore to seek to introduce more precision into these systems, and in doing so, to help make more effective use of home produced forages, by ensuring that concentrate allocation strategies are indeed optimal. This objective will be achieved by examining the response, especially the forage intake response, of individual cows when offered silages of different qualities within a feed-to-yield system. Studies will then seek to examine the impact of moving to enhanced precision feeding systems (as described in details below), and seek to identify if the precision within these systems can be further improved by modelling relative silage intakes of individual cows within a herd. Overlying these studies, assessments will be made to examine the role of precision technologies (individual cow monitoring equipment) and mid infrared spectroscopy milk analysis in providing both scientific and management information for individual cows. With regards precision technologies, great strides are being made in this area, although independent information on how effective some of these technologies are is absent. This proposal will begin to explore the role of these technologies, and especially scope for their integration into enhanced precision management systems.

Additional Information Provided by Project

This proposal seeks to goes beyond what is already known by:

Exploring relationships between silage quality and individual cow forage intakes and performance within a feed-to-yield system (previously only undertaken with high quality silages). This information is currently not available, and will help improve the accuracy of practical feeding assumptions within feed-to-yield systems.

Only one previous study has sought to feed cows according to their energy requirements, with positive effects observed. This proposal will seek to develop this strategy further by taking account of a wider range of parameters, including energy requirements for growth of heifers. The previous study was based on US rationing systems, while this will be based on FIM, the current feed rationing system for dairy cows within the UK. The proposal will seek to identify the impact of this approach on cow welfare, which has not been examined previously.

A number of equations exist by which to predict the intakes of individual cows, with these normally requiring detailed information on the composition of each individual feed stuff. The current project will not seek to predict actual intakes, but rather will seek to partition the total herd intake of the basal diet to individual cows based on readily available data (or proxies) including lactation number, live weight, current performance, stage of lactation etc. The proposal recognises the challenge of achieving this, but believe the approach may be able to lead to improved precision in feeding systems.

Inbuilt to the above studies will be the use of a range of precision technologies for monitoring individual cows. Individual studies have sought to test individual pieces of equipment, but this project will seek to integrate a range of these technologies into a production study involving very different nutritional regimes, and to test their usefulness in a practical situation, as well as examine the scientific relevance/usefulness of the data obtained. Equipment will be purchased under CIEL.

The project will allow AFBI to take its first steps into evaluating the use of Mid Infra Red Reflectance Spectroscopy as a means of developing management tools to provide early warnings of problems, and to improve efficiency of production. The AFBI studies will allow MIR spectra to be developed for higher yielding cows (and as such, for cows with a greater range of negative energy balance) than in most previous studies.

The project is proposed as encompassing 'two winters'. While nutritional regimes adopted in winter 2 will differ from those in winter 1, the actual strategies in winter 2 will be directed by the outcomes of winter 1.

Benefits

Objectives 1, 2 and 4: The main benefit will be a reduction in total concentrate usage on dairy farms through the adoption of precision feeding approaches, and more closely matching nutrient requirements of individual cows to concentrate levels in practice. This will be achieved in part by having a better estimate of forage intake during the winter period, and an improved understanding of how cows respond to poorer quality silage within a feed-to-yield system. CAFRE have estimated that the average cow in Northern Ireland is overfed concentrates by approximately 0.5 t/lactation. Based on the fact that this project tackles the winter feeding period when approximately 60% of concentrates are offered, a conservative estimate is that the project has the potential to reduce concentrate feed levels by 200 kg/cow/year on farms where the outcomes are adopted.

Assuming a concentrate cost of £250/t, and a saving of 200 kg/cow, this results in a cost saving of £50/cow. However, reduced concentrate intakes will result in increased forage intakes. Costing grass silage at £90/t DM, and assuming an extra 200 kg of forage DM is consumed (1: 1 substitution rate at higher concentrate levels), the cost of extra forage is £18/cow year. Thus the net benefit is £32/cow/year.

Objective 3: Improved cow welfare, through improved rumen health, and reduced incidence of mastitis and lameness. Improved targeting of concentrates to individual cows has the potential to improve energy balance, with improved energy balance associated with improved health, especially in early lactation. It is impossible to quantify the extent of these improvements, but with each case of mastitis and lameness costing between £100 - £200, a very conservative estimate puts a saving of £20/cow/year through improved health and welfare. Benefit = £20/cow/year.

Objectives 5 and 6: Improvements in cow management/health and fertility arising from precision technologies and the use of MIR: Precision technologies have the potential to improve cow health, fertility and overall management. Again, the magnitude of any benefit is difficult to quantify, especially as the potential of MIR developments are uncertain. However, a conservative estimate of £10/cow would appear to be achievable. Benefit = £10/cow/year.

Thus the sum of the total potential benefits from the entire project are £32 + £20 + £10 = £62/cow/year, assuming uptake of all aspects of the project.

With a dairy cow population in Northern Ireland of approximately 300, 000 cows, and assuming a 5% uptake of the full range of knowledge generated, 15, 000 cows will benefit from the research. It is of course recognised that no one farmer is likely to adopt all outcomes, but rather individual farmers would adopt components of the outcomes most appropriate to their own farm, and as such assuming a low adoption level for the full range of technologies is appropriate for this economic analysis (while in reality a higher adoption level of individual technologies is more likely in practice).

Thus if 15,000 cows are assumed to gain a benefit of £62/cow/year, the total benefit of the project in a single year is likely to be £930,000.

Benefits would begin to become apparent once the outcomes of the winter feeding studies are known. However, benefits associated with the outcomes of MIR spectra developed, and intake prediction equations would require adoption by industry partners, including milk recording agencies and milking parlour/feeder software manufacturers, and this is likely to take a number of years once the project is complete.

Other material related to this project:Improving milk composition during the winter period through feeding

Technical report can be found HERE.