Winter/Liquid Milk Production

Why is this research important?

Winter-milk producers are a vital component of the dairy sector to achieve a consistent daily supply of quality fresh milk for our domestic market. These producers also provide the volume of winter milk required for the manufacture of specific products. In 2021/22, there were approximately 1,286 registered liquid-milk producers that supplied 10% of national production (915 million litres). A further 600-800 producers are estimated to produce winter-milk under various non-registered price incentive schemes. Winter-milk production is reliant on indoor feeding of conserved forages and concentrate feeds, and hence sustainability challenges such as reducing annual feed costs, reducing dependency on imported protein sources and reducing greenhouse gas emissions are particularly pertinent to these producers.

What the research tells us

Pasture and Genetics

At the Teagasc Winter-Milk farm in Johnstown Castle, a strong emphasis is placed on maximising the proportion of high quality grazed pasture in the cow’s diet. Research has demonstrated that current grassland management tools provide a strong framework for winter-milk producers, subject to some slight adjustments. During the autumn period, pre-grazing yield should be maintained below 1800 kg dry matter/ha, as the freshly calved cow can struggle to achieve adequate intake on heavy autumn covers. Furthermore, a closing average farm cover of 650 kg dry matter/ha should be targeted to allow a greater opening farm cover in early spring. The Teagasc Winter-Milk herd consists of 90 high-EBI (€290) Holstein Friesian cows. The herd’s calving interval is 370 days with a 6-week calving rate of 78%. Over the last four years, the herd has averaged 7,540 kg of milk, 3.66% protein, 4.52% fat and 616 kg of milk solids with 1,600 kg of concentrate supplement (approximately 1,000 kg during winter-housing and 600 kg during the grazing-season). Strict breeding management rules (e.g. 10-wk breeding period and no recycling of cows between breeding seasons) ensures that the herd has an optimal calving pattern to maintain high feed efficiency, reduce annual feed costs and minimise the amount of surplus to contract milk sold during November to February.

Home-Grown Protein Sources

During the winter-feeding period, the demand for high-protein feed ingredients increases because of inadequate protein supply from conserved forages. Currently, there is a major deficit in the supply of these ingredients, with the EU agricultural sector importing the majority of its requirements (~71%). Several experiments have been performed investigating the inclusion of home-grown or EU-grown protein sources (e.g. field beans and rapeseed meal) in Irish winter-milk diets. Initial life cycle assessment modelling indicated that carbon intensity per hectare and per kg of milk was reduced when cows consumed the home-grown protein ingredients, but animal performance was also reduced (-20 kg of milk solids/cow/lactation) compared with cows fed standard protein ingredients. The reduced performance was likely due to inadequate metabolisable protein/amino acid supply and further investigations are currently on-going evaluating strategies to overcome these limitations. It is important to note that the experiments investigated the full replacement of imported protein ingredients. The practice currently used in the industry is to use some inclusion of home-grown protein sources in tandem with inclusion of imported soybean, resulting in satisfactory animal performance.

Reducing Methane Emissions

Enteric methane is responsible for 62.5% of Irish agricultural emissions; hence, reduction of methane emissions will play a critical role in achieving the green-house gas reduction target for the agriculture sector of 25% by 2030. Mitigation solutions currently available include improving animal genetics, improving pasture quality and methane reducing feed additives. At the Teagasc Winter-Milk farm, several strategies have been investigated to reduce the methane emissions from winter-milk cows. A promising outcome from the experiments was that cows fed a feed additive treatment produced 26% less methane (330 g/day) compared with cows fed a control diet that did not contain the feed additive (447 g/day).

Dissemination

A wide range of knowledge transfer events are held each year to achieve impact in the winter-milk sector. Examples include ‘Winter-Milk Open-Day 2023’, ‘Winter-Milk Week 2022’ and several podcasts and presentations. The key elements addressed included reducing annual feed costs, increasing total forage utilised at farm level, improving herd fertility outcomes and optimising forage digestibility.

Johnstown Castle Winter-Milk herd receiving their indoor experimental diets

Outputs

• Teagasc National Winter-Milk Open Day 2023
• Teagasc National Winter-Milk Week 2022
• Improving Profit and Sustainability on Winter Milk Farms - Key Management Practices

Links to papers

• TResearch Winter 2023 article (pp. 34-35)
• Teagasc Moorepark Open Day 2023
• Teagasc Johnstown Castle Open Day 2022 (pp. 95-96)

More information

• Teagasc National Winter-Milk Open Day 2023 podcast
• Examining the costs of winter milk production
• Pasture and Genetics
• Reducing methane emissions

Contacts

Winter-milk research: Michael Dineen (Michael.Dineen@teagasc.ie) and Joe Patton (Joe.Patton@teagasc.ie)
Winter-milk farm management: Aidan Lawless (Aidan.Lawless@teagasc.ie)
Winter-milk knowledge transfer: Joe Patton (Joe.Patton@teagasc.ie) and James Dunne (James.Dunne@teagasc.ie)