Since before joining Dairy Australia, in my role as Research Scientist with Agriculture Victoria and through my current role as National Feedbase and Nutrition Lead, I have been involved in a project to uncover better ways of feeding dairy cows during the first 100 days of lactation through dietary supplementation for optimal cow nutrition, health and production.
In a collaborative research initiative between Dairy Australia, Agriculture Victoria and Gardiner Foundation, the DairyFeedbase First 100 Days project has recently published practical outcomes for dairy farmers on post-calving feeding strategies that can improve lactation performance and increase profitability.
In pasture-based systems, freshly calved cows often cannot consume enough nutrients to meet the demands of milk production and must draw on body reserves. By about 70–80 days in milk, cows typically transition out of negative energy balance, allowing nutrients to be redirected toward tissue replenishment and reproduction, reinforcing the importance of adequate nutritional management during the fresh period and over the rest of the early lactation period.
The research project investigated diverse feeding strategies at different stages post-calving, including effects of different grain supplement combinations.
Central to each of these combinations was ensuring cows meet their nutritional needs for both peak milk production and superior health outcomes.
Critical stages post-calving
The first 100 days post-calving are critical for dairy cow health and productivity, as cows must rapidly increase feed intake to meet the demands of high milk production and minimise health issues.
While peak milk yield occurs about 5–6 weeks post-calving, peak dry matter intake is typically delayed until 10–12 weeks, creating a challenge to bridge this gap profitably.
The first three weeks post-calving, known as the fresh cow period, are particularly crucial as they set the foundation for milk production throughout lactation. During this time, it is essential to provide a well-balanced diet that maximises dry matter intake to mitigate negative energy balance, support peak production and maintain overall health.
Effective nutritional strategies during this period are key to ensuring a successful lactation and optimising herd profitability.
Fresh insights
The research investigated different supplements with optimal mixes of nutrients to improve feed intake after calving and focused on three key areas including:
- Nutrition in the first three weeks of lactation, commonly known as the fresh cow period.
- Nutrition from 22 to 100 days of lactation, or the early lactation period.
- Carryover effects up to 200 days of lactation.
Nutritional strategies during the fresh cow period
The first feeding strategy tested was to compare a maize grain-based mix fed with high-quality, low-fibre legume hay versus wheat grain-based mix with the same forage.
Introducing the maize grain-based mix made a big difference in dry matter intake, which increased by more than 2kg of dry matter per cow/per day, as well as milk production, which increased up to two litres per cow/per day of energy corrected milk.
This benefit also persisted from 22–70 days in milk when cows were changed to a common diet.
In contrast, a previous study using medium-quality pasture silage found no differences between maize and wheat-based mixes, underscoring the importance of feeding highly digestible, low-to-moderate fibre forages during the fresh period to maximise intake and production.
The research showed that a cow’s metabolism can be ‘programmed’ by nutritional interventions during this fresh period to produce more milk over the rest of the lactation.
Another experiment with cows grazing ryegrass pasture tested feeding a maize grain versus a wheat grain-based mix for the first three weeks post-calving, followed by a grain mix of wheat or wheat, barley and canola meal over the rest of the early lactation period.
Cows fed the maize grain in the first 21 days of lactation produced more milk and were more profitable than those fed the wheat, and this benefit persists if they received the wheat, barley and canola meal mix as opposed to wheat alone for the remainder of the early lactation period.
This outcome is estimated to lift profitability by $70 per cow over a 200-day period, compared with just feeding wheat grain.
This experiment demonstrated that maize has positive effects on dairy cows when fed in the fresh period and this benefit persists if they received the wheat, barley and canola meal mix as opposed to wheat alone for the remainder of the early lactation period.
When these grain-feeding strategies were tested on a commercial dairy farm with cows grazing ryegrass pasture, the results were encouraging.
The cows fed the maize grain mix produced about 2.4 litres per cow per day more milk than the cow fed wheat during the fresh period.
More information
We recommend dairy farmers talk to their nutritionist about feeding maize grain in the fresh cow period with high-quality pastures or forages to profitably achieve higher feed intake and milk production.
Similarly, chat to the nutritionist about formulating the early lactation grain mix with wheat, barley and canola meal, as this performs better in terms of milk production and profit.
Contact a Dairy Australia regional team to find out more about workshops or visit Feeding & Farm Systems | Dairy Australia.
