Supporting metabolic efficiency and performance through targeted nutrition, including rumen-protected B vitamins
The transition period, typically defined as four weeks before and four weeks after calving, is one of the most challenging and costly stages in dairy production. Getting this period right is critical to reducing fresh cow diseases, improving milk yield, and setting cows up for a strong lactation.
Research suggests that up to 50% of dairy cows experience at least one metabolic or infectious disorder during the transition period, with subclinical conditions affecting 60–70% of cows in some herds. Common issues include milk fever, ketosis, retained placenta, metritis, and displaced abomasum, all of which impact production, fertility, and profitability.
The cost of these conditions can be substantial (Table 1), but with early preparation and good management, these risks can be reduced. While several factors influence transition success, body condition, cow comfort, and nutrition remain central to improving outcomes. Nutritional strategies that support metabolic efficiency are therefore increasingly important.
Table 1. Estimated cost of transition diseases
| Disease | Estimated cost/case ($) | Range ($) |
|---|---|---|
| Milk fever | 400 | 249-408 |
| Subclinical hypocalcaemia | 125 | N/A |
| Clinical ketosis | 240 | 138-348 |
| Left displaced abomasum | 650 | 375-650 |
| Lameness | 200 | 180-500 |
| Retained membranes/metritis | 300 | 263-472 |
Adapted from Lean & DeGaris, 2021. Range not reported for subclinical hypocalcaemia.
Body Condition
Body condition at calving is a key determinant of transition success. Cows should enter the dry period at a BCS of 4.5–5.5 (8-point scale) and maintain this through to calving.
Over-conditioned cows (> BCS 5.5) have two- to three-fold greater risk of ketosis and fatty liver, while under-conditioned cows (< BCS 4.5) may lack reserves to support early lactation.
Managing body condition in late lactation is therefore essential to reduce metabolic risk and support subsequent lactation performance.
Cow Comfort
Cow comfort is essential to maintaining dry matter intake (DMI) and supporting transition into lactation. Providing adequate housing, shelter, comfortable bedding, and sufficient lying space helps reduce environmental and social stress. Cows require around 10–12 hours/day of lying to support rumination and productivity. Heat stress can occur at 20°C, reducing DMI by 10–15%, highlighting the importance of adequate shelter.
Well-maintained laneways and yard surfaces reduce lameness, while appropriate stocking density minimises overcrowding and competition for feed and water.
Together, these factors support feed intake, rumination, and cow behaviour, while reducing the risk of mastitis and lameness.
Nutrition
Nutrition underpins a successful transition management, particularly in pasture-based systems where feed quality can vary. A well-balanced diet throughout late lactation and the dry period supports metabolic adaptation, maintains body condition, and reduces disease risk.
Optimising dry matter intake, alongside balanced energy, protein, fibre, minerals, and vitamins, is essential.
While requirements vary, the following guidelines support a successful transition program (Table 2).
- DMI: 10–15 kg DM/cow/day pre-calving and 15–20 kg DM/cow/day in fresh cows will maintain rumen fill and reduce the risk of displaced abomasum.
- Energy & Protein: Adequate digestible carbohydrates (starch, sugar, fibre) and protein will support glucose and metabolizable protein requirements.
- Minerals: Effective macro-mineral balance, including DCAD strategies, supports calcium metabolism and reduce milk fever risk.
Table 2. Recommended nutrient specifications for dry and fresh dairy cows
| Nutrient (DM basis) | Far-off dry | Transition (Low DCAD) | Fresh cows |
|---|---|---|---|
| ME, MJ/kg | 10 | 11 | 11.5-12 |
| CP, % | >12 | 14-16 | 16-19 |
| Starch, % | Up to 18 | 18-20 | >20 |
| NDF, % | >36 | >36 | >32 |
| peNDF, % | 30 | 25-30 | >19 |
| Ca, % | 0.4 | 0.5-0.7 | 0.8-1.0 |
| P, % | 0.25 | 0.25-0.40 | 0.40 |
| Mg, % | 0.3 | 0.45min | 0.3 |
| DCAD, mEq/kg | N/A | <0 | >250 |
Adapted from Lean & DeGaris, 2021
- Vitamins A, D, and E are well established in transition diets. Increasingly, B vitamins are recognised as critical in dairy cows, particularly during periods of increased metabolic demand such as transition, supporting key metabolic functions including energy metabolism, liver function, and immune response.
Although B vitamins are present in feeds and synthesised by rumen microbes, supply is often inadequate, especially during transition. In addition, dietary B vitamins are highly susceptible to rumen degradation, with up to 90% or more degraded before reaching the small intestine, limiting their availability for absorption.
Supplementation with rumen-protected B vitamins allows these nutrients to bypass rumen degradation and be absorbed efficiently. This is typically achieved through technologies such as micro-encapsulation, which protect sensitive nutrients and enable more consistent delivery to the small intestine.
Research and field studies have demonstrated improvements in health, production, and reproductive performance when rumen-protected B vitamins are included in transition diets (Table 3).
Table 3. Effect of Rumen-Protected B Vitamins on health, reproduction and milk production
| Parameter | Control | Supplemented | Improvement |
|---|---|---|---|
| Subclinical ketosis (%)* | 20 | 12 | ↓ 40% |
| Metritis (%)* | 30 | 22 | ↓ 27% |
| Mastitis (%)* | 18 | 14 | ↓ 22% |
| Six-week in-calf rate (%)# | 48.5 | 69.7 | +21 pts |
| Milk yield (kg/day) (high production)* | 42.1 | 43.2 | +1.13 |
| Milk yield (L/day) (low production)# | 21.6 | 23.2 | + 1.6 |
Footnote: Results are indicative of published research and field trial (* global trials; # Australian trial)
Conclusion
Transition success is built on getting the fundamentals right: targeting a calving BCS of 4.5–5.5, ensuring cow comfort, and providing a well-balanced diet with adequate energy, protein, fibre, minerals, and vitamins.
Strategies such as DCAD support calcium metabolism, while rumen-protected B vitamin supplementation can further improve metabolic resilience and overall herd productivity.
To learn more about how rumen-protected B vitamin blends can support your herd, speak with your nutritionist or contact your local representative.
Key Takeaways
- Up to 50% of cows are affected during transition – early preparation helps reduce this risk.
- Target BCS 4.5–5.5 at calving to minimise metabolic challenges.
- Maximise cow comfort to support feed intake and adaptation into lactation.
- Balanced nutrition is essential—energy and protein first, with rumen-protected B vitamins supporting metabolic efficiency.
Talk to your local Reid’s dairy specialist today about the benefits of our mash and the products we can offer to suit your requirements on 1300 REID FEED or enquire here >
Author
Razaq Balogun PhD, M.Agric
Technical Sales Manager Ruminant
Jefo Australia
