Negative energy balance (NEB) occurs when the energy demands for lactation, maintenance, and activity surpass dietary intake, leading the cow to mobilize its fat and muscle to compensate for the energy deficit.
Causes of NEB
- Energy intake: if cows are not consuming enough feed to meet their energy requirements, they may experience negative energy balance. This can often occur from bad quality feed.
- Body condition score: cows with a low body condition score (BCS) when they enter the calving period may have inadequate energy reserves to support the demands of calving and early lactation, increasing the risk of negative energy balance.
- Metabolic disorders: certain metabolic disorders, such as ketosis, can disrupt a cow’s energy metabolism, leading to negative energy balance. Ketosis often occurs in early lactation when cows mobilize body fat to meet energy demands. This mobilization results in increased levels of ketone bodies in the blood.
- Stress: environmental stressors, such as heat stress or overcrowding, can reduce feed intake in cows, leading to negative energy balance.
- Health issues: an illness or disease can decrease feed intake and impair nutrient absorption, contributing to negative energy balance.
Losses incurred
- NEB affects milk yield, milk composition and the reproductive system, leading to significant economic losses. NEB can result in abomasal displacement, laminitis, ketosis, and other metabolic diseases. On average, cows experiencing high NEB incur losses of 5.5 litres of milk per day or €3.2 per cow per day.
- In dairy cows, the induced changes in key metabolic hormones have been associated with a reduction in reproductive potential and lower conception rates. An unsuccessful insemination is evaluated at approximately €100 loss per cow. (Liang D, Arnold LM, Stowe CJ, Harmon RJ, Bewley JM. “Estimating US dairy clinical disease costs with a stochastic simulation model.”)
How do we detect it?
The Brolis in-line milk analyzer measures the composition of each cow’s milk during every milking. The system detects negative energy balance by identifying any significant increase in the fat-to-protein (F/P) ratio. Additionally, the system considers factors such as the milk yield, content of other milk parameters, cow’s breed and lactation period to make accurate assessments.
Economic benefits of preventive NEB treatment
The NEB case study was conducted with the aim of assessing the economic benefits of preventive treatment for cows with negative energy balance. The results showed that, on average, treated cows produced 3.46 kg more milk (ECM) per day compared to untreated cows over the 122 days. Furthermore, the additional profit per treated cow over the same period was €133.36, considering the cost of treatment.
Case on the farm: detection and treatment of NEB
- The cow entered the high-risk stage of NEB from the beginning of lactation but did not show any clinical signs.
- On 27th of September, veterinary staff examined the cow and suspected subclinical ketosis. The cow was also limping slightly.
- The cow received a few days of treatment with propylene glycol, vitamins, probiotics, and liver-supporting medication.
- A significant improvement in the F/P ratio and milk production can be observed.
