Cows energy need

Why be concerned about the low-input cow´s need for energy?

With milk prices expected to remain volatile in the future, it is important that farmers look for options to reduce the costs of milk production. Feed inputs represent one of the most significant costs of milk production on most farms. So, it is important that cows are rationed correctly.

The SOLID project has demonstrated that different breeds and genotypes can utilise the energy for milk production with similar efficiency.  Yet, dairy farmers should be aware that cows managed on high-forage diets – like organic and low-input cows – have a greater energy requirement for maintenance.

Read more in the SOLID Technical Note:
Cows within low-input systems have greater energy requirements. Implication for ration planning  

1 photo Dairy cow energy nutritional requirements_FINAL_V2.pdf - Adobe Acrobat Pro

How does the cow use the energy? 

  • Milk production
  • Maintainance of  the basal body activity
  • Pregnancy
  • Body weight gain

The energy used for these activities is determined as consumed feed energy minus energy losses in faeces, urine and methane gas.

2 photo dairy cow energy nutritional requirements_FINAL_V2.pdf - Adobe Acrobat Pro
The energy lost in methane, and the energy lost while maintaining the cow’s body weight can be measured by using respiration calorimeters like those at The Agri-Food and Bioscience Institute (AFBI) in Northern Ireland.

Data collected from more than 1000 cows in over 50 studies conducted at the Agri-Food and Bioscience Institute in Northern Ireland (FDMI) was modelled by SOLID scientists. The aim was to determine whether cows of different breeds have different energy requirements for maintenance, and also whether the efficiency of energy use for milk production  is affected by breed.

In addition, the data were also used to identify if cows offered diets containing high levels of forage have different energy utilisation efficiencies compared to cows offered diets containing medium or high levels of concentrates.

Breeds used for SOLID´s data analysis  

  • Norwegian Red
  • Norwegian Red x Holstein crossbred
  • Jersey x Holstein crossbred
  • Holstein breed

The results demonstrated that there were no differences between Holstein cows and the ‘adapted breeds’ in terms of energy requirements for maintenance or milk production. So, the feed rationing systems, which generally speaking have been developed for Holstein cows, are also appropriate for cows of other breeds. Thus existing rationing systems are appropriate for a range of dairy cow breeds in organic and low-input production.

However, the metabolisable energy requirement for maintenance obtained within the SOLID project is much higher than currently adopted in the feed rationing systems used in a nuber of EU countries, while similar to the current UK feed rationing system (Feed into Milk models).

More forage – higher energy requirement for maintainance

The results of SOLID demonstrated that the proportion of forage in the diet did not alter the efficiency with which diet energy was used for milk production.

On the other hand it was shown that dairy cows managed under low input or organic farming regimes may require more feed energy for maintenance of their basal body activity than those managed within higher concentrate input systems.

Urgent need for a new enegy rationing system 

Cows offered high forage diets need more time and a greater effort to eat, ruminate and digest these bulky forage based diets. This issue has not been considered within energy feeding systems for dairy cows in many European countries. Thus many existing systems may underestimate the feed requirements of dairy cows managed within low concentrate input systems.

In summary, in order to improve the economic and environment sustainability of dairy farming in Europe, there is an urgent need to upgrade current energy rationing systems for low input and organic dairy farming, taking account of the findings of the current work.

How to improve sustainable organic and low-input dairying