Latest research: Reducing feed costs by outwintering

Published 19 August 16

OutwinteringOutwintering replacement heifers can lower rearing costs by £150/head during the winter period however careful management is vital to ensure optimal performance, writes AHDB’s Dr Debbie McConnell.

With heifer rearing the second largest cost on dairy farms after feed and forage, identifying cost-effective strategies for managing replacement youngstock is key. Through survey work, commercial farm monitoring and trials, researchers at Harper Adams University (HAU) and SRUC have been investigating current outwintering practices in GB and comparing the performance of outwintered animals with housed youngstock.

Around 70% of outwintering takes place on spring block calving farms, however outwintering replacement heifers may also be a cost-effective option for farmers managing a higher input system.

To investigate this, HAU followed 48 heifers, split into three management groups, through the winter period and into their first 100 days in milk. Two groups were outwintered, on either deferred grazing and grass silage or fodder beet and grass silage. The other group was housed and fed grass silage and concentrate through the winter months.

The results show early lactation milk performance and fertility were not affected by either forage type or outwintering, indicating that with careful management heifers destined for high-input systems can be successfully outwintered.

Throughout the winter months, animal live weight gains were high, averaging 1.1 kg/head/day and similar gains were observed for animals outwintered on fodder beet compared to those housed (Figure 1). The heifers outwintered on deferred grazing has lower live weight gains (0.95 kg/head/day) and had a small reduction in body condition score over the outwintering period. Results from the trial suggests animals outwintered on deferred grazing may require additional supplementation during January and February, when grass quality is lower, or in particularly wet periods.

Outwintering table

Figure 1: The effect of outwintering on fodder beet (F), deferred grazing (G) or housing (H) on the live weight gain (LWG) and body condition score (BCS) change of in-calf replacement heifers during the winter months.


Financial analysis of outwintering systems highlight that feed costs for outwintering on fodder beet or deferred grazing were approximately 70-80% of housed animals but varies dependent on crop yield.

However, the largest financial benefit from outwintering 1-2 year old heifers is the potential savings in capital costs. In total, the study highlight the potential to reduce rearing costs during the winter period by outwintering by approximately 50%, or £150/heifer.

Professor Liam Sinclair, who headed up the research team comments ‘ Outwintering can certainly be a cost effective method of managing replacement heifers in a range of systems, however cost savings can only be realised if good animal performance is achieved.’

‘Our on-farm work has shown that there can be a wide range in animal performance over the outwintering period regardless of the type of forage used. It is the farms that are regularly measuring and monitoring growth rates that achieve good animal performance and this will help them achieve maximum cost-benefit from the system’.