STUBBLE turnips can provide a cost effective winter diet and help deliver consistent eating quality in lamb, according to Adas.

A trial carried out by Adas at Walford and North Shropshire College looked at lambs slaughtered in November and March on three finishing systems – grass/grass silage, stubble turnips and ad-lib concentrates.

The lambs were managed in groups of 30, and spent six to seven weeks were on each finishing system.

Feed costs were estimated for each system and results showed that stubble turnips were the cheapest – regardless of slaughter date – both in terms of overall cost per head and cost per kg liveweight gain.

For example, the costs (£/kg) of liveweight gain for the lambs finished in March on grass/grass silage, turnips and concentrates were £1.25, 45p and £1.20 respectively.

In terms of performance, concentrate-fed lambs were significantly heavier at sale and had higher overall growth rates than either grass/grass silage or turnip lambs.

They also sold around six days earlier than grass/grass silage and turnip lambs.

Grass/grass silage lambs were significantly leaner and showed poorer conformation.

Concentrates were needed to supplement the grass silage for the lambs finished in March.

Lamb samples were subjected to meat quality and taste panel assessments, which showed that all the trial groups produced meat that was tender with flavour.

The lambs finished on stubble turnips in November and March scored high marks on both counts.

However, root crops can be low in Vitamin E and producers may need to consider giving Vitamin E supplementation for animals grazing on root crops, such as stubble turnips, to improve the shelf life of the meat.