Stubble turnips provide cost effective winter diet

Stubble turnips provide a cost-effective diet, which also helps deliver consistent lamb eating quality during the winter months, according to the results of an ADAS trial.

The trial carried out by ADAS at Walford and North Shropshire College, and funded by EBLEX, HCC, QMS, Defra and AWM looked at lambs slaughtered in November and March on three finishing systems; grass/grass silage, stubble turnips or ad-lib concentrates.

The lambs were managed in groups of 30, and were on each finishing system for 6 to 7 weeks.

Feed costs were estimated for each of the production systems 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, £0.45 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. Concentrate lambs were sold significantly earlier (by around 6 days) than grass/grass silage and turnip lambs. Grass/grass silage lambs were significantly leaner and showed poorer conformation, and 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 work has shown that meat with low levels of Vitamin E can have a reduced shelf life. Producers may need to consider giving Vitamin E supplementation for animals grazing on root crops, such as stubble turnips.