Cold milk feeding delivers strong growth in surplus lamb trial

With labour stretched during peak lambing, new trial results suggest surplus lambs can achieve strong growth rates when reared on cold milk replacer.

Research conducted in 2025 at Harper Adams University found that lambs fed Lamlac milk replacer mixed and delivered cold from eight days of age achieved solid performance through to weaning at 35 days.

The study reported an average weaning weight of 15kg at 35 days, with individual lambs ranging from 10kg to 19kg. Average daily liveweight gain up to weaning was recorded at 332g per day — figures in line with commercial growth targets for artificially reared lambs.

The trial involved 23 Lleyn cross Aberblack/Charolais lambs. Each lamb received colostrum from its ewe for 24 hours, or was fed artificially where required, before being introduced to a training pen and offered warm milk replacer ad-lib via a Ewe-2 feeder.

From day eight, lambs were moved to a larger pen and fed the milk replacer mixed and supplied cold at 10°C. Fresh creep feed and straw were introduced from day seven to support rumen development and help reduce digestive upset around weaning.

Lambs were weaned abruptly at 35 days once they reached a target bodyweight of 10kg and were consuming 250g of solid feed per day.

While the study group was relatively small, researchers said the findings demonstrate the potential of cold milk feeding where management is consistent and hygiene standards are maintained.

Dr Jessica Cooke, from Lamlac, said feeding ewe milk replacer cold should be considered a proven technique for managing surplus lambs.

“Feeding cold milk offers a simple, practical, time-effective method to rear surplus lambs on farm when warm water is not available, or when lambs of different ages require milk to be fed at a constant temperature,” she said.

“With good attention to detail and environmental temperature permitting, lambs can successfully maintain daily growth rates when reared on Lamlac, mixed and fed cold from week one, which requires less time input than mixing and feeding warm milk.”

She added that product quality remains critical.

“However, it’s vital producers use a high-quality milk powder, such as Lamlac, to avoid any potential problems with mixing quality.”

For sheep producers managing high lamb numbers and limited labour during lambing season, the findings indicate that cold, ad-lib milk feeding could provide a practical option for surplus lamb management.