Surplus lambs can thrive on cold milk

Surplus lambs reared on Lamlac milk replacer mixed and fed cold from about a week of age to weaning drink as much and perform as well as lambs reared on warm milk.

According to Dr Jessica Cooke from Volac Milk Replacers Limited, trial work conducted at Reaseheath College last spring highlights the opportunity to rear extra lambs on ad lib cold milk off ewes where boiler heating capability may be non-existent or compromised.

“After following recommended rearing practices during the first week of life, feeding lambs cold ad lib milk thereafter offers shepherds a simple, practical and highly cost-effective method of rearing any surplus offspring where or when warm water is not available. The ability to feed Lamlac cold can also be useful in situations when rearing lambs of different ages requires milk to be fed at a constant temperature,” Dr Cooke explained.

Designated surplus lambs from triplet-bearing ewes (largest lamb from each litter; leaving two equal sized lambs on the ewe) on the Reaseheath trial were left on the ewe to suckle colostrum for six to 10 hours. Ewe colostrum quality was tested at birth.

“Following this initial first colostrum feeding period, the trial lambs were removed and fed a second feed of ewe colostrum (own ewe or pooled) via a bottle and teat (or a tube) at a rate of 50ml/kg bodyweight.

“Lambs were then fed Lamlac via a bottle and teat every six hours for the first 24 hours. Lambs were then introduced to the training pen and fed warm milk ad lib (Lamlac at 25ºC) for seven days via a Volac Eco Feeder with white teats. On day nine, lambs were allocated to either the warm milk pen or the cold milk pen.”

Dr Cooke explained that the lambs able to access warm milk started off receiving it at 20ºC for a minimum of four days. After this training period the temperature of the mixed milk was dropped to 15ºC where it remained until weaning at 35 days.

“However, lambs in the cold milk pen only had ad lib access to milk at a much lower temperature. Milk was mixed at 10ºC but its temperature increased to around 12-13ºC throughout the day. The Lamlac mixing rate for both pens was 200g powder in 800ml water (making 1 litre of mixed milk). In addition, both groups of lambs had access to ad lib fresh water, a 17% crude protein creep feed and clean forage (straw).”

Both groups of lambs were weaned abruptly at 35 days of age, weighing a minimum of 10kg and eating at least 250g of creep a feed a day.

“When the results were analysed, it was clear that lamb performance was similar across both treatments, although the lambs fed cold milk tended to be heavier from day 14 through to weaning, resulting in a slightly greater body weight at weaning (13.1kg v 12.4kg).”

Dr Cooke pointed out that this slightly greater body weight at weaning finding in the cold milk fed group was probably explained by the fact that these lambs were observed as being more active in eating creep feed.

“It was clear that feeding lambs cold milk from just over a week of age had no negative impact on their performance. In fact, lambs fed cold milk performed marginally better through to weaning – achieving a daily live weight gain of 0.27kg/day compared with the 0.25kg/day delivered by the warm milk fed group of lambs. The advantage is thought to be due to the greater creep feed intake,” she concluded.

Commenting on the trial results, the Reaseheath College shepherd said that the lambs in the cold milk pen certainly seemed to be drinking as much milk.

“Warm water is available to us at no extra cost, so from a practical standpoint feeding milk at a higher temperature here isn’t a problem. But if boiler heating is not available for any reason, we’d certainly opt for cold milk feeding as the lambs appear to do just as well.”