The effect of temperature and method of feeding on the diestibility of two milk substitutes and on the performance of lambs

SUMMARYThe effects of temperature and method of feeding on the intake characteristics and digestibilities of two milk substitutes were examined.Forty Finnish Landrace x Dorset Horn lambs (20 males and 20 females) were fed one of two milk substitutes from 3 to 25 days of age when they were slaughtered and chemical composition of the empty body was measured.The two milk substitutes contained 30% fat in the dry matter as butter fat (diet B), or tallow and coconut oil (diet TC).The diets were offered at either 34°C (W) or 5 °C (C) and three methods of feeding were used. The diets were given: ad libitumcold (AL1), four feeds to appetite per day either warm or cold (AL2W and AL2C) and four feeds restricted to an intake of 62 g D.M./kg live weight0·5 either warm or cold (RW or RC).Digestibilities of the milk substitutes were not affected by the temperature at which they were offered or the feeding regime used. Diet B had an apparent dry-matter digestibility of 97·6% and diet TC 92·5%. The fat digestibility of diet TC was 13·6 units lower than diet B and this affected the digestibility of all the other dietary components.Lambs tended to consume more of diet B and grow faster.Lambs on treatment AL1 consumed 21% more milk substitute than those on treatment AL2.The composition of the body-weight gain was found to alter with rate of gain.The temperature at which the milk substitutes were offered had only a minor effect on the performance of the lambs. The type of milk substitute and feeding regime used had a greater influence on both lamb intake and growth.