Effects of dietary protein and energy intake on growth, body composition and nutrient utilisation in lambs reared artificially with milk replacers and pellet feeds

Growth and Body Composition of Artificially-Reared Lambs Exposed to Three Different Rearing Regimens

“…The high protein milk replacer contained 967.4 g/kg dry matter, 324.1 g/kg CP, 20.84 MJ/kg ME (CP:ME 15.55 g/MJ), 215.4 g/kg fat, 61.2 g/kg ash, 343.6 g/kg lactose, 13.6 g/kg calcium, 7.2 g/kg phosphorous, and 21.7 MJ/kg gross energy on fresh matter basis. Metabolisable energy content was calculated as metabolisability coefficient multiplied by gross energy considering metabolisability coefficient of milk replacer and milk protein concentrate as 0.96 [ 4 ]. To prepare the milk, the powdered milk replacer was mixed with warm tap water at a ratio of 1/4 ( w / w ) [ 4 , 5 , 18 ].…”

“…Metabolisable energy content was calculated as metabolisability coefficient multiplied by gross energy considering metabolisability coefficient of milk replacer and milk protein concentrate as 0.96 [ 4 ]. To prepare the milk, the powdered milk replacer was mixed with warm tap water at a ratio of 1/4 ( w / w ) [ 4 , 5 , 18 ]. Lambs were bottle-fed five times daily (at 8.00 a.m., 11.00 a.m., 2.30 p.m., 6.30 p.m., and 9.00 p.m.) up to two weeks of age, then four times daily (at 8.00 a.m., 11.00 a.m., 2.30 p.m., and 6.00 p.m.) up to the milk-weaning phase (days 38 to 42) for HFP42 and LFP42 lambs and until the end of experiment for HFP57 lambs.…”

“…Traditionally, fulfilment of a lamb’s nutrient requirement was considered to depend on milk intake due to negligible solid feed intake in the first few weeks of life [ 3 ]. Consequently, many studies have focused on optimisation of milk composition to improve lamb growth [ 4 , 5 ]. However, lambs have higher crude protein to metabolisable energy ratio (CP:ME) requirement during their first few weeks of life than current typical commercial lamb milk replacers, with static CP:ME, provide [ 4 ].…”

“…Consequently, many studies have focused on optimisation of milk composition to improve lamb growth [ 4 , 5 ]. However, lambs have higher crude protein to metabolisable energy ratio (CP:ME) requirement during their first few weeks of life than current typical commercial lamb milk replacers, with static CP:ME, provide [ 4 ]. When CP:ME requirements are either met or exceeded, improved lamb growth rates are observed [ 5 ].…”

“…Source of molasses is sugar beet 3. Cobalt 0.2 g/kg, Iodine 0.2 g/kg, Magnesium 0.14 g/kg, Selenium 0.04 g/kg, Sodium 0.14 g/kg, Zinc 4 g/kg, and vitamin E 1 IU/g 4. Calculated as gross energy multiplied by metabolisability coefficient 5.…”