caa a22 4500 388060190 CHVBK 20180307125118.0 cr unu---uuuuu 161130e199812 xx s 000 0 eng 10.1017/S135772980003294X doi S135772980003294X pii (NATIONALLICENCE)cambridge-10.1017/S135772980003294X Effect of intake level during milk-feeding period and protein content in the post-weaning diet on performance and body composition in growing lambs [Elektronische Daten] The effect of intake level during the milk-feeding period and dietary protein content during the post-weaning period on performance, weight of components of the digestive tract and carcass and non-carcass chemical composition was investigated in 28 Churra lambs. A 2 × 2 factorial design was used with two intake levels during the milk-feeding period (Lmilk: 0·9 and Hmilk: 1·5 MJ gross energy per kg M0·75 daily) and two concentrate supplements (Lprotein:barley grain and Hprotein: barley grain plus 200 g/kg fish meal) during the post-weaningperiod. After selecting an initial slaughter group of four 2-day-old lambs, 12 lambs were assigned randomly to each of two intake levels during a 4-week milk-feeding period and given food individually. Four lambs from each intake level were slaughtered at weaning (30 days old) and the remaining 16 were weaned between 30 and 49 days old (weaning period). Eight lambs from each nutritional regimen during the milk-feeding period were further divided into two equal groups and given food individually ad libitum with hay and the post-weaning concentrate, according to the experimental design until thefinal slaughter weight (20 kg) (post-weaning period). Lmitk lambs showed a capacity to grow as well as the Hmilk during the weaning and post-weaning period and there were no differences (P > 0·05) in dry-matter intake and food conversion ratio among treatments. Before weaning, the weight of the reticulo-rumen was not affected by the intake level during the milk-feeding period. The most affected component of the gastrointestinal tract was the small intestine as proportion of the digestive tract which was lower in Lmilk lambs (P < 0·05). At 20 kg live weight, the relative size of the reticulo-rumen was greater (P < 0·01) and the abomasum (P < 0·05) and large intestine (P < 0·01) were smaller in lambs which were given the Hprotein concentrate after weaning. The organic matter apparent digestibility (OMD, P < 0·05) and crude protein apparent digestibility (CPD, P < 0·05) of the post-weaning diets was greater in Lmilk lambs and the Hprotein post-weaning diet was associated with a greater dry-matter apparent digestibility, OMD and CPD when lambs were close to final slaughter weight. At 20 kg live weight, the proportion of protein in the carcass of Lmilk lambs was greater (P < 0·05) than in Hmilk lambs. The greater growth of the reticulo-rumen of the Lmilk lambs might have increased solid food intake after the milk-feeding period, led to greater CPD of post-weaning diets and had consequences in terms of carcass composition. Copyright © British Society of Animal Science 1998 body composition nationallicence dietary protein nationallicence growth nationallicence lambs nationallicence milk nationallicence Manso T. Departamento de Producción Animal, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid, Spain Mantecón A. R. Estación Agrícola Experimental (CSIC), Apartado de Correos 788. 24080 León, Spain Castro T. Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH Iason G. R. Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH Animal Science Cambridge University Press 67/3(1998-12), 513-521 1357-7298 67:3<513 1998 67 ASC https://doi.org/10.1017/S135772980003294X text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S135772980003294X text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Manso T. Departamento de Producción Animal, Facultad de Veterinaria, Universidad Complutense, 28040 Madrid, Spain NATIONALLICENCE 700 1- Mantecón A. R. Estación Agrícola Experimental (CSIC), Apartado de Correos 788. 24080 León, Spain NATIONALLICENCE 700 1- Castro T. Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH NATIONALLICENCE 700 1- Iason G. R. Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB15 8QH NATIONALLICENCE 773 0- Animal Science Cambridge University Press 67/3(1998-12), 513-521 1357-7298 67:3<513 1998 67 ASC CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge