Klein M, Neubert M, Strobel E, Hoffmann L
Forschungsbereich Ernährungsphysiologie Oskar Kellner, Forschungsinstitut für die Biologie landwirtschaftlicher Nutztiere Dummerstorf-Rostock, Germany.
Arch Tierernahr. 1998;51(4):263-77. doi: 10.1080/17450399809381925.
Energy metabolism and some performance parameters were investigated in laying hens of 3 different body weight-genotypes: 6 x 7 (normal-sized, crossbred from normal-sized male and female lines, group 1), 47 x 38 (dwarf-sized, breeding from a dwarf-sized male line and a normal-sized female line, group 2) and 44 x 47 (dwarf-sized, breeding from dwarf-sized male and female lines, group 3). Energy balance was measured by indirect calorimetry through C- and N-balances in 12 animals of each group during 10 consecutive days at production peak, within the period between the 27th and the 37th week of age. Hens were caged individually at 23 degrees C environmental temperature and fed ad libitum on a laying mash. The mean body weight in the dwarf-sized groups 2 and 3 was 32% lower than in the normal-sized group 1 during the energy balance period. The daily gross energy intake in group 2 and 3 was decreased by 33 and 34%, respectively. There were no significant differences in digestibility and metabolizability of gross energy between the groups. The energy requirements for maintenance [kJ ME/kg0.75.d] derived from the energy balances were lower by 4% (P > 0.05) and 14% (P < 0.05) in the dwarf-sized groups 2 and 3 as compared with the normal-sized group 1, when equal coefficients of partial efficiency of metabolizable energy utilization for energy retention in body and eggs are assumed for the 3 body-mass genotypes. There were no relevant differences in body composition at the end of the energy balance periods as well as in egg composition between the 3 experimental groups.
6×7（正常体型，由正常体型的公母系杂交而成，第1组）、47×38（矮小型，由矮小型公系和正常体型母系培育而成，第2组）和44×47（矮小型，由矮小型公母系培育而成，第3组）。在产蛋高峰期，即27至37周龄期间，通过间接测热法，利用碳平衡和氮平衡对每组12只动物连续10天测量能量平衡。母鸡在23摄氏度的环境温度下单笼饲养，自由采食产蛋鸡混合料。在能量平衡期，第2组和第3组矮小型母鸡的平均体重比第1组正常体型母鸡低32%。第2组和第3组的每日总能摄入量分别降低了33%和34%。各组之间总能的消化率和代谢率没有显著差异。假设三种体重基因型在体内和蛋中能量保留的代谢能利用部分效率系数相等，根据能量平衡得出的维持能量需求[kJ ME/kg0.75.d]，第2组和第3组矮小型母鸡比第1组正常体型母鸡分别低4%（P>0.05）和14%（P<0.05）。在能量平衡期结束时，三个实验组的身体组成以及蛋的组成没有相关差异。
