Bartov I
Department of Poultry Science, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel.
Poult Sci. 1996 May;75(5):632-41. doi: 10.3382/ps.0750632.
Four experiments were carried out to evaluate the effects of the composition and pelleting of diets fed to broiler chicks up to marketing age on changes in their liver size and the content and composition of liver fat due to feed withdrawal (FW) during 0, 10, and 24 h. Birds not exposed to FW that were fed diets with high energy to protein ratio (E:P) and diets in pelleted from-diets that increase fattening-had significantly (P < 0.05) higher liver fat content than those fed diets with the recommended E:P and in mash form, respectively. Those fed pellets also had higher liver weight. Dietary energy level did not affect these variables. Feed withdrawal for 10 or 24 h decreased, at times significantly, liver weight and its fat content, irrespective of the diets fed previously. The values observed after FW were not affected by the dietary factors evaluated. The composition of liver fatty acid in chicks not exposed to FW was markedly affected by increases in dietary energy (soybean oil) level and E:P. The main effects of the former were increased levels of stearic, linoleic, and arachidonic acids and a decreased level of oleic acid; those of the latter were an increased level of oleic and decreased levels of stearic, linoleic, and arachidonic acids. Irrespective of the diets used, FW increased the concentrations of stearic, linoleic, and arachidonic acids, and decreased those of palmitic and oleic acids. This effect on arachidonic acid was consistently significant, whereas the effects on the other fatty acids were significant in two out of three experiments. Due to these effects of FW, part of the differences in the composition of liver fatty acids caused by dietary factors observed in fed chicks, completely disappeared after FW. The length of FW (10 vs 24 h) did not affect liver size or fat content, but the concentrations of oleic and arachidonic acids in liver fat were significantly higher in birds exposed to 24 h of FW. It was concluded that the composition and form of the diets markedly affect liver weight and the content and composition of its fat in birds not exposed to FW. The effects of the dietary factors on liver size and its fat content completely disappear after 24 h of FW.
进行了四项实验，以评估饲喂至上市年龄的肉鸡日粮的组成和制粒对其肝脏大小变化以及因禁食0、10和24小时导致的肝脏脂肪含量和组成的影响。未禁食且饲喂高能蛋白比（E:P）日粮以及制粒形式日粮（可促进育肥）的鸡，其肝脏脂肪含量显著（P < 0.05）高于分别饲喂推荐E:P日粮和粉料形式日粮的鸡。饲喂颗粒料的鸡肝脏重量也更高。日粮能量水平未影响这些变量。禁食10或24小时会使肝脏重量及其脂肪含量有时显著降低，与之前饲喂的日粮无关。禁食后观察到的值不受所评估的日粮因素影响。未禁食的雏鸡肝脏脂肪酸组成受日粮能量（大豆油）水平和E:P增加的显著影响。前者的主要影响是硬脂酸、亚油酸和花生四烯酸水平升高，油酸水平降低；后者的影响是油酸水平升高，硬脂酸、亚油酸和花生四烯酸水平降低。无论使用何种日粮，禁食都会增加硬脂酸、亚油酸和花生四烯酸的浓度，降低棕榈酸和油酸的浓度。这种对花生四烯酸的影响始终显著，而对其他脂肪酸的影响在三项实验中的两项中显著。由于禁食的这些影响，在采食雏鸡中观察到的日粮因素导致的肝脏脂肪酸组成差异的一部分，在禁食后完全消失。禁食时间（10小时与24小时）不影响肝脏大小或脂肪含量，但禁食24小时的鸡肝脏脂肪中油酸和花生四烯酸的浓度显著更高。得出的结论是，日粮的组成和形式显著影响未禁食鸡的肝脏重量及其脂肪含量和组成。日粮因素对肝脏大小及其脂肪含量的影响在禁食24小时后完全消失。
