THE EFFECT OF DIFFERENT DIETARY-PROTEIN LEVELS IN THE REARING AND LAYING PERIODS ON PERFORMANCE OF WHITE LEGHORN CHICKENS
THE EFFECT OF DIFFERENT DIETARY-PROTEIN LEVELS IN THE REARING AND LAYING PERIODS ON PERFORMANCE OF WHITE LEGHORN CHICKENS
复制标题
DOI：
10.3382/ps.0632229
复制
发表时间：
1984-01-01
期刊：
影响因子：
4.4
通讯作者：
KESHAVARZ, K
中科院分区：
文献类型：
--
作者：
KESHAVARZ, K
本试验旨在研究3种饲养蛋白和4种产蛋蛋白对白色来航鸡商品品系生长和后续生产性能的影响。对照组在0-6、6-14和14-20周龄分别饲喂18%、15%和12%蛋白质的日粮。低蛋白饲养方案的雏鸡分别在0-6和6-20周龄时接受18%和12%的蛋白质，或在0-6、6-18和18-20周龄时分别接受18%、12%和15%的蛋白质。从20-72周龄开始，每组鸡接受4种产蛋方案。分别为20-36、36-60和60-72周龄的含16.5%蛋白质的日粮、含14.5%蛋白质的日粮、含18%、16.5%和15.5%蛋白质的中度递减蛋白质方案（MSP）和含16.5%、15.5%和15.5%蛋白质的低递减蛋白质方案（LSP）。20-36、36-48、48-60和60-72周龄的蛋白质含量分别为14.5%和13.5%。产蛋日粮中总S氨基酸水平维持在0.59%，赖氨酸最低水平为0.68%。饲喂低蛋白饲养方案的鸟在20周龄时显著较轻，在饲养期间消耗显著较少的饲料、能量和蛋白质，并且与对照饲喂的鸟相比，它们在50%产量时的年龄延迟2-3天。在第1产蛋期，饲喂低蛋白饲养方案的鸡产蛋较少，蛋的重量略轻。在饲养期，蛋白质水平对总体产蛋量、蛋重和饲料消耗量没有影响。与饲喂16.5%蛋白质日粮的母鸡相比，在产蛋期饲喂14.5%蛋白质日粮的母鸡产蛋量显著减少，蛋重显著减轻，蛋白质和赖氨酸的消耗量显著减少。MSP组的总体产蛋量、蛋重和营养素摄入量与饲喂16.5%蛋白质饲料的组没有显著差异。与接受16.5%蛋白质饮食的鸡相比，LSP组的鸡的产蛋量相似; LSP组的鸡的蛋重、蛋白质和赖氨酸摄入量显著较低。在饲养期间，饲喂低蛋白质方案的雏鸡的饲料成本最低。与对照组相比，低蛋白饲养方案的母鸡的净蛋收入更大。饲喂14.5%蛋白质日粮的雏鸡产蛋净收入最低;饲喂MSP方案的雏鸡产蛋期间产蛋净收入最高。
An experiment was conducted to determine the effects of 3 rearing and 4 laying protein regimens on growth and subsequent performance of a commercial strain of White Leghorn chickens. In the rearing period, the pullets of the control group received a sequence of 18, 15 and 12% protein of 0-6, 6-14 and 14-20 wk of age, respectively. The pullets of the low-protein rearing regimens received 18 and 12% protein for 0-6 and 6-20 wk of age, respectively, or 18, 12 and 15% protein for 0-6, 6-18 and 18-20 wk of age, respectively. Birds of each rearing group received 4 laying regimens from 20-72 wk of age. These consisted of a diet containing 16.5% protein, a diet containing 14.5% protein, a moderate step-down protein regimen (MSP) of 18, 16.5 and 15.5% protein for 20-36, 36-60 and 60-72 wk of age, respectively, and a low step-down protein regimen (LSP) of 16.5, 15.5, 14.5 and 13.5% protein for 20-36, 36-48, 48-60 and 60-72 wk of age, respectively. The level of total S amino acids was maintained at 0.59% and the minimum level of lysine was 0.68% in the laying rations. Birds fed the low-protein rearing regimens were significantly lighter at 20 wk of age, consumed significantly less feed, energy and protein in the rearing period, and their age at 50% production was delayed by 2-3 days compared to control fed birds. Birds fed the low-protein rearing regimens produced fewer eggs and slightly lighter weight eggs during the 1st laying phase. Overall egg production, egg size and feed consumption were not influenced by the protein levels in the rearing period. Pullets receiving the 14.5% protein diet in the laying period produced significantly fewer and lighter weight eggs and consumed significantly less protein and lysine than those fed the 16.5% protein diet. Overall egg production, egg weight and nutrient intake of birds of the MSP groups were not significantly different from those fed the 16.5% protein diet. Egg production was similar for the birds of the LSP groups compared to those receiving the 16.5% protein diet; egg weight, protein and lysine intake were significantly lower for the birds of the LSP group. Pullets fed the low-protein regimens had the lowest feed costs during the rearing period. Net egg incomes were greater for the pullets fed the low-protein rearing regimens compared to the control fed groups. Pullets fed the 14.5% protein diet produced the lowest net egg incomes; pullets fed the MSP program had the greatest net egg incomes during the laying period.