Chiba L I, Ivey H W, Cummins K A, Gamble B E
Department of Animal and Dairy Sciences, Auburn University, AL 36849-5415, USA.
J Anim Sci. 1999 Jul;77(7):1769-76. doi: 10.2527/1999.7771769x.
Sixty-four individually housed pigs were used to investigate the effect of amino acid content of finisher diets on growth performance of pigs subjected to marginal dietary amino acid restrictions (80% of the 1988 NRC lysine recommendation) during the grower phase. In each of the two trials, low- and high-amino-acid grower diets (.421 and .765 g lysine/MJ DE, respectively) and four finisher diets (.421, .516, .612, and .707 g lysine/MJ DE) were randomly assigned within sex to 16 gilts and 16 castrated males weighing 23.0 +/- 2.0 kg in a 2 x 4 factorial arrangement of treatments. The average weight of pigs after a completion of diet change was 50.4 +/- 2.1 kg. All pigs were slaughtered at an average weight of 105.2 +/- 4.1 kg. Ultrasound backfat thickness was measured at the time of diet change and before slaughter. Pigs were allowed ad libitum access to feed and water. During the grower phase, pigs fed the high-amino-acid diet grew faster (P < .001) and more efficiently (P < .001) and had less ultrasound backfat (P < .001) than those fed the low-amino-acid diet. The grower diet had no effect on weight gain during the finisher phase. Consequently, pigs fed the high-amino-acid grower diet had better overall weight gain (P < .01) than those fed the low-amino-acid diet. The rate of lean accretion was, however, similar between the two groups of pigs. Furthermore, pigs fed the low-amino-acid grower diet seemed to have better carcass quality, as indicated by less ultrasound backfat (P < .01) and larger carcass longissimus muscle area (P < .05). Average and 10th rib carcass backfat decreased linearly (P < or = .05) and lean accretion rate improved linearly (P < .05) as the amino acid content of finisher diets increased, but there was no grower x finisher diet interaction in these and other response criteria. Although no evidence of compensatory weight gain was observed, it is possible that compensatory lean tissue growth may have occurred in pigs subjected to early amino acid restrictions at the expense of fatty tissue growth.
选用64头单独饲养的猪，研究育肥期日粮氨基酸含量对生长育肥期日粮氨基酸摄入量处于临界限制水平（为1988年美国国家研究委员会赖氨酸推荐量的80%）的猪生长性能的影响。在两项试验中，分别将低氨基酸和高氨基酸生长育肥期日粮（分别含0.421和0.765 g赖氨酸/MJ消化能）以及四种育肥期日粮（含0.421、0.516、0.612和0.707 g赖氨酸/MJ消化能）按照2×4析因处理设计随机分配给32头体重为23.0±2.0 kg的后备母猪和32头去势公猪。日粮转换完成后猪的平均体重为50.4±2.1 kg。所有猪均在平均体重达105.2±4.1 kg时屠宰。在日粮转换时和屠宰前测量猪的超声背膘厚度。猪可自由采食和饮水。在生长育肥期，采食高氨基酸日粮的猪比采食低氨基酸日粮的猪生长速度更快（P<0.001）、生长效率更高（P<0.001）且超声背膘更薄（P<0.001）。生长育肥期日粮对育肥期的体重增加没有影响。因此，采食高氨基酸生长育肥期日粮的猪总体增重情况优于采食低氨基酸日粮的猪（P<0.01）。然而，两组猪的瘦肉沉积率相似。此外，采食低氨基酸生长育肥期日粮的猪胴体品质似乎更好，表现为超声背膘更薄（P<0.01）和胴体最长肌面积更大（P<0.05）。随着育肥期日粮氨基酸含量的增加，平均第10肋处的胴体背膘厚度呈线性下降（P≤0.05），瘦肉沉积率呈线性提高（P<0.05），但在这些以及其他反应指标上，生长育肥期日粮之间没有交互作用。尽管未观察到补偿性体重增加的证据，但在早期氨基酸受限的猪中，有可能发生了以脂肪组织生长为代价的补偿性瘦肉组织生长。
