Millet S, Ongenae E, Hesta M, Seynaeve M, De Smet S, Janssens G P J
Laboratory of Animal Nutrition, Faculty of Veterinary Medicine, Ghent University, Heidestraat 19, B-9820 Merelbeke, Belgium.
Vet J. 2006 May;171(3):483-90. doi: 10.1016/j.tvjl.2005.01.002.
The effects of three dietary protein levels on growth, meat, and carcass traits were studied in organic pigs fed a three-phase diet. Assuming lysine was the first limiting amino acid, feeds were formulated to ileal digestible (ID) lysine content, with the ID lysine:crude protein ratio set at a constant of 4%. Feeds were also formulated to an isocaloric rate (net energy: 9.4 MJ/kg during the first feeding phase, 9.25 MJ/kg during the second feeding phase and 9.1 MJ/kg during the finisher phase), with a high (HP), a medium (MP) or a low (LP) protein content ranging from 20% to 14% crude protein (CP). ID lysine content of the LP and MP feed was, respectively, 80% and 90% of the ID lysine content of the HP feed. The nutrient formulation of the HP feed was similar to nutrient levels commonly used in conventional Belgian pig farming. From 20 to 40 kg liveweight, the pigs showed better feed conversion ratios, with an increasing dietary protein concentration (r(2)=0.84). This effect was not observed in the second and third phases, although a significant effect of protein concentration on voluntary feed intake in the second phase did occur (P=0.018), probably as a compensation for the lower protein concentration in the LP diet. Analysis of the carcasses showed a lower meat percentage with lower protein concentration (P<0.05), whereas influences on meat quality were limited. It was concluded that whereas during the first phase of growth, higher protein concentration leads to better performance, from the second phase onwards (45 kg), at least with isocaloric diets, a decrease in protein content (corresponding to a 10% reduction in dietary ID lysine levels compared to conventional pig fattening) may be used in organic growing-finishing pig nutrition.
研究了三种日粮蛋白质水平对采用三阶段日粮喂养的有机猪生长性能、肉质和胴体性状的影响。假设赖氨酸是第一限制性氨基酸，日粮按照回肠可消化（ID）赖氨酸含量进行配制，ID赖氨酸与粗蛋白的比例设定为恒定的4%。日粮还按照等热量比例配制（净能：第一饲养阶段为9.4 MJ/kg，第二饲养阶段为9.25 MJ/kg，育肥阶段为9.1 MJ/kg），蛋白质含量高（HP）、中（MP）或低（LP），粗蛋白（CP）含量范围为20%至14%。LP和MP日粮的ID赖氨酸含量分别为HP日粮ID赖氨酸含量的80%和90%。HP日粮的营养配方与比利时传统养猪业常用的营养水平相似。从20至40千克活重阶段，随着日粮蛋白质浓度的增加，猪的饲料转化率更好（r² = 0.84）。在第二和第三阶段未观察到这种效果，尽管蛋白质浓度对第二阶段的自愿采食量有显著影响（P = 0.018），这可能是对LP日粮中较低蛋白质浓度的一种补偿。胴体分析表明，蛋白质浓度较低时肉的百分比也较低（P < 0.05），而对肉质的影响有限。得出的结论是，在生长的第一阶段，较高的蛋白质浓度可带来更好的性能，但从第二阶段（45千克）开始，至少在等热量日粮的情况下，蛋白质含量的降低（与传统猪育肥相比，日粮ID赖氨酸水平降低10%）可用于有机生长育肥猪的营养。
