Biochemical and morphological developments are partially impaired in intestinal mucosa from growing pigs fed reduced-protein diets supplemented with crystalline amino acids
Biochemical and morphological developments are partially impaired in intestinal mucosa from growing pigs fed reduced-protein diets supplemented with crystalline amino acids
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DOI：
10.2527/jas.2005-558
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发表时间：
2006-07-01
影响因子：
3.3
通讯作者：
Trottier, N. L.
中科院分区：
文献类型：
--
作者：
Guay, F.;Donovan, S. M.;Trottier, N. L.
本研究的目的是确定降低日粮CP，用结晶氨基酸(CAA)部分取代完整的蛋白质，是否会改变生长猪的生长、形态以及肠粘膜中游离或多肽结合的AA浓度。24头公牛(体重37.0+/-1.5 kg)饲喂4种日粮中的1种：不含CAA的16.1%CP，或含CAA的12.8%、10.1%或7.8%CP(分析值，饲喂前)。随着CP的降低，CAA逐渐增加，以满足真正回肠可消化基础上的需要。24 d后2 h处死猪，采集十二指肠、空肠和回肠粘膜标本。降低日粮粗蛋白质降低了日增重、日增重比和最终体重(线性，P<；0.05)。随着日粮粗蛋白质水平的降低，空肠粘膜蛋白浓度呈二次曲线下降，回肠呈直线下降趋势(P=0.062)。日粮CP浓度从16.1%降低到7.8%，十二指肠和空肠粘膜的隐窝深度(线形，P<；0.10)和绒毛宽度(线形，P<；0.05)均有减小趋势，但不会降低小肠各部位的绒毛高度和绒毛表面积。在十二指肠，日粮粗蛋白质的降低增加了游离的赖氨酸、蛋氨酸和苏氨酸(线性的，P<；0.05)和多肽结合的赖氨酸和苏氨酸(二次的，P<；0.10)。在空肠中，降低CP降低游离半胱氨酸(线性P<；0.05)，降低游离Asn和His(线性，P<；0.10)和多肽结合His(二次，P=0.061)和ILE、Leu和Val(线性，P<；0.10)。在回肠，降低CP降低了游离天冬氨酸、丝氨酸、酪氨酸、精氨酸、组氨酸、苯丙氨酸、亮氨酸和甘氨酸、丝氨酸，降低了多肽结合的Ile、Leu、Phe、Val和Lys。总而言之，添加CAA的低CP日粮会导致生长性能下降，这与肠道粘膜的生化和形态改变有关。
The objective of this study was to determine if a reduction in dietary CP, with partial replacement of the intact protein with crystalline AA (CAA), would alter growth, morphology, and free or peptide-bound AA concentrations of intestinal mucosa in growing pigs. Twenty-four barrows (37.0 +/- 1.5 kg of BW) were fed 1 of 4 diets for 24 d: 16.1% CP with no CAA, or 12.8, 10.1, or 7.8% CP (analyzed values, as-fed) containing CAA. As CP decreased, CAA were gradually increased to meet requirements on a true ileal digestible basis. Pigs were euthanized 2 h postmeal on d 24, and mucosal samples from duodenum, Jejunum, and ileum were collected. Reducing dietary CP decreased ADG, G:Y, and final weight (linear, P < 0.05). With reduced dietary CP, mucosal protein concentration decreased in the jejunum (quadratic, P < 0.05) and tended to decrease in the ileum (linear, P = 0.062). Reduction of the dietary CP concentration from 16.1 to 7.8% tended to decrease the crypt depth (linear, P < 0.10) and decreased villus width (linear, P < 0.05) in duodenum and Jejunum mucosa but did not reduce villus height or villus surface area in any regions of the small intestine. In the duodenum, a reduction in dietary CP increased free Lys, Met, and Thr (linear, P < 0.05) and peptide-bound Lys and Thr (quadratic, P < 0.10). In the jejunum, reducing CP decreased free Cys (linear P < 0.05) and tended to decrease free Asn and His (linear, P < 0.10) and peptide-bound His (quadratic, P = 0.061) and Ile, Leu, and Val (linear, P < 0.10). In the ileum, reducing CP decreased free Asn, Ser, Tyr, Arg, His, Phe (linear, P < 0.05), and Leu (linear, P = 0.054) and peptide-bound Gly and Ser (linear, P < 0.05) and tended to decrease peptide-bound Ile, Leu, Phe, Val (linear, P < 0.10), and Lys (linear P < 0.05). In conclusion, reduced-CP diets supplemented with CAA lead to a reduction in growth performance, associated with biochemical and morphological modifications of the intestinal mucosa.