背景:含有补充氨基酸(AA)的低粗蛋白(CP)配方可用于增强肠道健康,降低成本,尽量减少对环境的影响,保持猪的生长性能。然而,由于非必需AA的合成有限以及来自蛋白质补充剂的生物活性化合物的可获得性有限,即使在满足AA要求时,膳食CP的大量减少也会损害生长性能。此外,实施低CP配方可以增加饲料中的净能量(NE)含量,导致过多的脂肪沉积。补充功能性AA,加上低CP配方可以进一步增强肠道健康和葡萄糖代谢,提高氮素利用率,和增长业绩。进行了三个实验以评估添加AA的低CP制剂对生长育肥猪的肠道健康和生长性能的影响。
方法:在实验中。1,90头猪(19.7±1.1公斤,45只手推车和45只后备母猪)被分配到3种处理:CON(18.0%CP,补充Lys,Met,andThr),LCP(16.0%CP,补充Lys,Met,Thr,Trp,和Val),和LCPT(16.1%CP,LCP+0.05%SIDTrp)。在Exp中。2,72头猪(34.2±4.2kg体重)被分配到3种处理:CON(17.7%CP,符合Lys的要求,Met,Thr,和Trp);LCP(15.0%CP,遇见Lys,Thr,Trp,Met,Val,Ile,和Phe);和VLCP(12.8%CP,遇见Lys,Thr,Trp,Met,Val,Ile,Phe,他的,和Leu)。在Exp中。在图3中,将72头猪(54.1±5.9kgBW)分配到3个处理,并饲喂3个阶段的实验饮食(生长者2、完成1和完成2)。治疗均为CON(18.0%,13.8%,三个阶段的12.7%CP;会议Lys,Met,Thr,和Trp);LCP(13.5%,11.4%,三个阶段的10.4%CP;会议Lys,Thr,Trp,Met,Val,Ile,和Phe);和LCPG(14.1%,12.8%,3个阶段的11.1%CP;LCP+Glu匹配SIDGlu和CON)。所有饮食具有2.6Mcal/kgNE。
结果:在实验中。1、总体来说,不同处理的生长表现没有差异.LCPT增加了十二指肠和空肠中Claudin-1的表达(P<0.05)。LCP和LCPT升高(P<0.05),CAT-1,4F2hc,和空肠中的B0AT表达。在Exp中。2、总体来说,VLCP降低(P<0.05)G:F和BUN。LCP和VLCP增加了背脂厚度(BFT)(P<0.05)。在Exp中。3、总体来说,各处理之间的生长性能和BFT没有差异。LCPG降低了BUN(P<0.05),而增加了血浆中的胰岛素。LCP和LCPG降低了链球菌科的丰度(P<0.05),而LCP降低(P<0.05),和阿尔法多样性。
结论:实施低CP配方时,CP可以通过补充Lys来降低,Thr,Met,Trp,Val,和Ile,当调节NE以避免脂肪沉积增加时,不会影响生长育肥猪的生长性能。在低CP制剂中补充高于Glu的需求或补充Trp似乎有益于肠道健康以及改善的氮利用和葡萄糖代谢。
BACKGROUND: Low crude protein (CP) formulations with supplemental amino acids (AA) are used to enhance intestinal health, reduce costs, minimize environmental impact, and maintain growth performance of pigs. However, extensive reduction of dietary CP can compromise growth performance due to limited synthesis of non-essential AA and limited availability of bioactive compounds from protein supplements even when AA requirements are met. Moreover, implementing a low CP formulation can increase the net energy (NE) content in feeds causing excessive fat deposition. Additional supplementation of functional AA, coupled with low CP formulation could further enhance intestinal health and glucose metabolism, improving nitrogen utilization, and growth performance. Three experiments were conducted to evaluate the effects of low CP formulations with supplemental AA on the intestinal health and growth performance of growing-finishing pigs.
METHODS: In Exp. 1, 90 pigs (19.7 ± 1.1 kg, 45 barrows and 45 gilts) were assigned to 3 treatments: CON (18.0% CP, supplementing Lys, Met, and Thr), LCP (16.0% CP, supplementing Lys, Met, Thr, Trp, and Val), and LCPT (16.1% CP, LCP + 0.05% SID Trp). In Exp. 2, 72 pigs (34.2 ± 4.2 kg BW) were assigned to 3 treatments: CON (17.7% CP, meeting the requirements of Lys, Met, Thr, and Trp); LCP (15.0% CP, meeting Lys, Thr, Trp, Met, Val, Ile, and Phe); and VLCP (12.8% CP, meeting Lys, Thr, Trp, Met, Val, Ile, Phe, His, and Leu). In Exp. 3, 72 pigs (54.1 ± 5.9 kg BW) were assigned to 3 treatments and fed experimental diets for 3 phases (grower 2, finishing 1, and finishing 2). Treatments were CON (18.0%, 13.8%, 12.7% CP for 3 phases; meeting Lys, Met, Thr, and Trp); LCP (13.5%, 11.4%, 10.4% CP for 3 phases; meeting Lys, Thr, Trp, Met, Val, Ile, and Phe); and LCPG (14.1%, 12.8%, 11.1% CP for 3 phases; LCP + Glu to match SID Glu with CON). All diets had 2.6 Mcal/kg NE.
RESULTS: In Exp. 1, overall, the growth performance did not differ among treatments. The LCPT increased (P < 0.05) Claudin-1 expression in the duodenum and jejunum. The LCP and LCPT increased (P < 0.05) CAT-1, 4F2hc, and B0AT expressions in the jejunum. In Exp. 2, overall, the VLCP reduced (P < 0.05) G:F and BUN. The LCP and VLCP increased (P < 0.05) the backfat thickness (BFT). In Exp. 3, overall, growth performance and BFT did not differ among treatments. The LCPG reduced (P < 0.05) BUN, whereas increased the insulin in plasma. The LCP and LCPG reduced (P < 0.05) the abundance of Streptococcaceae, whereas the LCP reduced (P < 0.05) Erysipelotrichaceae, and the alpha diversity.
CONCLUSIONS: When implementing low CP formulation, CP can be reduced by supplementation of Lys, Thr, Met, Trp, Val, and Ile without affecting the growth performance of growing-finishing pigs when NE is adjusted to avoid increased fat deposition. Supplementation of Trp above the requirement or supplementation of Glu in low CP formulation seems to benefit intestinal health as well as improved nitrogen utilization and glucose metabolism.