Li W, Angel R, Kim S-W, Jiménez-Moreno E, Proszkowiec-Weglarz M, Plumstead P W
Department of Animal and Avian Sciences, University of Maryland, College Park, USA.
Department of Animal and Avian Sciences, University of Maryland, College Park, USA
Poult Sci. 2015 Dec;94(12):2917-31. doi: 10.3382/ps/pev273. Epub 2015 Oct 16.
A total of 1,152 straight-run hatchling Heritage 56M×fast feathering Cobb 500F broiler birds were used to determine Ca, age, and adaptation effects on apparent ileal digestibility of crude protein (AID of CP), amino acids (AID of AA) and phytase efficacy. Twelve treatments with 8 replicates, each were fed from 7 to 9 d (6 birds per replicate), 7 to 21 d (6 birds per replicate) and 19 to 21 d (3 birds per replicate) d of age. Diets were prepared with 3 Ca (0.65, 0.80, and 0.95%) and 2 non-phytate P, (0.20 and 0.40%) concentrations. A 6-phytase was added at 500 or 1,000 FTU/kg to the 0.20% nPP diet at each Ca concentration. The age and adaptation effects were determined by comparing the responses between birds fed from 7 to 9 and 19 to 21 d of age, 19 to 21, and 7 to 21 d of age, respectively. An age effect was observed regardless of Ca, nPP, or phytase concentration, with older birds (19 to 21 d) having greater apparent ileal digestibility (AID) of amino acids (AA) and CP than younger birds (7 to 9 d; P<0.05). Response to adaptation varied depending on Ca, nPP, and phytase concentrations. Constant lower AID of CP and AA was seen in adapted birds (7 to 21 d) compared to unadapted bird (19 to 21 d) when 0.20% nPP diets were fed at 0.95% Ca concentrations (P<0.05). At 0.40% nPP, there was no effect of adaptation on AID of CP and AA at any Ca concentration. Phytase efficacy was significantly lower in younger (7 to 9 d) compared to older birds (19 to 21 d; P<0.05), except at 0.65% Ca. Phytase inclusion increased AID of CP and AA regardless of Ca (P<0.05). In conclusion, the AID of CP and AA can be affected by diet, age, and adaptation.
总共1152只直放式孵化的传统56M×快羽科宝500F肉鸡用于确定钙、年龄和适应性对粗蛋白表观回肠消化率（CP的AID）、氨基酸（AA的AID）和植酸酶功效的影响。12种处理，每种处理8个重复，分别在7至9日龄（每个重复6只鸡）、7至21日龄（每个重复6只鸡）和19至21日龄（每个重复3只鸡）进行饲喂。日粮按照3种钙浓度（0.65%、0.80%和0.95%）和2种非植酸磷浓度（0.20%和0.40%）配制。在每个钙浓度下，向0.20%非植酸磷日粮中添加500或1000 FTU/kg的6 - 植酸酶。年龄和适应性影响分别通过比较7至9日龄与19至21日龄、19至21日龄与7至21日龄的鸡的反应来确定。无论钙、非植酸磷或植酸酶浓度如何，均观察到年龄效应，较年长的鸡（19至21日龄）对氨基酸（AA）和CP的表观回肠消化率（AID）高于较年幼的鸡（7至9日龄；P<0.05）。对适应性的反应因钙、非植酸磷和植酸酶浓度而异。当在0.95%钙浓度下饲喂0.20%非植酸磷日粮时，适应的鸡（7至21日龄）的CP和AA的AID持续低于未适应的鸡（19至21日龄；P<0.05）。在0.40%非植酸磷时，在任何钙浓度下适应性对CP和AA的AID均无影响。与较年长的鸡（19至21日龄；P<0.05）相比，较年幼的鸡（7至9日龄）的植酸酶功效显著较低，但在0.65%钙时除外。无论钙浓度如何，添加植酸酶均提高了CP和AA的AID（P<0.05）。总之，CP和AA的AID会受到日粮、年龄和适应性的影响。
