Departamento de Producción Agraria. Universidad Politécnica de Madrid, 28040 Madrid, Spain.
Departamento de Producción Agraria. Universidad Politécnica de Madrid, 28040 Madrid, Spain.
Poult Sci. 2020 Feb;99(2):1010-1018. doi: 10.1016/j.psj.2019.10.011. Epub 2019 Dec 6.
We studied the effects of restricting the access to feed on the anticipatory eating behavior, growth performance, and the development of the proximal part of the gastrointestinal tract (GIT) in broilers. The experiment consisted in physical restriction of the access of broilers to feed for 0, 4, 6, or 8 h per day from 7 to 19 D of age. At 10, 13, 16, and 19 D of age, immediately before the start of the feed restriction (FR) period, 2 birds per cage were euthanized to evaluate crop and gizzard development. The experimental design was completely randomized, and the linear (L) and quadratic (Q) effects of fasting length on growth performance and GIT traits were determined. In addition, the effect of broiler age on GIT development was studied. From 7 to 19 D of age, ADFI (L, Q; P ≤ 0.05) and BW gain (L; P ≤ 0.01) decreased as the length of the FR period increased, with most of the differences observed with 6 or more hours of fasting. However, feed conversion ratio was not affected by FR length. The relative weight of the crop (% BW) and its fresh content increased (L; P ≤ 0.001) and the moisture of the digesta (%) decreased (L; P ≤ 0.001) as the FR period increased. The DM content (g) of the crop increased with FR, with most of the differences observed with 6 or more hours of fasting (L, Q; P ≤ 0.001). At 19 D of age, the Lactobacillus spp. count in the crop increased (L; P ≤ 0.05) with increase in the FR period. Fasting did not affect any gizzard trait at any age. In summary, physical restriction of the access to feed for 6 h or more reduced BW gain but did not affect feed conversion ratio in broilers from 7 to 19 D of age. Feed restriction for 4 to 8 h stimulated the anticipatory feeding behavior and crop development in broilers.
我们研究了限制采食对肉鸡采食前行为、生长性能和胃肠道（GIT）近端发育的影响。该实验通过物理方式限制 7 至 19 日龄肉鸡每天采食 0、4、6 或 8 小时。在 10、13、16 和 19 日龄时，即在开始限时采食（FR）前，每个笼子中选取 2 只鸡进行安乐死，以评估嗉囊和肌胃的发育情况。试验采用完全随机设计，确定禁食时间的线性（L）和二次（Q）效应对生长性能和 GIT 性状的影响。此外，还研究了肉鸡年龄对 GIT 发育的影响。从 7 至 19 日龄，随着 FR 时间的增加，ADFI（L、Q；P≤0.05）和 BW 增重（L；P≤0.01）降低，其中大部分差异出现在禁食 6 小时或以上时。然而，FR 长度并不影响饲料转化率。随着 FR 时间的增加，嗉囊相对重量（%BW）和新鲜内容物增加（L；P≤0.001），食糜水分（%）降低（L；P≤0.001）。随着 FR 的增加，嗉囊的 DM 含量（g）增加，其中大部分差异出现在禁食 6 小时或以上时（L、Q；P≤0.001）。在 19 日龄时，随着 FR 时间的增加，嗉囊中的乳杆菌属数量增加（L；P≤0.05）。在任何年龄，禁食均未影响肌胃的任何性状。综上所述，7 至 19 日龄肉鸡限制采食 6 小时或以上会降低 BW 增重，但不影响饲料转化率。4 至 8 小时的 FR 刺激了肉鸡的采食前行为和嗉囊发育。
