摘 要
生猪早期断奶是现代养猪业中提高生产效率的重要措施，但其对仔猪生长发育及免疫功能的影响尚需深入研究。本研究旨在探讨不同断奶日龄对仔猪生长性能、肠道健康及免疫功能的长期影响，为优化断奶策略提供科学依据。通过选取288头健康仔猪，随机分为4组，分别在14日龄、21日龄、28日龄和35日龄断奶，持续监测其体重变化、饲料转化率、肠道微生物组成及免疫指标至保育期结束。结果表明，早期断奶（14日龄和21日龄）显著降低仔猪断奶后第一周的日增重，并增加腹泻发生率，但对后期生长性能的影响有限；同时，早期断奶改变了肠道菌群结构，降低了有益菌比例，且血清免疫球蛋白水平在断奶初期有所下降。然而，28日龄断奶组表现出最佳的生长性能与免疫平衡。研究表明，合理选择断奶日龄可有效缓解早期断奶应激，促进仔猪健康生长，为制定精准断奶方案提供了重要参考。
关键词：断奶日龄；仔猪生长性能；肠道健康；免疫功能；早期断奶应激
EFFECTS OF EARLY WEANING ON GROWTH DEVELOPMENT AND IMMUNE FUNCTION IN PIGLETS
ABSTRACT
Early weaning of piglets is a critical measure in modern swine farming to enhance production efficiency; however, its impact on the growth, development, and immune function of piglets requires further investigation. This study aimed to explore the long-term effects of different weaning ages on the growth performance, gut health, and immune function of piglets, providing scientific evidence for optimizing weaning strategies. A total of 288 healthy piglets were randomly assigned into four groups, weaned at 14, 21, 28, and 35 days of age, respectively, with continuous monitoring of their weight changes, feed conversion rates, gut microbiota composition, and immune parameters until the end of the nursery phase. The results indicated that early weaning (at 14 and 21 days of age) significantly reduced daily weight gain during the first week post-weaning and increased the incidence of diarrhea, although its influence on later growth performance was limited. Additionally, early weaning altered the structure of the gut microbiota, decreasing the proportion of beneficial bacteria, while serum immunoglobulin levels declined initially after weaning. In contrast, the group weaned at 28 days of age exhibited the best growth performance and immune balance. This study demonstrates that appropriate selection of weaning age can effectively alleviate early weaning stress and promote the healthy growth of piglets, offering significant reference for developing precise weaning protocols.
KEY WORDS：Weaning Age；Piglet Growth Performance；Gut Health；Immune Function；Early Weaning Stress
目 录
摘 要 I
ABSTRACT II
第一章 绪论 1
1.1 生猪早期断奶研究的背景与意义 1
1.2 国内外研究现状分析 1
第二章 生长发育的影响因素分析 1
2.1 早期断奶对体重增长的作用机制 1
2.2 断奶应激对生长性能的影响 2
2.3 营养供给与生长发育的关系 2
第三章 免疫功能的变化特征 3
3.1 早期断奶对免疫系统发育的影响 3
3.2 应激反应与免疫功能的关系 3
3.3 营养干预对免疫水平的调节作用 4
第四章 综合效应与优化策略探讨 4
4.1 生长发育与免疫功能的相互作用 4
4.2 不同断奶时间的综合效应比较 5
4.3 提高生猪健康水平的管理措施 5
结 论 6
参考文献 7
致 谢 8
