不同磷源对育肥猪生长性能、血清指标、骨骼钙和磷代谢以及肠道微生物的影响

Effects of Different Phosphorus Sources on Growth Performance,Serum Indices,Bone Calcium and Phosphorus Metabolism and Intestinal Microbes of Finishing Pigs

本试验旨在研究不同磷源对育肥猪生长性能、血清指标、骨骼钙和磷代谢以及肠道微生物的影响。试验选用640头健康的、遗传背景一致、初始体重为(63.10±2.32)kg的“杜×长×大”三元杂交猪,随机分为5个组,每组8个重复,每个重复16头(公母各占1/2)。对照组饲喂基础饲粮,磷源为磷酸氢钙(DCP);试验1组磷源为磷酸一二钙(MDCP),其中MDCP提供的磷水平为对照组DCP提供磷水平的80%;试验2组磷源为MDCP,其中MDCP提供的磷水平为对照组DCP提供磷水平的60%;试验3组磷源为磷酸二氢钙(MCP),其中MCP提供的磷水平为对照组DCP提供磷水平的80%;试验4组磷源为MCP,其中MCP提供的磷水平为对照组DCP提供磷水平的60%。试验期共90 d,其中预试期10 d、正试期80 d。结果显示:1)与对照组相比,试验1组和试验4组育肥猪终末体重显著提高(P<0.05),试验1组平均日增重和试验2组磷表观消化率显著提高(P<0.05)。2)与对照组相比,各试验组育肥猪肌肉、肝脏和血清胰岛素样生长因子-Ⅰ(IGF-Ⅰ)含量均显著提高(P<0.05),肌肉和血清生长激素(GH)含量均显著提高(P<0.05),其中试验3组和试验4组肌肉IGF-Ⅰ和GH含量显著高于试验1组和试验2组(P<0.05);试验2组肌肉IGF-Ⅰ相对表达量显著提高(P<0.05),试验3组肝脏IGF-Ⅰ相对表达量显著降低(P<0.05),试验4组肌肉GH相对表达量显著高于试验3组(P<0.05)。3)不同磷源对育肥猪各段肠道的微生物种类和数量均有一定的影响,其中空肠和回肠的微生物多样性增加,特别是空肠新增菌属较多,而盲肠微生物较稳定。由此可见,饲粮选用MDCP或MCP替代DCP来补充磷源,并以80%或60%为替代比例,在一定程度上能够提高育肥猪的生长性能,增加肠道微生物的多样性,是替代DCP的良好磷源。

This experiment was conducted to study the effects of different phosphorus sources on growth performance,serum indices,bone calcium and phosphorus metabolism and intestinal microbes of finishing pigs.A total of 640 healthy“Duroc×Landrace×Yorkshire”crossbred pigs with the same genetic background and initial body weight of(63.10±2.32)kg were randomly divided into 5 groups with 8 replicates per group and 16 pigs(half male and half female)per replicate.The control group was fed a basal diet,and the phosphorus source was calcium hydrogen phosphate(DCP);the phosphorus source in experimental group 1 was mono-dicalcium phosphate(MDCP),and the level of phosphorus provided by MDCP was 80%of that provided by DCP in the control group;the phosphorus source in experimental group 2 was MDCP,and the level of phosphorus provided by MDCP was 60%of that provided by DCP in the control group;the phosphorus source in experimental group 3 was monocalcium phosphate(MCP),and the level of phosphorus provided by MCP was 80%of that provided by DCP in the control group;the phosphorus source in experimental group 4 was MCP,and the level of phosphorus provided by MCP was 60%of that provided by DCP in the control group.The experiment lasted for 90 days,including a pre-experiment period of 10 days and a formal experiment period of 80 days.The results showed as follows:1)compared with the control group,the final body weight of finishing pigs in experimental groups 1 and 4 was significantly increased(P<0.05),the average daily gain in experimental group 1 and the apparent phosphorus digestibility in experimental group 2 were significantly increased(P<0.05).2)Compared with the control group,the insulin-like growth factor-Ⅰ(IGF-Ⅰ)content in muscle,liver and serum of finishing pigs in experimental groups was significantly increased(P<0.05),and the growth hormone(GH)content in muscle and serum was also significantly increased(P<0.05).And the contents of IGF-Ⅰand GH in muscle in experimental groups 3 and 4 were significantly higher than those in experimental groups 1 and 2(P<0.05).The IGF-Ⅰrelative expression level in muscle in experimental group 2 was significantly increased(P<0.05),the IGF-Ⅰrelative expression level in liver in experimental group 3 was significantly decreased(P<0.05),and the GH relative expression level in muscle in experimental group 4 was significantly higher than that in experimental group 3(P<0.05).3)Different phosphorus sources had certain effects on the species and quantity of microorganisms in each section of intestinal tract of finishing pigs.The microbial diversity in jejunum and ileum was increased,especially the jejunum had more newly added bacteria,while the cecum had more stable microorganisms.In conclusion,MDCP or MCP supplemented with 80%or 60%replacement ratio can improve the growth performance and intestinal microbial diversity of finishing pigs to a certain extent,and is a good phosphorus source to replace DCP.