The purpose of this experiment was to study the effects of different zinc sources and levels on growth performance and content of zinc in serum and feces of weaned piglets. Two new types of zinc oxide were the inclusion molecular zinc oxide which made by inclusion technology and the zinc oxide which coated with stearic acid. A total of 250 twenty?four?day?old " Duroc×Langdrance×Large White" weaned piglets with body weight of (6.74±0.35) kg were randomly divided into 5 groups: control group ( basic diet+2 250 mg／kg normal oxidation zinc, as zinc count, the same as below) , inclusion molecular zinc oxide 300 group ( basic di?et+300 mg／kg inclusion molecular zinc oxide ) , inclusion molecular zinc oxide 600 group ( basic diet+600 mg／kg inclusion molecular zinc oxide) , coated zinc oxide 300 group ( basic diet+300 mg／kg coated zinc oxide) and coated zinc oxide 600 group ( basic diet+600 mg／kg coated zinc oxide) , and each group contained 5 replicates and each replicated contained 10 pigs ( half male and half female). The pre?experimental period lasted for 3 days, and the experimental period lasted for 14 days. The results showed as follows: 1) compared with the control group, the final body weight, average daily feed intake, average daily gain, feed conversion ratio and diarrhea rate of experimental groups had no significant differences ( P＞0.05 ). Compared with the coated zinc oxide groups, the average daily gain of inclusion molecular zinc oxide group was significantly in?creased ( P＜0.05) , and the average daily feed intake showed an increasing trend (0.05＜P＜0.10). 2) Com?pared with the control group, the serum zinc contents of experimental groups were decreased by 62.01%, 39.94%, 56.17% and 48.70%, respectively; the faecal zinc contents were 0.25 fold, 0.41 fold, 0.31 fold and 0.32 fold of the control group, and there were all significant difference ( P＜0.05). In conclusion, 300 or 600 mg／kg inclusion molecule zinc oxide and coated zinc oxide both can achieve the same effects as high dose ( 2 250 mg／kg) zinc oxide on growth performance, and the fecal zinc emission reduced significantly.[ Chinese Journal of Animal Nutrition, 2019, 31(10) :4852?4858]

文章以湖南省为例,分别测定不同土壤类型(红壤、水稻土、潮土)玉米、稻谷常规养分及微量元素含量,并与《中国饲料成分及营养价值表》(2017年第28版)进行对比分析,旨在为饲料企业更好地利用当地饲料资源提供基础数据.对比分析结果表明:①来自湖南省不同土壤类型的玉米DM、CP、EE、Ca和P含量均高于标准量;红壤稻谷DM、CP、Ca含量大于标准值,但EE、P含量分别比标准低0.09个百分点和0.10个百分点;水稻土稻谷的DM、CP、EE、Ca含量高于标准,但P含量低0.04个百分点;潮土稻谷DM、CP、Ca和P含量均大于标准,但EE含量低于标准值0.16个百分点;②水稻土玉米和潮土玉米Cu含量分别比标准值低0.05 mg/kg和1.66 mg/kg,红壤玉米Cu含量较标准值高0.34 mg/kg;3种土壤类型的玉米Fe、Zn、Mn、Se含量均高于标准值;3种土壤类型稻谷Cu、Fe、Zn、Mn、Se含量均高于标准值.从湖南省3种土壤类型采集的玉米、稻谷分析结果表明,常规养分和微量元素含量与标准值之间存在差异,饲料企业在进行配方设计时,可以对微量元素配给进行适度调整.

The objective of this study was to investigate different zinc sources and levels on production performance,egg quality,blood parameters and egg selenium content of laying hens.Seven-hundred and twenty 21-week-old healthy Roma laying hens with a similar laying rate were randomly divided into 5 groups with 6 replicates of 24 hens each.The control groups was fed a basal diet without adding exogenous zinc source(measured values:20.56 mg/kg),and other four groups were fed basal diets supplemented with Av-Zn and ZnSO4 containing 35 and 70 mg/kg,respectively (The measured values of zinc content in experimental diets were 40.11,80.39,36.62,76.10 mg/kg,respectively).Pretrail period was 7 d and experimental period was 56 d.The results showed that:① Adding different sources and levels of zinc on laying the average daily feed intake,feed egg ratio and no significant effect on egg production rate (P＞0.05),but there were significant differences in the dirty broken egg rate (P＜0.05) and the average daily egg weight was significantly (P＜0.01).Adding 35 mg/kg Av-Zn can significant increase egg weight compared ZnSO4,but it increase the rate of dirty broken shell eggs;②There were no significant differences in egg quality besides the shell weight(P＜0.05);③ Different sources of zinc had no significant effect (P＞0.05)on serum zinc ions,SOD activity and CuZn-SOD activity of laying hens;different levels of zinc have highly significant effect (P＜0.01) on serum zinc ions,had a significant effect CuZn-SOD activity (P＜0.05),no significant effect on SOD activity (P＞0.05);④ There were significant differences on yolk Zinc content (P＜0.05).In conclusions,different zinc sources and levels on performance of laying hens certain influence significantly the average daily egg weight;different zinc sources and levels had a certain influence on the eggs quality;different zinc sources and levels could increase yolk zinc content.Different levels of zinc on laying significantly increased serum concentration of zinc ions,CuZn-SOD activity,SOD activity was not significantly affected,but with the increase in trend.Egg zinc content increased with the levels of diet content,and the yolk zinc content can be deposited more efficiently by Av-Zn than ZnSO4.

Epidermal growth factor (EGF) is one of the members of growth factor family, which has trophic ef-fects in the growth performance and the gastrointestinal tract including enhanced proliferation and differentiation. Also, it can improve the activity of gastrointestinal digestive enzymes, enhance immune function and reduce the rate of diarrhea. But, the application of EGF in feed industry was limited due to the high prices of EGF. Howev-er, with the development of biotechnology, the production of EGF was increased, and the price of EGF was re-duced greatly when the EGF was expressed in recombination strains, which made it a possible used in piglets. This review mainly introduced the situation of EGF expressed in recombinant strains and its application in piglets, and provided a better understanding of the utilization of EGF on piglets feed.

试验以大白猪为研究对象,采用PCR-SSCP方法对DECR1基因exon5(外显子5)的多态性位点进行了遗传结构的分析,并对这个多态性位点与胴体性状的关联性进行了研究,结果表明,DECR1基因在该位点上,由C、G 2个等位基因产生了CC、CG和GG 3种基因型,CG基因型为优势基因型,在该位点存在较大遗传变异。GG基因型脂肪率与CC基因型脂肪率存在显著差异(P<0.05)。