不同酶制剂对肉鸡生产性能的影响

研究在玉米-豆粕-菜籽粕型饲粮中添加不同的复合酶对肉鸡生产性能的影响。试验为两个:试验一设正对照组(处理1),负对照组1(处理2),负对照组1 酶R 200 mL·t-1(处理3),负对照组1 酶H 100 mL·t-1 (处理4)。试验二设正对照组(处理1),负对照组2(处理5),负对照组2 酶A 100 g·t。。(处理6),负对照组2 酶B 150g·t-1(处理7),负对照组2 酶C 150 g·t-1(处理8)。两个试验采用同一正对照组,共8个处理,每个处理8个重复,每个重复30只鸡,共用1 920只1日龄健康艾维茵肉公鸡。饲粮分1～21和22～42日龄两个阶段,负对照饲粮1在正对照组饲粮基础上降低代谢能0.34 MJ·kg-1、总氨基酸1.50%,其余营养水平保持一致;负对照饲粮2在正对照组饲粮基础上降低代谢能0.42MJ·kg-1、总氨基酸2.00%、磷0.12%、钙0.10%,其余营养水平保持一致。结果表明,在降低饲粮代谢能0.34 MJ·kg-1、总氨基酸1.50%的玉米-豆粕-菜籽粕型饲粮中添加复合酶R或H未表现出相应的促生长效果;在降低代谢能0.42 MJ·kg-1、总氨基酸2.00%、磷0.12%、钙0.10%的玉米-豆粕-菜籽粕型饲粮中添加复合酶A或B或C有改善肉鸡生长性能的趋势,达到正对照饲粮效果。     

Effects of ascites syndrome in broilers on their growth performances and the availability of energy and nutrients

An experiment was carried out to investigate the effects of ascites syndrome (AS) on the growth performance and availability of dietary energy and nutrients in broilers. One hundred and twenty one-day-old avian broilers were randomly allotted into two groups (control group and test group) with six replications of ten birds. In the test group, the addition of 3,3,5-triiodothyronine (T₃, 1.5 mg/kg diet) and low ambient temperature (LAT) were used to induce AS. Results showed that T₃ and LAT could successfully induce AS in broilers with an incidence rate of 66.7% and a mortality rate of 23.3%. Compared with the control, the bird growth performance of the test group was decreased (P < 0.05) and heart index was increased (P < 0.05). For the test group, the availability of dietary energy (P < 0.01), crude fat (P < 0.01), crude protein (P < 0.05), and most amino acids in the second week were lower compared with the control group. Results showed that the low availability of energy and nutrients and the poor growth resulted from the high AS incidence rate. Translated from Journal of Sichuan Agricultural University, 2005, 23(4): 461–465 [译自: 四川农业大学学报]     

种鸡维生素营养对种蛋孵化性能的影响

种鸡维生素营养不仅影响其产蛋性能,也影响蛋中维生素的沉积,进而影响种蛋孵化性能。文章就种鸡维生素营养影响蛋中维生素沉积、种蛋受精率、孵化率、健雏率的相关研究进行了总结,论述了种鸡维生素营养对种蛋孵化性能影响的程度和方式。     

饲粮添加脂肪酶对肉鸡生长性能及养分利用率的影响

本试验旨在研究低能饲粮中添加脂肪酶对肉鸡生长性能及养分利用率的影响。试验分为前期(1~21 d)、后期(22~42 d)2个阶段,并采用2×2+1因子完全随机设计,分别为正对照(PC,饲粮能量前期12.13 MJ/kg,后期12.76 MJ/kg)、负对照1(NC1,饲粮能量在PC基础上降低210 kJ/kg)和负对照2(NC2,饲粮能量在PC基础上降低420 kJ/kg),以及在NC1和NC2基础上添加200 g/t脂肪酶(1 000 U/kg脂肪酶),每个处理6个重复,每个重复22只鸡。结果表明:1)与PC相比,NC1 22~42 d料重比(F/G)有提高趋势(P<0.10),屠宰率及全净膛率显著降低(P<0.05);NC2 42 d体重(BW)、22~42 d和1~42 d体增重(BWG)有降低趋势(P<0.10),22~42 d F/G有提高趋势(P<0.10),1~21 d及1~42 d F/G显著提高(P<0.05),表观代谢能(AME)显著降低(P<0.05)。2)与负对照相比,NC1+脂肪酶有提高半净膛率和粗脂肪(EE)表观利用率的趋势(P<0.10);NC2+脂肪酶有降低1~21 d F/G、提高EE表观利用率的趋势(P<0.10)。3)NC1+脂肪酶和NC2+脂肪酶各阶段BW、BWG、F/G及AME与PC无显著差异(P>0.05),各处理采食量差异不显著(P>0.05)。双因素分析显示,脂肪酶有提高42 d BW、22~42 d和1~42 d BWG及干物质表观利用率的趋势(P<0.10),显著降低了22~42 d和1~42 d F/G(P<0.05),有降低1~21 d F/G的趋势(P<0.10),显著提高了EE表观利用率(P<0.05)。由此可知,饲粮能量分别降低210和420 kJ/kg后,不同程度降低了肉鸡后期及全期BW和BWG,提高了各阶段F/G。在低能饲粮中添加1 000 U/kg脂肪酶能够显著改善后期及全期F/G,从而改善肉鸡BW和BWG,且NC2+脂肪酶的效果优于NC1+脂肪酶。     

Dietary methionine source and level affect hepatic sulfur amino acid metabolism of broiler breeder hens

A study was carried out to investigate the effects of dietary methionine source and level on plasma free amino acids patterns and the expression of genes involved in hepatic methionine metabolism in broiler breeders. A total of 2184 broiler breeders were assigned to 13 dietary treatments, with eight replicates per treatment. The 13 treatments included one control group and 12 additional treatments employing two sources and six levels (0.05, 0.10, 0.15, 0.20, 0.25 and 1.00%). Higher plasma methionine concentration was measured for DL‐methionine (DLM) treated hens. Plasma alanine concentration was linearly increased as DLM or 2‐hydroxy‐4‐(methylthio) butanoic acid (HMTBA) supplementation level increased. There was a linear increase in concentrations of tyrosine, valine, glycine and serine as dietary DLM supplementation level increased. Hens treated with DLM had higher relative expression of ADA than those fed HMTBA. The expression of MS, ADA, SAHH and MAT2A changed quadratically as HMTBA supplementation level increased, while the expression of GNMT and SAHH changed quadratically as DLM supplementation level increased. In conclusion, the effects of HMTBA on plasma free amino acid patterns and the expression of hepatic genes involved with methionine are different from DLM.     

鸡蛋中胆固醇含量调控原理与措施

随着人口的老龄化,心血管疾病逐渐成为威胁人类健康的重要杀手。临床和流行病学研究发现,动脉粥样硬化是导致心血管疾病的重要因素。而高脂、高胆固醇膳食与动脉粥样硬化有着密切关系。膳食胆固醇(CH OL)来源于动物性食物,鸡蛋是动物性食品中CH OL含量较高的一种,平均213m g/枚[1]。鸡蛋中的CH OL具有升高血浆总CH OL、LDL-CH OL水平的潜在作用。由于担心其CH OL会引起动脉粥样硬化,人们减少了鸡蛋食用。美国人年均消费鸡蛋从1965年的402枚降至1991年的233枚,全美的鸡蛋消费量下降了16%~25%[1]。因此,从改善人们的饮食和健康、提…     

云南橡胶林冠面温度的初步研究

根据红外测温法和小气候观测，研究了云南西南季风区（景洪、瑞丽）橡胶林冠面温度（Ｔｃ）基本特征及其与林冠上方１．５ｍ处气温（Ｔａ）的差异（△Ｔ＝Ｔｃ－Ｔａ）。结果表明：在０９—１８时橡胶林冠具有加热作用，Ｔｃ较Ｔａ平均高５—６℃；强光、干燥的午后（１４—１５时）则达９—１１℃；在最低温度出现时，Ｔｃ与Ｔａ差异不显著。还详细讨论了其它环境因子对Ｔｃ或△Ｔ的影响，指出本区较高Ｔｃ有利于橡胶树安全越冬。     

Effects of commercial premix vitamin level on sternum growth,calcification and carcass traits in meat duck

The present study was conducted to investigate the effects of dietary vitamin level on sternum growth, calcification and carcass traits in meat duck. A total of 432 1‐d‐old mixed‐sex Cherry Valley ducks (216 males and 216 females) were randomly allocated and fed low‐vitamin level diet (70% NRC vitamin regimen), high‐vitamin level diet (DSM vitamin regimen) or medium‐vitamin level diet (50% low‐vitamin level diet and 50% high‐vitamin level diet). Sternum and serum were harvested after 49 d of feeding. Compared with the low‐vitamin level group, dietary high‐vitamin level increased body weight (BW) at d 49 (p = 0.029) but did not alter all parameters of carcass trait (p > 0.05). Medium‐ and high‐vitamin level increased sternum defatted weight, density, ash and calcium (Ca) concentration (p < 0.05). Meanwhile, the medium and high‐vitamin level group significantly decreased the relative proportions of the keel cartilage at 49 d (p < 0.05) and decreased the sternum length and height (p < 0.05) in meat ducks at 49 d. Likewise, high‐vitamin level improved serum Ca and phosphate (P) content (p < 0.05) and declined serum Alkaline phosphatase (ALP) activity (p = 0.003) compared with the low‐vitamin level group. Our study indicates that high‐vitamin level did not affect the examined carcass traits; however, high‐vitamin level improved growth performance and sternum calcification.     

Effects of vitamin E supplementation on performance,serum biochemical parameters and fatty acid composition of egg yolk in laying hens fed a diet containing ageing corn

This study investigated whether dietary vitamin E (VE) supplementation could alleviate any detrimental effects of ageing corn in the diet for laying hens on egg performance, egg quality, serum biochemical parameters, cholesterol content and the fatty acid (FA) profile of egg yolks. The experiment consisted of a 2 × 3 factorial design with two corn types (normal corn and ageing corn) and three concentrations of VE (0, 20 and 100 IU/kg). A total of 216 Lohmann laying hens (50‐week‐old) were randomly allocated into six treatment diets for 12 week. Each treatment had six replicates with six hens. The results showed that ageing corn significantly reduced average daily feed intake (ADFI; p < 0.01) and egg weight (p < 0.05). Dietary VE supplementation had no significant influences on egg production performance (p > 0.05). Egg yolk colour was decreased in ageing corn diets (p < 0.01), while 20 and 100 IU/kg VE significantly improved vitelline membrane strength (p < 0.01) compared with feeding of 0 IU/kg VE. Ageing corn also significantly decreased the content of cholesterol including total cholesterol (TC; p < 0.05), low density lipoprotein cholesterol (LDL‐C; p < 0.01) and very low density lipoprotein cholesterol (VLDL‐C; p < 0.05) in the serum. Feeding 100 IU/kg VE significantly increased the content of LDL‐C (p < 0.01) and VLDL‐C (p < 0.05) in the serum. Furthermore, the content of the oleic acid, docosahexaenoic acid and total monounsaturated fatty acid (MUFA) was lower (p < 0.05) and stearic acid and total saturated fatty acid (SFA) was higher (p < 0.05) in egg yolks in ageing corn diets. Ageing corn resulted in reduced feed intake, egg weights and yolk colour, but the effects of VE supplementation were independent of those of age of corn and were unable to counteract the negative effects of feeding ageing corn.     

枯草芽孢杆菌对产气荚膜梭菌攻毒肉鸡生长性能和肠道健康的影响

本试验旨在研究饲粮中添加枯草芽孢杆菌对产气荚膜梭菌攻毒肉鸡生长性能和肠道健康的影响。选用480只1日龄肉公鸡(Ross 308)随机分为5组,分别为对照组(CON组)、产气荚膜梭菌攻毒组(CP组)、CP+10 mg/kg恩拉霉素组(ENRA组),CP+10 mg/kg枯草芽孢杆菌(1010CFU/g)组(BS组)和CP+5 mg/kg恩拉霉素+10 mg/kg枯草芽孢杆菌组(ENRA+BS组),每组8个重复,每个重复12只,试验期42 d。所有攻毒组肉鸡在第14天时口服混合型艾美尔球虫悬浮液[11 000孢子/(mL·只)],第16～18天时口服产气荚膜梭菌悬浮液[108CFU/(mL·只)]。结果表明:1)与CP组相比,ENRA组、BS组和ENRA+BS组肉鸡第1～21天料重比有降低的趋势(P=0.051);与CON组相比,ENRA组和ENRA+BS组肉鸡第1～42天料重比显著降低(P<0.05)。2)与CP组相比,ENRA组、BS组和ENRA+BS组肉鸡第28天空肠病变计分极显著降低(P<0.01)。3)第21天和第42天时,ENRA组隐窝深度极显著低于CP组、BS组和ENRA+BS组(P<0.01)。第42天时,与CP组相比,ENRA组绒毛高度/隐窝深度(VH/CD)显著增加(P<0.05),BS组和ENRA+BS组VH/CD有提高趋势(P>0.05)。4)第21天时,与CP组相比,ENRA+BS组空肠黏膜分泌型免疫球蛋白A (SIgA)含量显著增加(P <0.05);第28天时,与CP组相比,BS组和ENRA+BS组空肠黏膜免疫球蛋白G (IgG)含量显著增加(P<0.05)。5)与CP组相比,ENRA组、BS组和ENRA+BS组第21天肉鸡大肠杆菌数量极显著降低(P<0.01); ENRA组、BS组和ENRA+BS组第28天肉鸡产气荚膜梭菌数量极显著降低(P<0.01)。由此得出,枯草芽孢杆菌可在一定程度上改善肉鸡肠道健康和生长性能,当与恩拉霉素(5 mg/kg)合用时,其效果更好,从而起到减少抗生素使用的作用。