低聚壳聚糖对母猪繁殖性能、泌乳性能和血浆生化指标的影响

本试验旨在探讨饲粮中添加低聚壳聚糖对母猪繁殖性能、泌乳性能和血浆生化指标的影响。选择24头胎次、体重和预产期相近的健康大白猪母猪,随机分为3个组,每组8个重复,每个重复1头猪。对照组饲喂基础饲粮,试验Ⅰ组和Ⅱ组饲粮在基础饲粮中分别添加50和100 g/t的低聚壳聚糖。试验从母猪妊娠第85天时开始,至分娩后第21天时结束。结果表明:1)与对照组相比,饲粮中添加低聚壳聚糖可显著增加母猪的健仔数和哺乳期平均日采食量(P0.05),显著降低母猪的产程(P0.05),且在一定程度上可改善母猪的便秘和降低母猪的背膘厚损失;与对照组相比,试验Ⅰ组仔猪的初生窝重显著增加(P0.05),试验Ⅱ组母猪的哺乳期泌乳量显著增加(P0.05)。2)与对照组相比,试验Ⅰ组和Ⅱ组母猪初乳中乳脂肪含量显著增加(P0.05),试验Ⅰ组初乳中尿素氮(UN)含量和常乳中精氨酸、总氨基酸、限制性氨基酸含量显著增加(P0.05)。3)试验Ⅰ组和Ⅱ组母猪的血浆谷丙转氨酶(GPT)活性显著低于对照组(P0.05),各组的血浆碱性磷酸酶(ALP)、乳酸脱氢酶(LDH)活性和总蛋白(TP)、白蛋白(ALB)、UN、甘油三酯(TG)、总胆固醇(CHO)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)含量均无显著差异(P0.05)。由此可见,饲粮中添加低聚壳聚糖对母猪的繁殖性能和泌乳性能均有一定的促进作用。综合本研究结果,50 g/t低聚壳聚糖为母猪饲粮中的最佳添加剂量。     

饲粮添加中药渣和发酵中药渣对母猪繁殖性能与子代发育的影响

本试验旨在通过研究微生物发酵中药渣对围产期母猪繁殖性能和子代发育的影响,为中药渣的二次开发利用提供依据。试验选用2~4胎次、预产期相近的妊娠85 d的健康二元母猪60头,随机分为3组,每组20头。3组分别在基础饲粮中添加2 kg/t米糠(对照组)、2 kg/t中药渣制剂(由黄芪、当归、熟地黄和白芍等组成,中药渣组)和2 kg/t发酵中药渣制剂(发酵中药渣组)。从产前21 d开始饲喂,到产后21 d结束。分别于妊娠110 d、产后21 d时测量母猪背膘厚,记录母猪的产仔数、产活仔数、死胎数、木乃伊数和母猪产后发情间隔;记录仔猪初生窝重,7、14和21日龄窝增重,并计算平均日增重;每天观察仔猪腹泻情况,并计算腹泻率。结果表明:与对照组相比,发酵中药渣组仔猪断奶窝增重显著增加(P0.05),中药渣组和发酵中药渣组仔猪1~14日龄、1~21日龄腹泻率显著增加(P0.05);与中药渣组相比,发酵中药渣组仔猪7日龄窝增重显著增加(P0.05),平均日增重呈升高趋势(P=0.053)。由此可见,围产期母猪饲粮添加中药渣制剂虽然造成哺乳仔猪一定程度的腹泻,但可促进其生长发育,添加发酵中药渣制剂效果更好。     

Polymer coated DAP helps in enhancing growth,yield and phosphorus use efficiency of wheat (Triticum aestivum L.)

Low phosphorus use efficiency (PUE) is one of the major reasons of poor wheat production worldwide. Among the various approaches used to enhance PUE, polymer coated fertilizers are relatively a new concept. Keeping this in view, a field study was conducted to evaluate polymer coated di-ammonium phosphate (DAP) to enhance growth, yield and PUE of wheat. Commercial DAP and polymer coated DAP (50%, 75% and 100% of recommended dose) were tested in wheat. Results revealed that application of 50% polymer coated DAP produced the same results or higher than 100% commercial DAP. However, the maximum increase in growth (plant height, root length, number of tillers m^?2, inter-nodal distance), yield (number of grains per spike, 1000 grain weight, grain yield and biological yield) and phosphorus acquisition by wheat was observed with 100% polymer coated DAP. Moreover, 100% polymer coated DAP increased phosphorus recovery and agronomic efficiency compared to other treatments.     

楸树植物资源的研究概况

楸树是我国特有的优质用材,药用和园林观赏树种之一.本文对楸树的栽培历史、资源调查和分类、生态学和经济学特性,药用价值、病虫害防治、繁殖方法等方面进行综述,并针对楸树生产中存在的问题提出了合理的开发策略和建议.     

黑皮果蔗茎尖脱毒不同代数种茎苗商品性能研究

以黑皮果蔗茎尖脱毒第1代(处理A)、第2代(处理B)、第3代(处理C)种茎为材料,研究其商品性能生产表现情况。结果表明,脱毒果蔗不同代数种苗的月生长速度、株高、茎径、蔗茎产量与对照相比差异性均达极显著水平,其中,蔗株最高、茎径最粗、蔗茎产量最高等均为第2代种茎苗,分别比对照高41cm、粗0.25cm、增产41.1%;在品质方面,脱毒果蔗的水分含量较高,纤维分含量较低,糖分略低于对照;在外观品质方面,脱毒果蔗的节间长度、均匀度、色泽等均优于对照,由花叶病引起的花皮蔗株低于对照;脱毒果蔗易受外界花叶病毒的传染,随种植年限的增加,花叶病发病率提高;脱毒果蔗叶片的叶绿素含量、ATP酶活性提高;第1代种茎苗可栽培成商品蔗,但存在一定的组培效应,主要表现为蔗茎的侧芽较大,在光线条件较好的地方较易萌动。     

母猪与仔猪的声音联系及互作

声音是母猪与仔猪沟通的桥梁,也是其生存小环境的一部分。笔者概述了猪听觉的形成原理、声音的特征、母猪与仔猪间声音的联系及声音对断奶仔猪生产性能和行为的影响,为进一步缓解断奶应激、提高猪的生产性能寻找新的路径。     

种植密度和氮肥对‘绿雄90’西兰花产量与商品性的影响

为明确不同种植密度和氮肥用量组合对秋播西兰花产量和品质的影响,进行种植密度和氮肥用量两因素试验。结果表明,密植少氮处理的定植至现蕾天数极显著地小于稀植多氮处理。中、高水平的种植密度和氮肥用量,蕾粒明显变细。较高的种植密度与氮肥用量有利于提高西兰花单位面积产量。中等水平的种植密度和氮肥用量则更有利于提高西兰花保鲜球合格率,稀植少氮则保鲜球合格率明显下降。结合生产实际,兼顾优质、高产、高效,并考虑保鲜外销之因素,西兰花种植密度以2 500～2 800 株/666.7m²,氮肥用量以纯氮25～40 kg/666.7m²,在中、高肥力水平的情况下,取其中下范围为宜。     

Effects of misty‐fan cooling and supplemental rbST on rumen function and milk production of crossbred Holstein cattle during early,mid and late lactation in a tropical environment

Two groups of five crossbred 87.5% Holstein cattle were housed in normal shade only (NS) as non‐cooled cows and in shaded housing with misty‐fan cooling (MF) as cooled cows. The cows were treated with recombinant bovine somatotropin (rbST) in early, mid and late lactation with three consecutive injections of rbST in every 14 days. Ambient temperatures and the temperature humidity index in the NS barn were significantly higher than those of the MF barn, whereas relative humidity in MF was higher than that of NS barn. The DMI of cooled cows were higher than those of non‐cooled cows, and cooled cows exhibited more response to rbST treatment. Exogenous rbST significantly increased milk yield throughout lactation. The rbST‐treated cows had higher total ruminal fermentation products as volatile fatty acid and ammonia nitrogen than the non‐rbST treated cows and associated changes were greater in cooled animals in all stages of lactation. Exogenous rbST increased the concentrations of milk urea nitrogen in both groups. These results suggest that the changes in ruminal fermentation with greater production of total VFA and NH₃N in response to rbST in crossbred cows whether under misty‐fan cooling or not, is in part through an increase in feed intake, thereby making more substrate available to the mammary gland for milk synthesis.     

妊娠母猪膘情对繁殖性能的影响

为研究妊娠母猪膘情与繁殖性能的关系,试验随机选用32头妊娠母猪,用B超活体测定其产前3 d倒数3、4肋骨间、胸腰椎结合处、腰荐椎结合处偏离背中线5~8 cm处背膘厚,并与其窝产仔数、产活仔数、死胎数、、仔猪初生重、初生窝重、18日龄断奶重、断奶窝重及断奶后发情天数等指标进行比较。结果显示,背膘厚度较薄组各项繁殖指标普遍优于背膘厚组,说明保持适当膘情对妊娠母猪繁殖性能的提高具有促进作用。     

母猪精氨酸营养研究进展

内源合成以及传统饲粮供给的精氨酸并不能满足母猪的最佳营养需要,因此需外源添加,其对母猪胎盘、胚胎和胎儿的生长发育具有重要意义.本文从精氨酸的理化特性、合成与分解代谢以及对母猪繁殖性能的影响等方面阐述精氨酸的营养生理作用,重点阐述精氨酸营养调节母猪繁殖性能的作用机制.