食物摄入与下丘脑能量平衡

能量平衡（energy balance）是能量摄入与能量消耗相平衡的过程。动物机体在处于能量平衡时才能维持正常的生命活动。下丘脑中的多个与摄食相关的神经核团，在神经和体液的调节下发挥关键作用，并构成了复杂而精密的神经网络。本文将从影响下丘脑能量平衡的神经核团、神经肽、神经投射和外周激素等方面，对食物摄入与下丘脑能量平衡进行论述。     

奶牛抗热应激的饲养管理

正奶牛应激损失最大的是产奶量的损失。研究表明,在采食量降低幅度相似的条件下,因为限制采食导致的产奶量降低只占热应激下采食量下降导致的产奶量下降幅度的35%~50%,而其他是由代谢变化引起的,也表明产奶量的下降不但与采食量的降低有关,而且更重要的是其他生理、代谢方面的变化。奶牛热应激采食量降低导致的能量负平衡也与泌乳早期的能量负平衡不同,并不会导致生长激素(ST)和游离脂肪酸水平     

波音达犬与马里努阿犬、史宾格犬的奔跑性能比对分析

一、实验内容 本次测试通过挑选犬类,对犬只进行编号,进行相关测试.针对不同的测试条件分别测试不同犬类奔跑所用的时长,并安排固定人员记录不同测试条件下的用时. 通过对每项测试中单犬时长、各犬种平均时长进行对比分析,进而比较不同犬类的奔跑性能,此次测试遵循控制变量的原则,尽可能地保证数据的真实性与可靠性.     

不同光周期条件下金花菜F_2代农艺性状的变异特征

通过在人工气候室内模拟10h短日照和16h长日照2种光周期,对来自江苏海安和浙江温岭的2种性状差异明显的金花菜材料进行了不同光周期条件下的开花诱导试验,研究了不同光周期条件下金花菜杂交F_2代株高、叶长、叶宽和分枝数的变异特征。结果表明:在不同光周期条件下,金花菜F_2代株高、叶长和叶宽都服从正态分布,而分枝数不服从正态分布;在不同光周期条件下,金花菜F_2代株高、叶长和叶宽都表现为极显著差异(P0.05),而分枝数表现为显著差异(P0.01);在不同光周期条件下,金花菜F_2代分枝数的变异都最为突出并且都倾向于分枝数为1的母本P2;本研究得出金花菜属于长日照植物。可以利用此特性进行短日照诱导延长金花菜生育期,改善目标性状,增加刈割茬数,获得高产。在金花菜的育种中,凭此特性还可以选育优质高产品种。     

归芪益母口服液对能量负平衡奶牛的治疗效果

<正>归芪益母口服液是一种常见的中药配方,可以增强人体免疫力,调节内分泌系统。近年来,该药物在治疗分娩后的奶牛能量负平衡方面也得到了广泛应用。分娩后的奶牛容易出现能量负平衡的状况,主要是因为产后恢复期内的奶牛需要大量的能量和营养物质来维持生理机能、产乳和生殖系统正常运作。如果奶牛无法摄取足够的营养物质,容易出现能量缺乏和代谢紊乱等问题,     

围产期奶牛能量负平衡的生理变化及关键缓解措施

围产期奶牛由于经历妊娠、分娩和产后泌乳等一系列生理代谢变化,极易发生能量负平衡现象。能量负平衡可导致奶牛生理代谢紊乱而产生能量代谢障碍性疾病,降低整个泌乳期的生产性能。本文从瘤胃消化、血液代谢和激素分泌以及内分泌和免疫机能等方面简单介绍了围产期奶牛生理代谢变化特征,并总结归纳近几年缓解奶牛能量负平衡的有效应用措施,为解决围产期奶牛能量负平衡问题提供参考。     

种鹅平衡饲料对马岗鹅繁殖性能的影响

选用饲养条件相近的2年龄健康马岗母鹅12栏共2 440只,按栏随机分配到4个处理中,每个处理3个重复。对照组饲喂70%稻谷+30%蛋鸭全价料,试验组(即Ⅰ、Ⅱ和Ⅲ组)分别用20%、23%和26%的种鹅平衡饲料取代相应的能量饲料,并用米糠和玉米调节日粮代谢能。结果显示,用20%~26%的种鹅平衡饲料和74%~80%的能量饲料饲喂马岗鹅种鹅,除平均蛋重Ⅰ组与对照组差异不显著(P0.05)外,其他各试验组均显著提高种鹅的只均产蛋数、蛋重、种蛋受精率和受精蛋出苗率。表明用23%的种鹅平衡饲料和77%能量饲料饲喂马岗鹅种鹅比较合理。     

选购廉价饲料的技术探讨 续完

三、普列斯通法(Preston,R.L.) 普列斯通法是在彼得森法的基础上,将饲料进行钙、磷、可消化蛋白及无蛋白可消化营养总量四种营养素剖分。同时,并针对反刍动物和单胃动物对营养素的消化特点,反刍动物能量采用消化能,蛋白用粗蛋白;单胃动物能量用代谢能,蛋白质用CP×BCP(蛋白平衡系数)。因而除可对强白质和能量进行评价外,还对氨基酸、钙、磷进行评价,特别是用于单胃动物,还能权衡氨基酸平衡的优点。 1.蛋白质平衡系数(BCP)概念及计算法原料的蛋白质平衡系数(balanced crude protein fac-tor),就是先求出猪和鸡对各种氨基酸的平均需要量,并以此为标准,求出各种原料中对应氨基酸的比率,     

氨基酸平衡对生长肥育猪生长的影响—配合饲料中有无鱼粉对比试验

一、前言蛋白质和能量是猪只生长发育最重要的营养物质。在能量进食水平一定的情况下,体蛋白质合成的速度和效率直接取决于饲粮所含蛋白质的数量和质量。饲粮蛋白质的质量高,氨基酸平衡,对提高猪的生长速度、饲料转化效率,胴体瘦肉率起着决定性的作用。因此,在配合饲料中一定的能量含量情况下与其相应的一定蛋白质含量的条件下,尽可能使得必需氨基酸达到基本平衡,对促进猪的生长发育,提高饲料有效率、降低饲养成本,提高养猪经济效益都具有十分重要     

荒漠草原家庭牧场不同放牧管理模式下草畜能量平衡模拟研究

本研究以内蒙古乌兰察布市四子王旗家庭牧场调研数据为基础,利用ACIAR草畜平衡模型对荒漠草原家庭牧场在全年放牧和季节牧场及补饲措施的家畜需求与草地供给之间的能量平衡关系进行模拟研究,目的是了解家庭牧场的草畜平衡状态,为草地畜牧业管理提供理论依据。结果表明,划分季节牧场利用可增加家畜在冬季的实际能量摄入,减少在夏季的能量摄入;补饲可以缓解在家畜关键生长期对于能量的需求,并在不额外增加补饲量的条件下,划分季节牧场的家畜也表现出冬季实际能量摄入增加,夏季能量摄入减少。     

基于NRC模型下不同程度热处理豆渣的营养价值与分子结构功能团特征的相关关系

本试验旨在研究基于NRC模型下不同程度热处理豆渣的营养价值与分子结构功能团特征的相关关系。利用烘箱对豆渣进行不同温度(100、115、130℃)下不同时间(2、4、6 h)的热处理,采用NRC(2001)模型预测不同程度热处理豆渣的代谢蛋白质产量、可消化养分含量和能值,同时利用傅里叶变换红外光谱(FTIR)技术分析不同程度热处理豆渣的分子结构功能团特征,并分析它们之间的相关关系。结果表明:1)随着温度的升高以及加热时间的延长,豆渣的代谢蛋白质产量、可消化养分含量和能值呈现出降低的趋势。2)温度和时间对豆渣的分子结构功能团存在显著的互作效应(P<0.05)。3)酰胺Ⅰ带与结构性碳水化合物峰面积比值(AmideⅠ_STCHO)和酰胺Ⅰ带与总碳水化合物峰面积比值(AmideⅠ_CHO)可以共同作为预测因子估测瘤胃可降解蛋白质(R^2=0.35,P<0.05)、过瘤胃蛋白质(R^2=0.35,P<0.05)、小肠可吸收过瘤胃蛋白质(R^2=0.33,P<0.05)和瘤胃可降解蛋白质可合成菌体蛋白质(R^2=0.35,P<0.05)含量。综上所述,不同程度热处理豆渣的分子结构功能团与其代谢蛋白质产量、可消化养分含量和能值之间存在相关关系,初步证明可以利用分子结构功能团对热处理豆渣的营养价值进行快速分析和估测。     

日照对Bt水稻花粉中杀虫蛋白含量和活性的影响

基于探讨转Bt杀虫基因水稻花粉对家蚕的生态安全性问题,研究了不同日照时间处理的Bt水稻花粉中杀虫蛋白的含量和活性变化。结果表明,Bt水稻花粉中杀虫蛋白的相对含量起初明显下降,之后随着日照时间延长,呈现上升趋势;日照处理对花粉中可溶性蛋白含量无显著影响。就不同日照时间处理的Bt花粉对家蚕蚁蚕的生物测定结果表明,随处理时间延长,LC50值虽有增高趋势,但变化不明显。以上结果显示:日照对Bt水稻花粉中的杀虫蛋白含量及活性均无显著影响。     

CoLM陆面模式对中亚干旱荒漠草地生态系统陆面过程的数值模拟

鉴于陆面模式在干旱半干旱区模拟性能较差,本研究运用Common Land Model(CoLM)陆面模式对中亚干旱荒漠草地生态系统进行了站点验证,检验其在该区域的模拟性能,并分析了其陆面特征。结果表明,不同水分状况的草地生态系统在能量分配上表现出明显的差异性,干旱特征明显的阜康站和咸海站能量分配表现为以感热通量为主;水分状况较好的巴尔喀什湖站能量分配以潜热通量为主。CoLM陆面模式对典型干旱荒漠草地生态系统的陆面过程有较好的模拟性能,能正确描述能量通量的日变化特征。模型对研究站点夜晚感热通量、土壤热通量的模拟效果不太理想,夜间感热通量模拟值略高于观测值,土壤热通量模拟明显低于观测值,在3个研究站点土壤热通量偏差均大于50 W/m²,不能很好地描述昼夜温差较大的干旱区夜间较强的土壤热通量交换过程。     

青藏高原高寒湿地地表能量分配的动态变化

依据中国通量网2005年在青藏高原高寒湿地观测的地表能量数据, 分析了青藏高原高寒湿地地表能量分配的日变化和季节动态, 及非生物因素对其的影响.结果表明,潜热通量是地表有效能量的主要消耗部分,净辐射通量和潜热通量呈现出明显的单峰式变化,分别在8月和7月达到其最大值,显热通量在8月达到最大,而后缓慢降低.降雨能显著降低能量通量的各分量.相关性分析的结果表明,净辐射通量和潜热通量与非生物要素的存在较为明显的相关性,显热通量的相关性则较差.能量平衡比率平均为50.7%,其在生长季节明显高于非生长季节.     

Dietary betaine supplementation affects energy metabolism of pigs

The effect of dietary betaine supplementation on energy partitioning in growing pigs under energy-restricted dietary conditions was assessed. The effect of betaine on the adaptation in energy metabolism of pigs over time after a change in diet and housing also was studied. Six groups of 14 group-housed barrows were assigned to one of two experimental diets: control or betaine-supplemented (0 or 1.29 g/kg of feed). Diets were corn- and soybean meal-based and were formulated to be limiting in energy content but sufficient in amino acids. The experiment comprised a 3-wk adaptation and a 3-wk experimental period. At the start of the experimental period, initial BW was 46 kg, each group of pigs was housed in a climate-controlled respiration chamber, and all pigs were subjected to a change in diet. During the experimental period, diets were diluted with 10% oat hulls. Pigs were fed at 2.5 times the energy requirements for maintenance, and during the experimental period, heat production, energy, and nitrogen balances were measured weekly. Metabolizibility of energy did not differ (P > 0.10) between diets. Averaged over the experimental period, betaine reduced heat production (P < 0.05) and energy requirements for maintenance (P < 0.10) and consequently increased energy retention (P < 0.10). Moreover, the difference in heat production between diets increased with time (P < 0.05). Similarly, the effect of betaine on the energy requirements for maintenance changed with time (P < 0.05). Maintenance requirements were similar in wk 1 and were decreased by betaine supplementation by 5.5% during wk 3 (477 vs. 452 kJ/[kg(0.75) x d]). Results of this study show that dietary betaine supplementation affects energy partitioning by growing pigs. However, based on the observed time-related changes in energy partitioning, it was concluded that dietary betaine supplementation did not influence adaptation by pigs to a change in housing and diet.     

Energy utilization and blood traits of ponies fed fat-supplemented diets

The digestibility and heat production values for three fats of different origin were determined. Four pony geldings (225 kg) were used in a study consisting of four successive digestion trials utilizing a 4 X 4 Latin square design. The four dietary treatments were basal alone and supplemented with 15% corn oil, blended fat or inedible tallow. The blended fat was composed of a mixture of animal and vegetable fats. A 7-d preliminary period preceded a 7-d total fecal collection period for each trial. Heat production values were obtained by indirect calorimetry and calculated from oxygen consumption data. Fat supplementation increased (P less than .05) dietary metabolizable energy from a basal value of 3,224 kcal.kg intake-1.d-1 to a mean value of 3,984 kcal.kg intake-1.d-1 for the three fat diets. No difference in heat production was observed among the diets, averaging 2,883 kcal.kg intake-1.d-1. Fats increased (P less than .05) the energy balance (metabolizable energy-heat production) approximately 88% over the basal. Corn oil and blended fat produced the greatest energy balance of the fats. Utilization of energy in fats, calculated by difference, was not different, but tended to be highest in blended fat and lowest in the corn oil. Apparent fatty acid digestibility increased (P less than .05) with the addition of fat to the basal, partially due to the dilution of endogenous fecal fat, but digestion coefficients were not different (P greater than .40) among the high fat diets.     

不同热应激强度及持续时间对獭兔血清抗氧化能力的影响

从不同热应激强度(25,30,35,40℃)和40 ℃热应激后不同处理时间(0.5,1.5,2,2.5,4,6 h)两个角度,检测分析了獭兔血清中的丙二醛(MDA)含量、总超氧化物歧化酶(T-SOD)活力和总抗氧化能力(T-AOC)的大小,结果表明:与对照组25℃相比,30 ℃时獭兔血清的MDA略有下降(P＞0.05)...     

Temporal and spatial variation in grassland ground surface soil heat flux on the Qinghai-Tibetan Plateau from 2003 to 2018北大核心CSCD

Based on measured data from 7 stations on the Qinghai-Tibetan Plateau,the ground surface soil heat flux （G0） was calculated,and the diurnal and seasonal variations were analyzed. Combining this data with a MODIS,1 km resolution all-weather surface temperature data set for Western China and a China regional surface meteorological element driven data set,the Ma model was used to retrieve the ground surface soil heat flux of Qinghai-Tibetan Plateau from 2003 to 2018,and the differences in surface soil heat fluxes of different grassland types were analyzed. It was found that：1） The soil heat flux G0 in the surface layer was greater than that in the subsurface layers. The diurnal curve of G0 showed an inverted“U”shape,and the flux was relatively gentle at night compared with that during the day. 2） The seasonal amplitude of soil heat flux,G0 in the surface layer ranked summer>spring> autumn>winter. The average value of G0 in spring and summer was typically positive,while the average value of G0 in autumn and winter was basically negative. The ground surface soil heat flux in the northwest of the plateau in summer is higher than that in the southeast,while the opposite occurs in winter. 3） The soil heat flux of plateau grassland ranged between 40 and 80 W·m−2. The highest average value of G0 among all categories of grassland in the 16 years surveyed was 76. 557 W·m−2 for the‘desertification’category of temperate grassland,and the lowest was 46. 118 W·m−2 for the alpine meadow category. 4） The G0 of plateau grassland increased and then decreased through any one calendar year and seasonally was ranked summer>spring>autumn>winter. The lowest G0 in spring and summer occurred in alpine meadow,while the highest in spring was in‘desertification’temperate grassland and the highest in summer was in the temperate grassland category; The highest G0 in autumn and winter was in the warm shrub grassland,while the lowest was in the alpine deserts steppe. The above results can provide reference data for the study of surface energy balance of plateau grassland. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

特殊医学用途配方食品配制过程中VB1、VD含量变化规律

以市场上销售的6 种特殊医学用途配方食品为研究对象，通过改变pH值、水温、贮存时间、光照、二次加热配制条件，研究其VB1和VD含量变化规律。结果表明：随着配制pH值增加、水温升高、光照下贮存时间延长，VB1含量降低；二次加热对样品VB1含量影响较小；随着配制后光照下贮存时间延长，VD含量降低，pH值和二次加热对VD含量影响较小；最佳配制条件为酸性条件（pH值控制在7以下）、配制温度40～60 ℃、避光保存、使用前现配，可以保证特殊医学用途配方食品中VB1和VD的最大利用率。     

不同热处理DDGS蛋白质营养价值及瘤胃降解特性与其分子结构的相关性研究

试验旨在研究不同热处理干酒精糟及其可溶物(DDGS)蛋白质化学成分、康奈尔净碳水化合物-蛋白质体系(CNCPS)组分、瘤胃降解特性和小肠消化率与蛋白质分子结构的相关性。采用CNCPS、尼龙袋技术及三步体外法对不同热处理的DDGS营养价值进行评定,利用傅里叶变换红外光谱技术(FTIR)分析蛋白质分子结构的变化,进而探求它们之间的相关关系。结果表明:加热使DDGS瘤胃降解率和小肠消化率降低,使小肠可消化蛋白增加;不同热处理对DDGS蛋白质分子结构均有显著影响(P<0.05);蛋白质分子结构中的酰胺Ⅰ和酰胺Ⅱ带的峰高和峰面积、酰胺Ⅰ带和酰胺Ⅱ带峰高和峰面积的比值与DDGS中蛋白质的营养价值、瘤胃降解参数及小肠消化率存在显著相关关系(P<0.05)。可见,不同热处理对DDGS蛋白质分子结构、营养价值和瘤胃降解特性及小肠消化率均有影响,DDGS中蛋白质分子结构可以有效地估测蛋白质营养特性,并可利用FTIR光谱技术对DDGS营养价值及加热程度进行评定。