酪啡肽研究新进展

酪蛋白是乳中最重要的成分。酪蛋白是乳源活性肽的重要来源,乳源生物活性肽是酪蛋白在消化酶作用下释放的,能被机体直接吸收,具有多种生物学功能。其中酪啡肽是最重要的乳源生物活性肽之一。作者就酪啡肽的检测、吸收及其生理功能进行综述,并介绍了近几年国内外酪啡肽研究的进展。     

酪啡肽对21日龄断奶仔猪胃酸分泌的影响

采用放射免疫、RT—PCR等方法,研究了酪啡肽对21日龄断奶仔猪消化道酸度、血清中胃泌素水平和胃肠道胃泌素mRNA表达的影响。将24头仔公猪分对照组(正常哺乳28 d断奶)、试验Ⅰ组(β-酪啡肽-7组) 和试验Ⅱ组(早期断奶组)。试验组于21d断奶后,再连续添喂β-酪啡肽-7或生理盐水,每天2次(共20 mL)。10 d后,3组动物各随机取6头同时宰杀,共测定了18头仔猪胃、空肠和回肠食糜pH值及血清中胃泌素的含量,并对胃幽门和十二指肠胃泌素mRNA的表达进行了分析。结果发现日粮中添加β-酪啡肽-7的仔猪胃内平均pH为2.76±0.51,低于对照组(5.08±0.43)和早期断奶组(4.26±0.62);空肠和回肠食糜中pH值各组无明显差异。血清中胃泌素含量β-酪啡肽-7组最高,为100.03±18.72 pg/mL与对照组相比差异极显著。RT- PCR检测分析表明:β-酪啡肽-7组仔猪胃窦胃泌素mRNA表达量高于对照组(P<0.01)和早期断奶组。十二指肠中胃泌索mRNA表达的变化情况与胃窦相似。认为酪啡肽类可以促进断奶仔猪的胃酸分泌,其机制可能是通过上调胃泌素mRNA的基因表达,使胃泌素分泌增加所至。     

仔猪胃肠道食糜和血液中酪啡肽的检测及阿片样活性分析

将24头仔公猪分为对照组(正常哺乳28 d断奶)、试验I组(添喂β-酪啡肽-7)和试验Ⅱ组(添喂酪蛋白酶解物)。试验组于21 d断奶,再连续添喂酪蛋白胃蛋白酶解液或β-酪啡肽-7 10 d,每天2次(共20mL),至32 d,3组动物各随机取6头同时剖杀,取血、胃食糜和空肠食糜。通过所建立的RP-HPLC方法,在胃食糜和空肠食糜中检测到β-酪啡肽-5、β-酪啡肽-7样物质。对照组、酪啡肽-7组和酪蛋白水解液组,β-酪啡肽-7的平均含量分别为21.12±2.38,23.58±7.49、21.81±9.93μg/g胃食糜和16.99±3.48、19.08±2.85、21.36±4.85μg/g肠食糜;胃食糜中-βCM-7的含量高于空肠食糜,试验组均高于对照组。在各组仔猪的血液中未检测到酪啡肽样物质。肠食糜的细胞生物学试验结果表明:与喂仔猪料的对照组比较,试验I组和试验Ⅱ组对细胞腺苷酸环化酶的活性均具有不同程度的抑制作用,抑制率分别为27.9%和89.0%,抑制作用均能被纳洛酮反转,逆转率分别是43.2%和89.07%。提示在21日龄断奶仔猪饲料中添加酪啡肽或酪蛋白酶解物,其肠道中有酪啡肽释放,阿片总活性升高。     

日本酪农经营动向

日本酪农经营动向○广西桂林地区农牧渔业局（桂林市５４１００１）唐万林日本除了科研所和良种场之外，没有国营奶牛场。奶牛场都是由酪农经营的。分析日本酪农经营动向对我国奶牛饲养业的发展有一定的参考价值。有些可能还是我们必走之路。日本酪农经营的动向主要表现在...     

β-酪啡肽-7对断奶仔猪胃酸分泌的影响

本试验旨在探讨β-酪啡肽-7对早期断奶仔猪胃酸分泌的影响及其可能机制。选取刚出生健康仔公猪24头,随机分为对照组和β-酪啡肽-7处理组,其中β-酪啡肽-7处理组仔猪在饲喂与对照组相同日粮的基础上,每天灌胃β-酪啡肽-7溶液。仔猪21日龄时一次性断奶,分别在21日龄和35日龄时屠宰,颈部采血分离血清、取胃肠内容物、胃底组织等,测定胃肠食糜的p H值、胃蛋白酶活性、血清中胃泌素的含量以及胃底组织中H~+-K~+-ATP/Na~+-K~+-ATP酶的活性。结果显示:β-酪啡肽-7能降低断奶仔猪胃内食糜p H,其中显著降低35日龄断奶仔猪的胃内p H值(P0.05),而对十二指肠、空肠以及回肠食糜p H无显著影响;β-酪啡肽-7能够升高21日龄断奶仔猪胃蛋白酶的活性,差异不显著(P0.05),但其能显著上调35日龄仔猪的胃蛋白酶的活性(P0.05);放射免疫分析法检测胃泌素结果显示:灌胃β-酪啡肽-7后仔猪血清中胃泌素含量均高于对照组,21日龄时差异不显著(P0.05),35日龄时极显著升高(P0.05);灌胃β-酪啡肽-7对断奶仔猪H~+-K~+-ATP/Na~+-K~+-ATP酶的活性作用不显著(P0.05)。说明添加β-酪啡肽-7可以有效缓解断奶应激引起的胃酸分泌不足以及胃蛋白酶活性较低等问题,其作用途径可能是通过促进胃泌素分泌实现的。     

酪啡肽及其酪蛋白水解肽对早期断奶仔猪分泌型免疫球蛋白A和细胞因子水平的影响

本文旨在研究酪啡肽及其酪蛋白水解肽对早期断奶仔猪分泌型免疫球蛋白A(SIgA)和细胞因子水平的影响。24头仔公猪随机分为对照组(正常哺乳28d断奶)、试验Ⅰ组(添加β-酪啡肽-7)和试验Ⅱ组(添加酪蛋白酶解物)。试验组于21d断奶,再连续添加酪蛋白胃蛋白酶解液或β-酪啡肽-710d,每天2次(共20mL),至32d,3组动物各随机取6头同时剖杀,取血、胃食糜和空肠食糜。观察其血清IL-2、TNF-α和胃肠内容物中SIgA的含量变化。结果表明:添加酪蛋白水解液组仔猪血清中IL-2的水平比对照组高75.9%,差异极显著(P<0.01);试验Ⅰ组血清中IL-2水平比对照组高35.7%,差异显著(P<0.05)。血清中TNF-α水平试验组略低于对照组。在对照组、试验Ⅰ和Ⅱ组仔猪的空肠食糜中均检测到SIgA,平均含量分别为(6.48±0.85)ng/g、(6.30±0.85)ng/g和(8.71±0.54)ng/g。与对照组相比,试验Ⅱ组差异极显著(P<0.05);胃食糜中未检测到SIgA。提示乳源活性肽对早期断奶仔猪细胞免疫和黏膜免疫活性具有一定的促进作用。     

乳蛋白源阿片肽—β—酪啡肽

在动物营养学界，完整蛋白质或其降解产生的寡肽能被动物直接吸收的观点被提出后，肽营养的研究也受到了广泛的重视。本文就目前国际上的研究热点－β-酪啡肽的生理活性和工业化生产作一简要论述，提出了利用基因重组技术生产活性小肽的新观点。     

β-酪啡肽在仔猪营养中的生理功能研究进展

β-酪啡肽可被新生动物吸收入血，影响仔猪机体的内分泌与免疫系统等功能。本文综述了其在仔猪营养中的生理功能研究现状。     

酪蛋白酶解物与胎儿宫内发育迟缓

胎儿宫内发育迟缓(Intrauterinegrowthretardation,IUGR)会阻碍动物和人的生长发育,一直是畜牧兽医学和人医等学科的难题。本文综述了酪蛋白酶解物的生物学功能,及其在IUGR补偿生长方面应用的可能性,提出酪蛋白酶解物可能对IUGR的治疗有重要意义,具有良好的应用前景。     

酪蛋白酶解物对断奶小鼠肠道生长发育的影响

本试验以小鼠为动物模型,研究了酪蛋白酶解物对断奶小鼠肠道生长发育的影响.结果表明每天灌注0.25ml浓度为20mg/ml的酪蛋白酶解液可显著提高小鼠小肠DNA、RNA的含量,灌注0.25ml浓度为12mg/ml的酪蛋白酶解液可显著提高小鼠小肠的蛋白质浓度,但对小肠长度、重量及体增重均无显著影响.     

夏季不同饲喂方式对两广小耳花猪哺乳母猪生产性能的影响

本试验旨在研究夏季不同饲喂次数和料水比对两广小耳花猪生产性能的影响,选择48头两广小耳花猪哺乳母猪,分为4组,每组12头母猪。4个处理组的饲喂方式分别为饲喂2次/d和料水比为1∶2.5(对照组)、饲喂2次/d和料水比为1∶3.5、饲喂3次/d和料水比为1∶2.5、饲喂3次/d和料水比为1∶3.5。监测母猪从产后至断奶25 d的采食量、仔猪生长性能以及环境温湿度等指标。结果表明:饲喂3次/d与2次/d母猪的日平均采食量分别为3.33、2.41 kg,哺乳期间母猪平均总采食量前者较后者高23 kg/头;哺乳仔猪平均断奶窝重分别为32.35、29.14 kg,窝增重前者较后者高3.17 kg/窝。综上,通过增加饲喂次数和选择与人工作息时间不一致的时间点饲喂可以提高哺乳母猪的采食量,但需要智能化自动化饲喂设备相配套。     

哺乳母猪采食量的重要性

哺乳母猪采食量低下是当前养猪生产中存在的一大难题,特别是现代瘦肉型品种的哺乳母猪这一问题更为严重。泌乳期母猪采食量低下会对种猪繁殖性能造成有害影响,提高泌乳期采食量将有利于提高母猪繁殖性能和养猪经济效益。本文综述了哺乳母猪的采食量,哺乳母猪采食量低下对繁殖性能的影响,哺乳母猪采食量的影响因素,弥补哺乳母猪采食量不足的营养与饲养措施,哺乳母猪采食量的营养生理调控方法。     

Standardized ileal protein and amino acid digestibility by growing pigs and sows

Experiments were conducted to determine the effect of the physiological condition of swine on standardized ileal digestibility coefficients (SID). The apparent ileal digestibility coefficients were determined for crude protein and amino acids in six feed ingredients (corn, barley, wheat, soybean meal, canola meal, and meat and bone meal) in growing pigs and in gestating and lactating sows. Growing pigs and lactating sows were given free access to their diets, whereas gestating sows were allowed to consume only 2 kg of feed daily. The nonspecific (basal) endogenous losses of protein and amino acids were determined under similar feeding regimens after feeding a protein-free diet. The SID for crude protein and amino acids were calculated by correcting the apparent ileal digestibility coefficients for the nonspecific endogenous losses of protein and amino acids. With a few exceptions, there were no differences (P > 0.05) in the SID for crude protein and amino acids between growing pigs and lactating sows. Overall, gestating sows had higher (P < 0.05) SID for crude protein and all amino acids, except for tryptophan and aspartate, compared with growing pigs. Likewise, the SID of most amino acids obtained by gestating sows were higher (P < 0.05) than those obtained by lactating sows. Interactions (P < 0.05) between animals and diets were observed for gestating sows compared with growing pigs as well as gestating sows compared with lactating sows. As a consequence, it is not possible to extrapolate data from one feed ingredient to another. On most occasions, the lowest SID among the indispensable amino acids was calculated for threonine, valine, and lysine. It is concluded that gestating sows fed 2 kg of feed per day have higher standardized digestibility coefficients than do growing pigs and lactating sows given free access to their diets. This difference may be due to differences in daily feed intake rather than to the physiological status of the animals.     

Efficacy of sucrose and milk chocolate product or dried porcine solubles to increase feed intake and improve performance of lactating sows

Two experiments were conducted to determine the voluntary feed intake and performance of lactating sows fed diets containing a sucrose/milk chocolate product (MCP) blend (Exp. 1) or dried porcine solubles (DPS; Exp. 2). Dried porcine solubles is a coproduct of heparin extraction from porcine small intestines. In Exp. 1, mixed-parity sows (n = 108) at two research centers were assigned to a corn-soybean-meal-based diet formulated to contain 0.9% total lysine or a similar diet that contained 4% sucrose and 2% MCP on an as-fed basis. Sows were allowed ad libitum access to dietary treatments from the day of farrowing until pigs were weaned at approximately 21 d postpartum. Diet had no significant effect on voluntary feed intake of sows during lactation, backfat depth, or postweaning interval to estrus, but it had variable effects on body weight changes. Inclusion of the sucrose/MCP blend in diets elicited a 2% improvement in litter weaning weight at one research center and a 6% depression in litter weaning weight at the other center (diet x research center, P < 0.05). Litter size throughout lactation was unaffected by dietary treatment. In Exp. 2, mixed-parity sows (n = 119) at two research centers were assigned to corn-soybean meal-based diets formulated to contain 0.9% total lysine with 0, 1.5, or 3.0% added DPS. Sows were assigned to dietary treatments within research center, farrowing group, and parity at parturition. Dried porcine solubles tended to increase (P < 0.10) total feed consumed in the first 9 d of lactation and average daily feed intake over the entire lactation (6.03, 6.53, and 6.30 kg) for sows fed 0, 1.5, and 3.0% DPS, respectively. Litter size and weight on d 18 of lactation were not affected by concentration of DPS in the diet. Days from weaning to estrus and percentage of sows displaying estrus were not influenced by diet. We conclude that inclusion of the sucrose/MCP blend in the diet for lactating sows had no consistent effect on voluntary feed intake of sows and weight gain of nursing pigs. Inclusion of DPS at 1.5 or 3.0% tended to improve feed intake of lactating sows but had no significant influence on litter performance.     

Comparative effects of sodium butyrate and flavors on feed intake of lactating sows and growth performance of piglets

We examined the effects of sodium butyrate and flavors on feed intake of lactating sows and growth performance of piglets. A total of 52 primiparous sows (Large White) were randomly divided into four treatments (n = 13) and received 6 g/kg sodium butyrate (SB), fruit‐milk (FM) flavor and fruit‐milk‐anise (FMA) flavor with pair feeding to the mothers receiving the control diet. The feeding trial lasted for 29 days, including 21 days of nursing and 8 days of post‐weaning period, respectively. The nursing and weaning piglets received creep diets with the same flavor or SB supplement as their mother. The results showed that FMA flavor increased average daily feed intake (ADFI) of lactating sows (P < 0.01), as well as improved litter weight gain (P = 0.05) and ADFI (P < 0.01) of nursing pigs among treatments. Indeed, greater ADFI and average daily gain of weaning piglets for the initial 8 days after weaning was observed in the FMA group compared with those in the control group (P < 0.01). These findings indicated that adding FMA flavor was superior to SB for increasing feed intake of lactating sows and improving growth performance of piglets.     

Effects of beet pulp supplementation on growth performance,fecal moisture,serum hormones and litter performance in lactating sows

This study was conducted to evaluate effects of beet pulp supplementation on growth performance, fecal moisture, serum hormones and litter performance in lactating sows. Ninety primiparous sows (Landrace × Yorkshire) were randomly allotted to one of three dietary treatments in a 21‐day trial starting 3 days before parturition. The three dietary treatments were supplemented with 0, 10 and 20% beet pulp, respectively. Backfat loss and fecal moisture content were increased (P < 0.05), where cortisol and norepinephrine levels were decreased (P < 0.05) in sows fed beet pulp supplementation diets compared with control diet, but there was no difference between 10% and 20% beet pulp supplementation treatments. No effect was observed on bodyweight, average daily intake, weaning to estrus interval, epinephrine level in sows and litter weight, litter size, survivability in piglets among dietary treatments. Taken together, beet pulp supplementation has no significant effect of growth performance of lactating sows and piglets with decreased cortisol and norepinephrine levels in lactating sows, but it can increase fecal moisture content which is beneficial for sow feces excretion.     

支链氨基酸对泌乳母猪的营养研究进展

支链氨基酸 (BCAA)是畜禽的必需氨基酸 ,有着重要的营养生理作用 ,对泌乳母猪尤其显著。本文着重阐述BCAA　　对泌乳母猪生产性能方面的影响 ,泌乳母猪对BCAA的需要量及缬氨酸需要量研究模式。     

分娩后不同饲喂模式对泌乳母猪生产性能、乳成分和生理代谢的影响

本试验旨在研究母猪分娩后3种饲喂模式(产后不限饲、限饲3 d和限饲7 d后自由采食)对泌乳母猪生产性能、乳成分和生理代谢的影响。挑选遗传背景一致、体况和健康良好、分娩日期接近的3~6胎次丹系长×大母猪45头,分娩后根据体重、背膘厚度和胎次随机均分成3个组,每组15个重复,每个重复1头。3组母猪饲喂相同的泌乳饲粮,执行对应的饲喂模式:不限饲组(FR0组)分娩后立即自由采食;限饲3 d组(FR3组)分娩后前3 d逐步增加饲喂量,之后自由采食;限饲7 d组(FR7组)分娩后前7 d逐步增加饲喂量,之后自由采食。分娩后第22天仔猪断奶,试验结束。结果表明:1)FR0组和FR3组第1周和泌乳期母猪采食量以及哺乳期仔猪平均日增重(ADG)显著高于FR7组(P<0.05);FR0组泌乳期母猪背膘厚度和体重损失显著低于FR3组和FR7组(P<0.05);FR0组第1周和泌乳期母猪采食量显著高于FR3组(P<0.05),但哺乳期仔猪ADG的差异没有达到显著水平(P>0.05)。2)各组间乳成分没有显著差异(P>0.05)。3)与FR7组相比,FR0组和FR3组血浆中催乳素、胃饥饿素和瘦素含量显著增加(P<0.05),胰岛素和皮质醇含量显著降低(P<0.05);FR0组血浆尿素氮含量显著高于FR7组(P<0.05),与FR3组差异不显著(P>0.05);各组间血浆葡萄糖和甘油三酯含量没有显著差异(P>0.05)。由此可见,分娩后饲喂模式会影响泌乳母猪的采食量、背膘厚度和体重损失以及机体生理代谢状况。本试验条件下,现代高产瘦肉型母猪产后不限饲和缩短限饲天数(限饲3 d)都可以提高泌乳母猪的采食量和泌乳性能,其中不限饲是适宜的饲喂模式。     

Effect of lactating sows’ diet supplemented with cactus (Opuntia ficus-indica) on feed intake and reproductive and productive post-weaning performances

Tropical Animal Health and Production - The effect of cactus (Opuntia ficus-indica) added to the diet of lactating (21&nbsp;days of lactation) sows on voluntary feed intake, and its impact on...     

浅析现代猪场不同猪群的饲养管理技术

对现代养猪场来说,后备母猪的健康水平是提高母猪生产力和使用寿命的保证;妊娠母猪的健康水平则直接关系到所产仔猪的健康水平和发育情况;哺乳母猪摄入的营养不仅要维持自身的生产需要还要满足哺育仔猪的需要;仔猪是现代养猪生产的基础,很大程度上关系到规模养殖场的经济效益。通过分析现代规模化养猪场特点,指出后备母猪、妊娠母猪、哺乳母猪、仔猪等的饲养管理侧重点,为现代化养猪场的生产、管理工作提供参考。