来源： Pig Progress
A healthy pig gut consists of long villi and well-functioning tight junctions. These essential components will come under pressure at weaning. How can swine producers help piglets overcome weaning challenges with minimal impact on the animal’s gastrointestinal tract?
健康的猪肠道由长绒毛和功能良好的紧密连接组成。这些必需成分在断奶时会承受压力。养猪场如何帮助仔猪克服断奶挑战，把对胃肠的道影响控制在最小呢？
One of the biggest challenges in the pork industry is piglet survivability and performance. The stress of weaning and loss of passive immunity from the sow’s milk increases the susceptibility of newly weaned pigs to infectious intestinal bacteria creating challenges to overall survivability. The average pre-wean mortality rate in the United States is around 16% with high variation, and opportunity for improvement. So, ensuring piglets develop strong gut health and a robust immune response is vital for survival.
猪肉行业面临的最大挑战之一是仔猪的存活率和生产性能。断奶的压力和从母猪乳汁获取母体免疫的丧失，使新断奶仔猪更易感染上感染性肠道细菌，从而对整体生存能力构成挑战。 美国的平均断奶前死亡率约为16％，变数很大，但有改善的可能。因此，确保仔猪拥有强壮的肠道健康和强大的免疫反应对于提高存活率至关重要。
Research has shown that by supplementing gestating gilts and sows with performance trace minerals, an improved performance response can be seen, and this has a lasting impact on the offspring by helping to improve gut integrity.
研究表明，通过给妊娠母猪和母猪补充微量矿物质，性能反应得以改善，并通过促进改善肠道完整性对后代产生持久影响。
Preventing leaky gut
防止肠漏
The lining of the intestinal tract is comprised of multiple epithelial tissue layers. The villi, or absorptive structures of the intestine are lined with enterocytes which is where nutrients are absorbed. These cells are bound to each other by complex protein structures, one of which is tight junctions. Their role is to prevent bacteria, pathogens and toxins from passing between the enterocytes and into the bloodstream, helping to create a protective physical barrier.
肠道内壁由多个上皮组织层组成。绒毛或肠道的吸收结构衬有肠细胞，也是肠内吸收营养的位置。这些细胞通过复杂的蛋白质结构彼此结合，其中一个是紧密连接。它们的作用是防止细菌、病原体和毒素通过肠道细胞进入血液，有助于形成保护性物理屏障。
A healthy intestinal wall has long, finger shaped villi that provide a large surface for digestion and absorption of nutrients. Before weaning, intestinal villi (responsible for nutrient absorption) are thin and elongated, whereas after weaning, villus height has been shown to decrease about 75% during the first 24 hours post-weaning, quickly becoming thick and short. Shortened villi can impair digestion and nutrient absorption. A reduction in nutrient intake also compromises the integrity of the tight junctions.
健康的肠壁有长绒毛，形似指状，为消化和吸收营养提供了大片面积。在断奶前，肠绒毛（负责营养吸收）很薄而且细长，而断奶后，绒毛高度在断奶后的最初24小时内减少了约75％，很快变得粗壮。缩短的绒毛有损消化和营养吸收，营养摄入减少也会影响紧密连接的完整性。
Factors, such as heat stress, reduced feed intake, bacteria, feed contaminants, etc., can weaken the quality of the tight junctions, leading to a syndrome called ‘leaky gut’. This condition – leaky gut – allows molecules such as bacteria, pathogens and toxins to pass between the epithelial cells, resulting in cell damage and inflammation of the intestine. When this occurs it triggers the immune system, which requires significant levels of nutrients to deal with the inflammation, reducing the amount of nutrients available for piglet growth.
热应激、采食量减少、细菌、饲料污染等因素会削弱紧密连接的质量，从而导致一种称为“肠漏”的综合症。这种情况会让细菌、病原体和毒素等分子在上皮细胞之间通过，造成细胞损伤和肠道炎症。当这种情况发生时，会触发免疫系统，大量的营养被用于应对炎症，从而也减少了仔猪生长可用的营养物质。
Research has demonstrated the nutrition of one generation can have a positive or negative impact on the nutrition of the next generation. This is true for humans, as well as animals. Zinpro partnered with the University of Alberta, Canada (in research by W.R. Caine and others, 2009) to evaluate how incorporating performance trace minerals into the diet of the gestating sow can help the piglet develop a more robust initial immune response.
研究表明，上一代的营养会对下一代的营养产生积极或消极的影响。这对人类和动物都是如此。Zinpro与加拿大阿尔伯塔大学（W.R.Caine等人的研究，2009年）合作，评估如何将功能性微量元素纳入妊娠母猪的饮食中，使仔猪产生更强大的初始免疫反应。
Sows were split into 2 groups and fed either inorganic trace minerals or performance trace minerals during the last stage of gestation (day 80 to 114):
1. Inorganic treatment: 120 ppm Zn from zinc oxide (ZnO)
2. Zinc amino acid complex treatment: 250 ppm of zinc from Availa-Zn added on top of the control diet from day 80 to 114 of gestation.
将母猪分成两组，在妊娠的最后阶段（第80天至第114天）喂食无机微量矿物质或表现微量矿物质：
1.无机处理：氧化锌（ZnO）中的120 ppm 锌
2.锌氨基酸复合物处理：从妊娠第80天至第114天，给对照组添加250ppm来自可利锌的锌。
Once the sows farrowed their litter, they transitioned to a common lactation diet and the piglets were harvested at 14 days of age to view their intestinal morphology.
一旦母猪开始分娩，就转变为普通的泌乳期饮食配方，并在仔猪14日龄时观察它们的肠道形态。
While villus height has been shown to decrease about 75% during the first 24 hours post-weaning, quickly becoming thick and short, the piglets born to sows receiving zinc from Availa-Zn had higher intestinal villi height and a higher villi height to crypt depth ratio. This resulted in a greater absorptive surface for the piglet to absorb nutrients, while also helping to reduce the incidence of diarrhoea, see Figure 1.
虽然在断奶后的头24小时，绒毛高度已显示减少约75％，很快变得又厚又短，但喂食了锌的母猪所生的仔猪肠，其绒毛高度、绒毛高深比均较高。这让仔猪有更大的吸收表面来吸收营养，同时也有助于减少腹泻率，见图1。
Figure 1 – Effect of supplying complexed zinca to sows on the villi of 14-day old nursing piglets
图1 - 给母猪喂食复合zinca，对14日龄哺乳仔猪绒毛的影响
A more robust immune response
更强大的免疫反应
The intestinal morphology also showed an increase in intra-epithelial lymphocytes which help to eliminate damaged or infected intestinal epithelial cells. This in turn helps improve the intestinal immune response of the pig. There was also an increase in goblet cells in the intestine. Goblet cells are responsible for producing mucin, and mucin creates that mucus layer along the walls of the intestine. Intra-epithelial lymphocytes target and destroy pathogens to help reduce overall pathogen load. Goblet cells are responsible for mucin production which helps act as a protective mucous barrier for the lining of the intestine, see Figure 2.
肠道形态也显示上皮内淋巴细胞增加，这有助于消除受损或感染的肠上皮细胞。这反过来也有助于改善猪的肠道免疫反应。肠道中的杯状细胞亦有所增加。杯状细胞负责产生粘蛋白，粘蛋白沿着肠壁产生粘液层。上皮内淋巴细胞靶向并破坏病原体，以帮助减少总体病原体负荷。杯状细胞负责粘蛋白的产生，这有助于作为肠道内壁的保护性粘膜屏障，见图2。
Figure 2 – Effect of supplying complexed zinca to sows on lymphocytes and goblet cells of 14-day old nursing piglets.
图2 - 向母猪提供复合zinca对14日龄哺乳仔猪体内淋巴细胞和杯状细胞的影响
（文/爱猪网记者刘坤颖编译，爱猪网原创请勿转载）
