Prevalence of Streptococcus suis Isolated from Clinically Healthy Sows in China

Streptococcus suis is an important pathogen in pigs. Transmission of this pathogen is generally believed to occur between healthy carrier sows and their offspring, so the carrier status of S. suis in healthy sows is important for the control of S. suis infections in pigs, especially in suckling and growing pigs. In this study, the prevalence of S. suis isolated from clinically healthy sows in China was studied for the first time. A total of 1 043 tonsil samples were collected from clinically healthy sows from 10 regions in China from 2005 to 2007. Among the 421 S. suis isolates, 31 strains were identified as capsular type 2. The results showed that S. suis was widespread in swine herds in China with the carrier rates in different herds ranging from 19.5 to 93.9%. Overall, 40.4 and 3.0% of clinically healthy sows harbored S. suis and capsular type 2 in their palatine tonsils, respectively. Statistically significant differences of carrier rates of S. suis and capsular type 2 between the different farms were observed, which was independent of herd sizes and geographic distributions of different herds.     

Evidence that oxidative stress is higher in replacement gilts than in multiparous sows

The recent success obtained in term of increasing the litter size of sows has not correlated with a reduction of replacement rate. There is thus an increased economic demand for gilts with optimal reproductive potential and longevity. Unfortunately, replacement gilts are known to be more susceptible to diseases and less productive than multiparous sows. Interestingly, reproductive performance, resistance to diseases and longevity could all be largely affected by oxidative stress. To investigate whether oxidative stress conditions could account for the poor longevity of gilts, three distinct groups of conventional Yorkshire × Landrace sows were formed based on their similar age and parity (gilts, second parity sows as well as fourth to fifth parity sows). All animals were slaughtered during the post‐ovulatory period, and blood as well as tissue samples were collected. Biomarkers of oxidative damage to proteins (carbonyls) and DNA (8‐OHdG) were analysed in samples. Specific mRNA expression of major antioxidants such as glutathione peroxidases 1, 3 and 4 (GPx1, GPx3, GPx4) as well as superoxide dismutases 1 and 2 (Sod1, Sod2) were monitored in liver and kidney samples by quantitative RT‐PCR. Specific enzymatic activities of both GPx and SOD were measured by spectrophotometric assays. The plasma concentration of protein carbonyls was significantly different between the three groups with the highest concentration being observed in gilts (p ≤ 0.001). The mRNA expression levels of GPx1 and GPx4 were also significantly increased in the liver of gilts when compared to multiparous sows (p ≤ 0.05). SOD2 enzymatic activity was found to be higher in the liver of gilts than multiparous sows (p ≤ 0.05). Taken together, these results indicate that replacement gilts sustain significantly higher oxidative conditions than multiparous sows. Current findings may contribute to the design of nutritional regimens that will increase the productivity of gilts by counteracting oxidative stress.     

噬菌体制剂对母猪生产性能、免疫指标及粪便微生物的影响

试验旨在研究噬菌体对母猪生产性能、免疫指标和粪便微生物数量的影响。试验选取96头健康长大二元母猪,随机分为4组,每组24头猪。空白对照组母猪饲喂基础日粮,试验组1、试验组2和试验组3分别在基础日粮中加入100、300、500 g/t的沙门氏菌噬菌体、大肠杆菌噬菌体和产气荚膜梭菌噬菌体组成的复合制剂,试验周期为35 d。结果显示:试验组2和试验组3相比空白对照组的窝产活仔数、断奶活仔数、平均奶均重和平均日增重均显著提高(P<0.05)。试验组1相比空白对照组的断奶活仔数、平均奶均重和平均日增重均显著提高(P<0.05)。在分娩当日,相比空白对照组,试验组3的免疫球蛋白A (IgA)含量显著提高(P<0.05)。试验组2和试验组3的免疫球蛋白M (IgM)和免疫球蛋白G (IgG)含量显著提高(P<0.05)。在断奶当日,相比空白对照组,3种剂量组的IgA、IgM和IgG含量均显著提高(P<0.05)。试验组2和试验组3的乳酸菌含量显著增加(P<0.05)。3种剂量组的大肠杆菌和沙门氏菌数量均显著降低(P<0.05)。试验表明,添加复合噬菌体制剂能提高母猪生产性能,提高机体免疫力,改善肠道微生态环境,日粮中添加300 g/t复合噬菌体制剂比较合适。     

添加缬氨酸和异亮氨酸对哺乳母猪及其仔猪生产性能的影响

本试验旨在探讨在哺乳母猪日粮中添加缬氨酸和异亮氨酸对母猪及其仔猪生产性能、母猪采食量和乳成分的影响.试验选用健康、体况、预产期相近的第2胎法系JALAX母猪144头,分成3个处理组,即对照组、试验A组和试验B组,每个处理48头母猪.对照组饲喂基础日粮,试验A组饲喂添加低水平支链氨基酸日粮(基础日粮 缬氨酸0.26% 异亮氨酸0.06%),试验B组饲喂添加高水平支链氨基酸日粮(基础日粮 缬氨酸0.36% 异亮氨酸0.14%).试验从母猪妊娠108 d进产房开始,到仔猪21日龄断奶时结束.试验结果表明:(1)添加缬氨酸和异亮氨酸提高了仔猪的断奶窝重、断奶窝增重、平均日增重和21日龄仔猪成活率,但以试验A组的效果较好,和对照组比,上述指标分别提高了23.10%(P<0.01)、30.45%(P<0.01)、19.26%(P<0.05)和7.16%(P<0.05);(2)添加缬氨酸和异亮氨酸提高了哺乳母猪哺乳11～15 d,16～21 d以及哺乳全期的采食量,试验A组比对照组分别提高了35.61%(P<0.01)、27.72%(P<0.01)和24.21%(P<0.01),试验B组虽然与对照组之间差异不显著(P>0.05),但有提高的趋势;(3)添加缬氨酸和异亮氨酸极显著提高了泌乳第1天、第7天和第15天乳中乳脂、乳蛋白、总固形物、非乳脂固体的含量(P<0.01),极显著降低了乳糖的含量(P<0.01),但以试验A组的效果最好;(4)添加缬氨酸和异亮氨酸极显著提高了初乳(泌乳第1天)的总必需氨基酸、总非必需氨基酸以及总氨基酸的含量(P<0.01),但对第7天和第15天乳中氨基酸含量影响不显著.因此,日粮中添加缬氨酸和异亮氨酸可以提高哺乳母猪的日采食量和改善母猪乳品质,从而提高哺乳仔猪的生长性能.     

诱导母猪同期分娩的技术

在集约化猪场中,要求严格按工艺流程有节奏地进行养猪生产。为了避免夜间产仔和有效地提高商品猪的整体质量,常采用同期分娩解决这一难题。作为调控繁殖节律的技术之一,药物诱导母猪同期分娩已成为集约化养猪业的一个重要研究课题。本文对前列腺素F2α和氦前列烯醇在母猪同期分娩中的应用作一简单介绍。     

母猪产后泌乳障碍综合征研究进展

母猪产后泌乳障碍综合征(PPDS)是种猪场的棘手问题之一,其病因多达30 多种,发病机理尚不明确,造成防治困难。PP DS的发病率具有明显的季节性,夏季的发病率明显高于其他3 个季节。其危害性主要表现在母猪生产性能下降、仔猪生长不良引起的经济效益下降。国内学者曾对PPDS的流行病学和防治方法进行了不少研究,积累了丰富的经验;国外文献报道了不少该病的病原及内分泌学方面的研究,对探明PPDS 的发病机理有重要意义。     

中药复方制剂补中益气散对母猪生产性能的影响

目的试验以中兽医理论为基础,运用中药复方制剂补中益气散对怀孕后期母猪进行产前调理,通过对其生产性能的影响展开研究,旨在为猪饲料中添加使用安全、绿色、有机的中药复方制剂奠定基础。方法将50头预产期相近的母猪,随机分为2组,每组各25头。第1组为对照组,饲喂常规日粮,第2组为试验组,饲料中按1.5%添加中药复方制剂补中益气散,试验组每头母猪添加中药量每天45 g。母猪产仔当天停止给药。母猪生产后,对产仔数、产活仔数、产健仔数、死胎数、弱仔数、木乃伊胎数,以及母猪有无流产等情况进行记录。23 d断奶后对仔猪的腹泻和死亡进行记录。结果①试验组有1头母猪产前出现发烧和食欲不振的情况;对照组有5头出现相同症状;②母猪生产后,对照组产下仔猪227头,死仔12头;试验组产下仔猪254头,死仔9头;③对照组平均窝产活仔数9.08头;试验组平均窝产活仔数10.16头;④对照组发生腹泻的仔猪74头,腹泻率为32.6%;试验组发生腹泻的仔猪10头,腹泻率为3.9%;⑤断奶后对照组窝均健仔数为7.16头;试验组窝均健仔数为9.28头。⑥对照组最后存活179头,存活率为78.9%;试验组最后存活232头,存活率为91.3%。结论①通过运用中药复方制剂补中益气散对母猪进行产前调理,能够有效预防哺乳期仔猪腹泻的发生。②在怀孕期母猪饲料中添加中药复方制剂补中益气散能够提高母猪免疫功能和生产性能。     

Net energy content of five fiber‐rich ingredients fed to pregnant sows

The present study was conducted to determine the net energy (NE) values and energy efficiency of wheat bran (WB), sugar beet pulp (SBP), corn gluten feed (CGF), soybean hulls (SBH), and defatted rice bran (DFRB) fed to pregnant sows. Thirty‐six multiparous pregnant sows were randomly assigned to six dietary treatments with six replicates per treatment. Each period lasted for 21 days including 14 days for adaptation. On day 15, sows were moved into respiration chambers for heat production (HP) measurement and provided feed at 544 kJ/kg BW^0.75/day. On day 20, sows were fasted to measure the fasting heat production (FHP). Experimental diets included corn‐soybean meal basal diet and five diets containing 29.20% WB, SBP, CGF, SBH, and DFRB, respectively. Results showed that inclusion of WB, SBP, CGF, SBH, and DFRB to basal diet decreased (p < 0.05) the apparent total tract digestibility of energy and nutrients. The average adjusted total HP and FHP were 418 kJ/kg BW^0.75/day and 326 kJ/kg BW^0.75/day, respectively. The average NE:ME ratio of experiment diets was 82.5%. In conclusion, the NE values of WB, SBP, CGF, SBH, and DFRB were 9.05, 8.59, 8.37, 7.64, and 7.93 MJ/kg DM, respectively.     

饲粮中添加中链脂肪酸甘油三酯对母猪繁殖性能、血清生化指标及初乳成分的影响

本试验旨在研究母猪妊娠后期和泌乳期饲粮中添加中链脂肪酸甘油三酯(MCT)对母猪繁殖性能、血清生化指标及初乳成分的影响。试验选取120头纯种大白妊娠母猪(3~5胎),根据母猪预产期相近,胎次、体况、历史繁殖成绩均衡分布的原则分为3组,每组40个重复,每个重复1头母猪。对照组饲喂基础饲粮(含3.17%豆油),油剂组以0.6%纯油剂MCT替换基础饲粮中0.6%的豆油(含2.57%豆油),粉剂组在基础饲粮中添加0.5%微胶囊粉剂MCT。试验从母猪妊娠第85天开始至仔猪断奶结束。结果表明:1)与对照组相比,油剂组和粉剂组母猪产程分别提高了17.58%(P0.05)和9.21%(P0.05),母猪泌乳期平均日采食量分别提高了5.92%和10.07%(P0.05),母猪断奶后7日发情率分别提高了6.52%和4.25%(P0.05);饲粮中添加MCT对母猪其他繁殖性能指标无显著影响(P0.05)。2)饲粮中添加MCT对母猪血清生化指标均无显著影响(P0.05)。3)与对照组相比,油剂组和粉剂组母猪初乳乳脂含量分别提高了18.09%和19.09%(P0.05),饲粮中添加MCT对母猪初乳成分均无显著影响(P0.10)。由此可见,在母猪妊娠后期及泌乳期饲粮中添加MCT未能改善母猪的生产性能、血清生化指标及初乳成分,但添加油剂型MCT可显著缩短母猪产程。     

Effects of Dietary Ginger Root,Star Anise and Dan-shen Root on Antioxidant Status and Reproductive Performance of Sows during Late Gestation and Lactation

The experiment was conducted to study the effects of diatary ginger root, star anise and dan-shen root on antioxidant status and reproductive performance of sows during late gestation and lactation.A total of 36 Laiwu Black pregnant sows with average weight of 164.28 kg±1.30 kg and similar parity were randomly divided into 4 treatments with 9 replicates per treatment.The control group was fed a basal diet, and the experimental groups were fed the basal diet supplemented with 10 g/kg ginger root, 5 g/kg star anise and 10 g/kg dan-shen root, respectively(ie Cont., GIN, SA, DS groups).The results showed that the concentrations of glutathione in serum and milk protein in colostrum, activity of total antioxidant capacity in colostrum of GIN, SA and DS groups were significantly higher than that of Cont.group(P<0.05).The concentration of milk fat in colostrum of GIN and DS groups were higher than that of Cont.group(P<0.05).Comparing to Cont.group, the concentration of lactose in colostrum was significantly higher(P<0.05) of SA and DS groups.All groups had similar number of born live, 21 d survival rate, birth weight of born and 21 d weight of born(P>0.05).In conclusion, dietary supplementation of 10 g/kg ginger root, 5 g/kg star anise and 10 g/kg dan-shen root could increase antioxidant status of serum and colostrum of sows, improve the nutritional value of colostrum, but had no effect on reproductive performance.