蓟马取食对苜蓿氨基酸组成及含量的影响

为了探究蓟马取食对苜蓿(Medicago sativa L.)氨基酸组成及含量的影响,本研究以'草原2号'(Medicago varia Martin.'Caoyuan No.2')感蓟马品种和'草原4号'(Medicago sativa L.'Caoyuan No.4')抗蓟马品种为材料,分别进行牛角花齿蓟马(Odo...     

1株具有免疫增强功能的乳酸菌筛选及其免疫效果评价

为筛选出具有较强免疫功能的益生菌用于临床研究,对分离自健康鸡粪便样品中的20株乳酸菌进行耐酸、耐胆盐、体外抑菌、黏附、胞外多糖含量测定试验以及小鼠免疫功能检测,并结合上述试验结果进行综合性评价.结果:筛选出20号菌株为目的菌株,耐酸、耐胆盐试验表明,该菌株在pH=2时的存活率为72.7％,在胆盐浓度为1.0％的环境中存...     

Effects of calcium salts of long-chain fatty acids and rumen-protected methionine on plasma concentrations of ghrelin, glucagon-like peptide-1 (7 to 36) amide and pancreatic hormones in lactating cows

Our objective was to determine the effects of calcium salts of long-chain fatty acids (CLFAs) and rumen-protected methionine (RPM) on plasma concentrations of ghrelin, glucagon-like peptide-1 (7 to 36) amide, and pancreatic hormones in lactating cows. Four Holstein cows in midlactation were used in a 4 by 4 Latin square experiment in each 2-wk period. Cows were fed corn silage-based diets with supplements of CLFAs (1.5% added on dry matter basis), RPM (20 g/d), CLFAs plus RPM, and without supplement. Jugular blood samples were taken from 1 h before to 2 h after morning feeding at 10-min intervals on day 12 of each period. CLFAs decreased dry matter intake, but RPM did not affect dry matter intake. Both supplements of CLFAs and RPM did not affect metabolizable energy intake and milk yield and composition. Plasma concentrations of NEFAs, triglyceride (TG), and total cholesterol (T-Cho) were increased with CLFAs alone, but increases of plasma concentrations of TG and T-Cho were moderated by CLFAs plus RPM. Calcium salts of long-chain fatty acids increased plasma ghrelin concentration, and the ghrelin concentration with CLFAs plus RPM was the highest among the treatments. Plasma concentrations of glucagon-like peptide-1, glucagon, and insulin were decreased with CLFAs, whereas adding RPM moderated the decrease of plasma glucagon concentration by CLFAs. These results indicate that the addition of methionine to cows given CLFAs increases plasma concentrations of ghrelin and glucagon associated with the decrease in plasma concentrations of TG and T-Cho.     

糖蜜酒精废液处理过程中生成的微生物蛋白的最佳水解条件研究

通过实验选择复合蛋白酶水解糖蜜酒精废液处理过程中生成的微生物蛋白,并通过正交试验分析得到最佳水解条件为水解酶加入量5.5g/150mL,水解温度65℃,pH值5和水解时间5h。     

道塞特、萨福克与阿勒泰羊5月龄杂交公羔肉品质分析

选取5月龄萨福克×阿勒泰(SAF1、SAF2)、道塞特×阿勒泰(DAF1、DAF2)杂交一、二代羔羊与同龄阿勒泰羊(ALT)各3只,对肉品质进行分析。结果表明:5月龄杂交羔羊肉品质得到明显改善,特别是蛋白质、脂肪和氨基酸含量变化尤为明显,且杂交二代优于杂交一代,杂交组合SA优于DA。     

Supplementing rumen‐protected methionine to lactating multiparous dairy cows did not improve reproductive performance

There is evidence that supplementing methionine has positive effects on uterine environment, oocyte quality and embryo development in cattle. Thus, the objective of this study was to evaluate reproductive traits of cows supplemented with rumen‐protected methionine (RPM) during early to mid‐lactation in comparison with an untreated control group (CON). An additional focus was on the effect of puerperal diseases on reproductive performance parameters in RPM‐supplemented group MET and in CON. A total of 1,709 multiparous Holstein‐Friesian cows were enrolled in this field trial conducted on a commercial dairy farm in Slovakia. Cows were allocated at approximately 12 days post‐partum (dpp) to either CON or MET, the latter supplemented with 25.0 g–27.2 g RPM per cow per day incorporated into the total mixed ration (TMR) until leaving the study pen at approximately 140 dpp. The amount of RPM was calculated based on individual feed ingredients analysis and adjusted during the study period when TMR changed. Cows were monitored during the post‐partum period by vaginal examination (day 5 pp), measuring of beta‐hydroxybutyrate in blood (3, 5, and 8 dpp) and by vaginal examination, uterine cytology and measuring of back fat thickness by ultrasound (all at 31 ± 3 dpp). Compared with CON, cows supplemented with RPM did not show better reproduction performance parameters (first service submission rate, days to first service, conception risk, days open 140). Results from binary logistic regression model for the risk of conception showed that metritis had a significant effect, but the supplementation of methionine had not. Results of Cox regression analysis for the odds of conception within 140 dpp revealed only metritis and clinical endometritis as significant factors. In conclusion, supplementation of RPM had no beneficial effect on reproductive performance in this study farm compared with an untreated control group.     

硫辛酸对海马CA1区锥体细胞凋亡的抑制作用

采用股动脉放血并双侧颈总动脉夹闭制作全脑缺血再灌注模型 ,于术后 1 d处死动物 ,取脑 ,制作石蜡切片 ,通过 HE染色、Tunel检测 ,以观察海马 CA1区锥体细胞的损伤形式 ,并探讨α-硫辛酸 (α-lipoic acid,L A)对实验性脑缺血再灌注的神经保护作用。结果表明 :在短暂性全脑缺血中 ,海马锥体细胞存在着凋亡和坏死两种死亡形式 ;与对照组相比 ,缺血再灌注后1 d,海马 CA1区损伤较重 ,出现了较多的凋亡细胞 ,而 L A可明显抑制锥体细胞的凋亡。实验证明 :在脑缺血再灌注损伤中 ,细胞凋亡是神经元死亡的一种重要形式 ;L A对脑缺血再灌注有明显神经保护作用     

杀菌型乳酸菌饮料的模糊数学综合感官评判方法

通过对市场上流行的5种杀菌型乳酸菌饮料的焦糖味、果味、发酵味、甜味、酸味、涩感的感官评定,采用组合赋权法得出杀菌型乳酸菌饮料焦糖味、果味、发酵味、甜味、酸味、涩感的质量权重.对5种杀菌型褐色乳酸菌饮料各指标以权重,然后结合模糊数学综合评判方法,得出模糊关系曲线.结果表明:5种杀菌型乳酸菌饮料的整体感官排序为:样品5＞样品2＞样品4=样品l＞样品3,与一般排序法所得结果样品2＞样品4=样品1＞样品5＞样品3相比较稍有不同.因此,模糊数学综合评判方法比常用的排序法更科学、合理、客观.     

低蛋白质氨基酸平衡饲粮对生长猪生长性能和氮素减排的影响研究

试验旨在研究饲喂低蛋白质氨基酸平衡饲粮对生长猪生长性能和氮排泄量的影响,采用单因子完全随机设计,将144头平均体重30 kg左右的杜长大三元杂种生长母猪分成3组,每组设6个重复,每个重复8头猪,对照组饲喂实测粗蛋白质含量为18.10%的普通饲粮,试验1组、试验2组分别饲喂实测粗蛋白质含量为16.08%和14.12%的氨基酸平衡饲粮。试验期37 d,前7 d为预试期,正试期30 d。结果显示,3组日采食量、日增重、料重比指标均没有显著差异(P0.05),而日氮素总排泄量试验1组、试验2组分别比对照组减少18.69%、38.68%,3组之间差异均显著(P0.05),且试验1组、试验2组猪每增重1 kg所需要的饲料成本分别较对照组节省0.11和0.23元。综合考虑,生长猪饲喂低蛋白质氨基酸平衡饲粮,可以作为实现养殖效益与环保双赢的主要技术措施予以推广。     

Ascorbic acid ameliorates dysregulated folliculogenesis induced by mono-(2-ethylhexyl)phthalate in neonatal mouse ovaries via reducing ovarian oxidative stress

Phthalates, including di-(2-ethylhexyl)phthalate (DEHP), are common industrial chemicals in the environment. Recent evidence indicates that DEHP and its active metabolite mono-(2-ethylhexyl)phthalate (MEHP) negatively modulate reproductive functions and induce reactive oxygen species. Ascorbic acid (AA) is a dietary requirement for primates, and it acts as a potent free radical scavenger to protect tissues against oxidative stress. In this study, to investigate the toxic effects of MEHP on the follicle development and the beneficial role of AA, neonatal mouse ovaries were treated with different concentrations of MEHP with or without AA for 6 days. Then, the follicle constitution and oxidative status were compared in different groups. Results showed MEHP accelerated primordial follicle recruitment by increasing the percentage of primary and secondary follicles and decreasing the percentage of primordial follicles in the ovaries. Moreover, MEHP-induced ovarian oxidative stress by significantly increasing malondialdehyde (MDA) concentration and the expression of GSS and SOD1. When ovaries were co-administrated with MEHP and AA, follicle constitution was normalized, and the oxidative status was significantly decreased. These results suggested that AA ameliorated MEHP-induced ovarian oxidative stress and follicular dysregulation, which attested the clinical significance of AA for ovary protection in the case of MEHP exposure.