猪肌肉肌纤维特性与肌肉品质的关系及品种、性别差异

【目的】研究猪肌肉肌纤维特性与肌肉品质的关系及品种、性别差异。【方法】国内外相关文献的收集、汇总及分析。【结果】①肌纤维的形成是一个非常复杂的生物学过程,肌纤维数目、大小及类型是肌纤维的基本特性。②肌纤维类型的划分,目前最常用的是根据肌纤维中MyHC基因的多态性表达对肌纤维进行分类。③出生前,MyHC异构体按照胚胎期→胎儿期→成熟期顺序表达,出生后,肌纤维类型具有相互转化的特性。④不同类型肌纤维由于代谢特征存在明显差异,因此会影响肌肉色泽、pH、系水力等肌肉品质性状。肌纤维大小、密度与肌纤维类型密切相关,因此也会影响肌肉品质。⑤不同品种猪肌纤维特性有明显差异,因而表现出不同的肌肉品质。为了适应各自生长发育及生理需要,猪不同性别间肌纤维特性也有所不同。【结论】猪肌肉肌纤维特性直接影响肌肉品质的优劣,品种、性别不同,肌纤维特性的形成有一定差异,表现出不同的肌肉品质。     

高仿野生条件养殖的野香猪体脂肪、胶原蛋白、氨基酸及硒含量分析

【目的】研究高仿野生条件下养殖的野香猪的肉质品质。【方法】用索氏提取法、羟脯氨酸比色 法和邻苯二胺紫外分光光度法及氨基酸自动分析仪对野香猪的脂肪、胶原蛋白、氨基酸及硒含量进行检测。【结果】 野香猪的肌肉（前后腿肉等量混合）、皮（含皮下脂肪）、大肠和小肠的脂肪含量分别为 29.8、417.6、124.9、 15.6 mg/g,胶原蛋白含量分别为 9.03、312.21、18.36、19.58 mg/g;肌肉的门冬氨酸、谷氨酸、丙氨酸含量分别 为 13.5、23.7、8.4 g/kg;硒含量为大肠 0.78 mg/kg,小肠 0.77 mg/kg,皮肉混合组 0.70 mg/kg;而饲用青料硒含量 为 0.43~1.06 mg/kg。【结论】野香猪肉中脂肪含量适中,胶原蛋白、氨基酸及硒含量丰富。     

肉用畜禽肌纤维发育特性

为了解肉用畜禽(牛、绵羊、猪和家禽等)肌纤维发育特性的最新研究现状,以"畜禽"、"肌纤维发育"和"肉品质"为关键词,对1981—2019年国内外相关研究进行了检索,分别从肌纤维特性、肌纤维生成过程、肌纤维生长发育的分子调控等方面归纳了不同畜禽的肌纤维发育特征。研究发现:不同畜禽肌纤维发育的一般过程基本相似;肌纤维发育的时间具有物种特异性;个别基因被确定具有调控肌纤维发育的主要功能;仍缺乏多物种肌纤维发育过程基因调控网络的构建与系统比较研究以及多物种肉品质鉴定的通用分子标记开发。     

兔肉品质的营养调控研究进展

肉的品质已经日益受到人们的关注。兔肉品质主要包括肉的色泽、嫩度、pH值、系水力、眼肌面积、脂肪含量等几个方面。改善肉品质量的途径主要有遗传育种,改善饲养环境和屠宰加工条件、营养调控干预体内代谢。近年来国内外研究者的大量试验结果表明,通过营养调控的方式改善兔肉品质,是一条切实可行的途径。文章就这些研究进展进行综述,以期对今后的研究有所帮助。     

The differences in postprandial free amino acid concentrations and the gene expression of PepT1 and amino acid transporters after fishmeal partial replacement by meat and bone meal in juvenile turbot (Scophthalmus maximus L.)

Meat and bone meal (MBM) is a high‐quality alternative protein source used to replace fishmeal (FM). However, the molecular mechanisms of over‐substituted FM by MBM resulted in growth reduction are still not clear. The objective of the study was to evaluate the effect of FM replacement by MBM on the concentration of postprandial free amino acid (FAA) and mRNA abundance of peptide and amino acid transporters in juvenile turbot (Scophthalmus maximus L.). Fish were fed with FM diet (60% FM), MBM diet (33% FM + 34.2% MBM) and MBM + AA diet (MBM diet with essential amino acid (EAA) added to match the AA profile of FM) for 30 days. Results showed that compared with the FM diet, MBM diet led to a reduction in FAA concentration peak values in plasma and muscle. MBM + AA diet significantly elevated the peak values of FAA concentrations to FM diet level in plasma, but not in muscle. Furthermore, compared with FM diet, MBM diet significantly increased gene expression of PepT1 and major amino acid transporters in intestine, whereas MBM diet greatly downregulated gene expression of T‐type amino acid transporter‐1, system ASC amino acid transporter‐2 and cationic amino acid transporter‐2 in muscle. Supplemented EAA did not ameliorate these different effects in intestine and muscle. Overall, this study provided a comprehensive explanation for the relationship between diet, FAA concentrations and AA transportations, which provides a molecular basis for further using MBM to replace FM in aquafeeds.     

The effect of dietary protein level on the apparent digestibility coefficient of two selected feed ingredients for Nile tilapia,Oreochromis niloticus L.

The effect of dietary protein level on the apparent digestibility coefficient (ADC) of meat and bone meal and rapeseed meal for Nile tilapia Oreochromis niloticus L. was examined. Three reference diets were formulated to contain 240 (RD24), 350 (RD35) and 450 (RD45) g kg^?1 crude protein, and chromic oxide was added at 10 g kg^?1 in the reference diets as an inert indicator. Six test diets were formulated by mixing one of the reference diets with each test ingredient at a ratio of 70:30. Fish (initial body weight 101.0 ± 0.6 g) were fed reference diets for 3 days and then fed test diets in the following 4 days cyclically for 4 weeks. Faeces of fish fed each reference diet or test diet was collected from the third day of each diet conversion. Dietary protein level significantly affected the ADC of protein and energy of reference diets, test diets and test ingredients. The ADC of protein and energy of meat and bone meal and rapeseed meal was the highest when these ingredients were mixed with diet RD35. The scope of variation in the ADC of protein and energy of meat and bone meal was 8% (from 69.9% to 78.3%) and 8% (from 70.2% to 78.0%), and the scope of variation in the ADC of protein and energy of rapeseed meal was 4% (from 79.8% to 83.3%) and 5% (from 56.0% to 60.7%) when the dietary protein level was increased from 300 to 480 g kg^?1. This indicates that the ADC of protein and energy of meat and bone meal and rapeseed meal for Nile tilapia varied considerably at different dietary protein levels.     

Effect of different forms of Artemia biomass as a food source on survival,molting and growth rate of mud crab (Scylla paramamosain)

An experiment was conducted to evaluate the effect of different forms of Artemia biomass as a food source on survival, molting and growth rate of mud crab Scylla paramamosain. Instar 1 crablets with a mean weight of 0.0082 ± 0.0007 g were reared both individually and communally and fed with different diets consisting of fresh shrimp meat (control feed), live Artemia biomass, frozen Artemia biomass and a dried Artemia‐based formulated feed for 40 days. The highest survival was obtained for crablets receiving live Artemia (92.5% and 75.8%) followed by the groups fed with frozen biomass (90.0% and 47.5%), the control feed (72.5% and 24.2%) and the dried Artemia‐based diet (60.0% and 21.7%) for individual and communal cultures, respectively. The intermolt period, the total number of moltings and the growth rate, which were determined on individually reared crabs, showed the same pattern as for survival. The results suggest that crab performance decreased in the following order: live Artemia>frozen Artemia > fresh shrimp meat > dried Artemia‐based formulated feed. Live Artemia biomass proved an ideal feed for nursery of Scylla paramamosain crabs. Frozen Artemia biomass may be an alternative in times of shortage. Our findings illustrate the high potential for local utilization of Artemia biomass in Vietnam for reliable production of mud crab juveniles.     

多不饱和脂肪酸组合对滩羊肉品质、血清抗氧化指标及背最长肌共轭亚油酸含量的影响

本试验为了探究多不饱和脂肪酸组合对滩羊肉品质、血清抗氧化指标及背最长肌共轭亚油酸含量等的影响,选取4月龄左右的滩羊公羔27只,随机分为3组,分别为对照组(基础饲粮)、试验Ⅰ组(基础饲粮+1％大豆油+1％裂壶藻粉)、试验Ⅱ组(基础饲粮+1％亚麻油+1％裂壶藻粉),测定每组平均日增重、肉品质、血清抗氧化指标以及背最长肌共轭...     

我国肉与肉制品标准体系存在的问题及建议

近几年,随着肉制品行业的迅猛发展,消费者对肉制品的质量安全关注度越来越高,产业标准化和品质化必须跟上当前发展趋势。总体来看,虽然我国肉制品标准体系已基本建成,但依旧存在标准复审周期长、标准协调性不强、标准涵盖范围不全等问题。为加快肉与肉制品标准体系的建设进程,促进肉制品行业健康发展,梳理了我国现行肉与肉制品相关标准,对肉与肉制品从原料、生产加工技术规范、产品等相关标准进行了分类研究与归纳总结,重点分析了我国肉与肉制品标准体系的现状及主要问题,以期加快肉与肉制品标准体系建设进程,促进肉制品行业健康发展。     

Potential regulation of linoleic acid and volatile organic compound contents in meat of chickens by PLCD1

Omega-3(linolenic acid(ALA), docosapentaenoic acid, eicosapentaenoic acid) and omega-6(linoleic acid(LA),arachidonic acid) polyunsaturated fatty acids are essential for health and normal physiological functioning in humans.Here we report a genome-wide association study(GWAS) on LA content in chicken meat. The 19 significant single nucleotide polymorphisms(SNPs) identified by the GWAS approach were annotated in VILL, PLCD1 and OXSR1 genes with highly polymorphic linkage blocks, and explained 4.5%...