Seasonal Variation of Physiological and Biochemical Indexes of White-tibetan Sheep

In this study, to understand the variation regulation of physiological and biochemical indexs of White-Tibetan sheep with seasons, the physiological and bio- chemical indexs of White-Tibetan sheep in Hongyuan Areas of Sichuan Province in four seasons were measured. The results showed that the respiratory change range of white-Tibetan sheep in four seasons was from （32.74±21.33） to （49.96±17.62） times/min, and the variation ranges of body temperature and heart rate were from （39.27±1.05） to （39.73±0.31） ℃ and from （88.75±8.32） to （104.63±10.39） times/min, respectively. The indexes of WBC, MCV, MCH and MCHC in autumn and winter were extremely significantly lower than those in spring and summer, while RBC,HCT and RDW-CV in autumn and winter were extremely significantly higher than those in spring and summer, HGB and PLT changed in different seasons with no signifi- cance. The indexes of AST,TP, ALB, GLO and LDH in summer and autumn were relatively higher than those in winter and spring, while the indexes of PCHE, GLU, CHOL and CA in summer and autumn were relatively lower than those in winter and spring, however, the indexes of ALT and ALP were relatively higher in spring and autumn.

Quantitative Study on Expression of MSTN Gene in Different Tissues of Tibetan Sheep at Different Ages

[Objective] The aim was to investigate the difference in MSTN gene expression in different tissues of Tibetan sheep at different ages.[Method] According to the sequence（NM_001009428.1）published in GenBank,a pair of specific primers was designed to amplify part of cDNA sequence of MSTN by using QRT-PCR technique.The relative expression level of MSTN gene in rennet stomach,rumen,leg muscle and cardiac muscle of Tibetan sheep at different ages were analyzed.[Result] After normalization with β-actin gene,the relative expression level of MSTN gene in the 6-month-old Tibetan sheep was the highest and it was 2.52 times than that in 12-month-old Tibetan sheep（P0.05）,the relative expression level of MSTN gene in leg muscle was the highest among all tissues and it was 3 984.78 times than that in rumen（P0.01）.[Conclusion] The results established theoretical foundation for the correct use of MSTN antibody.

Optimization of Drying Process for Plasma Protein from Tibetan Sheep

Fresh blood of Tibetan sheep was subjected to protein separation and spray drying, and the effects of drying process on water content, yield and nitrogen soluble index of plasma powder from blood of Tibetan sheep were investigated. The results showed that the optimum separation parameters were a centrifugal speed at 6 000 r/min, centrifugal time of 20 min, a mass fraction of dry matter of 20%, an inlet air temperature at 180 ℃ and a feed rate at 400 ml/h, under which the plasma protein was a pale yellow powdery solid, indicating a good separation effect.

Analysis of Physiological and Biochemical Indexes of White-tibetan Sheep at Different Months of Age

To study the physiological and biochemical indexes of White-tibetan sheep in plateau environment, we measured the physiological and biochemical inde- xes of White-tibetan sheep at 3, 6, 9, 12, 15, 18,21 and 24 months of age. The results showed that the body temperature, respiration and heart rate of White-ti- betan sheep at 3 - 24 months of age were （38.89 ±0. 56） - （39.83 ± 0.32） ℃, （26.00±6.67 ） - （58.64 ± 12.67 ） times/rain and （ 83.90 ± 7.64） - （111.36 ±7.46） times/rain, respectively. The blood physiological indexes of WBC, HCT and RDW-CV at 3, 6, 15 and 18 months of age were lower than those at 9, 12, 21 and 24 months of age. On the contrary, the indexes of RBC, MCV, MCH and MCHC at 3, 6, 15 and 18 months of age were higher than those at 9, 12, 21 and24 months of age, while HGB and PLT did not vary with months of age. For blood biochemical indexes, ALT, AST, TP, ALB, LDH and CHOL reached the maximums at 21 months of age, while ALP, PCHE and GLU reached the maximums at 3 months of age. Besides, the GLO and GA reached the maxi- mums at 18 and 24 months of age, respectively. The physiological and biochemical indexes of White-tibetan sheep followed certain rules in growth and development process, and might be affected by plateau climate and season.

Molecular characterization of two candidate genes associated with coat color in Tibetan sheep(Ovis arise)

Coat color is a key economic trait in sheep. Some candidate genes associated with animal＇s coat color were found. Partic- ularly, v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog （KIT） and microphthalmia-associated transcription factor （MITF） play a key role in the modulation of hair pigmentation in mammals. This study investigated those two candidate genes＇ mutations and expressions associated with wool color in Tibetan sheep. First, the gene polymorphisms of those two genes were analyzed, and then, relative mRNA expression levels of those two genes in skin tissue with different coat colors were compared. Thirdly, KIT and MITF protein expression levels were detected through Western blot and immune- histochemical. Allele C was predominant allele in the white coat color Tibetan sheep population of the MITF coding region g. 1548 C/T loci. The relative MITF mRNA expression in black coat skin tissue was significantly higher than white （P〈0.01）. However, no significant differences were detected in the KIT gene＇s mRNA expression of these two different coat color skin tissues （P〉0.05）, while the level of KIT protein expression in skin tissues of white and black coats was also roughly equivalent. Our study observed that, the level of MITF protein expression in black coat skin tissue was significantly higher than that in white coat skin tissue, and positive staining for MITF protein expression was detected mainly in the epidermis and the dermal papilla, bulb, and outer root sheath of hair follicles. We conclude that the black coat of Tibetan sheep is related to high MITF expression in the hair follicles, and MITF may be important for coat color formation of Tibetan sheep.

Studies of Sulphur- and Iron-induced Copper Deficiency in Tibetan Sheep

The clinical signs of Tibetan sheep with sulphur- and iron-induced copper deficiency in Maqu County of Gansu Province were defined as thin, decreased appetite, neonatal ataxia, pica, emaciation, and loss of hair color and anemia. The mineral composition of soil and forage, and samples of liver, blood and hair from Tibetan sheep in affected ranches in this region were compared with those from unaffected areas. The mean concentration of iron in soil and forage in affected pasture was 19 675 ±791 and 1 763 ±197 μg/g, respectively, compared with 8 761 ±871 and 357 ±39 μg/g in unaffected pasture. The mean concentration of sulphur in soil and forage in affected pasture was 1.98% ±0.79% and 0.88% ±0.16%, respectively, compared with 1.16%±0.26% and 0.47%±0.16%in unaffected pasture. The mean copper concentrations in soil and forage from the affected pastures were 15.9±1.8 and 6.7±1.6 μg/g, respectively, compared with 16.7±1.9 and 8.9±2.7 μg/g in unaffected pasture.The mean concentration of Cu in blood, liver, and hair from the affected Tibetan sheep were 0.32±0.12, 51.2±3.1 and 2.16±0.65μg/g, respectively, compared with 0.76±0.21, 191±11 and 3.27±0.96 μg/g for healthy animals. Oral administration of CuClO(OH)3prevented and cured anemia. We conclude that wool eating of Tibetan sheep in this region is probably caused by secondary Cu deficiency, mainly due to the high iron and sulphur contents in soils and forage.

Analysis of Physiological and Biochemical Indexes of White Suffolk Sheep,White-tibetan Sheep and Tibetan Sheep

In order to compare the physiological and biochemical indexes of different sheep populations in plateau area,we measured the physiological and biochemical indexes of White Suffolk sheep,White-tibetan sheep and Tibetan sheep in four seasons.The body temperature,respiration and heart rate of White Suffolk sheep,White-tibetan sheep and Tibetan sheep throughout the year were（38.96±0.23）-（40.80±0.74）℃,（27.20±7.73）-（74.56±10.91）times/min,and（83.10±2.42）-（106.25±7.07）times/min,respectively.The main blood physiological indexes of White-tibetan sheep were between those of Suffolk sheep and Tibetan sheep or close to that of Tibetan sheep,the indexes of WBC in summer,HGB and RDW-CV in autumn,RDW-CV in winter were close to that of White Suffolk sheep.The main blood biochemical indexes of White-tibetan sheep were between that of White Suffolk sheep and Tibetan sheep or close to that of Tibetan sheep,but the indexes of ALB in spring,AST in summer,ALP and CHOL in autumn,and ALP in winter were close to that of White Suffolk sheep.It revealed that the adaptability of White-tibetan sheep was prior to White Suffolk sheep,and tended to Tibetan sheep in the plateau environment.

Physiological and Biochemical Indexes of Tibetan Sheep at Different Months of Age

To study the changes in physiological and biochemical indexes of Tibetan sheep from the plateau area at different months of age,we measured the physiological and biochemical indexes of Tibetan sheep reared in Hongyuan County of Sichuan Province according to their growth stages. The results showed that the respiration,body temperature and heart rate of Tibetan sheep at 3- 24 months of age were( 24. 60 ± 6. 33)-( 50. 30 ± 21. 18) times / min,( 39. 14 ± 0. 28) ℃-( 39. 64 ± 0. 17) ℃ and( 91. 00 ± 13. 27)-( 112. 00 ± 8. 69) times/min,respectively. The blood physiological indexes of Tibetan sheep including white blood cell count( WBC),hematocrit( HCT) and red blood cell distribution width coefficient of variation( RDW- CV) at 3,6,15 and 18 months of age were relatively lower than those at 9,12,21 and 24 months of age. The blood physiological indexes including red blood cell count( RBC),mean corpuscular capacity( MCV),mean corpuscular hemoglobin concentration( MCHC) and mean corpuscular hemoglobin( MCH) at 3,6,15 and 18 months of age were relatively higher than those at 9,12,21 and 24 months of age,while hemoglobin( HGB) and platelet count( PLT) did not vary with months of age. For blood biochemical indexes,alanine aminotransferase( ALT),albumin( ALB),globulin( GLO) and total cholesterol( CHOL) reached the maximum values at 21 months of age; alkaline phosphatase( ALKP),lactate dehydrogenase( LDH),blood glucose( GLU) and pseudocholinesterase( PCHE) reached the maximum values at 3 months of age;and total calcium( CA),total protein( TP),aspartate aminotransferase( AST) reached the maximum values at 9,18 and 24 months of age,respectively.

Epidemiological Investigation and Analysis of Chlamydia in Yak and Tibetan Sheep in Qinghai Province

Epidemiological investigation of chlamydia in yak and Tibetan sheep were conducted in Haiyan and Guinan counties, and samples were collected for laboratory detection, to understand the incidence range and damage degree of chlamydia in yak and Tibetan sheep in Qinghai Province. The result will provide technical support for preparation of scientific prevention and control measures against Chlamydia in Qinghai Province.

Seasonal Changes of Physiological and Biochemical Indexes of Tibetan Sheep

To investigate the seasonal changes in physiological and biochemical indexes of Tibetan sheep in Hongyuan area,we measured the physiological and biochemical indexes of Tibetan sheep at four different seasons. The results showed that the body temperature,respiration and heart rate of Tibetan sheep at four seasons were 39. 18- 39. 60 ℃,27. 20- 49. 04 times / min,91. 87- 106. 25 times / min,respectively. The indexes of WBC,MCV,MCH and MCHC in autumn and winter were significantly higher than those in spring and summer（ P 〈 0. 01）,while the indexes of RBC,HCT and RDW-CV in spring and summer were significantly higher than those in autumn and winter（ P 〈 0. 01）. The PLT did not vary greatly in spring,summer or autumn,but were all extremely higher than that in winter（ P〈 0. 01）. The HGB maintained stable in the four seasons. The indexes of TP,ALB and GLO in summer and autumn were extremely higher than those in winter and spring（ P 〈 0. 01）,while the indexes of ALP and PCHE in summer and autumn were extremely lower than those in winter and spring（ P 〈 0. 01）. The indexes of AST,ALT,LDH,GLU,CHOL and CA maintained stable in all seasons.

Variation of DRB1 Gene in Tibetan Sheep

It reveals that the MHC （major histocompatibility complex） gene product always involved in the control of immune response and disease resistance. Nowadays many studies have indicated the OLA （ovine lymphocyte antigen） DRB1 gene is associated with some sheep diseases. Tibetan sheep is one of the three major shag sheep breeds in China, and also have the largest number of China＇s sheep breeds. But till now no report has been seen on studying DRB1 gene in Tibetan sheep of China. To understand the evolution and provide the basis for sheep disease resistance, polymorphism in the exon2 ofDRB1 gene in Tibetan sheep was analyzed. The PCR-SSCP, cloning and sequencing were used to analyse DRB1 gene variation in 600 Tibetan sheep of China. And the genetic relationship and evolutionary significance of the alleles had also been analyzed. Total of 31 alleles were identified, in which 15 alleles had not been reported before. And there were 70 SNPs （single nucleotide polymorphisms） sites in 31 sheep DRB1 gene haplotypes, the proportion was 29.5% to the whole exort2 sequence. All of this indicated that DRB1 exon2 is highly polymorphic in Tibetan sheep. The variation identified here might have an impact on both the function and level of expression of the OLA-DRB1.

Estimation of Economic and Ecological Value of Raising Sheep in Pastoral Area

Tibetan sheep is a unique breed of livestock in Alpine pastoral areas,which is one of the main economic pillars of animal husbandry in pastoral areas,in order to analyze and compare the estimated the economic and ecological benefits of Tibetan sheep under different feeding modes,this paper used a simplified model from multiple angles of animal production,economics and Ecology,The results show that:(i)Under the traditional grazing condition,the annual income of raising one ewe is only 23.4 yuan;(ii)Under the high-efficiency breeding mode,the average income of ewes bred by high-efficiency technology was 168 yuan/(head·year),which was 7 times higher than that of ewes under traditional grazing;each lamb could produce an indirect economic benefit of 500 yuan;(iii)The ecosystem service value affected by each Tibetan sheep through grassland was above 150000 yuan.

青海地区不同动物源志贺菌毒力相关基因的分布研究

为了解青海省不同动物源志贺菌相关毒力基因的分布情况,试验对分离自青海省不同地区的62株不同动物源志贺菌进行了DNA提取,将其作为模板对志贺菌的毒力基因set1B、virA、set1A、ial、ipaBCD、Sen、icsP、iutA、icsA、ipaH进行了PCR检测,并统计各毒力基因在不同动物源志贺菌中的检出率、不同动物源志贺菌毒力基因携带模式及携带毒力基因种类。结果表明:62株志贺菌毒力基因set1B、virA、set1A、ial、ipaBCD、icsP、Sen、iutA、icsA、ipaH的检出率分别为6.5%、43.5%、3.2%、25.8%、37.1%、0、12.9%、22.6%、50.0%、100%。在27株猪源志贺菌中,毒力基因ipaH、VirA、icsA、ipaBCD的检出率较高,然后依次为ial、iutA、Sen,未检出icsP。在27株鸡源志贺菌中,毒力基因ipaH、icsA、virA的检出率较高,然后依次为ipaBCD、ial、Sen、iutA,未检出set1B、set1A、icsP。在4株牦牛源志贺菌中,毒力基因ipaH、icsA、ipaBCD的检出率较高,然后依次为virA、ial、iutA,未检出set1B、set1A、Sen、icsP。在4株藏羊源志贺菌中,毒力基因ipaH、ipaBCD、iutA的检出率较高;然后依次为virA、ial,未检出set1B、set1A、Sen、icsP、icsA。在62株志贺菌中,有7株菌只检出毒力基因ipaH,55株菌携带两种及以上毒力基因,共呈现出30种携带模式,其中以virA-icsA-ipaH模式的菌株最多(11.3%,7/62),然后为ipaBCD-ipaH模式(9.7%,6/62);猪源和鸡源志贺菌毒力基因的携带模式均为18种,牦牛和藏羊源志贺菌毒力基因的携带模式均为4种。在62株志贺菌中,有18株菌携带2种毒力基因,15株菌携带3种毒力基因,13株菌携带4种毒力基因,7株菌携带5种毒力基因,2株菌携带6种毒力基因。27株猪源志贺菌中携带1,2,3,4,5,6种毒力基因菌株的占比分别为3.7%、40.7%、14.8%、18.5%、14.8%、7.4%,27株鸡源志贺菌中携带1,2,3,4,5,6种毒力基因菌株的占比分别为18.5%、18.5%、29.6%、22.2%、11.1%、0,4株牦牛源志贺菌中携带1,2,3,4,5,6种毒力基因菌株的占比分别为25.0%、0、25.0%、50.0%、0、0,4株藏羊源志贺菌中携带1,2,3,4,5,6种毒力基因菌株的占比分别为0、50.0%、50.0%、0、0、0。62株志贺菌单毒力基因携带率(11.3%,7/62)<多重毒力基因携带率(88.7%,55/62),其中猪源志贺菌的多重基因携带率最高(42.0%),然后依次为鸡源(35.5%)、藏羊源(6.4%)和牦牛源(4.8%)。说明青海地区志贺菌携带多种毒力基因,携带模式呈现多样性且因动物源不同有所差异,同时应重点加强青海地区猪志贺菌病的防治工作。

“特藏寒羊”群体遗传结构分析与选择信号的对比分析

旨在了解“特藏寒羊”群体遗传结构和优势性能的遗传来源,为配种方案和杂交利用提供依据,帮助组建特定性能的家系。本研究应用SNP 50K v3芯片对50只“特藏寒羊”(公羊18只,母羊32只)、24只特克塞尔羊(公母各半)和48只欧拉羊(藏系绵羊)(公羊20只,母羊28只)进行单核苷酸多态性(single nucleotide polymorphisim,SNPs)检测;使用Plink、GCTA和MegaX软件对“特藏寒羊”进行遗传结构分析;Tajima’D法对“特藏寒羊”、特克塞尔羊和欧拉羊(藏系绵羊)进行群体内基因组选择信号分析,将“特藏寒羊”的选择信号分别与特克赛尔羊和欧拉羊(藏系绵羊)的选择信号取交集进行GO和KEGG功能富集分析,找到可能影响“特藏寒羊”优势性能的亲本来源和相关基因。结果显示:“特藏寒羊”平均多态信息含量(PIC)为0.26±0.12,平均期望杂合度(He)为0.36±0.14,平均观测杂合度(Ho)为0.37±0.16,平均最小等位基因频率(MAF)为0.25±0.15,平均有效等位基因数(Ne)为1.59±0.07;ROHs长度主要分布在1~5 Mb,占比50.4%,长度20 Mb+的ROH占比9.52%,近交系数F_(ROH)中位数为0.085;遗传距离D值为0.1527~0.3491,平均遗传距离0.2796;NJ聚类分析共划分5个家系,家系内个体分布不均;“特藏寒羊”与欧拉羊(藏系绵羊)交集信号定位的基因与免疫相关,包括原发性免疫缺陷、造血细胞系和T细胞受体信号通路;“特藏寒羊”与特克塞尔羊交集信号定位的基因与生物代谢相关。综上所述,“特藏寒羊”存在一定程度近交,需加强管理;欧拉羊(藏系绵羊)更影响“特藏寒羊”免疫功能,特克塞尔羊更影响“特藏寒羊”生长发育和肉质性状。

西藏羊和白-藏杂交羊外周血IFN-α、IgG和IL-2的研究

为了解西藏羊和白萨福克羊与西藏羊的杂交后代羊生长发育中免疫因子的分泌特点和免疫学特征,以西藏羊和白-藏杂交羊为研究对象,应用ELISA方法检测0.5、1和1.5岁外周血中干扰素(IFN-α)、免疫球蛋白G(IgG)和白细胞介素-2(IL-2)的质量浓度,分析其变化规律。结果表明:随年龄的增长,藏公羊IL-2呈逐渐降低的趋势,而藏母羊呈逐渐升高的趋势(P<0.05);藏杂交公羊和藏母羊IgG含量都呈逐渐降低趋势,藏公羊下降较明显(P<0.05);藏公羊IFN-α的含量逐渐降低,0.5岁与1岁之间下降趋势明显(P<0.05),而藏母羊变化不大。随年龄的增长,白-藏杂交羊公羊和母羊IL-2含量先降低再升高;白-藏杂交羊公羊IgG含量变化不大,母羊则是先升高后下降趋势,且1岁和1.5岁之间下降明显(P<0.05);白-藏杂交羊公羊IFN-α的含量逐渐降低,而母羊是先升高后下降。

益生菌对藏绵羊和白-藏杂交羊羔羊生长性能的影响

为分析益生菌对藏绵羊和白-藏杂交羊羔羊生长性能的影响,探讨藏绵羊和白-藏杂交羊早期断奶的适宜时间,试验以藏绵羊和白-藏杂交羊羔羊为研究对象,通过在补饲料中添加益生菌来比较羔羊生长发育情况。结果表明,在相同的饲喂时间下,白-藏杂交羊羔羊的生长速度略高于藏绵羊,未达到显著水平,在添加益生菌的情况下,藏绵羊和白-藏杂交羊羔羊的生长速度略高于对照组,也未达到显著水平。试验结果为今后高原牧区藏绵羊及其他品种的益生菌应用提供理论基础。

低蛋白日粮中不同比例氨基酸对藏羊背腰最长肌肉品质、氨基酸和脂肪酸组成以及维生素和矿物质含量的影响

本试验旨在研究低蛋白日粮中不同比例氨基酸对藏羊背腰最长肌肉品质、氨基酸和脂肪酸组成以及维生素和矿物质含量的影响。选取90只体重相近[(15.60±0.10)kg],健康的高原型藏羊公羔,随机分为3组,每组30只,每组5个重复,每个重复6只羊。日粮精料中蛋白水平为12%,3组分别为LP-L组(赖氨酸与蛋氨酸为1∶1);LP-M组(赖氨酸与蛋氨酸为2∶1);LP-H组(赖氨酸与蛋氨酸为3∶1)。试验期共97 d,其中7 d预饲期,90 d正试期。结果表明:1)解冻损失指标LP-L组显著低于LP-H组(P<0.05),蒸煮损失和剪切力指标LP-L组显著低于LP-M和LPH组(P<0.05);2)添加不同氨基酸比例对各组肌肉中氨基酸的组成没有显著影响(P>0.05);3)在不饱和脂肪酸中,反式亚油酸、二十二碳三烯酸和十五碳烯酸含量LP-L组显著高于LP-M组(P<0.05);十七碳烯酸、亚油酸和α-亚麻酸LP-L组显著高于LP-M和LP-H组(P<0.05);4)α-维生素E、γ-维生素E和维生素E指标LP-L组显著高于LP-M组(P<0.05),矿物质元素钙LP-L组显著高于LP-M组(P<0.05)。综上所述,当日粮中赖氨酸与蛋氨酸比例为1∶1时能提高不饱和脂肪酸含量以及肉质中维生素和矿物质元素含量;且对氨基酸组成没有不良影响,并能有效改善肉品质。

SNP芯片评估欧拉藏羊群体遗传多样性和遗传结构

为了解欧拉藏羊群体的遗传多样性和遗传结构,利用SNP 50K芯片检测了45只欧拉藏羊(20只公羊、25只母羊)的SNP,并进行了血样DNA提取和检测、基因组DNA的SNA分型和数据质检、群体的PCA分析、近交系数分析、亲缘关系分析、遗传距离分析、家系构建分析。结果表明,45只欧拉藏羊共得到64 734个SNP标记,质检后符合要求的数量为57 066个,其中1号染色体上有6 170个SNP位点,24号染色体上有830个位点;45只欧拉藏羊共检测到380个ROH,ROH平均近交系数为0.034,其中公羊的平均近交系数为0.052,母羊的平均近交系数为0.018,说明欧拉藏羊的近交程度不太高。从家系构建分析可知,欧拉藏羊公羊群体可分为8个家系,有5个家系公羊只有1只。后期应加强后代的扩繁和选育,以保证血统的完整。

不同月龄黑藏羊肉品质及风味评价分析

试验旨在研究不同饲养月龄对黑藏羊肌肉食用品质、营养品质和风味的影响。选取体重相近,健康无病的黑藏羔羊15只,随机分成3组,每组5个重复,每个重复1只羊。3组黑藏羊以玉米、燕麦干草、燕麦青贮等作为主饲料,在相同饲养条件下分别饲养到6月龄、12月龄和24月龄。结果显示,与12月龄和24月龄黑藏羊相比,6月龄黑藏羊肌肉的剪切力和滴水损失最低(P<0.05),水分含量最高(P<0.05),脂肪含量最低(P<0.05)。与24月龄黑藏羊相比,6月龄黑藏羊肌肉蒸煮损失显著降低(P<0.05),6月龄和12月龄熟肉率显著上升(P<0.05)。与24月龄黑藏羊相比,12月龄黑藏羊肌肉的剪切力显著降低(P<0.05),熟肉率和水分含量显著增加(P<0.05)。3组黑藏羊肌肉通过GC-IMS技术共检测到37种挥发性风味物质,包含醇类、酮类、醛类、萜烯类和酯类。在6月龄黑藏羊肌肉中醇类、萜烯类和酯类含量最多,在12月龄和24月龄黑藏羊肌肉中酮类和醛类含量最多。通过正交偏最小二乘判别分析模型(OPLS-DA)和相对气味活度值(ROAV)确定了2,3-丁二醇、庚醛、己醛、乙偶姻、正壬醛、3-甲硫基丙醛是3组不同月龄黑藏羊肌肉的主要特征风味物质。研究表明,6月龄黑藏羊肌肉食用品质最佳,具有较多含量和种类的挥发性风味物质,其中2,3-丁二醇、3-甲硫基丙醛、柠檬烯、γ-松油烯、乙酸乙酯和丁内酯为其关键风味物质。

颗粒饲料中小麦添加比例对青海藏羊生长性能与肠道发育的影响

【目的】研究颗粒饲料中小麦添加比例对青海藏羊生长性能、小肠形态发育及空肠消化酶活性、免疫机能和抗氧化指标的影响。【方法】选择90只体质量相近((21.87±2.35)kg/只)、发育良好的3月龄高原型藏羊,随机分为3组,每组6个重复,每个重复5只羊,分别饲喂小麦质量分数为0%(对照组)、10%(试验Ⅰ组)、15%(试验Ⅱ组)的颗粒饲粮,饲喂试验为期90 d。饲养试验结束后,测算平均日增重(ADG)、平均日采食量(ADFI)和料重比(F/G);从每组中随机挑选5只羊进行屠宰,采集小肠各段(十二指肠、空肠和回肠)制备石蜡切片,测量绒毛高度(VH)、绒毛宽度(VW)、隐窝深度(CD)和肌层厚度(MT),并计算绒毛高度/隐窝深度(绒隐比,V/C);测定空肠食糜α-淀粉酶、纤维素酶(CE)、糜蛋白酶、脂肪酶、胰蛋白酶(TPS)活性,免疫球蛋白A(immunoglobulin A,IgA)、IgG、IgM、白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)质量浓度及抗氧化特性(超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活性,丙二醛(MDA)浓度及总抗氧化能力(T-AOC))。【结果】①试验Ⅱ组藏羊的终末体质量、平均日增重显著小于对照组(P<0.05),而料重比显著大于对照组(P<0.05)。②试验Ⅰ组藏羊的十二指肠VW显著高于对照组(P<0.05),对照组的十二指肠MT显著高于试验Ⅱ组(P<0.05);试验Ⅰ组藏羊的空肠VH、V/C显著高于对照组(P<0.05),试验Ⅰ组藏羊的空肠MT显著高于其余2组(P<0.05);各组藏羊间回肠的VH、VW、CD、MT及V/C差异均不显著(P>0.05)。③试验Ⅰ组藏羊的空肠CE、糜蛋白酶及TPS活性显著高于其余2组(P<0.05),对照组的空肠α-淀粉酶活性显著低于其余2组(P<0.05),各组间空肠的脂肪酶活性差异不显著。④试验Ⅰ组藏羊的空肠IgA、IgG质量浓度显著高于试验Ⅱ组(P<0.05),各组间空肠的IgM、IL-1β和TNF-α质量浓度差异不显著(P>0.05)。⑤对照组藏羊的空肠T-AOC及GSH-Px、CAT、SOD活性显著低于试验Ⅰ组(P<0.05),各组间空肠的MDA浓度差异不显著(P>0.05)。【结论】颗粒饲料中小麦质量分数为10%时,不会损害青海藏羊的生长发育,且会显著提高小肠发育能力、空肠抗氧化能力及免疫机能和消化酶活性,可考虑在藏羊育肥中推广应用。