饲喂青贮或精料的安格斯和黑白花-弗里生牛的小牛肉中芳香族化合物和脂肪酸组成的比较

作者比较了14月龄的阿伯丁安格斯和黑白花-弗里生小牛肉中芳香族化合物和脂肪酸组成，这2个品种的小公牛从6月龄开始催肥到14月龄屠宰，饲喂青贮或精料。饲喂精料的牛肉中亚油酸含量高，且加工熟的牛肉中由亚油酸分解后再合成的化合物含量高；饲喂以青贮为主的牛的牛肉中α-亚麻油酸以及由其合成的挥发性化合物的含量高。以精料为主的小公牛的牛排中1-辛基-3-醇己烷、2-呋喃、3-甲胺、顺式和反式-2-辛烯、4、5-二甲基-2-戊基-3-噁唑酮的含量是以青贮为主的3倍，但是以采食青贮为主的小公牛的牛排的植酸盐含量相当高。品种效应的影响很小。

重组牛碱性成纤维细胞生长因子滴眼液对白内障术后干眼症的预防效果

目的观察重组牛碱性成纤维细胞生子因子滴眼液(贝复舒滴眼液)对白内障术后干眼症的预防效果。方法选取该院2022年2月至2023年8月接受手术治疗的白内障患者82例,随机分为对照组与试验组各41例。两组均接受超声乳化白内障吸除术治疗,术前以5%聚维酮碘溶液+0.9%氯化钠注射液冲洗结膜囊,试验组在此基础上于术后第1 d开始术眼使用贝复舒滴眼液。比较两组术前与术后第7 d角膜形态、眼表指标变化及术后干眼症发生情况。结果术后第7 d试验组角膜表面规则性指数、角膜表面非对称性指数、泪膜破裂时间、角膜荧光素染色评分及基础泪液分泌试验长度明显优于对照组,术后干眼症发生率(7.3%,3/41)明显低于对照组(24.4%,10/41),差异有统计学意义(P<0.05)。结论贝复舒滴眼液配合5%聚维酮碘溶液,能改善白内障术后患者角膜情况及泪膜功能,预防术后干眼症的发生。

历史田野新方法——利用社交媒体外包“生牛贸易”口述史的一种尝试

口述史访谈是了解过往的一种重要途径与方式,需要研究者走近受访对象,了解地方性知识并倾听他们的声音。但新冠肺炎疫情的爆发,使得访谈人走进地方、走近受访对象受到了极大限制。为此,可采取将口述史研究项目外包给来自不同地区大学生的方式展开进行:培训、指导他们走进田野,开展针对性的访谈并将他们的发现总结为结构化的访谈报告。这些访谈人,既了解地方性知识,且能运用当地方言与受访对象进行交流。这一操作模式,便捷、高效、可靠,且有利于建构实际有效的线上调研共同体,可复制于其他类型的田野研究中去。

豫生早熟牛心甘蓝的选育

采用游离小孢子培养双单倍体技术育成中早熟春甘蓝杂交一代新品种豫生早熟牛心。豫生早熟牛心中早熟,耐抽薹,适应性强,抗病毒病、霜霉病、黑腐病等病害。平均667m2产净菜4473.0kg。叶球牛心形,商品性好,质地脆嫩,风味佳,每100g鲜样含维生素C34.6mg,粗纤维0.68g,可溶性糖4.68g。2006年2月通过国家蔬菜鉴定委员会鉴定。

韩国今年猪牛屠宰量不同境遇

今年韩国生牛的屠宰量出现增长，而生猪屠宰量则降到4年以来的最低值。

Association of Polymorphisms of Leptin Gene with Body Weight and Body Sizes Indexes in Chinese Indigenous Cattle

PCR-SSCP was used to analyze the polymorphism of leptin gene in 539 samples of six cattle breeds, namely Nanyang （NY）, Qinchuan （QC）, Jiaxianred （JXR）, Xizhen （XZ）, Luxi （LX）, and Holstein cow （HOL） breeds. PCR products with a 330 bp were amplified and sequenced. The results showed that the frequencies of alleles A/B of NY, QC, JXR, XZ, LX, and HOL breeds were 0.558/0.442, 0.492/0.508, 0.571/0.429, 0.658/0.342, 0.591/0.409, and 0.615/0.385, respectively. The association of variations of leptin gene with growth traits in NY, QC, JXR breeds was analyzed. Some indexes of the individuals with genotype BB were higher than that with genotype AA and AB in NY breed, such as the indexes of body length, heart length, body weight, hucklebone width, body height, and average day gain. The height at hip cross of the individuals with genotype BB was higher than that of those with genotype AA and AB in QC breed （P 〈 0.05）. So leptin gene may be one of the candidate genes for growth traits with height at hip cross, but not for body weight, heart length, and body length trait. However, the height at hip cross and hucklebone width of the individuals with genotype AB and BB were higher than that of those with genotype AA in JXR breed （P 〈 0.05）, but the difference was not statistically significant in body weight and body sizes （body height, body length, and heart length）. And the polymorphisms in leptin gene were caused by G→T transversion at the 66th bp position, A→C transversion at the 67th bp position and G→T transversion at the 299th bp position. These results may be applied to marker-assisted selection of Chinese cattle breeds.

Cloning and Bioinformatics Analysis of Lfcin Gene of Datong Yak

[Objective] This study was to clone Lfcin gene from Datong yak, so as to provide reference for applying this gene in feed industry and breeding industry. [Method] Using PCR technology, the lactoferricin(Lfcin)-encoding gene was obtained from genome of Datong yak; then it was cloned into pGEM-T easy vector, and then sequenced; the sequencing results were subsequently aligned with the sequences of dairy cow accessed in GenBank. Moreover, amino acid sequences of Lfcin gene from various species including yak, dairy cow, human and mouse were used for sequence alignment and phylogenesis analysis. [Result] The second exon of lactoferrin(LF) from Datong yak, which is 778 bp in length, was obtained, within which the coding region of Lfcin gene is 75 bp (25 amino acid residues); sequence analysis showed that there is discrepancy of eleven bases between Datong yak and dairy cow; Lfcin proteins from various species shared high homeology, of which that from Datong yak and dairy cow were completely identical; phylogenesis analysis showed that cladogram based on Lfcin was consistent with species evolutionary law. [Conclusion] This study laid a foundation for the prokaryotic or eukaryotic expression of Lfcin gene and further understanding the activity of Lfcin protein.

Study on the Correlation between Blood Enzyme Activity and Production Performance in Tibetan Yaks

Yak ( Bos grunniens ) is classified as Bovine genus,they live in Qingzang Plateau with elevation more than 3500m and it's neighbor highland,where the weather is high chilly,short of oxygen and large difference of temperature between day and night.But yak have adapted that circumstance after thousands of years' artificial and natural selection and has great anti adversity capacity.Yak is an important sustenance and means of production to Tibetan.China is a country with the largest number of yak,whose amount of livestock on hand accounts for 95% of the world and Tibet region takes the second place next to Qinghai in the number of yak.Tibetan yak has formed some groups for Tibetan's large area,complicated geological ecosystem conditions,geological isolation.The typical better groups are Yadong yak,Jiali yak and Sibu yak. Study about yak fell behind other animals due to the restriction of inconvenient transportation,difficult sampling and poor experimental technology.Study about the relationship between yak blood enzyme activities and milk production was little,only Jing (1992) studied correlation of milk production with serum amylase,esterase in Gansu Jiulong yak,Maiwa yak and no report was found in other groups.This study discussed six Jiali yak blood enzyme activities lactate dehydrogenase (LDH),alkaline phosphatases (AKP),acid phosphatase (ACP),catalase (CAT),amylase (Amy) and superoxide dismutase (SOD),and explored their relationship with milk production in Jiali yak,so as to supply with theoretical evidence by using blood enzyme activity as biochemical assisted selection marker in the breeding of Tibetan yak milk yield. This experiment investigated activity of six blood enzymes from 28 Tibetan yaks and explored its relationship to production performance.The results showed a extremely positive significant difference ( P <0.01) between activity of LDH and milk yield,CAT activity and length of belly hair respectively,while a positive significant difference ( P <0.05) was observed between AKP activity and body weight,Amy activity and body weight and a negative significant difference ( P <0.05) for SOD activity and body weight.Stepwise Regression Analysis showed that activity of LDH could be used for the prediction of milk yield,AKP,CAT,Amy for body weight,CAT,Amy for length of belly hair.So it is expected to use activity of LDH,AKP,CAT,Amy as biochemical genetic marker in the selection of milk yield,body weight and length of belly hair.

Analysis on Polymorphisms of GHR Gene in Improved Hybrid Yellow Cattle Groups from Liupan Mountain Area in Ningxia

[Objective] The paper aimed to analyze the polymorphism of the growth hormone receptor （GHR） in improved hybrid yellow cattle group from Liupan Mountain area in Ningxia Autonomous Region,so as to provide technological basis for hybrid improvement. [Method] Polymerase chain reaction-restriction fragment length polymorphisms （PCR-RFLP） technology was carried out to examine polymorphisms of GHR gene of 70 individuals. [Result] The target fragment of 338 bp was amplified. The PCR product digested by restriction enzyme Alu I showed polymorphisms. The frequencies of the two genotypes （AA,BB） were 75.71% （53 individuals） and 24.29% （17 individuals）,respectively. [Conclusion] Two genotypes of GHR gene were detected in improved hybrid yellow cattle groups from Liupan Mountain area in Ningxia.

全球原皮市场分析

美国牛皮市场分析2010年2月2日(Jacobsen提供)周一,美国牛皮市场颇为冷清。牛肉加工厂报出的NHNDC价格为43美元,比重型无烙印奶牛皮价格低6.5美元。

Analysis of Nutritional Characteristics of Boletus edulis Mycelium

This study aimed to investigate the nutritional characteristics of Boletus edulis mycelium. The results showed that the optimal carbon source was glucose;the optimal nitrogen source was peptone; the optimal inorganic salt was KH2PO4;the optimal vitamin was VB1. The optimal medium, in which B. edulis mycelium in-cubated at 28 ℃ and pH 5.5 exhibited the strongest growth vigor and the rapidest growth rate, contained 3.0% glucose, 0.20% peptone, 0.60% KH2PO4, 0.20% Mg-SO4＆#183;7H2O and 0.000 50% VB1.

Analysis of stability and bullwhip effect in production-inventory systems

To discuss the relationship between stability and bullwhip effect in the supply chain system,a basic model in a production-inventory control system is developed using difference equations.Z-transform techniques are applied to investigate the production ordering and inventory dynamics.For the two operational regimes of sufficient inventory coverage and insufficient inventory coverage,the scope of decision parameters which make the system stable or instable is investigated.Under two operational regimes and the actual system,production release rates,stability/instability and bullwhip effect in the stable region and instable region are examined based on different demand functions,and then the numerical simulation results are given.The results show that reasonable choices of fractional adjustment of inventory and supply line can make the system stable and decrease bullwhip effect.It is summarized that the piecewise linearization based on the stability analysis approach is a valid approximation to the analysis of production-inventory ordering systems with nonlinearities.Some interesting results are obtained and they have important implications for improving inventory and order decisions in supply chain systems.

Study on Multiplication, Rooting and Transplanting of Tissue Culture Plantlets of Rhododendron chrysanthum Pall

[Objective] This study aimed to shorten the multiplication culture and root- ing culture periods of Rh. chrysanthum Pall. [Method] The Rh. chrysanthum Pall tis- sue culture plantlets collected from Changbai Mountain were used as material, and the effects of different hormone combinations and coconut milk on the proliferation and differentiation of Rh. chrysanthum Pall tissue culture plantlets were investigated. In addition, the rooting medium and transplanting matrix for Rh. chrysanthum Pall tissue culture plantlets were explored. [Result] The medium composed of modified MS, iBA （3 mg/L） and ZT （1.5 mg/L） was the optimum medium for subculture mul- tiplication of Rh. chrysanthum Pall tissue culture plantlets. The multiplication multiple and average plant height were significantly improved by adding coconut milk into the medium （150 mg/L）. [Conclusion] For Rh. chrysanthum Pall tissue culture plantlets, the optimum rooting culture medium was composed of modified MS （1/4） and IBA （5.0 mg/L）, and the tissue culture plantlets began to root 8 d after the inoculation. The root induction treatment was carried out after a 15-d sand culture, and the suitable matrix was composed of tufty soil, humus soil and perlite （2：1：1） with a survival rate of 95.66%.

Why do brood parasitic birds lay strong-shelled eggs?

Brood parasitic birds constitute a model system for the study of coevolution.Such parasites are unique by having evolved unusually thick eggshells for their body size.ick eggshells have been hypothesized to evolve as 1) a means of preventing damage to parasite eggs when the brood parasite lays its egg at a distance from the host clutch(the laying damage hypothesis);2) a consequence of host puncture ejection(the puncture resistance hypothesis);3) a means for the brood parasite to allocate calcium to development of a disproportionately large skeleto-muscular system in evicting parasite chicks(the chick vigour hypothesis);or 4) a means of protecting the cuckoo embryo from microorganisms in the nest of the host(the anti-bacterial protection hypothesis).Here we review the literature studying the evolutionary mechanisms promoting thick eggshells in avian brood parasites,and provide proposals for future studies to test their validity.Available data are insu cient to rigorously test exclusive predictions and assumptions of these not necessarily exclusive hypotheses,although the laying damage and the puncture resistance hypotheses seem to currently be the most well supported alternatives.We discuss how quanti cation of rejection modes(grasp ejection,puncture ejection and desertion) may disclose the validity of the puncture resistance hypothesis,and nally we provide perspectives for future research on testing this speci c hypothesis.

Composition Analysis on Intermuscular Fatty Acid of Qinghai Datong Yak

[ Objective] The study aimed to provide a theoretical basis for rational utilization of Datong yak resource. [ Method] By qualitative and quantitative determination with gas chromatograph, the composition and content of intermuscular fatty acid of Datong yak were compared with those of Datong yellow cattle. [ Result] Comparing with Datong yellow cattle, Datong yak had lower saturated fatty acid （SFA） content and higher polyunsaturated fatty acid （PUFA） content at extremely significant level （P 〈0.01 ）, while the difference of monounsaturated fatty acid （MUFA） contents between them was not significant （P〉0.05）. The PUFA/SFA and n-6/n-3 PUFA of Datong yak were in accordance with the recommended proportions. [ Conclusion] The intermuscular fatty acid composition of Datong yak is superior to that of local yellow cattle, which indicates that Datong yak meat has high nutritive value and wide development prospect.

Effects of EMS Treatment on Leaf Regeneration and Heat Tolerance of Tissue-cultured Rhododendron chrysanthum Pall. Seedlings

With tissue cultured-seedlings of Rhododendron chrysanthum Pall. in Changbai Mountain as test material, the effect of EMS treatment on the heat toler- ance of R. chrysanthum, as well as the possible heat tolerance mechanism, was in- vestigated in this study so as to lay a foundation for the popularization, application and germplasm resource innovation of R. chrysanthum. The results showed that when the leaves of the tissue cultured seedlings were treated with medium with 0.1% of EMS for 2 d, the survival rate of the leaves was 48.92%, thus the con- centration of EMS was close to the semi-lethal dose, and the EMS concentration and treatment time could be used as screening conditions for heat-tolerant mutants. The plantlets regenerated from EMS-treated leaves were treated with different tem- peratures, and related physiological indicators were determined. The results showed that the chlorophyll content, MDA content, Pro content, SOD activity, POD activity and soluble sugar content of regeneration plantlets in the treatment group were sig- nificantly different from those in the control group. At the same temperature, the chlorophyll content, soluble sugar content, Pro content, SOD activity and POD ac- tivity were significantly higher and the MDA content was significantly lower in the treatment group compared with the control. In conclusion, EMS treatment improved the heat tolerance of tissue-cultured R. chrysanthum seedlings.

Induction of pancreatic duct cells of neonatal rats into insulin-producing cells with fetal bovine serum: A natural protocol and its use for patch clamp experiments

AIM： To induce the pancreatic duct cells into endocrine cells with a new natural protocol for electrophysiological study. METHODS： The pancreatic duct cells of neonatal rats were isolated, cultured and induced into endocrine ceils with 15% fetal bovine serum for a period of 20 d. During this period, insulin secretion, MTT value, and morphological change of neonatal and adult pancreatic islet cells were comparatively investigated. Pancreatic β-cells were identified by morphological and electrophysiological characteristics, while ATP sensitive potassium channels （KATP）, voltage-dependent potassium channels （Kv）, and voltage-dependent calcium channels （KcA） in β-cells were identified by patch clamp technique. RESULTS： After incubation with fetal bovine serum, the neonatal duct cells budded out, changed from duct-like cells into islet clusters. In the first 4 d, MTT value and insulin secretion increased slowly （MTT value from 0.024 ±0.003 to 3.028±0.003, insulin secretion from 2.6±0.6 to 3.1±0.8 mIU/L）. Then MTT value and insulin secretion increased quickly from d 5 to d 10 （MTT value from 0.028 ±0.003 to 0.052±0.008, insulin secretion from 3.1±0.8 to 18.3±2.6 mIU/L）, then reached high plateau （MTT value 〉0.052±0.008, insulin secretion 〉18.3±2.6 mIU/L）. In contrast, for the isolated adult pancreatic islet cells, both insulin release and MTT value were stable in the first 4 d （MTT value from 0.029±0.01 to 0.031±0.011, insulin secretion from 13.9±3.1 to 14.3±3.3 mIU/L）, but afterwards they reduced gradually （MTT value 〈0.031 ±0.011, insulin secretion 〈8.2±1.5 mIU/L）, and the pancreatic islet cells became dispersed, broken or atrophied correspondingly. The differentiated neonatal cells were identified as pancreatic islet cells by dithizone staining method, and pancreatic β-cells were further identified by both morphological features and electrophysiological characteristics, i.e. the existence of recording currents from KATP, Kv, and KCA. CONCLUSION： Islet cells differentiated from neonatal pancreatic duct cells with the new natural protocol are more advantageous in performing patch clamp study over the isolated adult pancreatic islet cells.

Obtaining Cheese with Milk Mixture and Inca Peanut （Plukenetia Volubilis）

The Inca peanut, a plant native to the Peruvian Amazon, has an important nutritional contribution to 53% oil and 33% protein [ 1, 2], high content of Omega 3 and 6, Vitamin E. Recent research suggests the nutritional and therapeutic significance of consumption for the control of free radicals [3], being an alternative food to reduce nutritional deficiencies of macro and micronutrients in the diet. The results show that the cheese made from a mixture of milk and Inca peanut （70：20 v/v） 0.15 M of Ca sulphate is of firm consistency, with a clotting time of 9 min and yields 14.56% at 80 ℃, is similar to fresh milk cheese sensory characteristics determined by the test of acceptability. Respect to nutrition cheeses present values of protein and fat （16.3% and, 25.05%, respectively）. Sensory evaluation process cheese 70：30 v/v showed an acceptance of 67% relative to a commercial cheese. The texture profile of the finished product, applying a deformation of 30%, have hardness values for 1.88 N, elasticity 0.08, cohesiveness 0.86, adhesiveness 0.36, gumminess 1.62 and chewiness 0.13.