塔额垦区放牧饲养夏洛莱牛肉质营养成分分析

试验旨在分析塔额垦区放牧饲养夏洛莱牛肉氨基酸组成含量及营养成分,为夏洛莱牛肉品质分析及改良当地土牛提供科学依据。试验选取体重500±45 kg的夏洛莱肉牛(公母各半),采集里脊、眼肌、肩肉、上脑、胸肉5个部位,分别测定其营养物质及氨基酸组成含量,并参照FAO/WHO模式进行氨基酸评分。结果显示,样品中水分含量公牛和母牛分别为73.10%和64.14%,符合国家标准,粗脂肪含量公牛最低为0.14%。检测出17种氨基酸,非必须氨基酸中天冬氨酸含量最高,公牛和母牛分别为30.74%和29.02%,其次为谷氨酸,分别为11.38%和10.73%,提示夏洛莱牛肉鲜味有降低的趋势。必须氨基酸中赖氨酸含量最高,公牛和母牛分别为9.23%和8.71%。母牛里脊中总氨基酸含量最低(P<0.05),为89.10%。氨基酸评分显示公牛EAA/TAA及EAA/NEAA分别为33.32%和50.00%,母牛EAA/TAA及EAA/NEAA分别为33.60%和50.62%,与FAO/WHO模式推荐量(EAA/TAA 40%,EAA/NEAA 60%)有一定差距,但可满足成人每日氨基酸需求量(EAA/TAA 27.3%,EAA/NEAA 37.5%)。综上,夏洛莱牛肉营养较好,品质中上,考虑其出肉量多的特点可以针对性的育肥或杂交改良。     

An anaphylactic reaction to highly purified pork insulin. Confirmation by RAST and RAST inhibition

Summary We describe a patient who had an anaphylactic reaction to highly purified pork insulin; he was not allergic however to beef insulin. The sensitivity to pork but not to beef insulin was confirmed by skin testing, radioallergosorbent test (RAST) and RAST inhibition. A scheme is suggested for the investigation of such patients.     

Detailed evaluation of a newly attained fungal pigment from Monascus purpureus in meat burgers

Beef burgers with red pigment extracted from Monascus purpureus, used as a natural colouring agent, were examined for chemical compositions, physical properties, microbiological aspects and organoleptic evaluation. Beef burgers with Monascus pigment showed higher nutritional values compared with control samples. Nutritional values were proportionally enhanced by increasing pigment concentration. Synthetic dye samples had the lowest values of nutrients. Cooking loss percentage and water holding capacity were lower in all treatments compared with control samples, and vice versa for plasticity. The initial total bacterial count, Staphylococcus aureus count and coliform count were determined. Extending storage period up to 90 days severely reduced all tested microorganisms. By increasing the M. pigment concentration, the colour was significantly increased. Insignificant differences in colours were noticed among various treatments. Flavour and body and texture scores were insignificantly different. Microbial inhibition percentage of beef burger samples was increased by increasing the Monascus pigment concentration up to 0.8 g/kg.     

从我国肉牛发展现状看新疆肉牛产业的发展

肉牛产业是盲牧业中一个不年轻的产业，但由于在我国的特殊性，决定了它要度过一个不平常的发展阶段。从“逐水草而居”到肉牛的产业化发展：良繁、改良、饲养管理、结构调整、产品加工、市场开发……，都在培育和发展之中，所以因地制宜和科学发展观才是肉牛产业兴旺发达的基础。     

Beef allergy: a review of 12 cases

BACKGROUND: Although beef allergy has long been considered a rare condition, the number of studies regarding the nature, epidemiology, and symptoms of beef allergy has been increasing. We aimed to describe the results of allergy work-up of 12 patients who have a convincing history of acute allergic symptoms following beef ingestion. METHODS: Detailed histories of 10 children and two adult relatives were obtained and patients underwent skin prick tests with commercial beef extract, raw beef and cooked beef. Serum total and beef-specific IgE were measured. Labial, and in selected cases, open food challenges were undertaken. RESULTS: Interestingly, the rate of family history of beef allergy was 67% (8/12). Three patients (two with commercial extract, and one with cooked beef) had positive skin test responses to beef. Ten (83%) patients had elevated serum IgE concentrations (median 316.5 kU/l, range 9-1321 kU/l) and the beef-specific IgE was positive in all patients (median 6.23 kUA/l, range 0.83-36.6 kUA/l). Labial food challenge was positive in four (30%) patients. Of the five patients who underwent open food challenges, three were positive and two tolerated the beef administered. CONCLUSIONS: We conclude that skin prick tests do not accurately diagnose IgE-mediated sensitization to beef. Thus, patients with suspected beef allergy should be screened additionally for beef-specific IgE antibodies, and in selected cases oral food challenge should be carried out to verify the diagnosis.     

Identification of bovine IgG as a major cross-reactive vertebrate meat allergen

BACKGROUND: Although beef is a main source of protein in Western diets, very little has been published on allergic reactions to beef or the main allergens implicated in these reactions. The aim was to evaluate the IgE antibody response to beef in suspected meat-allergic subjects and assess cross-reactivity of beef with other vertebrate meats. METHODS: Fifty-seven sera from suspected meat-allergic subjects were tested by grid blot for specific IgE antibodies to vertebrate meats (beef, lamb, pork, venison, and chicken), and the patterns of recognition of meat proteins were assessed by immunoblot studies. RESULTS: A 160-kDa band, identified as bovine IgG, was detected in raw beef in 83% (10/12) of beef-allergic subjects but in only 24% of the beef-tolerant subjects. IgE reactivity to a band of similar mol. mass was detected also in lamb and venison, but rarely in pork or chicken. Complete inhibition of the IgE reactivity to the bovine IgG was obtained with lamb, venison, and milk. IgE reactivity to this band also completely disappeared when beef or lamb extracts were separated under reducing conditions, indicating conformational epitopes. CONCLUSIONS: Bovine IgG appears to be a major cross-reacting meat allergen that could predict beef allergy. Further studies with oral IgG challenges should be performed to document the conclusion that in vitro reactivity correlates with clinical hypersensitivity. The role of bovine IgG in other bovine products such as milk, dander, or hair must also be studied, and the hypothesis that it is a cross-reacting allergen with other mammalian products validated.     

Characterization of bovine serum albumin epitopes and their role in allergic reactions

Objective:  This review provides updated information on conformational and sequential epitopes identified in bovine serum albumin (BSA) and summarizes available data about the role of structural modifications on BSA antigenicity/allergenicity.
Data sources:  Data on beef allergy and BSA antigenicity are reported, with reference both to the basic literature and to clinical results obtained by our group.
Results and discussion:  BSA is an important allergen involved in milk and beef allergy. The presence of conformational epitopes has been suggested by indirect evidence, while at least one sequential epitope has been experimentally identified. The role of structural modifications on BSA antigenicity is discussed as well as the increased tolerance observed in allergic subjects consuming beef as strained (homogenized) and freeze-dried derivatives.
Conclusion:  Study of the molecular characteristics of a known major allergen allows the identification of technological processes that may be capable of improving the tolerance of allergic subjects to a specific food. Even though any hoped for reduced allergenicity must be verified under medical supervision, the use of new products could obviate the need to avoid important foods such as meat in childhood.     

Semen quality of fertile US males in relation to their mothers' beef consumption during pregnancy

BACKGROUND To look at possible long-term risks from anabolic steroids and other xenobiotics in beef, we examined men's semen quality in relation to their mother's self-reported beef consumption during pregnancy. METHODS: The study was carried out in five US cities between 1999 and 2005. We used regression analyses to examine semen parameters in 387 partners of pregnant women in relation to the amount of beef their mothers reported eating while pregnant. Mothers' beef consumption was also analysed in relation to the son's history of previous subfertility. RESULTS Sperm concentration was inversely related to mothers' beef meals per week (P = 0.041). In sons of "high beef consumers" (>7 beef meals/week), sperm concentration was 24.3% lower (P = 0.014) and the proportion of men with sperm concentration below 20 x 10(6)/ml was three times higher (17.7 versus 5.7%, P = 0.002) than in men whose mothers ate less beef. A history of previous subfertility was also more frequent among sons of "high beef consumers" (P = 0.015). Sperm concentration was not significantly related to mother's consumption of other meat or to the man's consumption of any meat. CONCLUSIONS These data suggest that maternal beef consumption, and possibly xenobiotics in beef, may alter a man's testicular development in utero and adversely affect his reproductive capacity.     

Western Canada Study of Animal Health Effects Associated With Exposure to Emissions From Oil and Natural Gas Field Facilities. Study Design and Data Collection I. Herd Performance Records and Management

Beef cow-calf herds are the most common livestock operation in Western Canada. Beef cows also have the greatest opportunity for direct contact with their environment through continuous sampling of the air, water, vegetation, and soil. These factors combine to make cow-calf herds a potentially useful sentinel of environmental change. Researchers individually tracked more than 33,000 cows in 205 beef cow-calf herds from spring 2001 to the end of the calving season in 2002 to examine the potential effects of emissions from the oil and gas industry on productivity. This article describes the study design and methodology of the Western Canada Study, with emphasis on herd-selection criteria and study implementation, the collection of herd-production data, and the challenges of tracking individual animals in a large prospective observational study—as the Western Canada Study is the largest on-farm study of its kind in North American cow-calf herds to date. The primary objective of this project was to examine the potential association between reproductive success and cumulative chronic exposure to sulfur dioxide, hydrogen sulfide, and volatile organic compounds in beef herds. Herd-selection criteria included potential exposure to oil and gas facilities, herd size, quality of available records, an established relationship with a local veterinary clinic, and participant interest. With the cooperation of local herd owners and veterinarians, on-farm collection of detailed individual animal data was successful in this group of cow-calf operations. Of the 212 herds initially selected to participate, complete calving season data for 2002 were available for 203 herds (96%). Individual animal records were available for more than 98% of eligible cows for each measurement period throughout the study. Herd-production records were rated as satisfactory or better in 94% of the herds. These process outcomes confirm the practicality of using cow-calf herds as sentinel populations for environmental exposures and support the validity of subsequent research on these animal populations.