晋南牛饲养管理配套技术推广

“晋南牛饲养管理配套技术推广”是山西省科委１９９９年度下达“山西省农村技术承包”项目，其目的是针对我区广大农户养牛饲养管理粗放、商品牛出栏率低、产肉率低、母牛繁殖成活率低、经济效益差等缺点，通过采用肉牛杂交改良，改良肉牛饲养管理、加强母牛饲养营养、犊牛培育、秸杆氨化、放牧牛冬春补饲等配套技术，达到提高养牛业科技含量，增加养牛业经济效益的目的。     

Relationship between nutrition and reproduction in beef cattle

The primary nutrient consideration for optimum reproductive performance in beef cattle is energy. Low energy intake delays the onset of puberty in heifers and bulls. Heifers should reach approximately 66 per cent of mature body weight by 14 to 15 months of age and be bred 30 days prior to breeding the main cow herd. Body conditioning scores (BCS) (1 = emaciated, 9 = obese) should be used to evaluate pregnant cows entering their third trimester. Cows should calve with body conditioning score 5 to 7. Forage quality and environmental factors influence maximum dry matter intake and nutrient requirements and must be considered in the clinical setting. Crude protein dietary content should be 11 to 12 per cent for lactating beef cattle. Mineral (calcium, phosphorus, magnesium, potassium, sulfur, sodium, chloride) nutrition is not a major cause of decreased reproductive performance in beef cattle. Trace mineral deficiencies (particularly selenium, copper, and zinc) can cause decreased reproductive performance. Diagnosis of these trace mineral deficiencies can be confirmed by elemental analysis of blood or tissues.     

Treatment of mineral disorders in cattle.

It is difficult to identify mineral deficiencies and even harder to predict their occurrence. The best indicators of a particular disorder are the characteristic clinical signs. In their absence, biochemical tests or well-designed and properly conducted dose-response field trials are the only sure ways of defining deficient states and assessing their functional and economic significance. This article identifies treatments of the main mineral disorders in cattle and preventive strategies to minimize their occurrence. Dietary manipulations or oral treatments are indicated for chronic primary deficiencies in which there is insufficient mineral in the diet to meet cattle requirements. In severe and acute deficiency, parenteral treatment restores normal concentrations rapidly to a functional level in the animal's tissues. Advocate parenteral treatments if alimentary absorption is impaired or at times of increased mineral demand, such as late pregnancy, but be wary of toxicity. Many innovative products and delivery systems are now available for relatively cheap, effective, long-term mineral supplementation with minimal handling of cattle.     

内蒙古肉牛运输的动物福利问题及对策分析

随着近年来规模化肉牛养殖的兴起,内蒙古作为我国和世界重要的高品质牛肉输出基地,其肉牛产量持续增加,但由于运输环节福利理念的欠缺以及操作不规范,肉牛在运输后出现了瘀伤、血斑、DFD肉、胴体重量减轻、运输应激等问题,导致部分牛肉色泽不佳、风味劣化、肉品等级降低,严重影响着牛肉的营养和安全性、肉牛产业以及农牧民的经济效益。因此,肉牛运输过程中的动物福利日益成为生产者和消费者关注的热点。综述了内蒙古肉牛运输中的动物福利问题及国内外研究现状,并提出了改善肉牛运输中动物福利的措施,以期为改善肉牛运输福利提高牛肉品质提供借鉴。     

Alpharma Beef Cattle Nutrition Symposium: implications of nutritional management for beef cow-calf systems

The beef cattle industry relies on the use of high-forage diets to develop replacement females, maintain the cow herd, and sustain stocker operations Forage quantity and quality fluctuate with season and environmental conditions Depending on class and physiological state of the animal, a forage diet may not always meet nutritional requirements, resulting in reduced ADG or BW loss if supplemental nutrients are not provided It is important to understand the consequences of such BW loss and the economics of providing supplementation to the beef production system Periods of limited or insufficient nutrient availability can be followed by periods of compensatory BW gain once dietary conditions improve This may have less impact on breeding animals, provided reproductive efficiency is not compromised, where actual BW is not as important as it is in animals destined for the feedlot A rapidly evolving body of literature is also demonstrating that nutritional status of cows during pregnancy can affect subsequent offspring development and production characteristics later in life The concept of fetal programming is that maternal stimuli during critical periods of fetal development have long-term implications for offspring Depending on timing, magnitude, and duration of nutrient limitation or supplementation, it is possible that early measures in life, such as calf birth BW, may be unaffected, whereas measures later in life, such as weaning BW, carcass characteristics, and reproductive traits, may be influenced This body of research provides compelling evidence of a fetal programming response to maternal nutrition in beef cattle Future competitiveness of the US beef industry will continue to be dependent on the use of high-forage diets to meet the majority of nutrient requirements Consequences of nutrient restriction or supplementation must be considered not only on individual animal performance but also the developing fetus and its subsequent performance throughout life.     

A nationwide survey on seroprevalence of Neospora caninum infection in beef cattle in Uruguay

Bovine abortions due to Neospora caninum infection have been reported worldwide and its economic impact on the beef industry has been acknowledged as a problem. Uruguay has the largest export value of beef per acre in South America. However, no data on the prevalence of N. caninum infection have been available in this country. The objective of this study was to estimate the prevalence and distribution of N. caninum infection in beef cattle in Uruguay through a nationwide survey. A two stage sampling design was used with farms being selected in stage one and animals being selected in stage two. A brief questionnaire was administered on each farm. Seroprevalence of N. caninum in 4444 beef cattle from 229 farms in all the counties, except Montevideo, of Uruguay was determined by an ELISA. The data were then analyzed to identify associations between infection and variables such as type of animal (cow or heifer), herd size, use of veterinary advice, productivity of the soil in relation to the national average, use of improved grass, use of mineral salts, use of supplemental feed, and presence of a dog(s) on the farm. The estimated proportion of positive farms for all the beef cattle operations was 69.2% (95% confidence interval [CI], 53.7-84.7). The overall cattle seroprevalence was estimated as 13.9% (95% CI, 11.6-16.3). The prevalence estimation by animal category was 14.3% (95% CI, 11.4-17.2) for beef cows and 12.9% (95% CI, 10.0-15.8) for beef heifers. There was no significant difference in the estimated prevalence between the two animal types. There was no significant difference in the animal level prevalence of N. caninum infection among different herd sizes. None of the herd demographic or management variables was significantly associated with the seropositivity to N. caninum infection. In conclusion, these results show that N. caninum infection is common among beef herds across Uruguay. Since the beef industry is one of the key industries in Uruguay, the economic effect and risk factors of N. caninum infection among beef cattle in this country should be further evaluated in the near future.     

Parenteral selenium and vitamin E supplementation of weaned beef calves

BACKGROUND: The weaning process in beef calves elicits physiological stress responses that can negatively affect performance and health. Supplementation of vitamins and minerals, particularly selenium (Se) and vitamin E, might be warranted. HYPOTHESIS: That parenteral administration of Se or vitamin E would correct or prevent deficiencies of these nutrients in postweaned beef calves during a backgrounding period (42 days after weaning). ANIMALS: One hundred and forty-four weaned steers (200-250 kg) in 3 trials. METHODS: One trial was conducted with cattle on a dry lot fed a total mixed ration and 2 trials were conducted on cattle on pasture. Selenium was administered at 0.05 mg/kg BW (SC) and vitamin E was administered at 1500 IU on days 0 and 28 (SC). RESULTS: A treatment effect attributable to Se or vitamin E supplementation on average daily gain was not detected in any trials. Parenteral supplementation with Se on days 0 and 28 resulted in higher serum Se concentrations as compared with controls on day 42. Parenteral supplementation with Se on days 0 and 28 improved Se status from marginal to adequate in 1 trial. Parenteral supplementation with vitamin E did not improve serum vitamin E concentrations in any experiment. CONCLUSIONS AND CLINICAL IMPORTANCE: Supplementation with vitamin E or Se or a combination of both did not have a significant effect on calf performance during the 42-day backgrounding period.     

Effects of previous grazing nutrition and management on feedlot performance of cattle

Management strategies designed to improve grazing animal performance can influence feedlot performance and carcass traits both positively and negatively. In spite of the economic relevance of potential interactions between grazing and finishing performance, controlled experiments evaluating integrated production systems are limited in number. Effects of grazing treatments can result from, or be overshadowed by, changes in gut fill, thus making it difficult to assign precise costs to different phases of production. Published reports have considered the effects of stocking rate, duration of grazing, forage characteristics, supplementation, and growth-promoting implants on subsequent finishing performance. Improvements in cattle performance attributed to changes in stocking rate generally have been neutral to positive with respect to effects on finishing performance. Comparisons among forages have led to the suggestion that forage species may contribute to differences in gastrointestinal fill of grazing cattle, thereby influencing gain and efficiency during the subsequent finishing phase. Creep-feeding suckling calves generally has increased preweaning performance but has had relatively little influence on performance during the subsequent finishing phase. Grain supplementation of stocker cattle during the grazing period has improved grazing performance, but effects on subsequent feedlot performance have been inconsistent. Potential carryover effects from protein and mineral supplementation also have been inconclusive. Lack of congruence among studies is puzzling but may be the consequence of highly varied production systems, differences in experimental procedures, and changes in gut fill or mass of internal organs. Based on the studies reviewed, the expression or absence of compensatory growth during the finishing phase appears to be related to the nutritional quality of forages utilized in the grazing period, with higher quality forages tending to yield greater compensatory effects. The bulk of evidence with suckling cattle and stocker implants suggests that effects on subsequent finishing performance are minimal. Attention is drawn to the noticeable lack of research pertaining to integrated production systems. A more thorough understanding of the interactions among grazing nutrition and management, finishing performance, and carcass traits is needed to facilitate greater economic exploitation of these relationships.     

Case life of seven retail products from beef cattle supplemented with alpha-tocopheryl acetate.

Packages (n = 660) of clod, strip loin, tenderloin, bottom round, eye-of-round, and top round steaks, as well as ground beef, from beef cattle fed diets supplemented with vitamin E (500 IU/d for 100 d preharvest) were compared with packages of products derived from carcasses of beef cattle fed control diets to determine the duration of acceptable muscle color during simulated retail display. In addition, the effect of storage before steak fabrication, simulating distribution time, on the acceptability of each treatment and each cut during retail display was investigated. Dietary supplementation of animals with vitamin E increased muscle alpha-tocopherol concentrations (P < .05) in all cuts. The acceptable retail display time of ground beef from vitamin E-supplemented cattle was longer (P < .05) compared to ground beef from unsupplemented cattle by 10.2, 15.6, and 17.6 h following 7, 14, and 21 d of storage in chub packages prior to final grinding and retail display, respectively. However, length of storage in a vacuum package before retail display did not have a consistent effect on retail case life of steaks. Product drip loss during retail display was not affected by storage time or vitamin E treatment. The trained panel color score during retail display of high vitamin E strip loin, bottom round, inside round, and eye-of-round steaks remained acceptable longer (P < .05) by 11.5, 25.2, 8.4, and 29.4 h, respectively, than that of control steaks. The results demonstrated that vitamin E supplementation of cattle feed can be used as a management tool to reduce the economic losses associated with beef muscle color deterioration during retail display of products.     

蒸汽压片玉米加工工艺及其在肉牛生产中应用的研究进展

玉米是肉牛生产中的主要能量饲料,蒸汽压片处理可以提高玉米的淀粉消化率,并对玉米的淀粉糊化度和能值等产生一定影响,对肉牛的瘤胃发酵模式、生产性能、牛肉品质及其经济效益有积极的影响。本文综述了蒸汽压片技术、经蒸汽压片处理后玉米营养价值的变化以及饲喂蒸汽压片玉米对肉牛生产性能及肉品质影响等方面的研究进展,以期为蒸汽压片玉米在肉牛生产中的进一步推广应用提供参考。     

Interaction of cattle health/immunity and nutrition.

The usual means of assessing the health of newly received beef cattle susceptible to bovine respiratory disease (BRD) are subjective, typically involving visual evaluation aided by minimal clinical measurements. Recent evidence based on the occurrence of pneumonic lung lesions at slaughter indicates a need for more accurate methods of diagnosing BRD. Inadequate passive immune transfer at birth may be an important risk factor in susceptibility to BRD, suggesting the need for management to improve passive transfer success rates. Preweaning management and vaccination practices offer opportunities for beef cattle producers to improve the immune status of newly weaned calves and decrease postweaning BRD. Feeding diets with higher levels of concentrate typically improves performance by newly weaned or received cattle, as does feeding diets supplemented with protein; however, limited data suggest that increasing concentrate and protein in receiving diets increases the rate and severity of subjectively determined BRD morbidity. Research with receiving diet concentrate/protein level relative to humoral and cell-mediated immune function coupled with indicators of health and performance is needed. Supplemental B vitamins are sometimes useful in receiving diets, but the effects have been variable, presumably reflecting differences in stress and associated feed intake responses. Vitamin E added to receiving diets to supply > or = 400 IU/animal daily seems beneficial for increasing gain and decreasing BRD morbidity; however, further dose titration experiments are needed. Supplemental Zn, Cu, Se, and Cr can alter immune function of newly received calves, and some field trials have shown decreases in BRD morbidity rate with supplementation; however, several experiments have shown no performance or health/immune benefits from supplementation of these trace minerals. Formulation of receiving diets should take into account decreased feed intake by highly stressed, newly received beef cattle and known nutrient deficiencies, but fortification of such diets with trace minerals beyond the levels needed to compensate for these effects is difficult to justify from present data.     

宁夏肉牛产业链现状、问题及建议

肉牛产业是我国农业的重要组成部分，也是宁夏回族自治区确定的“六特”产业之一。肉牛产业的发展对宁夏的经济发展起着至关重要的作用。本文从产业链角度出发，综合分析了遗传繁育、疾病防控、饲料营养、养殖育肥、生产加工、销售等肉牛产业发展相关现状和问题，并提出了产业发展建议，为宁夏肉牛产业高质量协调发展提供参考。     

新疆伊犁州肉牛产业发展对策思考

肉牛产业是新疆建设优质畜产品产业集群、全面推进乡村振兴的重要产业之一,伊犁州是新疆重要的肉牛繁育生产基地,也是肉牛存栏最多、牛肉产量最高的地区。本文从肉牛产业链延炼、补链、拓链出发,从新疆伊犁州当前肉牛产业发展情况、短板等方面,全面剖析伊犁周肉牛产业高质量发展之路,为新疆伊犁州肉牛产业发展提供对策参考。     

Effect of long- or short-term feeding of alpha-tocopheryl acetate to Holstein and crossbred beef steers on performance, carcass characteristics, and beef color stability.

Three experiments were conducted to examine the effects of vitamin E supplementation on feedlot cattle. Vitamin E supplementation did not affect feedlot performance or carcass characteristics of cattle fed a high-concentrate diet (P greater than .1). The major finding was the effectiveness of vitamin E in extending the color stability of displayed beef (P less than .01). Color stability during display of longissimus lumborum steaks from cattle supplemented with 300 IU/d for 266 d, 1,140 IU/d for 67 d, or 1,200 IU/d for 38 d was extended by 2.5 to 4.8 d. Gluteus medius steaks had an extended color display life of 1.6 to 3.8 d. The accumulation of lipid oxidation products, but not aerobic microbes, associated with displayed longissimus lumborum was suppressed for muscle from vitamin E-supplemented steers. Taste panelists detected no difference among longissimus lumborum steaks from control and vitamin E-supplemented steers but found (P less than .01) steaks aged for 21 d to be more tender than steaks aged for 7 d. Supplementing cattle with vitamin E should reduce economic losses associated with discolored beef during retail display.     

不同营养水平对肉牛肥育效果的研究

为了探索酒泉地区舍饲肉牛的肥育模式,用3个不同营养水平的精料对62头小公牛进行了肥育试验,并从日增重、耗料量和经济效益3方面进行了分析.结果表明:3个营养水平对肉牛日增重差异不显著,中营养组日增重略高于其它两组;从耗料情况来看,高营养组耗料最多,中、低营养组耗料基本相同;从经济效益看,中营养组最好,高营养组最差.综合分析表明在酒泉地区肥育肉牛应以中等营养水平为宜.     

草原放牧肉牛发生跛行病因分析与防治试验

赤峰市巴林右旗索博日嘎镇草原放牧的肉牛大面积发生异嗜和跛行症状,经流行情况调查、牧草钙磷营养分析、血清钙磷含量测定、防治试验和大群防治结果表明,是由于严重干旱导致草场上牧草中磷含量降低,钙、磷比例严重失调,造成放牧肉牛矿物质营养缺乏性代谢病.放牧肉牛异嗜发病率平均为33.70％,其中哺乳母牛出现跛行症状的占群体的11.31％.采取以增磷为主的增磷补钙措施进行防治,迅速控制了病情的发展,群体防治总有效率达98.50％.     

2013年国外肉牛营养价值评定的研究进展

文章从精饲料营养和粗饲料营养两个方面综述了2013年国外肉牛营养价值评定的研究进展.精饲料营养主要包括蛋白质原料（亚麻籽、葵花籽、棉籽和油菜籽）、蛋白质水平、能量饲料以及精饲料对肉牛和犊牛的综合评价四个方面;粗饲料营养主要包括粗饲料品种和青贮饲料两个方面的研究.文章对上述研究成果进行了总结分析,以期为我国内年产业的快速发展提供一些借鉴.     

添加肉牛补充料和蛋白质饲料对后期育肥肉牛生理效应的研究

选择２岁以上的肉牛３０头在云南会泽县新街乡王家村进行补饲试验，根据品种、年龄、性别随机分为３组，每组１０头，试验Ａ组每头每天补饲５００ｇ肉牛补充料，试验Ｂ组每头牛在每天补饲５００ｇ肉牛补充料的基础上再补加５００ｇ菜籽饼和１００ｇ豆饼，试验结果表明：（１）添加肉牛补充料和蛋白质饲料，肉牛日增重、采食量、饲料转化效率显著提高（ｐ〈０．０５）；（２）该地区微量元素铜处于临界缺乏状态，碘处于缺乏状态；（３     

Mineral status of beef cattle in Papua New Guinea

Groups of 22 steers grazed eight diverse environments in Papua New Guinea for one year. Haemoglobin, packed cell volume, MCHC, plasma albumen, calcium, magnesium, phosphorus, zinc, copper and saliva sodium and potassium were measured; half of each group received cobalt supplements. Growth rate was measured. Cobalt deficiency was tentatively diagnosed at two sites, sodium deficiency at five sites and phosphorus at three with two other sites marginal. Sodium supplementation at the three most affected sites corrected sodium status and increased growth rate. Additionally, at two of these sites plasma phosphorus concentration increased to more normal levels presumably due to increased appetite. Statistically significant differences between sites occurred in the concentrations of other minerals but were not related to growth rates. The significance of these results is discussed in relation to assessment of mineral status in beef cattle.     

Neospora caninum causes severe economic losses in cattle in the humid pampa region of Argentina

This work estimates the economic losses due to Neospora abortions in the humid pampa region of Argentina. The total dairy and beef cattle population at risk of abortion is 1,771,326 and 9,726,684 head, respectively. In dairy cattle, there was an 8 % risk of experiencing abortion due to a variety of causes, but 16.5 % of them were due to Neospora caninum. The economic losses were estimated at US$1,865 (range, 1,400–2,331) per abortion, which equates to a total loss of US$43,607,430 (range, 15,622,600–194,412,390) for the dairy industry at the humid pampa region of Argentina. In beef cattle, the overall risk of abortion was estimated to be 4.5 % for all pregnancies, whereas 6.7 % are specifically due to N. caninum, with an economic loss of US$440 (range, 150–730) per abortion. This amounts to an annual loss to the beef industry of US$12,903,440 (range, 1,130,700–42,070,630) in the same area. The results of this study show that Neospora infections and thus abortions cause severe economic impacts in the dairy and beef industries in the humid pampa region of Argentina, which is one the most important areas of cattle production in the world.