Assessing the Environmental Impact of Extensive Beef Production in Grazing Lands of Argentina

Because of environmental constraints,beef cattle was for more than a century the only viable farming option in the extensive semiarid and subhumid lands of Argentina and the main source of nutrients for humans as well.However,a growing concern and criticism have risen today about its possible negative impact on the climate and the environment.These worries tend to affect current public opinions,national policies,and international trade.Based on 40 beef cattle farms scattered across different semiarid and subhumid regions of Argentina,here we evaluated the impact of extensive cattle production on carbon,water,and nutrient pollution.Life-Cycle Assessment(LCA)and Land-Based Assessment(LBA)were the two approaches we used here to compare the environmental impact of beef production.While the environmental footprint(EF)resulting from LCA expresses the impact per unit of food,the environmental balance(EB),derived from LBA,aims at quantifying the impact per unit of land.As such,the EB considers both negative and positive impacts on the farm as an integrated system.Following standardized procedures,we evaluated EF and EB up to the farm gate,leaving aside delocalized post-farm impacts such as those of processing,packaging,and transportation that occur beyond the farm gate.In agreement with previous evidence,our results show that the EF tends to decrease as per-head production increases.Correlation coefficients and statistical significance were the following for carbon(R=−0.574;p<0.01),water(R=−0.561;p<0.01),and N(R=−0.704;p<0.01)and Phosphorus(P)pollution(R=−0.802;p<0.01)footprints.On the contrary,the EB seems to be highly sensitive,and as per-hectare beef production increases.Correlations were the following for carbon emissions(CE:R=0.955;p<0.01),water consumption(WC:R=0.822;p<0.01),nitrogen excretion(NE:R=0.948;p<0.01)and phosphorus excretion(PE:R=0.945;p<0.01).What our results suggest is that the notion of EF is useful to evaluate the environmental impact in intensive beef production systems,and the EB is suitable to assess the impact of the extensive ones.In practice,both approaches provide different perspectives on the environmental-impact problem and they should be complementary used.We concluded that the methodological rigidity of EF does not allow proper discrimination among farms in the extensive systems.On the contrary,the EB approach tended to be highly sensitive to detecting differences between individual farms and farmers,thus allowing the identification of successful options for extensive beef production in terms of public image,policy-making,and commercial opportunities.

Antimicrobial usage and resistance in beef production

Antimicrobials are critical to contemporary high-intensity beef production. Many different antimicrobials are approved for beef cattle, and are used judiciously for animal welfare, and controversially, to promote growth and feed efficiency. Antimicrobial administration provides a powerful selective pressure that acts on the microbial community, selecting for resistance gene determinants and antimicrobial-resistant bacteria resident in the bovine flora. The bovine microbiota includes many harmless bacteria, but also opportunistic pathogens that may acquire and propagate resistance genes within the microbial community via horizontal gene transfer. Antimicrobial-resistant bovine pathogens can also complicate the prevention and treatment of infectious diseases in beef feedlots,threatening the efficiency of the beef production system. Likewise, the transmission of antimicrobial resistance genes to bovine-associated human pathogens is a potential public health concern. This review outlines current antimicrobial use practices pertaining to beef production, and explores the frequency of antimicrobial resistance in major bovine pathogens. The effect of antimicrobials on the composition of the bovine microbiota is examined, as are the effects on the beef production resistome. Antimicrobial resistance is further explored within the context of the wider beef production continuum, with emphasis on antimicrobial resistance genes in the food chain, and risk to the human population.

Feed profile analysis of oil palm‐integrated beef cattle farming systems by metabolic energy budgeting and implications for beef production and pastoral system design

Background:Oil palm is a tropical crop with worldwide plantings approaching 20 million ha and large areas in Indonesia,Malaysia and Thailand.The plantations are readily managed as silvopastoral systems incorporating cattle grazing(Oil Palm Silvopastoral System for Cattle,OPSC)but there is a need for analytical tools and data to understand system herbage supply and feed conversion efficiency(FCE).Methods:Metabolic energy budgeting was used to estimate herbage harvested by cattle in three OPSC subsystems,9 and 12 years after oil palm establishment,and FCE of the subsystems was determined.Understorey herbage was also analysed for nutritive value,botanical composition and herbage accumulation within one grazing‐regrowth cycle.Results:The herbage‐harvested estimate was 2.0−2.4 t dry matter(DM)ha^(-1) year^(-1) for 9 year old subsystems and 1.4-1.7 tDMha^(-1) year^(-1) for a 12 year old subsystem.Herbage metabolisable energy(ME)was 8.3−8.5 MJ kg^(-1) DM and crude protein(CP)was 15%-16%DM.FCE values for subsystems ranged from 32 to 94 kg DM kg^(-1) liveweight‐gain.Conclusions:Herbage DM yield is declining,while herbage ME is marginal but CP is adequate.FCE is suboptimal but can be optimised by defining the trajectory of declining herbage production with canopy closure as plantations age and matching stocking rate to herbage supply using a comparativestocking‐rate‐type statistic.

Effects of Plant Oil Mixture on Production Performance,Carcass and Beef Quality in Beef Cattle

[Objective] To study the effects of plant oil mixture on production performance, carcass and beef quality in beef cattle. [Method] Single-factor randomized blocks design was used. Sixteen healthy Yanbian yellow bulls having close body weight were selected and randomly divided into four groups, four cattle per group. Been oil, safflower oil and sunflower oil were mixed respectively at a volume ratio of 11：5：4. The oil blend was added to the daily diets of beef cattle respectively at a proportion of 4%, 5% and 6%. The effects of the plant oil mixture on production performance, carcass and beef quality were investigated. [ Result.] Compared with the control cattle, the experimental cattle had significantly lower feed intake （P 〈 0.05）, non-significantly higher efficiency of feed utilization, and significantly lower digestibility of crude fiber and calcium （P 〈 0.05）. With the increasing level of plant oil, the digestibility of dry matter showed a decreasing trend. The digestibility of dry matter was significantly lower in the cattle fed on the plant oil mixture at a level of 6% than in the control （ P 〈 0.05）. The plant oil mixture had no effect on the digestibility of crude protein, ether extract, crude ash, nitrogen-free extract and phosphorus. With the increasing level of plant oil, the serum content of high-density lipoprotein showed an increasing trend. The serum content of high-density lipoprotein was significantly higher in the cattle fed on the plant oil mixture at a level of 6% than in the control （ P 〈 0.05）. With the increasing level of plant oil, the content of total cholesterol showed an increasing trend, whereas the content of low-density lipoprotein showed a decreasing trend. Moreover, other indicators did not change significantly. The experimental cattle had larger eye muscle area and better beef quality than the control group. The content of crude protein and ether extract in beef increased with the increasing level of plant oil. [ Conclusion] The plant oil mixture added to the daily feed decreases intake and digestibility of crude fiber and calcium but has no remarkable effect on production performance of beef cattle. The addition also increases eye muscle area and improves beef quality, thereby improving quality of carcass and beef. The proportion of the plant oil mixture should be added at a proportion lower than 5%.

Economics of early weaning in northern great plains beef cattle production system

Early removal of the calf from its dam reduces forage needs of the cow-calf enterprise and has been found to improve BW gain and pregnancy rates in the cow herd. However, early weaning may not always be economically viable for producers and the risk should be considered carefully. This study was conducted to evaluate the effect of early and normal weaning of steer and heifer calves on net income at weaning. Calves from Angus xHereforddams were randomly assigned to one of two weaning treatments. Calves were either early weaned (EW) at 80-d of age or remained with their dams until normal weaning (NW) at 213-d of age. Calves assigned to EW treatment received a 17.5% crude protein and 0.82 Mcal/kg net energy diet for approximately 130-d in a drylot. All economic analyses were conducted at normal weaning for both NW and EW calves. At normal weaning, price of steers ($US/kg) was lower (P = 0.003) and weaned steer value ($US/steer) was greater (P P = 0.18) was found in price of heifers ($US/kg) and weaned heifer value ($US/heifer) between NW and EW heifers. Feed cost was increased (P < 0.001) in EW steers and heifers compared to NW calves. Net revenue for both weaned steers and heifers was reduced (P < 0.001) in EW calves due to the feed cost of the growing diet. This study indicates that early weaning calves at 80-d of age decrease weaned calf value and net revenue for the cow-calf segment.

Effects of Different Compound Trace Element Premixed Materials on Beef Cattle Production Performance and Anti-oxidation Capacity

In this study,the effects of two types of premixed materials with different combinations of trace elements on the production performance and antioxidant capacity of simmental beef cattle were examined.Fifteen healthy simmental beef cattle of similar weight(approximately 330 kg),the same age(12 months),without castration,and a good physique were divided into three groups,with five beef cattle in each group.Food of Group Ⅰ beef cattle was supplemented with a commercially marketed 5% compound trace element premixture for fine beef cattle.Food of Group Ⅱ beef cattle was supplemented with a 5% compound microelement premixture for beef cattle that was designed to address local nutrient deficiencies and surpluses.In the blank control group,the beef cattle were not fed a premixture.The pretest period was 15 days,and the test period was divided into prefattening(45 days)and postfattening(45 days)stages.Body weight and body size indices were recorded at 1,2 and 3 months,and blood samples were collected regularly.In Group Ⅰ,the daily weight gain increased significantly by 15.7% compared with that of the control group.The largest daily weight gain was in Group Ⅱ,which increased by 31.6% compared with that in the control.During the test period of 90 days,the body size indices of the three different groups increased in different months,with significant increases in the indices for both test groups compared with those of the control.In Group Ⅰ,the activity of CP,the total activity of SOD and Cu-Zn-SOD increased significantly(p<0.05)compared with those in the control group,with a highly significant increase observed in GSH-PX activity(p<0.01).In Group Ⅱ,the increases in the activity of CP and the total activity of SOD and Cu-Zn-SOD were highly significant compared with those in the control group(p<0.01).In addition,a significant increase was observed in GSH-PX activity(p<0.05).Based on pretest results,the concentrations of Cu,Zn,Mo,Mn,Se and Co in the blood of experimental beef cattle were lower than those of the normal range.After feeding for 90 days,the concentrations of Cu,Zn,Mo,Mn,Se and Co in the blood of Groups Ⅰ and Ⅱ were significantly higher than those in the control group(p<0.05).The concentrations of elements in the blood of Group Ⅱ were close to the appropriate levels.Thus,the effects of the specifically designed compound microelement premixture on the prevention of nutrient imbalances and control of beef cattle nutrition metabolism and the production of fattened beef cattle were significant.

Implications of Land Use Land Cover Change and Climate Variability on Future Prospects of Beef Cattle Production in the Lake Victoria Basin

This paper presents the lessons learnt from a research project titled “Improving Beef Cattle Productivity for Enhanced Food Security and Efficient Utilization of Natural Resources in the Lake Victoria Basin” which includes Tanzania, Uganda and Rwanda. The key focus is on the implications of land use land cover change and climate variability on the future prospects of beef cattle production in this region. The study utilizes information and data from natural resources and climate components to deduce the impact of land use and land cover changes on climate variability. Additional analysis is conducted to summarize the land use and land cover data to carry out analysis on climate data using the Mann-Kendal test, linear regression and moving averages to reveal patterns of change and trends in annual and seasonal rainfall and temperature. The findings reveal that the study areas of Rwanda, Uganda and Tanzania in the Lake Victoria Basin (LVB) have changed over time following land cover manipulations and land use change, coupled with climate variability. The grazing land has been converted to agriculture and settlements, thereby reducing cattle grazing land which is the cheapest and major feed source for ruminant livestock production. Although the cattle population has been on the increase in the same period, it has been largely attributed to the fact that the carrying capacity of available grazing areas had not been attained. The current stocking rates in the LVB reveal that the rangelands are greatly overstocked and overgrazed with land degradation already evidenced in some areas. Climate variability coupled with a decrease in grazing resources is driving unprecedented forage scarcity which is now a major limiting factor to cattle production. Crop cultivation and settlement expansion are major land use types overtaking grazing lands;therefore the incorporation of crop residues into ruminant feeding systems could be a feasible way to curtail rangeland degradation and increase beef cattle production.

特色腊肉源细菌发酵剂对发酵牛肉品质的影响

目的:研究特色腊肉源细菌对发酵牛肉品质的影响。方法:将来自于湖南湘西腊肉的马葡萄球菌和来自信阳腊肉的肠膜明串珠菌作为发酵菌株,生产发酵牛肉,并将其与地方特色产品及空白组进行对比,分析产品的水分含量、水分活度、pH、蛋白质含量、色泽、质构及感官评价、N-亚硝胺类物质含量等品质指标的差异性。结果:两株菌株单菌株发酵产品亚硝胺含量,显著低于传统腊肉制品(P<0.05);弹性显著高于传统产品(P<0.05);肠膜明串珠菌发酵产品咀嚼性和四川腊肉没有显著性差异(P>0.05);马葡萄球菌发酵产品的硬度显著低于其他处理组(P<0.05),且马葡萄球菌发酵产品的整体接受性最高,但四川绵阳腊肉及湖南湘西腊肉的整体可接受性没有显著差异性(P>0.05)。结论:两种菌株对发酵产品品质影响不同,但都可以作为发酵剂应用于肉制品加工,未来可以考虑将两种菌株进行复配发酵,综合改善产品品质,提高产品安全性。

腊肉源酵母菌对发酵牛肉品质特性的影响

在发酵牛肉加工中,添加源于河南信阳腊肉的季巴蒙毕赤酵母以及四川绵阳腊肉的汉逊德巴利酵母作为发酵菌株,以研究特色腊肉源单菌株发酵对发酵牛肉品质的影响,选择地方特色产品和空白作为对照,进行产品水分含量、水分活度(aw)、pH值、蛋白质含量、亚硝胺含量、质构及感官评价等特性指标的测定与分析。结果表明,两株菌株单菌株发酵牛肉硬度适中,弹性和咀嚼性显著高于传统产品,其整体可接受性和传统腊肉未见显著差异,而且水分含量,pH值与亚硝胺含量显著低于传统腊肉制品。综合分析显示两种酵母菌均可作为发酵剂用于发酵肉制品生产,以提升产品品质和安全性。

全株玉米青贮饲料的制作及在肉牛养殖中的应用

全株玉米青贮饲料在养殖中的应用范围越来越广,但在实际操作中仍然存在不少问题。本文总结了全株玉米的制作方法及在肉牛养殖中的应用,旨为广大收贮企业规范制作全株玉米青贮饲料及肉牛养殖场户科学饲喂提供参考。

磁化水对6月龄肉牛生产性能及血清指标的影响

试验旨在研究磁化水对6月龄肉牛生产性能及血清指标的影响。将同一批6月龄左右、体重约300 kg的西门塔尔架子牛212头,随机分为2组。对照组(110头牛)饮用普通水,试验组(102头牛)饮用磁化水。试验期87 d。结果显示,与普通水相比,磁化水的pH值提高了7.91%,总硬度和耗氧量降低了0.36%和13.70%,磁化前后水的菌落总数和大肠杆菌数均为0。与对照组相比,试验组10 d的平均日采食量和平均日增重分别增加了4.41%和5.36%(P>0.05)。与对照组相比,试验组血清超氧化物歧化酶和过氧化氢酶活性分别提高了32.82%(P<0.05)和73.36%(P<0.01),丙二醛含量降低,免疫球蛋白A、免疫球蛋白G和免疫球蛋白M含量分别提高了13.85%、3.21%和5.99%,血清尿素氮含量增加了30%(P<0.05),总蛋白含量降低了34.53%(P<0.01),血清胰岛素、生长激素和促生长激素释放激素水平分别提高了10.73%、13.00%和5.04%。研究表明,水被磁化后水质有所改变,磁化水能够增加肉牛采食量和体重,增强血清抗氧化水平、免疫力和生长相关激素水平。

我国地方肉牛品种差异化高质量发展模式探究

近年来,肉牛产业比较效益较低,受猪牛肉市场价格非常态联动以及地方品种普遍的生产效益较低等因素影响,肉牛产业发展的支撑效应逐渐弱化。该文解析了新常态下我国肉牛产业的新特征,并对地方品种支撑肉牛产业差异化发展新模式进行了探究,提出了我国地方肉牛差异化高质量发展模式的关键举措。

日粮中添加不同益生菌水平对肉牛生产性能和肠道菌群的影响

该研究旨在评估在肉牛日粮中添加不同水平的益生菌对肉牛生产性能和肠道菌群的影响。本试验选择体重相近(320±20)kg、健康的西门塔尔杂交肉牛72头,随机分为4组。试验Ⅰ、Ⅱ、Ⅲ和Ⅳ组。结果表明,在试验期结束时,与试验Ⅰ组相比较,试验Ⅱ、Ⅲ和Ⅳ组的平均日增重和平均日采食量显著增加(P<0.05),而各组之间的料肉比没有显著差异(P>0.05);与试验Ⅰ组相比较,添加益生菌的试验Ⅱ、Ⅲ和Ⅳ组可显著提高肉牛中肠道乳酸杆菌的含量(P<0.05),同时显著降低肠道中大肠杆菌的含量(P<0.05),但添加益生菌对肠道中的双歧杆菌和总需氧菌含量无显著差异(P>0.05)。本研究结果表明,在肉牛日粮中添加2%的复合益生菌发酵培养物,能够显著改善肉牛的生产性能,包括增加日增重和改善饲料转化率,对肠道菌群结构具有正向调节作用。

玉米芯+芦苇草不同组合对西杂肉牛生产性能及血液生化指标的影响

为研究日粮中添加不同比例玉米芯、芦苇草对西门塔尔杂代肉牛生长性能、血清生化指标的影响,试验选择体重500 kg左右的健康西门塔尔杂交肉牛32头,随机分为4组,每组8头,每头为一个重复。对照组为添加4%玉米芯+4%芦苇草基础TMR日粮,试验1组、2组、3组基础TMR日粮中玉米芯和芦苇组合比例分别为8%玉米芯+4%芦苇草、6%玉米芯+6%芦苇草、4%玉米芯+8%芦苇草,预饲期15 d,正式期60 d。结果表明:试验1组、2组、3组平均日增重分别比对照组提高了27.03%、3.60%、22.52%(P> 0.05),平均料重比分别比对照组降低了16.67%、12.34%、22.05%(P> 0.05)。试验2组尿素氮含量分别比对照组、1组、3组降低了28.16%、27.67%、35.20%,差异显著(P <0.05);试验2组甘油三酯(TG)含量比3组降低了43.90%(P <0.05);结果提示,在肉牛育肥后期饲粮中添加适量玉米芯和芦苇草,可一定程度提高西门塔尔杂交肉牛平均日增重,降低料重比,促进机体对蛋白质的吸收代谢,可降低饲料成本,提高养殖效益,建议全混合日粮中添加4%~8%玉米芯+4%~6%芦苇草为宜。

去势对肉牛生产性能、肉品质及生理指标影响的研究进展

肉牛生产中,对公牛进行去势主要是为了降低公牛的好斗性或侵略性,避免胴体挫伤和肉色发暗,同时还可以防止对饲养人员和牛群中其他个体造成伤害。对去势公牛进行育肥可提高牛肉的嫩度、大理石花纹及口感,使售卖价格更高。文章分析了去势对肉牛生产性能、屠宰性能、生理生化指标及肉品质等的影响,并汇总了近年来有关去势对肉牛生产影响机制的研究,以期为肉牛育肥及牛肉品质提高提供参考。

基于体外产气法的不同种类菌糠肉牛日粮效果评价

试验旨在通过体外产气法对用不同食用菌菌糠设计的低成本肉牛日粮配方进行效果评定。试验采用单因素试验设计,以不同种类菌糠全混合日粮(TMR)为发酵底物,设计对照(CON)、香菇、木耳、平菇、元蘑、白玉菇、榆黄蘑、羊肚菌、杏鲍菇处理,通过体外产气法,根据产气量、产气参数、发酵参数和营养物质体外消化率等指标,结合隶属函数进行综合分析。结果表明:①在发酵4~10 h时,CON产气量显著高于其他处理(P<0.05);在发酵12~16 h时,木耳处理、白玉菇处理、榆黄蘑处理、羊肚菌处理产气量均显著低于CON(P<0.05);在发酵48 h时,木耳处理、元蘑处理、白玉菇处理、榆黄蘑处理、羊肚菌处理产气量均显著低于CON(P<0.05)。②除木耳处理和元蘑处理外,其他处理理论最大产气量均显著高于CON(P<0.05);除元蘑处理外,其他处理产气速率均显著低于CON(P<0.05)。③CON和杏鲍菇处理pH显著高于其他处理(P<0.05);各处理氨态氮(NH3-N)、挥发性脂肪酸(VFA)和甲烷产量均无显著差异(P>0.05)。④除香菇处理和平菇处理外,其他处理可消化有机物(DOM)、有机物降解率(OMD)、代谢能(ME)值均显著低于CON(P<0.05)。⑤在体外发酵24 h时,除香菇处理和平菇处理外,其他各处理营养物质体外消化率均显著低于CON(P<0.05);在体外发酵48 h时,除香菇处理、平菇处理和杏鲍菇处理外,其他各处理营养物质体外消化率均显著低于CON(P<0.05)。综合分析认为,不同种菌糠肉牛日粮的瘤胃发酵参数和降解特性存在一定差异,其中香菇和平菇菌糠具有作为肉牛日粮的潜力。

动物福利在肉牛生产中的应用现状与展望

规模化、集约化肉牛养殖方式在一定程度上可以降低生产成本,是提高生产效益的有效途径。然而,集中式、拴系式、高密度的生产方式下,常常导致肉牛的动物福利得不到有效保障,会对肉牛的生长和健康产生不利影响。改善肉牛动物福利可提高生产性能和养殖效益,实现绿色健康可持续发展。文章介绍了动物福利的概念、肉牛在饲养管理中的福利标准要求,以及在肉牛养殖过程中动物福利的重要意义,同时对我国肉牛生产福利的研究发展进行了展望,以期为生产实际提供指导和参考。

机会成本视角下新疆肉牛养殖的全要素生产率测度——基于DEA-Malmquist指数分析

在传统肉牛养殖全要素生产率的研究中,机会成本的考量往往被忽视。然而,不考虑机会成本会导致对养殖户在肉牛养殖中的隐性投入被忽略,从而无法真实地反映肉牛养殖的全要素生产率。为了准确测算新疆肉牛养殖的全要素生产率,在以2008—2022年新疆肉牛主产值为产出指标,以仔畜费、饲草料费、人工费为投入指标的基础上引入机会成本要素,采用DEA-Malmquist指数从静态和动态视角对新疆肉牛养殖的技术效率和技术进步的相关情况进行分析。结果表明:从静态角度来看,新疆肉牛养殖的水平并不高,收益较低,主要受到规模效率的影响,个别年份受到纯技术效率的影响,说明在目前的养殖规模和技术水平下,新疆肉牛养殖的效益尚未达到理想状态,仍有较大的提升空间;从动态角度来看,新疆肉牛养殖全要素生产率变动的主要原因是技术进步,说明随着新技术的不断应用和推广,新疆肉牛养殖的生产效率有望得到进一步提升。最后,从优化养殖规模和布局、加强技术创新与推广、加大对职业养殖户的培育等3个方面提出促进新疆肉牛产业高质量发展的的对策建议。

不同包装方式对牛排预制品的品质影响

为探究不同包装方式对牛排预制品的品质影响,通过分析牛排预制品中的pH、色差值、蒸煮损失率、剪切力、质构特性和感官评定指标综合分析真空包装、热收缩包装和贴体包装3种包装方式对牛排预制品的品质影响。结果表明:随着储存时间的延长,热收缩包装和贴体包装对牛排的蒸煮损失率均显著小于真空包装;真空包装的pH呈显著性下降趋势,热收缩包装的pH在第15 d后有轻微的起伏,贴体包装组的pH略有下降。此外,贴体包装剪切力明显大于其他两组,不适于牛排预制品的包装。综上所述,总体保鲜效果为真空包装>热收缩包装>贴体包装。

纳米孔测序技术在牛肉及其制品鉴定中的应用研究

目的:牛肉及其制品掺假掺杂情况时有发生,主要掺假方式为高价肉制品中掺入低价的肉类原料,使消费者的合法权益受到损害,因此本文探讨纳米孔测序技术在牛肉及其制品真伪鉴定上的应用。方法:利用纳米孔测序技术对市售的牛肉及其制品进行测序分析。结果:新鲜牦牛肉样品、新鲜黄牛肉样品及标注成分为黄牛肉的牛肉制品,测序分析结果均与样品标注成分相符,符合率为100%;标注成分为牦牛肉的牛肉制品仅3份测序分析结果与标注成分相符,符合率为50%。结论:纳米孔测序技术能够快速、准确地鉴定产品成分,为鉴定牛肉及其制品真伪提供技术研究。