Energy minimised v. cost minimised alternatives for the US beef production system

A model of the US beef production system has been utilised to project tradeoffs between minimised cost of feeding and minimised fossil energy use to produce amounts of beef similar to 1976 consumption. Cost minimisation approaches the present actual beef production system, but suggests increases in bull feeding and the use of silage and grass finishing of cattle. Energy minimisation indicated energy savings could exceed the equivalent of 240 million barrels of crude oil/year. If energy costs increased three times the 1979 levels, energy and cost minimised solutions appear equivalent.USDA ‘Choice’ grade has been a cost effective strategy, even without consideration of price differentials for the higher quality beef. However, maintenance of current levels of ‘Choice’ beef production does not appear optimal from an energy efficiency standpoint. The model results for energy minimisation suggest an increase in grass finishing and feeding of large bulls, rather than steers, practices which could further reduce fossil fuel inputs, but would result in less ‘Choice’ quality meat. Each increase in energy efficiency in the beef system (other than simple elimination of waste) may be anticipated to have a cost penalty over current practice, given constant or moderately increasing energy costs.However, if energy prices were to reach three times their present level, the model suggests that national cost minimisation would require more energy efficient production systems, and the production of the higher quality beef grades would increase in relative expense. The beef industry does not, at present, minimise energy input because energy's apparent real cost has been low compared with other inputs.     

A predictive model for beef cattle growth and carcass composition

Due to public concerns over food quality and animal welfare, beef producers are under increasing pressure to produce a high-quality product while still maintaining economic efficiency. Hence the need for a model for the accurate prediction of growth and carcass composition of beef cattle that is flexible enough to deal with the wide range of breeds of cattle and feeding regimes, either silage only or supplemented with concentrates, encountered on UK farms. This paper describes a model that has been developed based on a substantial database of experimental observations from a series of trials carried out by the Department of Agriculture for Northern Ireland. If animal and feed costs are provided, the model can provide information on the most economic level of concentrate feeding to achieve the animal growth and quality of carcass composition required.     

农用柴油机在肉牛养殖中的应用

柴油机是我国农业生产中不可或缺的动力源,农用柴油机种类繁多、经济性好、适应性强。近年来,伴随我国饮食结构调整实施“粮改饲”、“粮改畜”,以肉牛养殖等为主的畜牧养殖业得到大力发展,机械化养殖是现代化肉牛养殖的重要支撑,养殖各环节以柴油机为动力的农业机械得到了大量应用。本文以肉牛养殖为例,阐述农用柴油机在牧草生产、收获、加工、饲喂、废弃物处理环节的配套应用,分析农用柴油机发展中存在的工作稳定性较差、噪声和排放较大问题,进一步提出应用电控高压喷射等先进技术提升农用柴油机性能、做好农用柴油机与专业机具的配套适应性以及加强农用柴油机制造工艺和强化生产过程管理的发展策略。     

A general cattle production systems model. I: Structure of the model

A deterministic model for simulating beef cattle production under a wide range of management schemes and environments with cattle differing widely in genotypes for size, growth and milk production is described. In the model, genotypes are specified as production potentials, which are reached only if past and present planes of nutrition are adequate. Intake of forage and/or other feed is simulated as a function of the size and physiological status of the animals and the availability, digestibility and crude protein content of the feed. Animal performance is calculated from the nutrient intake and the animals' condition (fatness), degree of maturity and genetic potential. The model has been used for simulating beef cattle production under several widely differing sets of environmental and management conditions in Guyana, Colombia, Venezuela, Botswana, Texas and Mid-western United States and for simulating dairy-beef production systems in Colombia, Tanzania and Botswana. Results of simulations of existing conditions have coincided rather closely with actual production levels.     

瓦努阿图肉牛养殖饲草加工设备选型及应用

结合国内饲草加工设备和瓦努阿图肉牛养殖现状,完成瓦努阿图饲草加工设备选型和适应性改进研究,调整揉草机锤片和动力配置,使其能够加工瓦努阿图当地的椰蓉、椰壳、棕榈叶和皇竹草等来饲喂肉牛,提高了瓦努阿图肉牛饲养的产能和养殖技能.     

A dynamic bio-economic model to simulate optimal adjustments of suckler cow farm management to production and market shocks in France

Tactical adjustments to seasonal weather conditions and beef price may generate additional income or avoid losses in French beef cattle farms. Due to the length of the suckler cow production cycle, adjustment decisions may impact not only on current production and profit but also on future farm outcomes. To better understand the consequences of shocks and subsequent production adjustments on the evolution of farm earnings and production over time, we built a dynamic recursive bio-economic farm model. Our model introduced simultaneously the possibility of adjusting herd size and herd composition, diet composition and diet energy content, as well as crop rotation, haymaking and feed stocks, taking into account both their short- and long-term consequences. An application is provided to test impacts of crop yield and beef price shocks of different intensities. Main simulated adjustments to face unfavourable weather shocks are (1) purchased feed in order to maintain animal production objectives, and (2) area of pasture harvested for haymaking. Very severe beef price shocks induce forced sales. Weather shocks affect farm net profit not only of the current year but also of the following years. Profit losses caused by unfavourable weather conditions are not compensated by gains in favourable ones and this differential is amplified when intensity of shocks rises.     

A risk efficiency analysis of backgrounding and finishing steers on pasture in Saskatchewan, Canada

This paper combines an agricultural production decision support tool, GrassGro, with economic risk efficiency theory to examine several cattle feeding options that include various grazing systems for three climatic environments in Saskatchewan, Canada. Historical weather data were used to simulate a distribution of forage and cattle production data for each of several grazing systems during a 21-year period, 1978–1998. Price variability was included by varying year 2000 prices using historical price margin changes between the buying and selling weights of cattle. The risk efficiency analysis was completed using the Mean Standard Deviation (MSD) framework, and stochastic dominance principles.

Results of the study suggested that feeding systems, which included grazing, were economically competitive with traditional feedlot feeding systems and grain farming. Finishing cattle on pasture with the addition of a barley supplement was an attractive option, especially when high pasture productivity can be achieved. In all locations, more intense systems that included pasture fertilization and provision of an energy supplement, improved production and risk efficiency. Although the average net returns of all these feeding simulations were negative, the returns of traditional grain crops were even more negative. It is these negative returns in grain operations that lead to the incentive for producers to diversify into cattle production. Despite the negative net returns, the cash flow (range −$15.59 to $407.54 ha⁻¹) was mostly positive in all three locations.     

Development of an in-field cattle finishing system for the tropics

An in-field cattle finishing system that takes advantage of the year long growing season in the tropics is described. This system exploits the interrelationships of the feed production and cattle feeding components to increase the cost and energy efficiency of the system in tropical environments. The system is based on regulated feeding of mature zones of standing corn crop to cattle. The corn crop is planted at weekly intervals year round in continual rotation. When the first planting gets to the dough-dent stage of maturity, cattle are put in the cornfield within a movable cattle pen. The feeding is regulated by moving the pen a fixed distance twice a day. This system may reduce the cost of fattening an animal from 250 to 475 kg by about 26%. To test the practicality and engineering feasibility of this program, an exploratory experiment was conducted using three steers, a 6 m × 6 m movable cattle pen and 0·23 ha land area.

It was observed that the trampling loss of corn ears by the cattle was minimal after the initial learning period of 2 to 3 weeks. The cattle also utilized about 50% to 80% of the leaves and 20% to 65% of the cornstalks. The uneaten stalks provided an excellent bedding material during wet periods. The animal weight gain performance was similar to that of feedlot cattle of the same age, weight and breed. No major health or disease problem was observed. The performance of the movable cattle pen was satisfactory during normal weather periods, but a more positive locomotion system is needed for wet conditions.     

A timothy-beef production model for Atlantic Canada

A five-part timothy-beef deterministic simulation model was prepared to integrate information on various production processes and hence to improve the basis for management advice given by extension workers.The five parts or sub-models are: the growth of the timothy, harvesting the crop, storing it, converting the timothy and other feeds to beef and, lastly, the feeding of cattle and the disposal of manure. Costs and returns are estimated.The model structure and principal biological relationships are described in some detail. Sample outputs for three different cow-calf-feeder regimes are shown and compared.The uses, limitations and potential of the model are discussed.     

Comparative economics of Holstein/Gir F1 dairy female production and conventional beef cattle suckler herds – A simulation study

Three cow–calf production systems were compared using simulation: N (straightbred Nelore), AN (Nelore cows producing Angus by Nelore calves) and HG (Gir cows producing Holstein by Gir calves). All three systems produced their own straightbred replacement females. Male calves were sold at weaning and female calves in excess of those required to keep the herd size constant were sold at one year of age. In the base situation, F₁ HG females were priced at twice as much as the price per kg of the beef male calves, according to present market values. Typical 1000 ha beef cattle farms were simulated for each system, based on Brachiaria brizantha pastures managed according to recommended practices. Herd dynamics were controlled by reproduction and survival. Literature figures on monthly pasture nutrient production, live weights and milk yield were used to estimate nutrient requirements to match stocking rate to nutrient availability in each system. For calving rate set to 0.8 in all three systems, the total numbers of cows for the N, AN and HG systems were, respectively, 803, 795 and 885 and the total live weight sold annually was 129,070, 133,120 and 127,680 kg. The annual economic return on investment was 5.21%, 5.81% and 10.84%, respectively, for the N, AN and HG systems. Reducing the relative price of the HG heifers diminished the economic superiority of this system over N and AN. The difference was zero when the price of HG heifers was reduced to approximately 1.2 times the beef calf price. This also happened when the calving rate of the Gir cows was set to 0.6 keeping N cows at 0.8 or higher.     

全国种粮养牛发展分析

1951—2010年全国的粮食总产量是波动性增长。波动原因是粮食种植面积的波动,增长原因是粮食种植技术的进步。2010年全国粮食供给已是“北粮南运”。东北地区是全国的“粮仓”,黄淮海地区次之,长江中下游地区人均粮食产量只略高于全国平均水平。全国秸秆养牛已由畜力生产转为肉、奶生产,但人均水平较低。全国种粮养牛今后发展的目标应是人均粮食产量适度、粮食产量结构合理和秸秆养牛规模适量,其实现途径是科学化种粮养牛、综合开发种粮养牛乡村以及保证开发方针政策的正确。      

商业化肉牛繁育大数据平台设计与关键技术

针对当前中国肉牛繁育管理水平和信息化智能化水平不高等问题,本研究借鉴国际先进肉牛养殖国家的经验,建立了适合中国的商业化肉牛繁育大数据平台。该平台主要完成肉牛种质信息资源的整合,在线自动测定肉牛关键繁育性状,全程服务支撑肉牛繁育过程,形成肉牛种质资源大数据分析决策,并实现肉牛联合育种创新模式。本文详细介绍了商业化肉牛繁育大数据软件平台开发思路,包括数据中心的实现、软件平台前端开发技术和后端开发技术等,并总结了该平台的关键技术创新和模式创新内容,包括肉牛种质资源与良种管理系谱深度挖掘技术,非接触式繁育性状自动获取评价技术,以及多源异构信息融合提供智能决策支持等,为中国肉牛种业发展提供可持续发展的信息化解决方案,以促进肉牛育种整体水平的提高。     

Greenhouse gas emissions from the Canadian beef industry

Commodity-specific estimates of the greenhouse gas (GHG) emissions from Canadian agriculture are required in order to identify the most efficient GHG mitigation measures. In this paper, the methodology from the Intergovernmental Panel on Climate Change (IPCC) for estimating bovine GHG emissions, for census years from 1981 to 2001, was applied to the Canadian beef industry. This analysis, which is based on several adaptations of IPCC methodology already done for the Canadian dairy industry, includes the concept of a beef crop complex, the land base that feeds the beef population, and the use of recommendations for livestock feed rations and fertilizer application rates to down-scale the national area totals of each crop, regardless of the use of that crop, to the feed requirements of the Canada’s beef population. It shows how high energy feeds are reducing enteric methane emissions by displacing high roughage diets. It also calculates an emissions intensity indicator based on the total weight of live beef cattle destined for market. While total GHG from Canadian beef production have increased from 25 to 32 Tg of CO₂ equiv. between 1981 and 2001, this increase was mainly driven by expansion of the Canadian cattle industry. The emission intensity indicator showed that between 1981 and 2001, the Canadian beef industry GHG emissions per kg of live animal weight produced for market decreased from 16.4 to 10.4 kg of CO₂ equiv.     

A model to evaluate the economic merits of dry season feeding of growing/fattening cattle in the sub-humid tropics

The economic effect of increased stocking rate permitted by the introduction of dry season feedin is evaluated with reference to the growing/fatening system of beef production in the sub-humid tropics. A widely applicable model is derived which requires few input variables, all of which will be easily obtainable in a specific location. The economic break-even point in terms of feeding cost and dry season length can be determined in order to assess the value of local diets or attempt the formulation of new ones. Increae in profitability due to dry season feeding is assessed taking into account increase in stocking rate, seasonal de-stocking practices, length of dry season, growth rates, feed costs and beef price. The model is appropriate for use in developing countries and can be employed manually to determine rapidly those management options worthy of more detailed consideration.     

基于信息融合的智能推料机器人设计与试验

饲料的定期推送是奶牛饲喂过程中的重要环节,针对现有推料机器人功能单一,无法满足奶牛饲喂需求的问题,开发了奶牛智能推料机器人。构建奶牛、饲料和牛栏参照物识别与分割的YOLACT模型,融合掩膜图像、深度图与ORB-SLAM3定位信息,实现觅食奶牛的快速定位与机器人导航信息的提取;基于信息融合提出智能推料算法,根据觅食奶牛的定位信息、投料时间信息、机器人的导航信息,自动选择工作模式,控制机器人沿着预定的轨迹,实现推料、集料送料、清料等多模式推料功能,满足奶牛个性化自由采食需求,提升饲料利用率。试验结果表明：觅食奶牛的位置识别定位精度为±0.1 m,奶牛识别率为100%,机器人导航精度为±0.8 cm,智能推料准确率为100%,算法运行速率为12 f/s,满足复杂环境下机器人智能推料的要求。     

基于ECA-YOLO v5s网络的重度遮挡肉牛目标识别方法

肉牛目标检测和数量统计是精细化、自动化、智能化肉牛养殖要解决的关键问题,受肉牛个体颜色及纹理相近和遮挡等因素的影响,现有肉牛目标检测方法实用性较差。本研究基于YOLO v5s网络与通道信息注意力模块(ECABasicBlock),提出了一种融合通道信息的改进YOLO v5s网络(ECA-YOLO v5s),在YOLO v5s模型的骨干特征提取网络部分添加了3层通道信息注意力模块。ECA-YOLO v5s网络实现了重度遮挡环境下多目标肉牛的准确识别。对养殖场监控视频分帧得到的肉牛图像采用了一种基于结构相似性的冗余图像剔除方法以保证数据集质量。数据集制作完成后经过300次迭代训练,得到模型的精确率为89.8%,召回率为76.9%,全类平均精度均值为85.3%,检测速度为76.9 f/s,模型内存占用量为24 MB。与YOLO v5s模型相比,ECA-YOLO v5s的精确率、召回率和平均精度均值分别比YOLO v5s高1.0、0.8、2.2个百分点。为了验证不同注意力机制应用于YOLO v5s的性能差异,本研究对比了CBAM(Convolutional block attention mo...     

Economic evaluation of current and alternative dual-purpose cattle systems for smallholder farms in the central Peruvian highlands

In four communities in the Peruvian Andes, 56 farmers were interviewed every three months over a period of one year. Information linked to milk and cattle production such as activities, inputs (labour, means of production, capital) and outputs (milk, cheese, animals) were recorded using a closed-ended questionnaire. The communities were divided into two groups with low (LC) and high (HC) level of dependence on income from milk and animal sales. The survey results showed that cattle production on the LC farms was based on less land and a smaller herd (3.32 ha/farm, 1.06 lactating cows) than on HC farms (10.28 ha/farm, 4.19 lactating cows). The data from the survey and the results of the nutritional analyses of 74 feed samples were introduced into a model that applied linear programming techniques in order to estimate the farm household income under the current production systems and evaluate the economic impact of improved forage varieties for hay production. Furthermore, the economic viability of other changes in fodder and herd management was tested. Both groups were characterised by a dual-purpose system generating a gross income from the sale of both, milk and live animals in the amount of -21 (LC) and +1057 US$/farm and year (HC). Due to higher production costs for forages and better access to markets, LC communities were characterised by an integrated crop–livestock system whereas in the HC group income was mainly based on livestock. Introduction of improved and fertilized barley for hay production, was estimated to increase the annual farm income to 127 and 1257 US$ for LC and HC, respectively. This increase was accompanied by an increment of the animal number. Maintaining the animal number but increasing the milk production/cow by feeding additional forage was a less profitable option generating 50 and 1221 US$ of income per farm and year for LC and HC, respectively. The production of hay was limited by high costs (external labour) in LC communities and the restricted availability of family labour in the HC group. A scenario based on the use of improved cow genotypes led to the highest estimated annual farm income for HC communities (1280 US$) but was less favourable for LC. The modelling results showed that the best development strategy depends on various factors such as production costs, access to the markets and to irrigation and availability of different feed resources.     

牛肉眼肌图像在线采集和实时分割系统

根据肉牛屠宰现场牛肉自动分级的技术要求,设计并构建了一个以TMS320DM642处理芯片为核心的牛胴体眼肌图像在线采集和实时分割系统.首先利用所开发系统在线采集牛肉图像,然后通过蒙板方法,对所采集图像进行背景分割;由于DM642系统采用y、Cb、Cr 3个色度分量来分别描述和存储图像,为节省算法处理的数据量,对Cr(红色)色度空间图像进行二值化处理,然后再用区域面积标记法和小区域消除法提取眼肌区域.实验结果表明,利用DM642系统能够实现牛肉图像的在线采集和眼肌区域分割,眼肌图像提取的准确率平均值为92.9％.     

奶牛精确饲喂装置检测系统的研究

精确饲喂装置检测系统的核心技术是奶牛个体采食量检测技术.系统采用了螺旋输送料技术、非接触式的无线射频识别(RFID)技术和称重传感器技术.采食活动前,系统核对奶牛个体信息和启动螺旋输料系统进行投料,收集奶牛个体的采食数据,在上位机中利用Visval Basic 6.0 编写系统应用软件,实现对采食数据的接收、显示、存储和分析处理.     

基于深度图像的多姿态肉牛体尺自动测量方法

养殖场中肉牛较为活跃,采集得到的图像数据中肉牛姿态多变,肉牛姿态端正帧较少,导致自动测量肉牛体尺困难。针对以上问题,本研究通过分析肉牛骨架特征和肉牛图像边缘轮廓特征,提出一种多姿态肉牛体尺自动测量方法。首先,利用深度相机Azure Kinect DK从正上方采集肉牛俯视深度视频数据,对视频数据进行分帧处理;其次,对原始深度图像进行预处理,将肉牛从复杂的背景中提取出来;再次,利用Zhang-Suen算法提取目标图像肉牛骨架,检测骨架交点和端点,分析肉牛头部特征,并确定头部去除点,去除图像中肉牛头部信息;最后,利用改进的U弦长曲率算法提取肉牛轮廓曲率曲线,根据曲率值确定体尺测点,将体尺测点转换到三维空间中,计算体尺参数。本研究通过分析大量深度图像数据,将图像中肉牛姿态分为左歪、右歪、姿态端正、低头和抬头五类。试验结果表明,本研究提出的基于骨架的多姿态肉牛头部去除方法在5种姿态下的头部去除成功率均高于92%;在23头肉牛不同姿态共46帧深度图像中,利用基于改进U弦长曲率的体尺测点提取方法,测得体直长测量的平均绝对误差为2.73 cm,体高测量的平均绝对误差为2.07 cm,腹宽测量的平均绝对误差为1.47 cm。研究结果可为精确测量多姿态下肉牛体尺提供支撑。