Influence of Involuntary Culling on Optimum Culling Rates and Annualized Net Revenue

Dynamic programming was used to make optimum insemination and culling decisions. Revenue depended on the sale of milk, calves, and cull cows. Costs were based on feed costs, health costs, replacement costs, housing costs, and interest. Conception probabilities, genetic improvement, variation in production, and repeatability of production and involuntary culling probabilities were considered when making the optimum decisions. Annualized net revenue, optimum culling rates, and the optimum average productive life were determined for various involuntary culling rates. Results indicated that involuntary culling probabilities have a large impact on annualized net revenue. Reducing involuntary culling rates by 2.9% (marginal involuntary culling rates by 20%) resulted in about $22 more net revenue per cow per year. Increasing average mature equivalent milk yield by 122 kg resulted in the same increase in net revenue. Value of lowering the overall rate of involuntary culling was not affected by assuming that higher yielding cows were more prone to culling for involuntary reasons; however, optimum voluntary culling patterns were altered. Less intense culling in young cows was optimum when compared with the situation where the probability of involuntary culling was independent of production. Management and breeding policies should be directed toward increasing milk yield and decreasing the causes of involuntary culling.     

Dairy Cow Culling Decision. 2. Profitability and Genetic Trend in Herds with Culling on Production Versus Income

A technique has been described for culling cows on a combination of screening the entire herd on short-term income and then culling the cow making the smallest contribution to herd income over probable remaining herd life. The objective of this study was to determine the long-term effects on herd profitability and herd genetic trend of culling on a combination of short-term and long-term cow income instead of culling on age adjusted production. In addition, the effect of timing of the culling decision either prebreeding (to save insemination costs) or postbreeding (when time of next freshening can be predicted) on herd income was evaluated. Culling on projected income increased herd income over 20 yr by 4.3 to 4.8% relative to culling on age adjusted production for complete lactation. Breeding only the highest producing cows and then culling infertile cows at the point of peak income in the lactation increased herd income over 20 yr by 4.3 and 5.7% relative to breeding all cows and then culling the lowest producing cow in the herd when a heifer freshened. Cow culling on income projections decreased the genetic trend to 65.3 to 86.2% of the gain observed with cow selection on age adjusted production. Due to the potential economic benefits from both choosing culls prebreeding and utilizing a profitability criterion for cow culling, income projection techniques that describe the reproductive performance of the open cow need to be developed.     

Comparison of Culling Rates,Reasons for Disposal,and Yields for Registered and Grade Holstein Cattle

Survival of cows was investigated using data from the USDA files for daughters of 199 Holstein sires with at least 500 progeny each. Records included cows that first calved from 1965 to 1980 (n = 1,145,616). A smaller subset of data (n = 199,982) was summarized for age at first and last record, termination codes, Modified contemporary deviations of milk yield, and calving intervals. Grade cows leaving the herd were more likely sold for low production and less likely sold for dairy. Modified contemporary deviations in first lactation averaged 339 kg for grade cows and 331 kg for registered cows. Cows with only one record had lower yields in first lactation by 589 kg (grade) and 506 kg (registered). Compared with cows with more than two lactations, cows with two records had lower yields in first lactation by 199 kg (grade) and 259 kg (registered) and longer first calving intervals by 3.5 d (grade) and 5.0 d (registered). Grade and registered daughters of these sires left herds at different rates and for different reasons.     

基于服装智能吊挂系统的优化生产

通过ETON SOFT 2智能吊挂传输生产流水线与课桌型捆包式传输生产流水线的对比分析,阐述了服装智能吊挂生产系统在服装生产过程中降低浮余率、降低返修率、控制生产平衡、缩短生产周期、减轻工人身心疲惫等方面的优化功能,为企业选择提高综合生产能力和效益的途径提供了参考。     

现代家用蚊帐的设计与生产

现代家用蚊帐除了应具有防蚊实用功能外,更应体现出个性化、时尚化和高档化.通过市场调查和设计实践,从面辅料选择、流行款式设计、色彩与图案搭配三方面介绍了蚊帐产品造型设计的要点.通过时生产流程的跟踪,指出了蚊帐产品生产制作中的注意事项及质量检验要求.     

网络协同技术在服装生产上的应用

介绍了网络化协同技术的概念和基本特点 ,探讨了网络化协同技术在服装生产上的应用优势 ,提出了服装网络协同技术的实现方法     

The Influence of Oxygen Volumetric Mass Transfer Rates on Cyclodextrin Glycosyltransferase Production by Alkaliphilic Bacillus circulans in Batch and Fed-Batch Cultivations

In this work, the influence of oxygen mass transfer rates on the production of cyclodextrin glycosyltransferase (CGTase) by the alkaliphilic bacterium Bacillus circulans ATCC 21783 was investigated. Experimental design and response surface methodology were applied to optimize agitation speed and air flow rate in batch cultivations, in order to identify their significant effects and interactions with the synthesis of CGTase. Results were expressed as the volumetric mass transfer rates of oxygen (k_la, [per hour]). The maximal CGTase productivity of 155 U mL⁻¹ h⁻¹ was achieved with k_la of 48 h⁻¹. CGTase production was also studied in fed-batch cultures using the optimized parameters obtained in the batch experiments. The maximal CGTase productivity on fed-batch cultivations was 137 U mL⁻¹ h⁻¹ with feeding rates of starch at 0.17 g L⁻¹ h⁻¹.     

Mortality, Culling by Sixty Days in Milk, and Production Profiles in High- and Low-Survival Pennsylvania Herds

The objectives were to describe culling patterns and reasons for culling across lactation, estimate mortality and the proportion of cows leaving from 21 d before an expected calving date through 60 d in milk (DIM; CULL60) for Pennsylvania (PA) dairy herds, and to describe production measures for herds with high and low mortality and CULL60. Weekly culling frequencies and reasons for culling from 3 wk before a reported expected calving date through ≥100 wk of lactation were calculated for all PA cows with at least 1 Dairy Herd Improvement test in 2005. It was estimated that at least 5.0% of PA dairy cows died in 2005, and that at least 7.6% were culled by 60 DIM. The majority of cows exiting the herd by 60 DIM either died (35.1%) or had a disposal code of injury/other (29.9%). A total of 137,951 test-day records from 20,864 cows in herds with high mortality (>8.0%) and CULL60 (>12.0%) and 136,906 test-day records from 12,993 cows in herds with low mortality (<1.4%) and CULL60 (<2.9%) were retained to describe differences among herds with high and low survival. Least squares means for weekly milk yield, fat and protein percentages, and somatic cell score (SCS) were estimated with a model that included fixed effects for herd environment (high or low survival) and week nested within herd environment and lactation; random effects were cow, herd-test-day, and error. Cows from herds with high mortality and CULL60 produced more milk in lactations 1 (+1.9 ± 0.15 kg/d) and 2 (+0.9 ± 0.16 kg/d), but less in lactations 4 (−0.7 ± 0.22 kg/d), 5 (−1.4 ± 0.29 kg/d), and ≥6 (−0.7 ± 0.32 kg/d) and had higher SCS (+0.24 ± 0.02), more change in early-lactation fat percentage (−1.77% vs. −1.59%), and a greater frequency of fat-protein inversions (3.6 ± 0.3%). There is an opportunity to manipulate management practices to reduce mortality and early-lactation culling rates, which will improve cow welfare and the efficiency of dairy production by capturing a greater proportion of potential lactation milk yield, increasing cow salvage values, and reducing replacement costs.     

古玉璧拍卖价格影响因素分析及估价方法初探

古玉评估一直是珠宝评估界棘手的问题。确定古玉的市场价格主要采用市场比较法,拍卖市场的古玉成交价是古玉评估的主要资料来源。收集了近几年40多家拍卖公司的古玉璧拍卖成交价和估价。通过分析不同时期、不同材质与工艺的古玉璧的拍卖成交价与估价,得出年代、形制、工艺、材质等因素对其价格的影响,为古玉璧的估价提供思路。     

Dairy Cow Culling Decision. 3. Risk of Culling on Predicted Income (An Application of Bayes Criterion)

Comparison of cows on their potential for income production or cash flow over multiple calving intervals has been utilized for culling. The reliability of income projections several years in the future may be questioned when the economic environment is uncertain. The problem would be apparent when cull candidates differ in age since a mature cow would be selected for immediate productivity whereas the immature cow would be selected for her long-term potential. When an uncertain change in the economic environment (e.g., milk price) results in a difference in ranking of two cull candidates, the Bayes criterion of selecting the animal with the highest expected value for income can be utilized. A sensitivity analysis can then determine the dependence of the decision on variation in milk price or other states of nature. The value of perfect information would assess the financial risk associated with the decision. In an example analyzed with a probable 5% decline in milk prices, information that would reduce the variability in predicting animal performance had more effect on the payoff of the culling decision than more accurate predictions of future milk prices.     

直支链淀粉对白酒生产的影响

本文比较了不同直支链淀粉含量的大米、高粱的糊化情况和蒸煮香气,并进行了实验室和窖池发酵试验。结果发现酿酒微生物代谢出的酶既能水解支链淀粉也能水解直链淀粉;同一品种的粮食直链淀粉越高,淀粉结构越紧密,糊化时间越长,粮香越浓;不同品种的粮食淀粉颗粒大小、结构不同,糊化时间也不同。不管是直链淀粉还是支链淀粉,只要糊化得好,出酒率差别不大。     

海盐生产过程的优化控制

文章通过对海盐生产过程的生产因素的敏感性分析,找出影响海盐生产的关键因素,引导盐田技术改造方向,寻找生产过程优化控制的重点,以实现进一步提高有效生产面积单产。     

2009年北美地区油墨销售额前20名企业揭晓

<正>金融危机和经济衰退对全球油墨工业造成了一定的冲击,北美地区油墨市场也不例外。《油墨世界》杂志公布的2009年北美地区油墨销售额前20名企业数据(见表1)显示,北美地区主要油墨制造商     

基于Petri网的包子生产线模型建立与仿真分析

在介绍包子生产流程及生产系统现状的基础上,运用Petri网建模方法建立加工生产线的Petri网模型,并运用witness对模型进行了仿真,对该加工生产车间的生产系统进行分析。     

草原编结网用钢丝生产工艺技术

根据用户对产品的使用要求合理选用原料，制订新的生产工艺，锌层控制适量生产的草原编结网用钢丝能满足畜牧建设需要。     

乳蛋白水解产生肽工艺条件的优化

以肽含量为指标，确定了酶添加量及复合酶（胰凝乳蛋白酶、胰蛋白酶）的酶比，且分别考察了奶粉浓度、温度、pH、反应时间对酶解乳蛋白产生肽的影响。通过正交试验确定了复合酶酶解乳蛋白的最佳工艺条件：加酶量2500U/ml，胰凝乳蛋白酶：胰蛋白酶=1：3，奶粉浓度25%（W/V），温度45℃，pH8.0，水解时间2h。在此条件下，肽浓度可达1.82mg/ml。     

织造设备与厂房振动对生产的影响

通过分析研究出织机振动频率、幅度和厂房振动频率及幅值的计算实例及方法,介绍了振动对生产的影响和振动安全范围及预防振动的有效方法。从生产角度提出了克服振动的措施,给织厂设计提出了相关理论参考依据。     

浅谈木材含水率对刨花板生产的影响

阐述在刨花板生产过程中,含水率对木质原料储备、木片制备、刨花制备、刨花干燥、调施胶、热压的影响。     

浅谈温湿度对纺纱生产的影响

为了研究在不同温湿度条件下棉纺各工序对棉纤维的可加工性,对棉纺生产中各工序的半制品与制成品的合理化回潮率与温湿度间的相互关系进行了测试分析.利用数值计算和图形处理计算软件工具(Matlab)找出回潮率与车间温湿度之间的关系,得出各工序的最佳温湿度控制范围,保证棉纺生产顺利进行.     

圣女果软糖最佳工艺参数组合的灰色分析

为了解决圣女果软糖生产中工艺参数的不稳定性。我们采用多目标灰色组合决策原理对圣女果软糖生产中溶液的不同的pH值、果胶量、加糖量进行了灰色分析。结果表明:以pH值2.7～3.1、果胶含量1.4%～1.6%、含糖量60%～65%。制成的成品质地好,色、香、味俱佳。