Incorporation of Uncertainty in Composition of Feeds into Least-Cost Ration Models. 1. Single-Chance Constrained Programming

Ration formulation by linear programming techniques assumes a perfect knowledge of all coefficients involved. Because of variation in composition of feedstuffs, this assumption cannot hold in practical situations. However, the problem can be reformulated as a chance-constrained programming model for which a deterministic equivalent can be derived. In the case where only one nutrient is considered random, the methodology is labeled as single-chance constrained programming. The exact deterministic equivalent requires nonlinear programming methods for which algorithms are not available to the feed industry. Three linear approximation algorithms were derived and compared with the exact solution given by nonlinear programming in the formulation of a premix feed. Prices from 1970 to 1979 for 17 feed ingredients were used. An algorithm based on a linear function of the standard deviation of the random nutrient within each feedstuff, for which a penalty parameter is iterated in a search for a desired probability, yielded results very similar to the exact solutions found by nonlinear programming methods. This methodology could be implemented easily by the feed industry.     

Uncertainty in Composition of Ingredients and Optimal Rate of Success for a Maximum Profit Total Mixed Ration

Chance constrained programming methodology, which accounts for uncertainty in composition of feedstuffs, was applied to a total mixed ration set for a 650-kg cow producing 27.2 kg of milk/d. Available ingredients were legumegrass hay, legume-grass silage, corn silage, high moisture ground ear corn, soybean meal, dry fat, and a mineral mix. Four models were derived and their performances were compared when both net energy for lactation and crude protein were considered as random constraints. A model based on a Bonferroni inequality with unequal weight on rows’ probability appeared to be best over the range of probability considered (.5 to .95). The value of a feed analysis program was assessed by reducing variances in composition of farm-grown ingredients to those equivalent to a coefficient of variation of 3%. Also, an approximate method was derived for assessing the optimal rate of success. It appears that the optimal rate of success is close to .6 and is not greatly affected by a feed analysis program or a change in price of milk. However, such a program increases income over feed cost by an estimated 27 e/cow per d.     

胶原蛋白饲料粉的制备、组成分析及在饲料中的应用

研究了从新鲜猪皮中提取胶原蛋白粉的制备工艺,结合傅立叶变换红外光谱对提取胶原蛋白的结构进行鉴定以及采用高效液相色谱对胶原蛋白的氨基酸组成进行分析,并概述了胶原蛋白粉在饲料行业的应用前景。     

高氯酸湿消化-原子荧光光度法测定饲料中总砷的不确定度评定

对高氯酸湿消化法处理饲料样品后用原子荧光光度法测定总砷含量的测量不确定度进行了评定。通过建立测量过程中各分量的数学模型,分析、识别了不确定度来源,其测量不确定度来源于样品测试液总体积、样品称量、样品重复测定、回收率、标准物质、标准曲线等因素,估算出各不确定度分量对测量不确定度的影响,在对各不确定度分量进行量化的基础上,合成得到了测量结果的相对标准不确定度。结果表明,样品重复测定和回收率,是影响该方法不确定度的主要因素,从而为采用该方法测定饲料中总砷含量的质量控制提供了理论依据。     

Stress Relaxation of Fruit Gels. Evaluation of Models and Effects of Composition

Stress relaxation behavior of kappa carrageenan (1%) gels (C) and kappa carrageenan (0.5%) plus locust bean gum (0.5%) gels (G) was studied. Effects of addition of sugar (18.3, 36.6 and 55° Brix) and fruit pulp (15%) on relaxation response were analyzed. Curves were fitted to Maxwell (M), Peleg (P) and simplified Maxwell (SM) equations. All three equations were valid to quantify relaxation behavior of fruit gels and to evaluate the effects of changes in composition, with P and SM equations being simpler. Locust bean gum increased initial stress decay rate and decreased proportion of unrelaxed force. Sucrose produced the opposite effect. Fruit pulp effects were weak and dependent on gelling system.     

Composition of Montmorency Cherry Essence. 2. High-boiling Components

SUMMARY: Volatile components of commercial Montmorency cherry essence boiling above ethanol were extracted from the essence by ether and concentrated by distillation. This concentrate was fractionated by gas chromatography. Individual components were identified using the methods of functional group analysis, gas co-chromatography, infrared analysis and mass spectrometry. The concentrations of the components in the original essence were estimated. The major components identified were n-propyl alcohol, isobutyl alcohol, isoamyl alcohol, and benzaldehyde. Minor components identified include n-butanol, n-hexanol, a hexenol, benzyl alcohol, α-terpineol, furfural, isoprene, myrcene and numerous higher terpenes, methyl benzoate, ethyl benzoate, benzyl acetate, ethyl caprylate, ethyl caprate, n-propyl benzoate, isobutyl benzoate, isoamyl benzoate and di-butyl phthalate.     

Prediction of Average Daughter Performance from Sire Proofs for Use in Linear Programming Sire Profit Models

When linear programming is used to rank sires on daughter profits, coefficients of input are required for representative daughters of each sire. Within herd-year-season regressions of daughter's actual 305-day milk, fat percent, days open, 2-min milk yield adjusted for total yield, total milking time, and body weight at birth and first calving on sire's proofs for production, conformation, milking speed, and nonreturn rate were computed from progeny data from 71 Canadian Holstein-Friesian artificial insemination sires, to provide these coefficients. Coefficients of determination for prediction equations were .23 to .71. A production function was fitted for milk production and days open. First lactation 305-day milk was predicted from sire's milk rating and linear and quadratic terms of size ratings. Fat percent proof and its squared term predicted daughter's fat percent. Days open was predicted by milk and fat proofs. Milk yield in the first 2-min of milking, adjusted for milking yield, was predicted by proofs for milking speed and the quadratic term for fat percent. Total milking time was obtained from 2-min yield by regression (?.3837) of total milking time on 2-min yield. Daughter's body weight at first calving was predicted from sire's size proof, as was birth weight. Milk yield was curvilinearly associated with days open. Incidence of mastitis was derived indirectly from regression (.00172) on sire's milk proof for milk.     

Photochemical modeling of emissions trading of highly reactive volatile organic compounds in Houston, Texas. 2. Incorporation of chlorine emissions

As part of the State Implementation Plan for attaining the National Ambient Air Quality Standard for ozone, the Texas Commission of Environmental Quality has created a Highly Reactive Volatile Organic Compounds (HRVOC) Emissions Cap and Trade Program for industrial point sources in the Houston/Galveston/Brazoria area. This series of papers examines the potential air quality impacts of this new emission trading program through photochemical modeling of potential trading scenarios; this paper examines the air quality impact of allowing facilities to trade chlorine emission reductions for HRVOC allocations on a reactivity weighted basis. The simulations indicate that trading of anthropogenic chlorine emission reductions for HRVOC allowances at a single facility or between facilities, in general, resulted in improvements in air quality. Decreases in peak 1-h averaged and 8-h averaged ozone concentrations associated with trading chlorine emissions for HRVOC allocations on a Maximum Incremental Reactivity (MIR) basis were up to 0.74 ppb (0.63%) and 0.56 ppb (0.61%), respectively. Air quality metrics based on population exposure decreased by up to 3.3% and 4.1% for 1-h and 8-h averaged concentrations. These changes are small compared to the maximum changes in ozone concentrations due to the VOC emissions from these sources (5-10 ppb for 8-h averages; up to 30 ppb for 1-h averages) and the chlorine emissions from the sources (5-10 ppb for maximum concentrations over wide areas and up to 70 ppb in localized areas). The simulations indicate that the inclusion of chlorine emissions in the trading program is likely to be beneficial to air quality and is unlikely to cause localized increases in ozone concentrations ("hot spots").     

利用Excel的图表函数化功能使试差计算程序化

以黑液多效蒸发设计型计算为例,介绍用Excel实现图表数据函数化的方法。通过图表数据函数化可以使试差计算程序化,因而有效减少试差计算时间,还能方便地调节有关参数。     

Importance and utilization of amaranth in food industry. Part 2. Composition of amino acids and fatty acids

Content of amino acids and fatty acids in whole amaranth flour from Amaranthus hypochondriacus was investigated. In comparison with fine wheat flour, used in our experiments, high lysine content was observed (5,95 g/16 g N in comparison with 2,90 g/16 g N). Similarly, a higher amount of essential amino acids in amaranth was found. The highest content from fatty acids had linoleic acid about 50%. On the basis of the results obtained, the analysed raw material proves to be very valuable for the enrichment of some cereal products especially regarding protein content, amino acid composition, mainly essential ones, fatty acid composition, and some important mineral substances and vitamins. It is expected, that amaranth will be utilized in some branch of food industry as well.     

A Study of the Forces Involved in the Incorporation of L-Methionine into Soy Protein by the One-Step Plastein-Like Process

Ultrafiltration was used to study the forces involved in the incorporation of methionine into soy protein. Various solvents were used to determine the extent of noncovalent binding. When analyzed with 0.2M citric acid, 60% of the methionine was incorporated into the soy protein. However, when analyzed with 8M Guanidine HCl and 3M KSCN the incorporation was only 20 and 13%, respectively. This reduction in percent incorporation of methionine by protein denaturants indicates that it was not incorporated by covalent bonds. Incorporation is probably due to hydrophobic attraction of the side chain of methionine with apolar regions in the protein.     

前纺重定量与细纱牵伸型式和胶辊胶圈纺纱性能的研试

前纺重定量是棉纺工程技术发展的方向,为了提高棉纱质量,应遵循纺纱牵伸原理.对前纺重定量的负面效应,研试对策,细纱采用V型牵伸气动加压并配置高弹性、低硬度、重加压胶辊;根据细纱不匀产生机理同时降低前纺、细纱工艺流程附加不匀率,前纺并、粗、精胶辊也向高弹性、低硬度、重加压等适纺纱性发展.     

前纺重定量细纱大牵伸工艺机理与专件器材的应用(二)

围绕棉纺工程优化技术发展的趋势--前纺重定量、高速度、大卷装,根据棉纺梳理与牵伸原理对前纺重定量及细纱大牵伸的工艺机理进行初步分析,提出系统的工艺及相关专件、器材的优化组合.指出应将重定量大牵伸结合提高棉纱质量协调发展,将提高梳理性能与细纱牵伸性能协调发展.     

超临界CO_2萃取西伯利亚白刺籽油工艺研究

以西伯利亚白刺籽油的收率为评价指标,在单因素实验基础上,采用L9(34)正交实验优化白刺籽油的超临界CO2萃取工艺条件,并用GC-MS对最佳工艺条件萃取的白刺籽油脂肪酸成分进行分析。结果表明:超临界CO2萃取白刺籽油的最佳工艺条件为萃取压力40 MPa,萃取温度55℃,CO2流量10 L/min。从白刺籽油中分离并鉴定出8种成分,其中不饱和脂肪酸以亚油酸(65.671%)和油酸(25.747%)为主,占总含量的90%以上。     

Incorporation of amino acids by isolated submitochondrial fractions of lactating goat mammary gland in vitro.

Incorporation of amino acids by mitochondria and its subfractions from mammary gland of the goat during lactation was studied in vitro. Assessment of distribution of radioactivity incorporated by intact mitochondria into its subfractions revealed maximum specific activity in the inner membrane. During lactation the inner membrane of mitochondria exhibited further stimulation in such incorporation. Matrix was the next active fraction whereas outer membrane and peripheral space had negligible radioactivity. In isolated submitochondrial fractions from mammary gland incubated with radioactive amino acids under similar conditions of assay, the inner membrane was the most potent subfraction in incorporation. In mammary tissue during lactation this fraction was the most active site. The relative sequence of the subfractions appeared to remain unaltered in lactation and was in the order of inner membrane greater than matrix greater than outer membrane greater than peripheral space. The ratio of specific activity in inner to outer membrane appears to increase significantly during lactation.     

Incorporation of dietary n-3 fatty acids into ovarian compartments in dairy cows and the effects on hormonal and behavioral patterns around estrus

The objective of this study was to examine the incorporation of dietary n-3 fatty acids (FAs) into ovarian compartments and the effects on hormonal and behavioral patterns around estrus. Multiparous 256-day pregnant cows were fed either a standard diet both prepartum and postpartum (PP) (control; n=22) or supplemented with extruded flaxseed (E-FLAX) providing C18:3n-3 at 172.2 and 402.5 g/day per cow prepartum and PP respectively (n=22). The estrous cycle was synchronized, and at day 7 of the cycle, the cows were injected with prostaglandin F(2)(α) (PGF(2)(α)) and then subjected to 5 days of intensive examination. Compared with those in the control, in the E-FLAX group, the interval from PGF(2)(α) injection to behavioral estrus peak tended to be longer (3.6 h; P<0.1), that to estradiol (E(2)) peak was 6.5 h longer (P<0.03), and that to LH peak tended to be longer (5.3 h; P<0.07). The durations of behavioral estrus and E(2) surge were longer, and the area under the E(2) curve was greater in the E-FLAX cows. Afterward, 7-8 days following behavioral estrus, follicular fluids (FFs) from >7 mm follicles were aspirated. The proportions of n-3 FA increased in plasma, FF, and granulosa cells in the E-FLAX group. The concentrations of PGE(2) in the E(2)-active follicles tended to be lower in the E-FLAX cows (P<0.06). In conclusion, several modifications in hormonal and behavioral estrus patterns were demonstrated in cows fed n-3 FA, which might be attributed to alterations in membrane FA composition and partly mediated by lower PGE(2) synthesis.     

Changes in Composition of Potatoes Solanum Tuberosum cv. Huinkul Stored in Clamps

Changes in tuber composition related to potato (Solanum tuberosum cv. Huinkul) storage in clamps for 120 days, were studied. Dry matter (22.5g ± 2.9) was unaffected by storage. Protein, vitamin C, total lipids and phospholipids were calculated on a 100g dry weight basis. Initial protein content (4.71 g ± 0.5) fluctuated during storage, having a similar percentage value at the end of the storage period. Vitamin C at harvest was 100 mg ± 8.1 and decreased to 55.8 mg ± 8.4 (120th day).Total lipids were 0.6g ± 0.15 and 0.25g ± 0.06 at the beginning and at the end of storage, respectively. Initial and final phospholipid content were 0.14g ± 0.02 and 0.16g ± 0.02, respectively.