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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Study of Rehydration Properties of Powder Produced from Chelated Skim Milk

Tan, Kristina Ellice 01 June 2016 (has links)
Poor rehydration properties of skim milk powder (SMP) can impact processing efficiency and functionality in finished product applications. Rehydration can be split into four stages: wettability, sinkability, dispersibility, and solubility. Previous work has suggested that chelator addition during SMP manufacture leads to higher solubility compared to SMP without chelators. This study focuses on the addition of ethylene diamine tetraacetic acid (EDTA) or sodium citrate dihydrate (SCD) at concentrations of 5, 10, and 15 mM to skim milk prior to evaporating and spray drying. The objective of this investigation was to determine the effects of the chelator additions on each SMP rehydration property (wettability, sinkability, dispersibility, and solubility) during reconstitution to 10% total solids. SCD 15 mM, SCD 10 mM, and SCD 5 mM did not have a significant effect on wettability as measured by IDF method (p-value 0.3234, 0.6376, and 1.0000, respectively). However, SCD 15 mM, SCD 10 mM, and SCD 5 mM had higher levels of solubility as measured by particle size analysis of reconstituted 10%TS samples (p-value
62

Lactation Curves of Holstein Cows as Influenced by Age, Gestation, and Season of Freshening

Patterson, George Edward 01 May 1955 (has links)
Lactation curves of dairy cows have been studied by dairy scientists for many years. The effects of various hereditary end non-hereditary influences on the lactation curve have been observed. Factors have been developed to standardize production to a common basis, correcting for differences in age, length of lactation, milking per day, gestation and environment.
63

Group Grain Feeding Versus Individual Grain Feeding of Lactating Dairy Cows

Sudweeks, Earl Max 01 May 1962 (has links)
Grain feeding is an important part of a dairy feeding program. Grain supplies energy in a concentrated form and when fed as a supplement to forage permits cows to maintain high levels of production. Also, if the forage is of low quality, additional protein and other nutrients can be supplied with the grain in a concentrate mix. By feeding a balanced concentrate mix, according to individual production, each cow receives the necessary nutrients for production. Dairy cows are usually fed grain individually. During recent years dairy herds have increased in size and milking parlors have been developed in which to milk cows more efficiently. In milking parlors cows are generally fed grain individually. However, the cows are milked so rapidly that there is insufficient time for them to consume more than a few pounds of grain. Cows not consuming all of their grain, while being milked, are left in the stall until the remaining grain is eaten, thus delaying the milking operation or turned out without consuming the allotted amount of grain.
64

Wool Scouring Tests in Utah

Esplin, Alma C. 01 May 1941 (has links)
Wool as it is shorn from the sheep, is known as grease wool. The first tep in the manufacturing of wool is scouring, or removal of all grease and foreign matter. Within any given grade, as determined by length of staple and fineness of fiber, the yield of clean wool is the primary factor in determining the value of the original grease wool. The price of scoured or clean wool is multiplied by the percentage yield of clean wool to determine the value of the grease wool. Wool is graded and sorted before being scoured by the manufacturer. Large quantities are prepared for the scouring vate and the identity of the grower's clip is lost. Hence, the grower is entirely dependent upon the buyer's estimate of shrinkage or yield of clean wool, unless he obtains a representative sample of his clip and has it scoured to determine the yield. The object of the work reported in this thesis was to obtain information on the variability in yields of clean wool in Utah herds, and to add to work already done on methods of sampling and dtermining yields. Three methods have been used: (1) Whole fleece samples, (2) composite samples, and (3) side samples from individual sheep. Literature concerning each of these methods and other pertinent material is reviewed, and results obtained in Utah are presented.
65

Development and Evaluation of an Expert System for Use as an Aid in Culling Dairy Cattle

Checketts, Max L. 01 May 1991 (has links)
An expert system for identifying cows to be culled, MAXCULL, was programmed to run on an IBM or compatible personal computer . It was designed to be used with Dairy Herd Improvement (DHI) records as an aid in decision making. MAXCULL used fifty-two health, seventeen reproduction, and thirty-nine production rules in the analysis. MAXCULL was initially developed using two expert system tools. VP-Expert and Super Expert both had inductive abilities and were reasonably priced . VP - Expert was selected to continue the development of the MAXCULL system . The program u sed a rule-based method of storing knowledge, which was obtained from literature reviewed in the health, reproduction and management areas. Three blocks of rules were developed. MAXCULL used a backward- chaining control strategy. The information on each cow was obtained from a special report obtained from DHI Provo . The diagnosis from MAXCULL produced an explanation paragraph identifying possible reasons for removing the cow. Twenty herds with DHI records were identified, ten assigned as controls and ten to be evaluated with the MAXCULL system . General linear model procedures were used to compare thirteen variables after using MAXCULL for one year. No significant differences were noted for any of the variables. The chi- square analysis showed that the decisions of MAXCULL were significantly different from the decisions of the manager. The final survey supports the idea that dairy management expertise can be provided to the dairy manager through an expert system.
66

Comparison of Various Types of Milk Sampling Devices

Hoskisson, William A. 01 May 1940 (has links)
Volatiles of peach (Prunus persica L., cultivar, Gleason Early Elberta) fruit were studied by gas-liquid chromatography, thin-layer chromatography, and infrared spectrometry. Hard mature, firm mature, soft mature, tree ripe, and artificially ripened hard mature fruit obtained from four seasons, 1964 to 1967, were used. A total of 86 peaks were observed in the chromatogram of the tree ripe peach volatiles. Major components of the volatiles identified were mainly esters, gamma and delta lactones, aldehydes, alcohols, and terpenes. In general, concentration of the volatile components were found to increase with the maturity of the fruit. However, that of the artificially ripened fruit did not reach the same level of the tree ripe fruit.
67

Lactation Efficiency of holstein Cows as Related to Rate and Efficiency of Growth

Mickelsen, Charles H. 01 May 1963 (has links)
The relationship of quantity and quality of feed to milk production has been studied for many years. Feeding standards have been developed to systematize feeding of dairy cows according to their requirements. Recently, interest in efficiency of cows in converting feed nutrients into milk has increased.
68

The Challenges of Making a Blastocyst-Stage Embryo: Impact of Heat Stress & Technical Factors Associated with IVP Procedures

Peixoto, Estanislao 01 August 2010 (has links)
It was hypothesized that technical factors associated with in vitro production (IVP) of embryos may influence rate of blastocyst development of oocytes matured at 38.5 or 41.0 C. To test this hypothesis, a retrospective meta-analysis was performed. Simple linear regression was performed to analyze continuous variables and ANOVA for categorical variables. Interactions among factors and maturation temperature on blastocyst development were analyzed using dummy regression for continuous variables, and using a factorial treatment design and ANOVA for categorical variables. Month of collection was the only variable that impacted responsiveness of ova to heat stress. Independent of maturation temperature, variables that explained most variation in blastocyst development included technician, total number of sliced ovaries per collection, ova number placed per well of oocyte maturation media, oocyte collection time, bull ID, sperm concentration added to ova, and ova age at IVF. The proportion of 8 to 16-cell embryos at time of cleavage assessment was the best predictor of blastocyst development. Results of model selection showed that development of ova matured at 38.5 C was associated with size of the collection, while development of ova matured at 41.0 C was mainly associated with ova age at fertilization. When data for ova matured at 38.5 and 41.0 C were combined, the effect of number of PZ per well on blastocyst development became evident. Use of these findings for optimizing efficiency of IVP procedures would effectively reduce experimental costs related to embryo production and increase laboratory productivity.
69

The Challenges of Making a Blastocyst-Stage Embryo: Impact of Heat Stress & Technical Factors Associated with IVP Procedures

Peixoto, Estanislao 01 August 2010 (has links)
It was hypothesized that technical factors associated with in vitro production (IVP) of embryos may influence rate of blastocyst development of oocytes matured at 38.5 or 41.0 C. To test this hypothesis, a retrospective meta-analysis was performed. Simple linear regression was performed to analyze continuous variables and ANOVA for categorical variables. Interactions among factors and maturation temperature on blastocyst development were analyzed using dummy regression for continuous variables, and using a factorial treatment design and ANOVA for categorical variables. Month of collection was the only variable that impacted responsiveness of ova to heat stress. Independent of maturation temperature, variables that explained most variation in blastocyst development included technician, total number of sliced ovaries per collection, ova number placed per well of oocyte maturation media, oocyte collection time, bull ID, sperm concentration added to ova, and ova age at IVF. The proportion of 8 to 16-cell embryos at time of cleavage assessment was the best predictor of blastocyst development. Results of model selection showed that development of ova matured at 38.5 C was associated with size of the collection, while development of ova matured at 41.0 C was mainly associated with ova age at fertilization. When data for ova matured at 38.5 and 41.0 C were combined, the effect of number of PZ per well on blastocyst development became evident. Use of these findings for optimizing efficiency of IVP procedures would effectively reduce experimental costs related to embryo production and increase laboratory productivity.
70

ASSESSING THE EFFICACY OF AUTOMATED DETECTION OF ESTRUS IN DAIRY CATTLE

Mayo, Lauren M. 01 January 2015 (has links)
The detection of estrus continues to be a primary factor contributing to poor reproductive performance in modern dairy cattle. The objectives of this research were 1) to evaluate performance of automated detection of estrus using a reference standard of ovulation detection with temporal progesterone patterns 2) to evaluate the efficacy of parameters measured by automated detection of estrus systems 3) to evaluate the efficacy of alerts generated by several commercially available systems used for automated detection of estrus and 4) to determine the differences in these parameters among cows with or without poor health conditions at the time of estrus. Systems used for automated detection of estrus can perform better than the previous original reference standard, visual observation for standing behaviors. All systems used for automated detection of estrus tested were similar for estrus detection efficiency.

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