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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.
81

O uso de critérios quali-quantitativos de alimentação e práticas de ordenha na tipologia de sistemas de produção leiteira / The use of quality-quantitative feeding and milking practices criteria in the typology of dairy production systems

Dias, Angélica Petersen January 2018 (has links)
O objetivo do presente estudo foi verificar se o uso de critério quali-quantitativos da estimativa da quantidade de alimentos ofertados e das práticas de ordenha permite a tipificação das unidades produtoras de leite com base na composição do leite. Foram coletadas 555 observações por meio da aplicação de questionários mensais em 30 propriedades de leite localizadas na região Leste do Rio Grande do Sul abrangendo a estrutura do rebanho, aspectos sociais dos produtores, tipo e quantidade estimada dos alimentos ofertados, manejo e higiene da ordenha. Resultados de qualidade do leite através das amostras coletadas para composição centesimal, contagem de células somáticas e contagem bacteriana total também foram utilizados. Os dados foram analisados usando análises multivariadas: fatores principais, discriminante, canônica e de agrupamento. A produtividade média dos rebanhos foi de 13,2 kg/vaca/dia com predomínio de animais da raça Holandesa. Na análise de fatores principais, o primeiro fator representa as relações entre a produtividade, quantidade de silagem de milho ofertada na matéria natural, grau de instrução do produtor rural, utilização de pré e pós-dipping e de detergentes alcalinos e ácidos para higiene da ordenha; o segundo fator compreende a raça predominante no rebanho, quantidade de RCU e de massa de soja ofertada na matéria natural e ESD; o terceiro fator está relacionado com a quantidade de feno e de concentrado ofertada na matéria natural, o cultivo de pastagens de inverno e o uso do CMT. Na análise de agrupamento, foram formados três grupos, sendo (1) não especializado, (2) semi-especializado e (3) especializado. O uso inadequado de concentrado foi relacionado com menor produtividade e com leite de qualidade inferior. As propriedades que apresentaram melhores resultados de composição do leite mantendo uma boa produtividade são aquelas que oferecem uma dieta mais balanceada, com uso adequado de concentrado, forragens conservadas e coprodutos e com uso de raças especializadas para produção de leite. / The objective of this study was to confirm if quality-quantitative feeding and milking practices criteria allows the typification of dairy farms at milk composition basis. This survey was run applying monthly questionaries to 30 dairy farmers located East at Rio Grande do Sul, generating 555 observations regarding herd structure, social conditions of dairy farmers, type and quality of food and milking practice and milking hygiene. We also used milk quality results obtained from milk samples collected for composition, somatic cells count and total bacterial count. The data was analyzed using multivariate analysis: principal factors, discriminant, canonical and cluster analysis. The mean herd productivity was 13.2 kg/cow/day with Holstein cows predominantly. On the factor analysis, the first principal factor represents the relation among herd productivity, amount of corn silage offered in natural basis, degree of education of farmers, the use of pre and pos-dipping and use of alcaline and acids detergents; the second factor comprises the predominant breed in the herd, the quantity of food coproducts offered on natural basis and solids non fat in milk and the third factor is associated with the quantity of hay and concentrate offered on natural basis, cultivation of winter pastures and use of CMT. The cluster analysis grouped observations into three clusters, being (1) non-specialized, (2) semi-specialized and (3) specialized. The inadequate use of concentrate was related with low productivity and inferior milk quality. The dairy farms with better milk composition with high productivity were those that offer adequate use of concentrate, conserved forages and coproducts in the diet and use specialized breeds for milk production.
82

Comparison of Several Forms of Equations for Predicting Cheddar Cheese Yield from Milk Composition

Moore, Craig A. 01 May 1984 (has links)
This study was conducted to evaluate several forms of equations for predicting Cheddar cheese yields based on the fat and protein content of milk and moisture content of cheese. Production and quality control data from a Cheddar cheese plant for one entire year was used. This included the pounds of milk that went into each vat of cheese, yield of cheese from each vat, cheese moisture from each vat, and fat and protein percentages of the milk. Seven models were derived to predict the yield of Cheddar cheese. The seven models were statistically fitted to the data by applying the Marquardt non-linear least squares method of iteration. These were compared with the commonly used Van Slyke and Price formula, with casein estimated as a percentage of total protein. The differences among the eight models were small.
83

An evaluation of nanofiltration and lactose hydrolysis of milk UF permeate for use in ice cream

Chaudhary, Manoja Nand, University of Western Sydney, Hawkesbury, Faculty of Science, Technology and Agriculture, School of Food Science and Technology January 1997 (has links)
This study aimed to obtain 15% total solids and reduced mineral content in milk UF permeate by nanofiltration, hydrolysing the lactose content of nano-concentrate enzymically, partially substituting sucrose in ice cream formulations with hydrolysed lactose nano-concentrate (HLNC), and investigating the effects of HLNC on the physio-chemical and sensory characteristics of ice cream. The desired 15% total solids in the nano-concentrate was achieved after three fold concentration of milk UF permeate. The colour of milk permeate changed, pH and mineral content decreased, and crude protein content, lactose content and titratable acidity increased. The lactose content was hydrolysed by enzyme lactase. HLNC was used to replace 25% and 50% of sucrose in ice cream formulations. Springiness, cohesiveness, chewiness, adhesiveness, hardness, iciness, Ph and colour were not significantly affected. Viscosity, freezing point, glass transition temperature, melting temperature, gumminess and sweetness were significantly decreased, whereas freezing time, saltiness and cooked flavour were significantly increased. The overall acceptability of ice cream significantly decreased at 50% but was insignificantly affected at the 25% level. These results indicate that about one quarter of sucrose could be replaced by HLNC. / Master of Science (Hons) (Food Technology)
84

The effect of gin trash on milk production

Halbach, Gerald David, 1951- January 1975 (has links)
No description available.
85

The effect of adding various protein supplements to pelleted cottonseed hulls on milk production

El Hassan, Yassin Mohammed January 1981 (has links)
No description available.
86

Sezono, laktacijos mėnesio ir laikymo sąlygų įtaka pieno sudėties pokyčiams ir kokybės rodikliams LVA praktinio mokymo ir bandymų centro karvių bandoje / The influence of the conditions of a season, lactation month and keeping on the changes of milk composition and quality indices in a cow herd of Practical Instruction and Research Centre under Lithuanian Veterinary Academy

Lakačauskienė, Asta 17 March 2008 (has links)
Darbo tikslas: ištirti praktinio mokymo centro karvių bandos pieno sudėties ir kokybės rodiklių kaitą atskirais laktacijos mėnesiais, sezonais bei keičiantis laikymo sąlygoms. Darbo uždaviniai: 1. Susipažinti su LVA praktinio mokymo ir bandymų centre karvių veislėmis; 2. Išnagrinėti atrinktų karvių grupių pieno kokybės rodiklius ir kokybę, palyginti su atitinkamų veislių Lietuvoje vidurkiu; 3. Išnagrinėti laktacijos mėnesio įtaką pieno kokybės rodikliams; 4. nustatyti sezono įtaką pieno kokybės rodikliams. Išvados: 1. Lietuvos juodmargių įprastinėmis laikymo sąlygomis pieno kiekis buvo 9 % didesnis nei Lietuvos juodmargių, laikomų šaltomis sąlygomis, Vokietijos juodmargių – 22 % didesnis nei tos pačios veislės karvių, laikomų šaltomis sąlygomis, Olandijos juodmargių – 14,9 % didesnis nei tos pačios veislės juodmargių šaltoje karvidėje ir Danijos juodmargių – 7 % didesnis nei tos pačios veislės juodmargių šaltoje karvidėje; 2. Lietuvos juodmargių produktyvumas šalto tipo karvidėje buvo didesnis už kitų juodmargių veislių produktyvumą tomis pačiomis laikymo sąlygomis (14,4 % didesnis už Vokietijos juodmarges, 14,6 % didesnis už Olandijos juodmarges ir 25 % didesnis už Danijos juodmarges). Šis rodiklis demonstruoja Lietuvos juodmargių veislės didesnį atsparumą šalto laikymo sąlygoms; 3. Didžiausias pieno riebalų kiekis (4,63 %) buvo nustatytas Danijos juodmargių karvių piene, laikomų šaltomis sąlygomis; 4. Pieno riebalai ir pieno baltymai kito nepriklausomai nuo laktacijos... [toliau žr. visą tekstą] / Place and methods of work fulfillment: the work was carried out in the Department of Animal Science of Lithuanian Veterinary Academy and Practical Instruction and Research Centre under Lithuanian Veterinary Academy in 2006 – 2008 years of postgraduate studies. 84 cows of equal period of lactation were selected: 58 cows in Muniškiai farm and 26 cows in Giraitė farm. Cows were selected considering that the most producing period of lactation would coincide with cattle-shed period. The conditions of cow keeping are different. In Muniškiai cattle-shed they are kept in standard conditions: they spend time in a pasture in summer and bound to standing places in winter. They are milked in their standing places. Giraitė cattle-shed is of cold type, where cattle are kept loosely. Here cows are kept in cold conditions in groups consisting of 30 – 40 cows. They are herded in a pasture in summer. The cows are milked in Swedish DeLaval “Tandem” type milker. The cows are fed with the same fodder and the schedule of work is also the same. The data has been analyzed statistically using “Excel” spreadsheet. Review of the work: in a period of 2006 – 2007 years milk yield of Lithuanian black-and-white cows was 434 kg less than of German, 768 kg less than of Dutch and 1409 kg less than of Danish black-and-white cows. Lithuanian black-and-white cows provided 25 – 77 kg of butterfat less than Dutch, German or Danish cows. Lithuanian black-and-white cows had proteins 0,05 % less than the same Danish... [to full text]
87

Evaluation of single-bounce attenuated total reflectanceFourier transform infrared and two-dimensional correlation spectroscopy in quantitative analysis

Cocciardi, Robert Arthur January 2003 (has links)
The utility of single-bounce attenuated total reflectance (SB-ATR) and heterospectral two-dimensional correlation spectroscopy (H2D-CS) in quantitative analysis by Fourier transform infrared (FTIR) spectroscopy was investigated by exploring several potential applications of these techniques. Enzymatic hydrolysis of lactose in milk was monitored by SB-ATR/FTIR spectroscopy, and changes in the concentrations of glucose, galactose and lactose during the process were successfully measured quantitatively. SB-ATR/FTIR spectroscopy was shown also to perform comparably to Fourier transform near-infrared (FT-NIR) spectroscopy for the determination of the alcohol content of distilled liquors and better than FT-NIR spectroscopy and comparably to transmission FTIR spectroscopy for the analysis of alcohol, total reducing sugar, total acidity and pH in wines. In addition, a set of 149 pre-analyzed wine samples was employed to develop and validate an SB-ATR/FTIR calibration for 11 different parameters and constituents in wines with the use of partial-least-squares (PLS) regression, demonstrating the potential utility of this method in the routine analysis of wines. The application of SB-ATR/FTIR spectroscopy and H2D-CS in the selection of wavelengths for multiple linear regression (MLR) calibration for FT-NIR analysis of ternary aqueous solutions of fructose, glucose and galactose was also investigated. NIR wavelengths were identified for the three sugars by H2D-CS of the SB-ATR/FTIR spectra of binary sugar solutions in relation to their FT-NIR spectra. An MLR calibration developed based on these wavelengths gave better results than PLS calibrations and comparable results to those obtained by MLR using wavelengths selected by examination of 1st and 2nd derivative spectra. H2D-CS was extended to include 2D correlations between high-pressure liquid chromatography (HPLC) and SB-ATR/FTIR data for the purpose of identifying HPLC peaks without the need to isolate the eluted compounds. The potential utility of this approach, termed spectroscopic/chromatographic 2D correlation (SC2D-C), was investigated by generating FTIR slice spectra corresponding to the HPLC peaks of wines spiked with sucrose, glucose and fructose and comparing them to 404 reference spectra in an IR spectral library. It was found that these constituents were correctly identified provided there was sufficient random variability of their concentrations in the samples analyzed.
88

Žirnių ir vikių mišinio įtaka karvių pieno sudėties rodikliams / The influence of peas and vetch mixture on cows' milk composition parameters

Skaburskytė, Kristina 26 April 2013 (has links)
Šio darbo tikslas buvo išanalizuoti ir įvertinti žirnių ir vikių mišinio įtaką pieno sudėčiai X ūkyje. Tikslui pasiekti buvo iškelti šie uždaviniai: 1. Išanalizuoti žirnių ir vikių mišinio įtaką pieno kiekiui ir sudėčiai. 2. Palyginti pieno sudėties rodiklius ganykliniu ir tvartiniu laikotarpiais. 3. Apibendrinti tyrimų rezultatus, pateikti išvadas ir pasiūlymus. Išvados: 1. Karvių, šertų žirnių ir vikių mišinio grūdų koncentruotaisiais pašarais, vidutinis pieno riebumas 0,08 proc.ir baltymingumas 0,04 proc. buvo mažesnis nei karvių, kurios buvo šertos visaverčiais kombinuotais pašarais. 2. Karvės, šertos visaverčiais kombinuotais pašarais, davė 0,023 kg pieno daugiau, nei karvės, šertos žirnių ir vikių mišinio koncentruotaisiais pašarais. 3. Laktozės kiekis piene buvo didesnis vidutiniškai 0,01 proc karvių , šėrtų žirnių ir vikių mišinio koncentruotaisiais pašarais. Laktozės kiekis statistiškai patikimas ( p<0,05). 4. Vidutinis urėjos kiekis abiejų grupių karvių piene buvo vienodas (18,77 mg/proc.). 5. Ganykliniu laikotarpiu 0,3 proc.(p<0,05) riebesnio ir 0,25 proc.(p<0,05) baltymingesnio pieno primelžta iš visaverčiais kombinuotais pašarais šertų karvių, o tvartiniu laikotarpiu 0,29 proc.(p<0,05) riebesnio pieno davė žirnių ir vikių mišinio miltais šertos karvės. / Tasks of work: overlook basis and ration of fodder given to milch-cows. Clarify how preparation of concentrated fodder, portioning out, and norming to the cows is managed. Identify what is the impact of concentrated mixture of vetch and bean stems to the cow’s productivity of milk composition. Generalize results of research, give conclusions and suggestions. Work placement and method. Work accomplished in X farm, in district of Rokiškis, duration 2011.11.01 – 2012.09.30. During the work: science literature was used, as well as statistical analysis, methods of data filing and summation. From results of research was found out that cows which were fed with concentrates of peas’s and vetch mixtures, average of milk fat 0.08% and proteins 0.04% was lower then cows which were fed full combined forage. Cows which were fed with complete combined forage gave 10.6kg more milk then those which were fed with concentrates of peas and vetch mixtures. Quantity of lactose in milk was higher average 0.01% of those cows which were fed with peas and vetch mixtures concentrates. Average urea quantity were equal (18,77 mg/%) in both cows groups. During pasturable period cows which were fed complete combined forage were milking 0.3% fatter and with more proteins 0.25% milk. During the cow-house period fatter milk 0.29% were given from cows which were fed of peas and vetch mixtures concentrates. In research it was observed lack of cellular tissue and protein in milk. Suggestion - pay... [to full text]
89

Racionų baltymų kiekio ir kokybės įtaka karvių produktyvumui ir pieno sudėčiai / A diet protein content and quality on productivity of cows and milk composition

Vaičiulaitis, Petras 18 June 2013 (has links)
Darbo tikslas: nustatyti racionų baltymų kiekio ir kokybės įtaką karvių produktyvumui ir pieno kokybei. Darbo uždaviniai: apskaičiuoti karvėms šertų racionų energinę ir maistinę vertę. Nustatyti racionų baltymų kiekio ir kokybės įtaką karvių produktyvumui. Nustatyti racionų baltymų kiekio ir kokybės įtaką karvių pieno sudėčiai. Bandymas atliktas 2012 metais X ūkininko galvijininkystės ūkyje. Darbo tikslas buvo nustatyti racionų baltymų kiekio ir kokybės įtaką karvių produktyvumui ir pieno sudėčiai. Analogų principu atrinkta 20 karvių, kurios suskirstytos į 4 grupes (3 tiriamųjų ir 1 kontrolinė), po 5 gyvulius kiekvienoje. Vidutinis karvių produktyvumas per ankstesnę laktaciją buvo 6000 – 6300 kg pieno. Eksperimentiniais racionais karvės šertos keturis mėnesius sausio - balandžio mėn., t.y. pirmąsias 120 laktacijos dienų. Kitu laikotarpiu buvo tik registruojami produktyvumo ir pieno sudėties duomenys. Išanalizavę 2011–2012 metų X ūkio karvių racionus, jų sudėtį, energinę ir maistinę vertę, įvertinę skirtingo šėrimo poveikį produktyvumui ir produkcijos kokybei nustatėme: Didžiausias produktyvumas buvo antros grupės karvių. Lyginant su kontroline grupe, natūralaus pieno iš jų buvo primelžta 228 kg (p<0,05), o perskaičiuoto į bazinį - 666 kg (p<0,01) daugiau. Mažiausias primilžis per 10 laktacijos mėnesių buvo kontrolinės grupės karvių. Jos davė 300 kg mažiau natūralaus pieno arba 965 kg perskaičiuoto į bazinį pieną negu II (produktyviausios) grupės karvės. Daugiausia pieno... [toliau žr. visą tekstą] / The aim: to identify the diet of protein quantity and quality on cow productivity and milk quality. The tasks of the work: to calculate the cows fed rations energy content and nutritional value. Set the ration protein content and quality on milk production of cows. Set the ration protein content and quality on the composition of cow's milk. Experiment was carried out in 2012 X farmer's cattle farm. The aim of the research was to identify the ration protein content and quality on cow productivity and milk composition. Analogues of the principle of sample 20 cows, which are divided into 4 groups (3 test and 1 control), followed by five animals each. The average of productivity per cow during the previous lactation was 6000 - 6300 kg of milk. Cows were fed the experimental diets for four months of January - April., that is to say the first 120 days of lactation. The next period, there were only recorded productivity and milk composition data. The analysis of X holding the 2011-2012 cows fed rations composition, nutritional indicators, the results obtained. The maximum productivity was the second group of cows comparison with a control group of natural milk from their milk yield was 228 kg (p <0.05), and the terms of base - 666 kg (p <0.01) and more. Minimum yield within 10 months of lactation were control cows. They gave 300 kilos of liquid milk, or 965 kg of milk in terms of base than in the second (productive) group of cows. Most milk fat obtained from the second treatment... [to full text]
90

Lietuvos juodmargių galvijų populiacijos karvių eksterjero ir produktyvumo rodiklių įvertinimas bei jų tarpusavio ryšiai / Evaluation of cows’ exterior and productivity traits and their relationships in Lithuanian Black-White cattle population

Gavelis, Aurimas 18 June 2013 (has links)
Darbo tikslas: Įvertinti Lietuvos juodmargių galvijų populiacijos pieninių karvių eksterjero ir produktyvumo rodiklius bei nustatyti jų tarpusavio ryšius. Darbo uždaviniai: 1. Įvertinti skirtingų veislių pieninių karvių eksterjerą. 2. Palyginti skirtingų veislių karvių eksterjero rodiklius. 3. Nustatyti karvių pieno kiekį, pieno riebumą ir baltymingumą. 4. Nustatyti tirtų rodiklių tarpusavio ryšius. Išvados: 1. Įvertinus skirtingų veislių pieninių karvių eksterjero rodiklius, nustatyta, kad tirtų karvių bendras kūno įvertinimas 79,54, galūnių – 78,44, tešmens – 78,18. Bendras eksterjero įvertinimas buvo 78,71 ir atitiko gero eksterjero įvertinimą. 2. Geriausiai bendro kūno išsivystymo rodikliai buvo įvertinti Danijos juodmargių veislės karvių (82,25±0,881), prasčiausiai įvertintos Lietuvos juodmargių veislės karvės (79,42±0,149). Geriausiai galūnių išsivystymo rodikliai buvo įvertinti Holšteinų veislės karvių (79,71±0,707), prasčiausiai įvertintos Švedijos juodmargių veislės karvės (77,75±0,996). Geriausiai tešmens išsivystymo rodikliai buvo įvertinti Švedijos juodmargių veislės karvių (79,88±0,718), prasčiausiai įvertintos Danijos juodmargių veislės karvės (78,00±0,779). 3. Įvertinus skirtingų veislių karvių pieno kiekį ir sudėties rodiklius nustatyta, kad iš visų tirtų karvių vidutiniškai primelžta 56356,0 kg, 4,71 proc. riebumo, 3,35 proc. baltymingumo pieno. Geriausiu produktyvumu išsiskyrė Danijos juodmargių veislė. Prasčiausiai produktyvumas buvo Švedijos juodmargių... [toliau žr. visą tekstą] / Aim of work: To analyze dairy cattle‘s exterior and productivity traits and to define their relationships. Place of research: The work was carried out in the Department of Animal Breeding and Genetics of Veterinary Academy and also in the dairy cow‘s farm during 2011 – 2013 years of studies. The Results of Survey: Having evaluated the exterior traits of different breeds dairy cows, the general evaluation of examined cows’ body was 79.54, limb‘s – 78.44, udder – 78.71 and it coincided with a valuation of a good exterior. The best evaluation of the general body development was of Denmark‘s Black-White breed cows (82.25±0.881). The worst evaluation had Lithuanian Black-White breed cows (79.42±0.149). The best evaluation of limbs was Holstein breed cows (79.71±0.707), the worst was Sweden‘s Black-White breed cows (77.75±0.996). The best evaluation of udder development had Sweden‘s Black-White breed cows (79.88±0.718), the worst was Denmark‘s Black-White breed cows (78.00±0.779). From the analysis of different cows’ breeds milk yield and milk composition was evaluated that from the all of investigated cows, there was an average 56356.0 kg, 4.71 proc. fat and 3.35 protein milk. With the best productivity spotlighted Denmark‘s Black-White breed cows. The biggest relation was between exterior traits (p<0.01). The biggest correlation coefficients was between milk type and udder‘s band strength (r=0.649), udder back part height (r=0.576), body depth (r=0.564) and heel joint (r=0.538)... [to full text]

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