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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.
431

Avaliação da contagem de células somáticas do leite como indicador da ocorrência de mastite em vacas Gir / Evaluation of milk somatic cell count as an indicator of mastitis occurrence in Gyr cows

Reis, Carolina Barbosa Malek dos 31 March 2010 (has links)
Os objetivos deste trabalho foram determinar a sensibilidade e especificidade do limiar de contagem de células somáticas (CCS) de vacas Gir para o diagnóstico de mastite subclínica causada por patógenos primários e secundários e avaliar os efeitos de rebanho, vaca, mês de coleta, quarto mamário, presença de infecção intramamária, tipo de microrganismo e suas interações sobre o logCCS e composição do leite. Avaliou-se a hipótese que o limiar da CCS para detecção de mastite subclínica é igual entre vacas Gir e Holandesas. Foram utilizadas 221 vacas Gir em lactação, provenientes de três fazendas comerciais. Foram coletadas amostras de leite individuais por quarto mamário e compostas uma vez por mês, durante um ano. Foram realizadas análises de CCS, composição do leite e cultura microbiológica. O quarto mamário e a vaca foram considerados unidades experimentais. Para determinar a sensibilidade, especificidade e odds ratio (OR) dos limiares da CCS para identificação de quartos infectados, foram utilizados quatro valores de CCS: 100, 200, 300 e 400 (x 103 células/mL), assim como a correlação entre a CCS e composição do leite. Não houve efeito do rebanho sobre o logCCS para amostras individuais de quartos mamários e compostas, mas vaca dentro de rebanho foi o principal fator responsável pela variação do logCCS. Houve efeito do rebanho sobre a composição do leite, assim como o mês de coleta apresentou efeito tanto sobre o logCCS quanto para a composição do leite, considerando as duas unidades experimentais. A presença de infecção intramamária afetou negativamente a composição do leite, exceto sobre o teor de gordura; sendo que os maiores teores de lactose, proteína e ESD foram encontrados em amostras sem isolamento bacteriano. Os maiores logCCS foram obtidos em amostras infectadas. O limiar da CCS de 100 x 103 células/mL apresentou, em ambas as unidades experimentais, maiores valores de sensibilidade e valor preditivo negativo. O limiar de 200 x 103 células/mL apresentou maior chance da ocorrência de mastite do que o limiar de 100 x 103 células/mL. Foi observada correlação negativa entre CCS com lactose e extrato seco desengordurado (ESD), mas a correlação foi positiva entre CCS com gordura e proteína, tanto em nível de quarto mamário quanto de vaca. Portanto, a composição do leite foi influenciada pela CCS, os teores de lactose e ESD diminuíram em altas CCS, enquanto que as concentrações de gordura e proteína aumentaram. / The aim of this study was to determine the sensibility and specificity of somatic cell count (SCC) threshold in Gyr cows to diagnosis the subclinical mastitis caused by primary and secondary pathogens, and to evaluate the effect of herd, cows, month, mammary quarter, intramammary infection, type of microorganism and their interactions on logSCC and milk composition. The hypothesis to be tested was that the SCC threshold to detection of subclinical mastitis is the same for Holstein and Gir cows. A total of 221 lactation Gir cows from three commercial dairy farms was selected. Composed and quarter individual milk samples were collected once a month, during one year for SCC, milk composition and bacteriological analysis. The mammary quarter and the cow were considered experimental units. To determine the sensibility, specificity and odds ratio (OR) from SCC threshold to identify the infected quarters four values of SCC: 100, 200, 300 and 400 (x 103 cells/mL) were used. It was also evaluated the correlation between SCC and milk composition. There was no effect of herd on logSCC in individuals and composed samples, but cow nested within herd was major factor responsible for the logSCC variation. The month of sampling presented significant effect on logSCC and milk composition in both experimental units. The intramammary infection presence affected negatively the milk composition, except of fat concentration. Higher lactose, protein and non-fat solids (NFS) percentages were found in negative samples and higher logSCC were observed in infected samples. The SCC threshold of 100 x 103 cells/mL presented the major sensibility and negative predictive value for subclinical mastitis detection. The threshold of 200 x 103 cells/mL had higher chance to have mastitis than the threshold of 100 x 103 cells/mL. It was observed a negative correlation between SCC with lactose and NFS; but the correlation was positive between SCC with fat and protein in mammary quarters and cow level. Milk composition was influenced by SCC, once the lactose and NFS percentages decreased in samples with high SCC and the protein and fat concentration increased.
432

Personlighetsvariationer hos mjölkkor / Personality variations in dairy cows

Andersson, Natasja January 2010 (has links)
<p>Syftet med denna studie var att undersöka om det fanns olika personlighetstyper hos mjölkkor av raserna SRB och SLB och om dessa personlighetstyper skilde sig mellan ras, ålder och vilken sida djuren stått på i lösdriften. Korna observerades i tre olika testmiljöer för att se huruvida konsistenta de var i deras beteenden: ostörda i lösdriften, vid mjölkning och med ett främmande objekt i lösdriften. Beteenden som studerades var normala beteenden, sociala beteenden, tramp och sparkningar vid mjölkning och interaktioner med det främmande objektet. Tolv beteendevariabler användes i en PCA (principal component analysis) och visade två komponenter som tillsammans kunde förklara 51,2 % av den totala variansen. Den första komponenten speglade aggression och extraversion, som ingår i medgörlighet och extraversion i den mänskliga femfaktorsmodellen. Den andra komponenten speglade ett mer introvert beteende och rädsla, som går under extraversion och neuroticism i samma modell. Oberoende T-test visade inga signifikanta skillnader mellan någon av komponenterna och ras eller sida i lösdriften p>0,05, däremot en tendens till skillnad mellan den första komponenten och ålder, där den äldre gruppen individer visade tydligare personlighetsdrag p<0.1. Tidigare studier har visat att personlighetsdimensioner som medgörlighet, neuroticism och extraversion ofta förekommer bland flera arter. Då olika personligheter hanterar stressfulla situationer på olika sätt, är detta ämne av stor vikt när det gäller förbättrandet av djurens välfärd.</p> / <p>The purpose of this study was to investigate if different personality dimensions existed in dairy cows of two breeds (SRB and Holstein) and if these personality dimensions differed between breed, age and how the animals were placed in the loose housing system. To investigate behavioural consistency, the cows were observed in three different situations: uninterrupted in their home pen, during milking and with a novel object in their home pen. Normal and social behaviour was observed as well as stepping and kicking during milking and interactions with the novel object. Twelve behavioural variables were used in a principal component analysis, which showed two components that together explained 51,2 % of the total variance. The first component reflected aggression and extraversion, which are included in agreeableness and extraversion in the human five-factor model. The second component reflected fear and introversion, which are included in neuroticism and extraversion in the same model. Independent-samples T test showed no significant differences between any of the components and breed or placement in the loose housing system p>0,05, however there was a tendency between the first component and age, where the older group showed a more defined personality p<0,1. Other studies have showed that personality dimensions such as agreeableness, neuroticism and extraversion often exist in several species. Different personalities cope with stressful situations in different ways, making this topic relevant to the improvement of animal welfare.</p>
433

Analytical considerations and biology of milk conjugated linoleic acid synthesis in the bovine

Mohammed, Riazuddin 06 1900 (has links)
Biosynthesis of milk conjugated linoleic acid (CLA), a component of milk fat with demonstrated health benefits, requires a dietary source of PUFA. Even with PUFA supplementation, milk CLA is highly variable. Therefore, this study was aimed at identifying factors responsible for the variations in rumen CLA precursors and milk CLA. Study 1 evaluated the efficiency of CLA production by grazing cows compared to those fed grass silage or fresh grass. Grazing cows were more efficient than those fed grass silage or fresh grass in milk CLA production. About 75% of the variability in milk CLA was related to the differences in PUFA (l8:2n-6 + 18:3n-3) intake and the remainder was related to factors regulating the extent of PUFA biohydrogenation in the rumen. This study demonstrated that PUFA intake is important but it is not the only factor responsible for the observed variation in milk CLA production. Study 2 evaluated the effect of diets differing in rate of starch degradation on rumen PUFA biohydrogenation and milk CLA. Concentrations of ruminal t11-18:1 and milk CLA were greater for barley-based diets than corn-based diets and were not different between rolling and grinding, indicating that factors inherent in the source of starch were responsible for the observed differences and these factors could not be modified by rolling or grinding the grain. Study 3 examined the effect of stage of lactation on persistency of milk t10-18:1, t11-18:1 and CLA for control and test (supplemented with PUFA and monensin) diets from calving to 270 days in milk. Milk concentrations of t11-18:1 and RA remained similar across the lactation length and were greater for the test diet compared to the control. Changes in milk t10-18:1 concentration during lactation appeared to reflect an effect of the degree of rumen fermentation on PUFA biohydrogenating bacteria. Although PUFA intake is important for milk CLA production, only those diets that give rise to increased ruminal t11-18:1 result in greater milk CLA. Concentrations of rumen t11-18:1 is influenced by the amount of PUFA consumed, degree of shift to t10-18:1 and the extent of PUFA biohydrogenation in the rumen. / Animal Science
434

Personlighetsvariationer hos mjölkkor / Personality variations in dairy cows

Andersson, Natasja January 2010 (has links)
Syftet med denna studie var att undersöka om det fanns olika personlighetstyper hos mjölkkor av raserna SRB och SLB och om dessa personlighetstyper skilde sig mellan ras, ålder och vilken sida djuren stått på i lösdriften. Korna observerades i tre olika testmiljöer för att se huruvida konsistenta de var i deras beteenden: ostörda i lösdriften, vid mjölkning och med ett främmande objekt i lösdriften. Beteenden som studerades var normala beteenden, sociala beteenden, tramp och sparkningar vid mjölkning och interaktioner med det främmande objektet. Tolv beteendevariabler användes i en PCA (principal component analysis) och visade två komponenter som tillsammans kunde förklara 51,2 % av den totala variansen. Den första komponenten speglade aggression och extraversion, som ingår i medgörlighet och extraversion i den mänskliga femfaktorsmodellen. Den andra komponenten speglade ett mer introvert beteende och rädsla, som går under extraversion och neuroticism i samma modell. Oberoende T-test visade inga signifikanta skillnader mellan någon av komponenterna och ras eller sida i lösdriften p&gt;0,05, däremot en tendens till skillnad mellan den första komponenten och ålder, där den äldre gruppen individer visade tydligare personlighetsdrag p&lt;0.1. Tidigare studier har visat att personlighetsdimensioner som medgörlighet, neuroticism och extraversion ofta förekommer bland flera arter. Då olika personligheter hanterar stressfulla situationer på olika sätt, är detta ämne av stor vikt när det gäller förbättrandet av djurens välfärd. / The purpose of this study was to investigate if different personality dimensions existed in dairy cows of two breeds (SRB and Holstein) and if these personality dimensions differed between breed, age and how the animals were placed in the loose housing system. To investigate behavioural consistency, the cows were observed in three different situations: uninterrupted in their home pen, during milking and with a novel object in their home pen. Normal and social behaviour was observed as well as stepping and kicking during milking and interactions with the novel object. Twelve behavioural variables were used in a principal component analysis, which showed two components that together explained 51,2 % of the total variance. The first component reflected aggression and extraversion, which are included in agreeableness and extraversion in the human five-factor model. The second component reflected fear and introversion, which are included in neuroticism and extraversion in the same model. Independent-samples T test showed no significant differences between any of the components and breed or placement in the loose housing system p&gt;0,05, however there was a tendency between the first component and age, where the older group showed a more defined personality p&lt;0,1. Other studies have showed that personality dimensions such as agreeableness, neuroticism and extraversion often exist in several species. Different personalities cope with stressful situations in different ways, making this topic relevant to the improvement of animal welfare.
435

Holšteino veislės įtaka Lietuvos juodmargių karvių produktyvumui ir pieno sudėčiai / Influence on Holstein breed on the milk production and composition of black and white cows

Kačinskaitė-Žuvaitienė, Dovilė 19 April 2007 (has links)
The aim of Master work is to valuate Lithuanian black and white cows productivity and milk composition considering the blood dimensions of holstein breed. All data had been made through statistical analysis by EXCEL computation as well as by statistical package „R“ (http://www.r-project.org) in the LVA Laboratory of Animals Research of Breeding Worth and Selection. It was stated that the average of the Holsteinization grade of the researched cows in stock was 79,38 percent, and only 7,1 percent of the researched cows average of the Holsteinization grade didn’t reach 50 percent. Intermediate correlation between the milk productivity and milk protein was found an unfavourable but statistical reliable coherence (r=-0,346, p<0,001) The highest milk productivity was by cows with Holsteinization grade of 87,5-98,5 percent, the best milk fat consistence in percent 62,5-74,0 percent of Holsteinization grade cows, and the best milk protein consistence was by cows with Holsteinization grade reaching up to 50 percent. Having developed holsteinization grade in a stock, the percent of cows productivity was set the little statistical reliable coherence (r=0,224, p<0,01). The greatest number of somatic cells (532,7 thousand/ml.) was found in milk of cows which had the holsteinization grade to 50 and 50,0-62,4 percent.
436

Evaluation of factors associated with resistance to sub-acute ruminal acidosis

Schlau, Nicole A Unknown Date
No description available.
437

Analytical considerations and biology of milk conjugated linoleic acid synthesis in the bovine

Mohammed, Riazuddin Unknown Date
No description available.
438

Šėrimo sezoniškumo poveikis karvių sveikatai ir produkcijos kokybei / The Influence of Seasonality Feedings Rations on Cows Health and the Production Quality

Baltrušaitytė, Monika 05 March 2014 (has links)
Ūkininko karvės žiemą laikomos ant kilimėlių. Taikomas trumpasaitis laikymo būdas. Karvės vasarą išgenamos į ganyklas. Tiek tvartiniu, tiek ganykliniu laikotarpiu, karvės melžiamos automatizuotai į pieno linijas. Girdomos iš automatinių girdyklų, šeriamos du kartus per parą. Karvės tvartiniu laikotarpiu šeriamos koncentruotais pašarais, kukurūzų ir žolės silosu, šienu. Ganykliniu laikotarpiu jos gauna koncentruotųjų pašarų ir kultūrinių ganyklų žolės. Fermoje yra laikoma 100 melžiamų karvių, 38 telyčios, 26 veršeliai (iki 6 mėn. amžiaus). Fermoje laikomų galvijų veislės : Lietuvos juodmargės, Holšteinų, Lietuvos žalosios. 2013 metais vidutinis bandos produktyvumas buvo 5391,2 kg pieno, vidutinis pieno riebumas – 4,34 proc., pieno baltymingumas – 3,63 proc. Tyrimo rezultatai: Tvartiniu laikotarpiu kraujo serume nustatyta bendrųjų baltymų – 63,5 g/l,(p > 0,05), gliukozės – 3,35 mmol/l,(p<0,05), kalcio – 2,2 mmol/l, magnio – 0,95 mmol/l, fosforo – 1,75 mmol/l, (p<0,01). Ganykliniu laikotarpiu kraujo serume nustatyta bendrųjų baltymų – 65,4 g/l, gliukozės – 3,0 mmol/l, kalcio – 2,5 mmol/l, magnio – 0,87 mmol/l, fosforo 1,58 mmol/l. Kraujo tyrimai parodė, kad karvės yra sveikos, didelių nuokrypių nuo fiziologinių normų nebuvo. Pieno tyrimuose tvartiniu laikotarpiu nustatėme riebalų - 4,24 proc. (p<0,01), baltymų – 4, 05 proc. (p<0,01), laktozės – 4,51 proc. (p>0,01), urėjos – 19,8 mg% (p<0,01), somatinių ląstelių – 166,47 tūkst./ml (p<0,01). Ganykliniu laikotarpiu pieno... [toliau žr. visą tekstą] / In winter period those cows lives on the mats. The short leash storage method is applied. In the summer period cows stays in pasture. In both indoor and outdoor periods cows are milked in automated milk lines. They drink from automated watering place and they are fed twice a day. During the stable period cows are fed with concentrate food, corn and grass silage, hay. Following a free-range period they eat a concentrated food and cultivated pasture grass. In this farm there are a 100 dairy cows, 38 heifers and 26 calf (up to six months). The breeds of cows: Lithuanian Black and White, Holstein, Lithuanian red. In 2013 the average productivity of the herd was 5391,2 kg of milk. The average fat level - 4,34 prercent, milk protein level - 3,63 percent. The results: The results of blood test in indoor period have shown : crude protein – 63,5 g/l (p > 0,05). Glucosis – 3,35 mmol/l,(p<0,05). Ca – 2,2 mmol/l, Mg – 0,95 mmol/l, P – 1,75 mmol/l, (p<0,01). In grazing period, milk test have shown : crude protein – 65,4 g/l. Glucosis – 3,0 mmol/l. Ca – 2,5 mmol/l, Mg – 0,87 mmol/l, P - 1,58 mmol/l. The blood tests showed that the cows are healthy. There were no significant deviations from the norms. The results of milk in indoor period have shown : milk fat - 4,24 proc. (p<0,01). Milk protein – 4, 05 proc. (p<0,01). Milk lactose – 4,51 proc. (p>0,01). Milk urea – 19,8 mg% (p<0,01). Somatic cell – 166,47 tūkst./ml (p<0,01). The results of milk in grazing period have shown: milk fat –... [to full text]
439

Gydymo įtaka slaptojo mastito kontrolei / Effects of treatment on subclinical mastitis control

Juškevičiūtė, Laura 05 March 2014 (has links)
Darbo tikslas: Išanalizuoti karvių bandos pieno kokybinę sudėtį ir patikslinti trūkinamų karvių profilaktikai taikomų medikamentų poveikį. Darbo uždaviniai: 1. Išanalizuoti karvių bandos pieno kokybinę sudėtį. 2. Tiriamojoje karvių fermoje reagentu CMT ištirti pasirinktų tyrimams karvių tešmens ketvirčius, prieš užtrūkinant ir po apsiveršiavimo praėjus 10dienų . 3. Atlikti bakteriologinius pieno tyrimus, prieš užtrūkinant ir po apsiveršiavimo praėjus 10dienų . 4. Nustatyti preparatų gydomąjį efektyvumą. Mokslinis - tiriamasis darbas buvo atliekamas 2010 – 2013 metais, privačiame ūkyje, Tauragės raj. Tyrimui buvo atrinktos 20 karvių, kurios buvo sugrupuotos į dvi grupes po 10 karvių. Grupėms buvo skirtas skirtingas gydymas, 1 –oji grupė gydyta preparatu „Rilexine 500“, 2 – oji grupė preparatu „OrbeSeal“. Prieš gydymą ir po gydymo buvo stebėtas SLS, pieno baltymų, riebalų, laktozės ir urėjos kiekio kitimas. Taip pat mastito sukėlėjų diagnozavimas, tešmens ketvirčių užkrėstumas. Išanalizavus bandos pieno kokybinę sudėtį, galima teigti, kad pieno kokybiniai rodikliai ima gerėti, po sėkmingo mastito gydymo. Prieš užtrūkinant abiejų grupių karvių teigiamai į CMT testą reagavo 55 % ketvirčių. Po veršiavimosi praėjus 10 dienų, pirmos grupės karvių į CMT teigiamai reagavo tik 10 %, o antros grupės karvių – 37,5 % ketvirčių. Pažeisti dažniau buvo galiniai ketvirčiai, lyginant su priekiniais. Prieš užtrūkinant 1 grupės karves, pagrindinė pieno mėginių mikroflora buvo sąlyginai... [toliau žr. visą tekstą] / Goal of the work: To analyze the qualitative composition of milk in the cow herd and effects of medications used for prevention of the termination of cow lactation. Tasks of the work: 1. To analyse the qualitative composition of milk in the cow herd. 2. Using the CMT reagent in the analysed cow farm, to examine the udder quarters of cows is selected for analysis, before termination of lactation and in 10 days after calving. 3. To perform bacteriological milk tests before termination of lactation and in 10 days after calving. 4. To determine the effectiveness of therapeutic preparations. The research work has been carried out in 2010–2013 in the private farm in Tauragė district. 20 cows were selected as the sample for research, and grouped into two groups of 10 cows. Groups received different treatment, the first group was treated with Rilexine 500, the second group with OrbeSeal preparation. Changes in the SCC, milk protein, fat, lactose and urea content were monitored before and after treatment along with diagnostics of mastitis pathogens and infection of the udder quarters. The analysis of the qualitative composition of the herd milk allows the state that the qualitative milk indicators start to improve after successful treatment of mastitis. Before termination of lactation, 55% quarters of both groups of cows showed positive response to the CMT test. 10 days after calving, only 10 % quarters of the first group of cows and 37.5% quarters of the second group of cows... [to full text]
440

PIENO SUDĖTIES IR KOKYBĖS RODIKLIŲ ANALIZĖ PRIKLAUSOMAI NUO KARVIŲ LAIKYMO IR MELŽIMO BŪDO / MILK COMPOSITION AND QUALITY INDICATORS ANALYSIS DEPENDS OF COWS KEEPING CONDITIONS AND MILKING TECHNOLOGY

Alūzaitė, Laura 05 March 2014 (has links)
Darbo tikslas buvo išanalizuoti skirtingai laikomų ir melžiamų karvių pieno sudėties ir kokybės rodiklius. Darbo uždaviniai buvo išanalizuoti tiriamų melžiamų karvių pieno sudėtį ir kokybę, įvertinti ir palyginti skirtingai laikomų ir melžiamų karvių pieno sudėtį, įvertinti ir palyginti skirtingai laikomų ir melžiamų karvių somatinių ląstelių skaičių piene. Tyrimui buvo pasirinktas ūkis, kuriame karvės laikomos dviejose fermose ir gyvuliai buvo laikomi bei melžiami skirtingais būdais. Kontrolinio melžimo metu buvo paimtas pienas tyrimams atlikti. Buvo nustatyti pieno riebalų, baltymų kiekiai, somatinių ląstelių skaičius tiriamajame piene. Duomenys analizuoti skaičiuokle „Excel“. Skaičiuojami statistiniai rodikliai: narių skaičius, aritmetinis vidurkis, aritmetinio vidurkio paklaida, duomenų statistinis patikimumas. Rezultatai laikyti patikimais, kai p<0,05. Nustatyta, jog didesnis pieno baltymingumas proc., riebumas proc., bei somatinių ląstelių skaičius tūkst./ml buvo karvių piene, kurios laikomos pririštos. Tai reiškia, kad šios fermos karvių pieno sudėties rodikliai aukštesni, bet dvigubai didesnis somatinių ląstelių skaičius (kokybės rodiklis) parodo, kad pienas gaunamas ne toks kokybiškas ir ferma turi problemų su karvių sveikatingumu. 8,3 proc. visų palaido laikymo karvių piene, bei 20,2 proc. visų pririšto laikymo būdo karvių piene, somatinių ląstelių skaičius viršijo 500 tūkst./ml. Rugpjūčio mėn. laikant karves palaidu būdu pieno riebumas proc. nustatytas mažiausias... [toliau žr. visą tekstą] / The main goal of this thesis is to analize milk quality and composition in differently held dairy cows. To achieve this goal, first we analyzed the quality and composition in investigated cows; secondly, we eveluated and compared milk composition in differently held cows; finally, we eveluated and compared the number of somatic cells in differently held dairy cows. For analysis we chose a farm, which was divided into two. In both parts of the farm cows were held and milked differently. During the control milking we collected milk for analysis. We determined the amount of fat, protein and somatic cells in the analyzed milk. The data was analyzed using Excel with which we calculated the number of members, arithmetic average, standart deviation, and reliability. The results were reliable, if p < 0,05. We determined that the greater amount of protein (%), fat (%), the number of somatic cells thousands/ml was in dairy cows that are held tethered. This shows that, in this farm, milk composition is greater, but also the number of somatic cells is twice as big, which means that the milk quality is not good, and that there are health problems in this farm. 8,3 percent all loose cow's milk, and 20,2 percent pegged all manner of storage of cow milk somatic cell count exceeded 500 thousand./ml. In August keeping cows loose manner percent milk fat the lowest of the entire study period. In June and August keeping tethered cows milk protein content by percent was lower than in other... [to full text]

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