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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.
261

Pregnancy-associated glycoprotein (PAG) profiles in cows and goats and attempts to measure PAG in milk

Shahin, Mazhar 07 November 2012 (has links)
No description available.
262

Vitamino D, kalcitonino ir parathormono kiekių kaita karvių kraujo serume bei reikšmė mineralinių medžiagų apykaitos procesams / Variation of blood serum vitamin D, calcitonin, parathyroid hormone levels in cows and their importance for processes of mineral metabolism

Bandzaitė, Virginija 30 December 2005 (has links)
Change particularities of the blood serum levels of vitamin D, calcitonin and parathyroid hormone were analysed in healthy cows of different feeding, age and productivity and in sick cows with metabolic diseases. It was investigated how biochemical indicators vary in cows with metabolic diseases (parturient paresis, osteomalacia and mastitis) and the most informative indicators for diagnostics of these diseases (for levels of calcium, phosphorus and magnesium) were determined. Obtained findings were processed statistically. The method of electrochemiluminescence analysis used for analysis of the blood serum levels of PTH in humans was applied. Compared with radioimmunic method, this method is not expensive and quite fast; in addition, this method is sensitive and reliable, because it permits to detect low levels of PTH in the blood serum (up to 0.127 pmol/l). The method of chemiluminescence immunometric analysis used to find the level of CT in humans was tested. Also the method of immunoferment analysis (ELISA) was tested to measure the blood serum level of 25-OH vitamin D in cattle using human antibodies.
263

Kai kurių reprodukcijos rodiklių įtaka somatinių ląstelių skaičiui karvių piene / Reproductional indicator influence on the somatic cell count of cow's milk

Jonikaitė, Inga 19 April 2007 (has links)
Research data show that the somatic cell count increases during the transition period when dairy cows are transferred from barns to pastures (month of May) and during the transition period when dairy cows are transferred from pasture to barn (month of October). During these period’s feedstuff composition changes, as does the temperature, microclimate parameters, which also have an influence on cows with Sub-clinical mastitis. Somatic cell counts are lowest in 1st lactation cows. 1st lactation cow somatic cell count in milk was 440,000 ± 66,400 cells/ml (2004) and 326,000 ± 55,500 cells/ ml (2005). Later lactation’s cow somatic cell counts in milk is higher, however the highest cow somatic cell count in milk is in 5th and upward lactations. Reproduction is usually evaluated during the span of the service period, taking into account the animal’s age at 1st parturition, its fertilisation index, timeframe between parturitions, and duration of pregnancy. These are important herd reproduction traits. Due to disorders in reproduction functions, costs of fertilisation increase and economic losses are sustained (Borman, 2006). The cow’s age at 1st parturition affects the heifer’s rate of maturity which also depends on the husbandry conditions and breed. During 2003 – 2004, the average age of 1st parturition Lithuanian Black/White breed cows was 26.7 - 32.6 months (Republic of Lithuania, Ministry of Agriculture, 2005). An early 1st parturition age (up to 23 months) is followed by a... [to full text]
264

Laktozės kiekio nustatymas Lietuvos juodmargių karvių piene LVA Praktinio mokymo centre / Estimation of lactose quantity in milk from Lithuanian black-and-white cows from Centre for Practical Instruction of LVA

Pranckevičius, Virginijus 18 March 2008 (has links)
Darbo tikslas ir uždaviniai: 1. Ištirti laktozės kiekio kintamumą LVA Praktinio mokymo centro karvių piene. 2. Įvertinti tvartinio ir ganyklinio laikotarpio įtaką laktozės kiekiui. 3. Įvertinti sezono įtak�� laktozės kiekiui. 4. Nustatyti ir įvertinti mėnesio įtaką laktozės kiekiui karvių piene. 5. Nustatyti ir įvertinti laktacijos įtaką laktozės kiekiui. 6. Nustatyti ir įvertinti laktacijos mėnesio įtaką laktozės kiekiui Buvo skaičiuojami statistiniai rodikliai Vidurkis (mean), vid. paklaida (std. Error of Mean), median (mediana), minimum, maximum. Darbe naudojama programinė įranga: Exsel, Word. Susisteminta, sugrupuota bei analizuota Excel pagalba. Tam panaudoti pirminės informacijos sisteminimo, apibendrinimo ir matematiniai duomenų apdorojimo metodai. Karvės buvo sugrupuotos pagal laktacijas, laktacijos mėnesius, pagal sezonus, metų mėnesius. Teorinės šio darbo medžiagos kaupimui ir jos analizei panaudoti loginio mąstymo, sisteminimo, monografinis ir apibendrinimų metodai. Praktinės tyrimų medžiagos analizavimui panaudoti analitiniai, statistiniai metodai. Rezultatai ir išvados: 1.Tvartiniu ir ganykliniu laikotarpiais laktozės kiekiai karvių piene skyrėsi 0,07 % 2. Didžiausias laktozės kiekis karvių piene buvo pavasarį, o mažiausias – rudenį ir žiemą. 3. Kovo ir gegužės mėnesiais buvo didžiausi laktozės ir riebalų kiekiai piene. 4. Pirmos laktacijos karvių piene yra daugiau (0,21%) laktozės, nei III ir vyresnių laktacijų karvių piene. 5. Laktacijos mėnesio atžvilgiu... [toliau žr. visą tekstą] / Object and tasks of work: 1. To evaluate the variability of lactose quantity in milk from cows from Centre for Practical Instruction of LVA. 2. To evaluate the influence of periods, when cows are in cowshed and when in pasture, to lactose quantity. 3. To evaluate the season‘s influence to lactose quantity. 4. To institute and evaluate month‘s influence to lactose quantity of cows milk. 5. To institute and evaluate lactation influence to lactose quantity. 6. To institute and evaluate influence of lactation months to lactose quantity. There were being calculated the following statistical indexes: mean, error of mean, median, minimum, and maximum. There were used the following software: Excel, Word. Data was systemised, grouped and analysed using Excel. There were used processing methods of primal information filing, generalization and mathematics data. Cows were grouped according to lactations, months of lactation, seasons, and according months of the year. For accumulation and analysis of this theoretical material, there were used the following methods: logical thinking, filing, monographic and generalization. For analysis of practical research material there were used analytical and statistical methods. Results and conclusions:1. Lactose quantity during the periods, when cows were in cowshed and when in pasture, in cow milk differed in 0,07 %; 2. The biggest lactose quantity in cows’ milk was in spring and the smallest in autumn and winter; 3. In months of March and May... [to full text]
265

Karvių melžimo operacijų įtaka somatinių ląstelių skaičiui piene / Effect of milking procedures on milk somatic cell count

Martinkus, Nerijus 18 March 2008 (has links)
Modernios pienininkystės fermos sėkmė priklauso nuo to, ar joje gaminamas pienas yra aukštos kokybės. Pagrindiniai veiksniai, turintys įtakos somatinių ląstelių skaičiui piene, yra gera melžimo organizacija, melžimo įrangos taisyklingas veikimas, klinikinių mastitų gydymas antibiotikais ir kt. Mokslininkai įrodė, kad melžti karves kas dvylika valandų yra optimaliausia, kai jos melžiamos du kartus per parą. SLS piene daug priklauso nuo taisyklingos melžimo darbotvarkės, kuri apima skirtingas melžimo operacijas (tešmens ir spenių paruošimas melžimui, spenių dirginimas, pirmųjų pieno čiurkšlių numelžimas, melžiklių užmovimas ant spenių, melžiklių numovimas pamelžus ir efektyvi spenių antiseptika po melžimo) ir nuo šių operacijų trukmės. Teisingai atliekamos melžimo procedūros yra svarbios mastito prevencijai ir užtikrina visišką pieno išmelžimą iš tešmens. Tyrėjai įrodė, kad daugiau kaip 50 % melžimo proceso laiko užtrunka pats melžimas. Dabartiniu metu melžimo operacijos vis labiau mechanizuojamos. Netaisyklingas melžimas gali pailginti pieno atleidimo laiką, didėja rizika susirgti tešmens uždegimais. Pablogėja pieno kokybė, todėl gaunami ekonominiai nuostoliai. Padidėjęs somatinių ląstelių skaičius piene ¬ svarbus mastito požymis. Perdirbamajai pramonei karvių mastitas buvo ir liks vienu iš svarbiausių trukdžių gaminant aukštos kokybės pieno produktus. Klinikine forma serga 2 – 5 % laktuojančių ir užtrūkintų karvių, o slaptuoju uždegimu – iki 50 % karvių. Viena dažniausiai... [toliau žr. visą tekstą] / Data were collected from two dairy farms. On the farm A cows were milked using full automatised milking equipment „Milkmaster“. On the farm B cows were milked with „Interpuls“ milking equipment. The DeLaval milking system was supplied with automatic cluster remover. On dairy farms A and B cows were milked twice daily. The goal of our studies was to analyse consumption of main milking operations (cow udder preparation before milking, milking and over-milking) and their influence on milk somatic cell count. Were selected 20 cows in each farm. The duration of main milking procedures were recorded. Data on milk, fat and protein yields and somatic cell count were collected.The mean duration of pre-milking udder preparation was 42 s (farm A) and 46,03 s (farm B). Some cows were prepared only for 25,50 Afarm A) s, whereas the udder preparation comprised merely inadequate cleaning of teats. The maximum duration of over-milking was 41,10 (farm B).
266

Lietuvos juodmargių galvijų bandos melžimo savybių įvertinimas ūkininko Z. Armino ūkyje / The assessment of milking qualities of black and white Lithuanian dairy cattle at the farmer’s Z. Arminas farm

Burinskas, Valdas 28 June 2008 (has links)
Šio darbo tikslas buvo ištirti ir įvertinti Lietuvos juodmargių galvijų melžimo savybes, išanalizuoti produktyvumo priklausomybę nuo melžimo savybių. Įvertinus skirtingų tešmens ketvirčių produktyvumą, nustatyta, kad 0,53 kg daugiau pieno primelžta iš užpakalinių ketvirčių nei iš priekinių. Melžimo trukmė iš skirtingų ketvirčių buvo nuo 4,81 min.(priekinis kairys) iki 5,18 min (užpakalinis kairys).Priekiniai ketvirčiai vidutiniškai 0,35 min. išsimelžė greičiau nei užpakaliniai ketvirčiai. Melžimo greitis skirtinguose ketvirčiuose buvo panašus. Melžimo greitis 0,03 kg/min. Didesnis buvo užpakalinių ketvirčių lyginant su priekiniais. Išnagrinėjus skirtingų laktacijos karvių melžimo savybes, nustatyta, kad ilgiausia melžimo trukmė buvo III ir vyresnių laktacijos karvių. Ji buvo 0,09 min. ilgesnė nei visų laktacijos karvių. Mažiausia melžimo trukmė buvo II laktacijos karvių. Ji buvo 0,11 min trumpesnė nei vidutinė visų laktacijos karvių. 0,07 kg/min didesnis melžimo greitis nustatytas II laktacijos karvių lyginant su visų laktacijų karvių vidurkiu. I bei III ir vyresnių laktacijos karvių melžimo greitis 0,02 kg/min mažesnis lyginant su visų laktacijos karvių melžimo greičio vidurkiu. Suskirsčius karves pagal melžimo balus nustatyta, kad didesnis pieno kiekis gautas iš tų karvių kurių melžimo balai aukščiausi. Daugiausia pieno primelžta iš tų karvių, kurių melžimo balas 4. Šių karvių primelžtas pieno kiekis 1,34 kg didesnis nei vidutinis visų karvių pieno kiekis. Lyginant su visų... [toliau žr. visą tekstą] / Aim of work: was to examine and assess the milking qualities of Lithuanian black and white diary cattle, also to analyze the dependence of productivity upon milking qualities. The work was performed in Lithuanian Academy of Veterinary, during Master studies 2006-2008. During the analysis, data of controlled cows’ productivity was analyzed according to accounting information of cattle breeding. Data was statistically analyzed using calculator EXCEL and “R” statistic package. Arithmetical average of features (M), their biases (Se) and characteristics of dispersion – average square deviations (Sd) and variation coefficients (Cv) were calculated. During the analysis we evaluated 28 Lithuanian black and white cows. The Results of Survey: Taking into account the different productivity of each quarter of the udder, it was measured, that from the back parts of udder was milked 0.53 kg more milk than from the front parts. The milking time from different quarters was from 4.81 minutes (front left) to 5.18 minutes (back left). Front quarters were milked 0.35 minutes faster than the back ones. The milking speed in different quarters was almost the same 0.03 kg/min. The speed was higher in the back quarters in comparison with the front ones. After examining the milking qualities of different lactation cows, it was established that the longest milking duration had cows of lactation III and older. It was 0.09 minutes longer than average milking duration of all cows. Lactation II cows had... [to full text]
267

Fiziologinių duomenų tyrimai šliužo dislokacijos diagnostikai, profilaktikai ir gydymui / The research of the physiological parameters in the diagnostics, prophylactics and treatment of the abomasums displacement

Antanaitis, Ramūnas 19 December 2008 (has links)
Darbo tikslas: Įvertinti šliužo dislokacijos (ŠD) prognostinės diagnostikos galimybę, karvių fiziologinę būklę po šliužo repozicijos pagal būdingą ŠD sergamumo specifiką, pieno kiekio, elektrinio pieno laidumo, aktyvumo, kūno masės, melžimo trukmės nuokrypius. Uždaviniai: 1. Atlikti sergamumo ŠD tyrimą; 2. Įvertinti, kaip kinta pieno kiekis, elektrinis pieno laidumas, gyvulio aktyvumas, kūno masė, melžimo trukmė prieš susergant ŠD; 3. Įvertinti ŠD diagnostikos galimybę pagal kraujo serumo biocheminius rodiklius, pieno sudėtį, fiziologinių rodiklių nuokrypius, ŠD klinikinės diagnozės nustatymo dieną; 4. Įvertinti, kaip kinta pieno kiekis, elektrinis pieno laidumas, gyvulio aktyvumas, kūno masė, melžimo trukmė po ŠD repozicijos; 5. Įvertinti teoriškai pieno kiekio kitimo prognozę, atlikus ankstyvąją diagnostiką ir profilaktiką. Įvertinta karvių ŠD prognostinės diagnostikos galimybė, fiziologinė būklė po šliužo repozicijos pagal būdingą ŠD sergamumo specifiką, pieno kiekio, elektrinio pieno laidumo, aktyvumo, kūno masės, melžimo trukmės nuokrypius. Pagrįsta praktinė tiriamų parametrų panaudojimo galimybė. / The objective of this work: To evaluate the possibility of the prognostic diagnostics of the displaced abomasums, the physiological status of the cow after the reposition of abomasums according as the particularity of the displaced abomasums’ morbidity, deviation of milk yield, milk conductivity, walking activity, body weight and milking duration. The problems of this work: 1. To do the research about the morbidity of the displaced abomasums; 2. To estimate the dynamics of the milk yield, milk conductivity, cow’s walking activity, body weight, milking duration before the abomasums was displaced; 3. To estimate the possible diagnostics according as the biochemical results of the blood serum, milk composition, deviations of the physiological indicators at the day of clinical diagnosis of the displaced abomasums; 4. To evaluate the dynamics of the milk yield, milk conductivity, cow’s walking activity, body weight, milking duration after the abomasums was displaced; 5. To evaluate in theory the prognosis of the milk yield changes after the early diagnostics and prophylactics. The possibility of prognostic diagnostics of the displaced abomasums, physiological status of the cow after the reposition of abomasums according as the particularity of the displaced abomasums’ morbidity, deviation of milk yield, milk conductivity, walking activity, body weight and milking duration were evaluated. The possibility of practical appliance of the examined parameters was justified.
268

Karvių kiaušidžių funkcijos tyrimas po apsiveršiavimo / Assessment of ovarian function in post partum dairy cows

Rutkauskas, Arūnas 22 November 2005 (has links)
Measurements of ovarian, corpus luteum, follicles of Lithuanian Black and White and German Black and White breed cows made by ultrasound scanner were revised. Effect of different factors, such as age, breed and season determining persistence of corpus luteum was statistically evaluated. Validation of treatment efficacy of persistent corpus luteum was carried out based on testing of progesterone concentration in peripheral blood plasma.
269

Nutrient excretion and soil greenhouse emission from excreta of overwintering beef cows fed forage-based diets supplemented with dried distillers’ grains with solubles

Donohoe, Gwendolyn R. 17 January 2011 (has links)
A study was conducted to examine the impact of diet and cold weather on the excretion of nitrogen (N) and phosphorus (P) from beef cows, and the potential for these nutrients to be lost to waterways or as greenhouse gases (GHG). Feces and urine were collected from mature cows fed low-quality forage supplemented with DDGS to 0%, 10%, and 20% ww-1 in the fall of 2008 and winter of 2009. A detailed nutrient analysis was performed to determine forms of N and fractions of P in excreta. Feces, urine, and a simulated bedding pack were then applied to grassland to determine soil GHG emission. Cattle receiving DDGS supplementation excreted greater proportions of labile P in feces and greater concentrations of P in urine. The 20% DDGS diets had greater nitrous oxide emission from urine patches and greater proportions of available N in urine and feces.
270

THE EFFECTS OF NUTRITIONALLY‐MODULATED PREPARTUM BCS ON PRE‐ AND POSTPARTUM METABOLIC RESPONSES, <em>IN VITRO</em> LIPID METABOLISM AND PERFORMANCE OF MULTIPAROUS BEEF COWS

Hudson, Melissa Dale 01 January 2011 (has links)
Increased BCS at calving due to nutritional manipulation during the prepartum period resulted in greater mobilization of body fat after calving, regardless of plane of nutrition during the last 60 d of gestation. Although fatter cows were shown to have greater mobilization of reserves during the postpartum period, they maintained greater BCS at all points from calving to weaning compared to cows calving with fewer reserves at calving. A unique finding of this experiment was that the variation in BCS at calving was positively associated with BCS loss for cows fed to accrete BC during the prepartum period but was not associated with BCS loss for cows fed at maintenance levels during gestation. This finding suggests a threshold response in which BCS loss postpartum is only related to BCS at calving of 6.5 or greater. Progeny of fatter cows were heavier at d 40 and 84, but no treatment differences existed at weaning. The relationship between BCS at calving and calf BW at d 40 differed by treatment. This suggests a threshold response in which calf BW is positively related to increases in BCS up to 5.75. At BCS ≥ 5.75 calf weights were greater than at lower BCS levels but were unrelated to incremental changes in BCS. Altering dietary energy level during mid and late gestation altered the net lipolytic rate of beef cows and altered the timing of changes in tissue sensitivity and total lipolysis. Basal release of NEFA did not change for cows on a maintenance diet, but increased significantly for fatter cows prior to calving, whereas basal glycerol was unaffected by treatment. The stimulated release of glycerol was also unaffected by treatment, but increased across all periods. The ratio of stimulated glycerol and NEFA release to basal release of glycerol and NEFA indicate that the AT of HI cows has a delayed response to the increase in sensitivity to lipolytic stimulants that is associated with homeorhetic adaptations; however, at 7 d after calving, no differences were observed for net or total lipolytic capacity of the tissue. Providing mature beef cows ad libitum access to a high‐energy diet alters pre‐calving sensitivity of AT, but after calving and when animals are receiving a common diet, no differences in lipolysis were observed. Thus, BCS (4.91 to 6.56), as manipulated by diet, does not appear to impair lipolytic function and regulation in beef cows as observed in dairy cows.

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