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]

To analyze fluctuation of indexes of consist and quality of milk of black and white and red-spotted cows during different months and seasons of lactation. The work was performed in Lithuanian Academy of Veterinary, department of stockbreeding as well as public enterprise Pieno Tyrimai during Master studies 2005-2007. During the analysis, data of controlled cows’ productivity was analyzed according to accounting information of cattle breeding. During the analysis we evaluated 98 Lithuanian black and white cows, Lithuanian red-spotted cows, as well as Ayrshire cows. Milk yield of Lithuanian black and white cows was 1160 kg of milk more than Ayrshire and 252 kg of milk more than Lithuanian red-spotted. Average milk yield of Ayrshire cows was 92 kg more than Lithuanian red-spotted. There was 0.53–0.83% of fat in milk of Lithuanian black and white cows, protein was 0.24–0.25% less than in Ayrshire or Lithuanian red-spotted. Lithuanian black and white cows had 1.0–15.0 kg of milk fat (or 0.3 –4.8%), milk protein – 23.0–25.0 kg (or 11.2–9.4%) more than in Ayrshire or Lithuanian red-spotted. During all periods of lactation most milk fat were found in milk of Ayrshire cows (5.05%), least in Lithuanian black and white cows (4.21%). Milk fat of Lithuanian black and white and Lithuanian red-spotted was less in comparison with Ayrshire cows. During all months of lactation most amount of protein was found in Lithuanian red-spotted and Ayrshire (3.69-3.68%), and least – in Lithuanian black... [to full text]

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.