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Estimating Genetic Parameters using a Random Regression Model
53-55Views:99One of the most important part of the genetic evaluation using a random regression model is the estimation of variance components. This is the topic of many papers because the large computational costs. We can use restricted maximum likelihood (REML), Gibbs sampling and ℜ method for the estimation of genetic parameters. The variance components are necessary to calculate the heritabilities and repeatabilities.
The aim of our paper is to estimate the variance components using a random regression repeatability model from test day data set of Hungarian Holstein-Friesian dairy cows and to analyse the change of additive genetic and permanent environmental variance, heritability and repeatability over lactation. -
The effect of season on the microbiological status of raw milk
95-99Views:117Many factors can influence the microbiological quality of raw cow’s milk. In this study, our aim was to determine whether there was any difference between the microbiological statuses of milk produced in different seasons. Samples were collected and analysed from five dairy farms in Hajdú-Bihar County, from February to November in 2019. During our studies, total plate count (TPC), coliform count and Staphylococcus aureus count of raw cow’s milk samples were determined.
There was no significant difference (P>0.05) between the mean TPC values detected in the milk collected in winter and autumn, but that values were significantly (P<0.05) lower than in the milk samples collected in spring and summer. Similarly to the TPC, in the case of coliform bacteria the lowest mean colony count was detected in the samples collected in winter. The difference was significant (P<0.05), compared to the values observed in the samples collected in summer. S. aureus was detected in bulk milk of only two farms in excess of 1.0 log10 cfu/ml. Also in case of S. aureus, there was a significant difference (P<0.05) between the values observed in the samples collected in winter and in summer. Samples from spring and summer contained the highest amount of S. aureus.
Based on the results of our studies, in the case of almost all farms the mean TPC, coliform and S. aureus counts were lower in the samples collected in winter, than in the samples collected in summer. The fact that the samples collected in winter contained the lowest amount of colonies could be attributed to the inhibition of growth of mesophilic microorganisms below 8 °C. Furthermore, the fact that we observed the highest colony counts in samples collected in summer, can be related to the heat stress of cows during the summer due to unfavorable weather conditions (high temperature and humidity).
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The possibilities of the development of functional dairy products
33-36Views:119Because of our new aged world’s emerging stress, over exhausting and move less lifestyle the pollution, the not appropriate food consuming and the low calories in the consumed food there are more and more the called „civilian” disorders.
Many people have diabetes and osteoporosis others fight with lung, cardiovascular system, problems and find cancers of many kinds without age exemptions.
There could be a solution in changing lifestyle. In the developed side of the world there are presence of food lines with higher content in nutritious and/or vitamins and fibers such as: kalium, calcium, selen, magnesium, plus it contains less saturated fat. Because of that there is a new word in dietetics as functional foods.
Food having more inner content and/or biological values, so healthier, are called functional foods. Those foods components picked carefully for healthiness by modern knowledge of dietetics.
One of the best raw materials for functional food is the milk. It is already healthy by itself. The Körös-Maros Biofarm Ltd. has a goal of developing and marketing, health protecting organic functional foods in hungaricum products from cured milk. The Jedlik Ányos project helps the Ltd. to achieve this goal. We just finished an antioxidant test and we check if the antioxidant in present in the milk than we check the final product of the presence of the original antioxidant and the form and amount of it.
It had been feeding, for two weeks for three herd of cows selected for age, milk output and consanguinity. All of the three herd had been feeding with basic forage. One of the herds had been getting vitamin-E in the amount of 250 mg/bwkg the other group got licopin in the amount of 200 mg/bwkg once a day each by each orally, the third herd was the control group.
After two weeks we toke a sample of every herd were processed the samples into yogurt and cheese. Than we checked the raw milk, the cheese and the yogurt for antioxidant content with HPLC method. The test ended with good results by finding a great amount of antioxidant, in not only the raw milk but also in the final product.