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The effect of breed and stage of lactation on the microbiological status of raw milk
37-45Views:318The microbiological quality of the milk is important not only for food safety, but it can also influence the quality of dairy products. The microbiological status of raw cow milk can be influenced by many factors. Our aim was to determine whether there was a difference between the microbiological quality of milk of two different cow breeds (Holstein Friesian and Jersey) kept and milked in the same conditions, and how the microbiological quality of the raw cow milk changed during lactation (beginning, mid, and end). Samples were taken and analysed in July, August and September in 2018 from two dairy farms in Hajdú-Bihar county. During the conducted studies, the total plate count (TPC), the coliform count, the Staphylococcus aureus count and the coagulase-negative Staphylococcus (CNS) count of raw milk samples were determined.
There was no significant difference (P>0.05) between the milk of the Holstein Friesian and Jersey breeds in the case of TPC. However, the mean coliform count of milk samples taken from Holstein Friesian cows was significantly lower (P<0.05) than the mean coliform count of milk samples taken from Jersey cows. S. aureus was detected in one of the twelve milk samples taken from Holstein Friesian cows, and in two of the eleven milk samples taken from Jersey cows. CNS was found in larger amount in milk samples taken from Holstein Friesian cows, and the difference was significant (P<0.05). Both TPC and CNS count were significantly higher (P<0.05) in individual milk samples taken at the end stage of lactation, than in samples taken in the earlier stages of lactation from Farm “A”. However, in the case of Farm “B”, there was no significant difference (P>0.05) in colony counts at different stages of lactation. S. aureus was only present in milk samples that collected from cows, which were at the beginning and middle stages of lactation. Testimg the hemolysin production ability of S. aureus strains isolated from the raw milk samples, only weak hemolysis was observed on blood agar. In case of antibiotic resistance testing, it was found that all strains were susceptible to cefoxitin, chloramphenicol, clindamycin, erythromycin, gentamicin, penicillin G, tetracycline and trimethoprim/sulphamethoxazole.
Based on the results of our studies, staphylococci were detected in a higher amount in the milk of Holstein Friesian cows, and coliform bacteria were detected in a higher number in the milk of Jersey cows. Summing up the results of the milk samples taken from the different stages of lactation in one of the farms, it can be concluded that higher TPC and CNS count could be detected at the end stage of lactation than in the samples taken from the earlier stages of lactation. The fact that at the end of lactation the microorganisms could be detected in a higher colony count may be related to the fact that teats could be damaged during lactation by the milking machine, which increased the chance of imvading the microorganisms into the udder.
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Estimating Genetic Parameters using a Random Regression Model
53-55Views:113One 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. -
Horn and coat color varieties of the Hungarian grey cattle
44-48Views:109Due to the intensification of agricultural production, genetic diversity has been reduced to a large extent. Presently, in the period of worldwide genetic conservation, we try to preserve as much of the gene pool of our valuable indigenous domestic animal breeds as we can. Therefore, traits that have no economic value at the moment should also be conserved. The different horn and coat colour varieties of Hungarian Grey Cattle are such valuable traits. Research has been done on the largest Hungarian Grey Cattle stock, at the Hortobágy Kht. Rates of the different horn and coat colour varieties were determined and relationships were analyzed between the above mentioned qualitative traits
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The effect of the queen's age on the Varroa mite (Varroa destructor) burden of honey bee (Apis mellifera L.) colonies
83-87Views:289An apiary trial was conducted in 2016 August to October in Szabolcs-Szatmár-Bereg County, Nyírmada to evaluate the influence of queen’s age on the Varroa destructor-burden in the treatment colonies. Sixty colonies of bees belonging to the subspecies Apis mellifera carnica pannonica in Hunor loading hives (with 10 frames in the brood chamber/deep super) were used. The colonies were treated with amitraz and the organophosphate pesticide coumaphos active ingredients. The amitraz treatment includes 6 weeks. The coumaphos treatment with Destructor 3.2% can be used for both diagnosis and treatment of Varroasis. For diagnosis, one treatment is sufficient. For control, two treatments at an interval of seven days are required. The colonies were grouped by the age of the queen: 20 colonies with one-year-old, 20 colonies with two-year-old and 20 colonies with three-year-old queen. The mite mortality of different groups was compared. The number of fallen mites was counted at the white bottom boards. The examination of spring growth of honey bee colonies has become necessary due to the judgement of efficiency of closing treatment. The data was recorded seven times between 16th March 2017 and 19th May 2017.
Data on fallen mites were subjected to one-way analysis of variance (ANOVA) and Post-Hoc Tukey-test. Statistical analysis was performed using the software of IBM SPSS (version 21.). During the first two weeks after treatments, the number of fallen mites was significantly higher in the older queen’s colonies (Year 2014). The total mite mortality after amitraz treatment in the younger queen’s colonies was lower (P<0.05) compared to the three-year-old queen’s colonies. According to Takács and Oláh (2016) although the mitemortality tendency, after the coumaphos (closing) treatment in colonies which have Year 2014 queen showed the highest rate, considering the mite-burden the colonies belongs to the average infected category. The colonial maintenance ability of three-year-old queen cannot be judged based on the influencing effect on the mite-burden. The importance of the replacement of the queen was judged by the combined effect of several factors.
During the spring-growth study (16th March–19th May) was experienced in the three-year-old queen’s colonies the number of brood frames significantly lower compared to the one- and two-year-old queen’s colonies. In the study of 17th April and 19th May each of the three queen-year-groups were varied. Therefore in the beekeeping season at different times were determined the colonial maintenance ability of queens by more factors: efficiency of closing treatment in early spring, the spring-growth of bee colonies, the time of population shift (in current study, this time was identical in each queen-year), honey production (from black locust).
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Evaluation of egg quality parameters of two Hungarian ostrich populations
51-57Views:216The aim of our study was to evaluate the quality parameters, porosity and weight loss of eggs deriving from the two most significant ostrich farms in Hungary. Quality parameters included weight, length, width, shape index, egg volume, surface area, circumference and shell volume. The effect of storage conditions in both farms and the incubation technology on egg weight loss in farm “A” were also examined. The research objective was to impart a comprehensive knowledge on egg quality parameters of the main ostrich populations in Hungary and to compare the trios and the farms with each other and the international literature. We could reveal significant differences between trios in all egg quality traits. In conclusion, the shorter and the narrower the eggs were, the more spherical shape they had. Narrower eggs showed smaller surface area, volume, circumference and shell volume and vice versa. Eggs from farm “B” indicated significantly greater width, shape index, surface area, circumference and shell volume than farm “A”. A significant difference was observed in weight loss during storage between the farms. Weight loss in farm “A” was a multiple of farm “B”. In farm “B” there was a weak, positive correlation between storage period and weight loss (r=0.22, P≤0.05), in farm “A” it was not significant (P=0.52). There was no relationship between the initial egg weight and weight loss either in farm “A” or farm “B” (P=0,21, P=0,69). A slight positive correlation could be noted between egg porosity and weight loss (r=0.24, P≤0.05). Pores count presented here was less than the international results. Poultry eggs contain the most pores at the blunt end, less via the equator and the least at the pointed end. In ostrich egg we found more pores via the equator against the blunt end. To draw more precise conclusions, further investigation should be carried out on porosity. Considering the fact that the length of storage period and the weight loss during incubation are in strict correlation with hatchability, we intend to extend our research aims to these traits.
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Effect of feeds with different crude fiber content on the performance of meat goose
5-8Views:353In the last 50 years, poultry meat production has increased dynamically. The role of crude fiber content in feed is unclear based on a small amount of literature about goose feeding.
The aim of theis experiment was to determine how various crude fiber content (55; 60; 65g crude fiber/kg feed) influences the performance of meat geese in the second phase of the rearing period. 150 goslings (3 treatments, 5 cages/treatment, 10 birds/cage) were included in the test. The experiment started and finished at the age of 21st and 63rd day, respectively.
The obtained results suggest that various crude fiber content did not influence the performance of meat geese significantly; however, a feed of 55g crude fiber/kg resulted in better fattening results (final body weight, body weight gain, specific feed protein and energy conversion rate). In addition, compound feed of 65g crude fiber/kg proved more favourable with respect to cost-efficiency. Based on the obtained results so far, further models and farm experiments are required.