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The effect of breed and stage of lactation on the microbiological status of raw milk
37-45Views:296The 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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The effect of keeping technology on the microbiological status of raw milk
67-75Views:100The importance of the quality of raw milk increased after Hungary had joined to the EU. On delivery of raw milk, the microbiological quality, especially total plate count of the milk is very important. Twenty-two farms (7 large, 4 medium-sized, and 11 small farms) were included in the study. We considered the different farm size, keeping- and milking circumstances during the selection of farms. The examined large farms use loose housing system (cubicle, deep litter) and milking parlour. Most of them use preand post-milking disinfection. In the medium-sized farms, loose,
deep litter and tie-stall housing system, as well as milking parlour, pipeline milking and bucket milking occurred. All of them use preand post-milking disinfection. Small farms use tie-stall housing system, bucket milking and udder preparation by water. Unfortunately, they do not use pre- or post-milking disinfection. In the large and medium-sized farms mainly Holstein Friesian, in the small farms Hungarian Simmental breeds can be found.
The aim of our research was to examine the microbiological status of the raw milk produced in dairy farms (total plate count, coliform count, Escherichia coli count, Staphylococcus aureus count, psychrotroph bacteria count, furthermore yeast and mold count); sources of the contamination; connection between the microbiological quality of produced milk and housing-, milking technologies of farms; furthermore the hygienic circumstances of milking and milk handling of the farms, by the examination of coliform bacteria and Escherichia coli contamination.
During the examination of the connection between the different farm sizes, various housing- and milking forms and the microbiological characteristics we observed similar tendencies in the case of total plate count, coliform count, yeast and molds count, furthermore psychrotroph bacteria count. The value of these parameters was significantly higher in small farms, and infarms which use tie-stall housing forms, bucket milking, udder preparation with water, and which do not use pre- and post-milking disinfection.
The results showed that besides cooling, the milking procedure and the type of udder preparation had the largest effect on the total plate count. Statistical analysis shows that in medium and small farms the combination of pipeline milking – tie stall housing system – disinfectant preparation of the udder; in large farms the combination of milking parlour – loose cubicle housing system – dry preparation of the udder are the most appropriate in the aspect of the total plate count. We experienced that in farms where the hygienic instructions are not followed – and therefore
equipment used during the milking and handling of milk is very contaminated – or rather the separation of mastitic cows’ milk is not appropriate, different microorganisms may contaminate the produced milk. -
Examinations connected with productive life in Hungarian Holstein Friesian populations
32-39Views:90In Hungary, an intensive dairy population has developed in the last few decades as the result of upgrading to Holstein-Friesian. Intensive milk production, adjusted with housing and feeding, unfavorably affected secondary traits. The number of days between two calvings has increased remarkably and productive lifetime has decreased drastically. In the interest of profitable milk production, it is important that cows should be able to stay in the herd as long as possible, in order to have great lifetime productivity.
The aim of this paper was to compare the production and pedigree of cows with eight or more lactations to cows which were culled after their first lactation.
It can be stated that cows with longer herd lives produced more milk in their first lactation than those which were culled after their first lactation. When analyzing the pedigree effect of sires, this could not be proven, although some bulls, mainly of Hungarian origin, appeared at a higher frequency. In the analysis of the effect of dams, it was found that many of the offspring of the cows with longer herd lives had similarly great lifetime productivity. Correlation between herdlife and milk production quantity traits was found to be mild or stronger (r>0,60), while according to our analysis, there is no correlation between herdlife and milk production quality traits. -
Analysis of longevity in Holstein Friesian cattle using proteomic approaches
21-25Views:124The aim of the present study was to determine marker proteins those are associated with functional longevity of dairy cattle. Holstein-Friesian cows were grouped based on their performance as follows: group 1) individuals with good longevity traits; group 2) short production life because of poor reproduction traits; group 3) short production life with low milk yield. Twelve individuals were sampled in each group, blood and milk samples were collected from cows. Blood samples were analysed with two dimensional polyacrylamide gel electrophoresis (2D PAGE), MALDI TOF/TOF and nanoLCMS/MS. The milk samples were analysed with MALDI TOF/TOF and nanoLC-MS/MS. Using the optimized gel based proteomic approach,
we have succesfully separated 143 proteins in the group1, 139 proteins in the group2 and 136 proteins in the group3, but we could not find significant differences between groups in the expression pattern. Using MALDI TOF/TOF and nanoLC-IonTrap MS, we have found eleven protein sequences those were expressed only in the samples of good longevity group. -
The role of type traits of dairy cattles in long productive life
11-18Views:92In the last few decades, a new intensive milking stock has developed as a result of breed-converter crossing in Hungary. Additionally, the reproduction biology of the population was adversely affected by keeping and feeding technologies. Productive lifetime has shortened and the service period has lengthened. However, profitable milk production requires cows with longer productive lives and larger life-time productions. In our study, we made a comparison between production, culling causes, and type traits of culled Holstein Friesian cows after first calving and of cows with a minimum of eight lactations. We established that the first lactation production of cows with longer productive lives was more or less homogeneous. Disease of metabolism as well as digestive and respiratory problems, were the main causes of the culling of cows with short productive lives, and reproduction and udder problems as well as low production, were the main causes of the culling of cows with long productive lives. We found a significant difference in the distributions of strength, body depth, dairy form, croup width, rear leg side view, foot angle, fore udder attachment and teat placement between the two groups. Furthermore, we established that cows with lower stature, less strength, a somewhat deeper body, better dairy form, narrower croup width, smaller foot angle, looser fore udder attachment and some outside teat placement had longer productive lives.
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Livestock production development in AP Vojvodina
501-513Views:59The aim of this paper is to present the effects of breeding program implementation on the development of animal breeding in Vojvodina since 2010. Data from the Main breeding organization (controlled population) and data from the Statistical Office of the Republic of Serbia (total population) were used as a basis for this research. The main breeding organization is the Departmant of
Animal Science, Faculty of Agriculture, University of Novi Sad that implemented the main breeding programs in cattle, pig, sheep, goat, horse and poultry production. The milk yield in a recorded population of Holstein Friesian and Simmental cows shows evident phenotypic increasing trend as opposed to a population that is not controlled. The results of the selection measures in Vojvodina show that pig breeding has an upward trend and that we have an increasing number of small and medium (family) farms. Interest in sheep and goat production is increasing primarily because of the high demand for products made from sheep meat and goat milk and meat. In the recent decades, Vojvodina has been faced with a decrease in the number of horses. At the same time, there is an increasing interest in sports horses and recreation. According to poultry production results of parental flocks, an increasing tendency was observed in the production of controlled flocks recently, while the number of breeding stock breeders was reduced.