Objectives |
An automatic milking system can be explained as a system that milks 24 hours a day, milks more frequently and at different intervals, has different cleaning procedures and complicates visual control. These features may influence milk quality. It is known that AM-systems, in general, have a negative effect on milk quality. However, results per quality parameter may be contradicting and the factors affecting the outcome of the parameters are, thus far, not identified. The quality of milk is a very important aspect of milk production. Milk payment systems and consumer acceptance are, to a great extent, based on it. In dairy processing, milk quality can be a decisive factor for the choice of the product. In order to acquire more information regarding the problems as described preceded, objectives are:
In the following, methodology, deliverables and workpackage-milestones will be presented by subpackage.
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1. Effect of AM-system on milk quality
Partners 8, 9 and 10 will identify all dairy farms with an AM-system in the countries of the participating partners 1, 2 and 3 (respectively The Netherlands, Denmark, Germany), with date of installation. In the above mentioned countries bulk milk quality data monitoring systems are readily available. |
For the farms concerned, routinely collected data over the 2 years before the start date of the project will be obtained from the milk quality databases. Data analysed will only regard those farms that have used an AM-system for at least one year. In this way, data before (approximately one year) and after installation of AM-systems are available. In addition, milk quality data from samples of farms milking with a traditional milking parlour will be collected. Distinction will be made between farms that milk twice and three times a day. Sample size of farms milking twice a day will equal the number of selected farms with an AM-system (n»150-200). Data of all farms that milk three times a day will be collected. Data include the bulk milk somatic cell count, total bacterial count, free fatty acids and freezing point. If one of these parameters is not available routinely, additional samples will be taken. Moreover, extra samples will be taken to determine the differential bacterial count for clarification of the origin of high bacterial counts found on farms with an AM-system. This part may be integrated with work package 6.
Several statistical analyses will follow this data collecting.
Deliverables |
Methodology and study materials |
Data used for part 2 will be the data from the farms with an AM-system used in part 1. Only bulk milk somatic cell count and bacterial count will be considered. Based on bulk milk somatic cell counts (BMSCC) and Bacterial Counts (BC) a stratified sample of 90 Dutch, 18 German and 18 Danish farms will be selected as indicated in table 1.
Table 1 Strata of farms.
| Strata | Characteristic | Number of farms | ||
|---|---|---|---|---|
| Holland | Germany | Denmark | ||
| 1 | Low BC | 15 | 3 | 3 |
| 2 | High BC | 15 | 3 | 3 |
| 3 | Low BMSCC | 15 | 3 | 3 |
| 4 | High BMSCC | 15 | 3 | 3 |
| 5 | Low BC & low BMSCC | 15 | 3 | 3 |
| 6 | High BC & high BMSCC | 15 | 3 | 3 |
| Total number of farms | 90 | 18 | 18 | |
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BC = bacterial count / BMSCC = bulk milk somatic cell count
A farm will be classified as having a low bacterial count when the average BC was equal to or less than 10.000 cfu/ml over the past year milking with an AM-system, and as having a high bacterial count when average BC was equal to or more than 30.000 cfu/ml over this period. For BMSCC these limits are 150.000 cells/ml and 250.000 cells/ml, respectively.
A workshop, with participation of dairy industry, farmers, partners involved in this work package and other experts, will be organised in order to develop a work hypothesis on factors that may influence milk quality on farms with an AM-system and have to be examined on the selected farms. The list of factors will be limited and chosen by priority in order to make an adequate statistical analysis possible. Information on the selected factors will be obtained by means of a questionnaire, the management program of the farmer, the outcomes of the software belonging to the AM-system and by means of observation of the parlour and walking area of the lactating cows. The farms will be visited once. During these visits, information serving work package 8 can also be assembled. Subsequently the information gathered will be related to the milk quality parameters. Additional information (BC and BMSCC) on the Dutch farms will be gathered from 'Zuivelnet', a Dutch internet site providing all quality aspects of the milk for each farm, for a period of10 months. If a problem with the milk quality arises on the participating farms, short-term intervention can take place. In this way sudden and short-term problems can be recognised, noted, resolved and evaluated. This may yield accurate relationships between inferior milk quality and the factor(s) causing it.
This part results in analyses on:
Deliverables |
Methodology and study materials |
For part 3, no exact methodology can be given yet, since further detailed research depends on the outcome of part 2. Time available in year 3 of the project allows for 2 to 3 experiments of approximately one month each to be done on an experimental farm of partner 1. Options are conditioned experiments on backgrounds of, and solutions for, increased bacterial counts, somatic cell counts or amount of free fatty acids. Detailed protocols will be made up and forwarded to the Commission in due time.
Deliverables |
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© Animal Sciences Group -
Wageningen UR. Last update:
20-02-2008 10:03. |
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