Pipeline Milking Research Articles

Dairy Cows Produce Less Milk and Modify Their Behaviour during the Transition between Tie-Stall to Free-Stall.

Simple SummaryThe purpose of this study was to evaluate the influence of moving cows from the barn with stanchion-stall housing to free-stall housing on their behaviour and production. Cows lay down up to ten hours after removing. The cows in their second lactation and open cows tended to lie sooner after removing than cows in their first lactation and pregnant cows. The times of total lying and rumination were increasing from the first day to the tenth day after removing. Cows produced 23.3% less milk at the first day following the transfer than at the last day prior to moving (23.76 ± 7.20 kg vs. 30.97 ± 7.26 kg, p < 0.001). Loss of milk was gradually reduced and on the 14th day, cows achieved maximum production. The difference was found in milk losses due to the shift between cows in first and second lactation.Transfer of cattle to an unknown barn may result in a reduction in its welfare. Housing and management practices can result in signs of stress that include a long-term suppression of milk efficiency. The purpose of this study was to evaluate the influence of moving cows from the stanchion-stall housing to free-stall housing on their behaviour and production. The Holstein cows were moved into the new facility with free-stall housing from the old barn with stanchion-stall housing. Cows lay down up to ten hours (596.3 ± 282.7 min) after removing. The cows in their second lactation and open cows tended to lie sooner after removing than cows in their first lactation and pregnant cows. The times of total lying and rumination were increasing from the first day to the tenth day after removing (23.76 ± 7.20 kg vs. 30.97 ± 7.26 kg, p < 0.001). Cows produced 23.3% less milk at the first day following the transfer than at the last day prior to moving (p < 0.001). Loss of milk was gradually reduced and maximum production was achieved on the 14th day. The difference was found in milk losses due to the shift between cows on the first and second lactation (p < 0.01). The results of this study suggest that removing from the tie-stall barn with a pipeline milking system into the barn with free-stall housing and a milking parlour caused a decline in the cows’ milk production. However, when the cows are moved to a better environment, they rapidly adapt to the change.

Relationship of goat milk flow emission variables with milking routine, milking parameters, milking machine characteristics and goat physiology

The aim of this paper was to study the relationship between milk flow emission variables recorded during milking of dairy goats with variables related to milking routine, goat physiology, milking parameters and milking machine characteristics, to determine the variables affecting milking performance and help the goat industry pinpoint farm and milking practices that improve milking performance. In total, 19 farms were visited once during the evening milking. Milking parameters (vacuum level (VL), pulsation ratio and pulsation rate, vacuum drop), milk emission flow variables (milking time, milk yield, maximum milk flow (MMF), average milk flow (AVMF), time until 500 g/min milk flow is established (TS500)), doe characteristics of 8 to 10 goats/farm (breed, days in milk and parity), milking practices (overmilking, overstripping, pre-lag time) and milking machine characteristics (line height, presence of claw) were recorded on every farm. The relationships between recorded variables and farm were analysed by a one-way ANOVA analysis. The relationships of milk yield, MMF, milking time and TS500 with goat physiology, milking routine, milking parameters and milking machine design were analysed using a linear mixed model, considering the farm as the random effect. Farm was significant (P<0.05) in all the studied variables. Milk emission flow variables were similar to those recommended in scientific studies. Milking parameters were adequate in most of the farms, being similar to those recommended in scientific studies. Few milking parameters and milking machine characteristics affected the tested variables: average vacuum level only showed tendency on MMF, and milk pipeline height on TS500. Milk yield (MY) was mainly affected by parity, as the interaction of days in milk with parity was also significant. Milking time was mainly affected by milk yield and breed. Also significant were parity, the interaction of days in milk with parity and overstripping, whereas overmilking showed a slight tendency. We concluded that most of the studied variables were mainly related to goat physiology characteristics, as the effects of milking parameters and milking machine characteristics were scarce.

Short communication: Effects of pulsation type (alternate and simultaneous) on mechanical milking of dairy goats (II)—Effect of milk pipeline height on the milking efficiency and status of teat-end in Murciano-Granadina goats

The aim of this experiment was to determine the effect of alternate and simultaneous pulsation on milking in Murciano-Granadina goats. To this end, four experiments were carried out in Latin square design at two milk pipeline heights (high line and low line) and two stages of lactation (onset and end). For each Latin square, 42 animals were selected and divided into two lots of 21 animals with similar features in terms of parity, machine milk, milking duration and mammary gland health status. Sampling was then carried out to determine the milking efficiency (milk extracted and milking time), teat- end status and variables related to vacuum level in the milking unit, comparing both pulsation types (alternate and simultaneous). Results showed that the use of alternate or simultaneous pulsation presented no relevant differences in milking efficiency or teat-end status after milking at either of the two milk pipelines heights or in the two stages of lactation studied. In low line, no differences were found in the variables related to vacuum level. However, in high line, deeper vacuum fluctuations were observed when simultaneous pulsation was applied. It was concluded that subsequent studies are needed to determine how alternate pulsation affects production and milk composition in the long-term, and whether the deeper vacuum fluctuations observed in high line when applying simultaneous pulsation might affect mammary gland health status.

DAIRY PRODUCTIVITY SAANEN GOATS OF SELECTION OF LATVIA

DAIRY PRODUCTIVITY SAANEN GOATS OF SELECTION OF LATVIA

Impact of the System of Air Supply to a Milking Unit on Selected Parameters of Milking Machine Operation

Abstract Air is supplied to a milking machine installation most usually in a constant manner by supply of a small amount of air to a milking chamber of a claw or periodically to a connection pipe of a liner, which enables milk outflow to a milking pipe and improves stabilization of vacuum and limits its fluctuations. On the market of milking machines there is a new solution in the form of mouthpiece vented liners - impulseair®, where air is supplied constantly by a calibrated nozzle in the head of a liner. The objective of the paper was to analyse and assess the selected parameters of milking determined in a milking machine with a claw with fixed volume of a milking chamber (250 cm3) with mouthpiece vented liners in comparison to other solutions used for air supply in milking machines. Measurements were carried out in laboratory conditions with milking to the upper milk pipeline, at variable mass intensities of liquid flow (within 0-8 kg·min−1), for three penetrations of artificial teats (46, 48, 62 mm), at three values of the system vacuum (46, 48 and 50 kPa). A significant impact of the manner of air supply to a milking machine and remaining independent variables of an experiment on the selected milking parameters was proved with the use of a statistical analysis. It was found that a milking unit with mouthpiece vented liners, although it reduces average vacuum of suction [pss], at the same time it limits fluctuations of underpressure in the dp cycle.

Impact of Gestation and Lactation Stage on the Dairy Cow Response Following Removal to Unfamiliar Housing and Milking System

The objective of this study was to test the hypotheses that milk yield and behaviour at milking after relocation are impacted by gestation and lactation stages. Forty-one Holstein cows were relocated from the tie-stall barn with pipeline milking system into the barn with free-stall housing and herringbone milking parlour. Milk yield and order at the milking were recorded electronically. A significant decrease in daily milk yield was detected immediately after relocation (the first day) compared with the last day before treatment (23.76±7.21 kg vs 30.97±7.26 kg; P<0.001). However, the performance drop did not last long; after fourteen days milk production exceeded the mean original level (32.16±8.87 kg). No significant differences were found in the comparison of cows according to gestation stages. Cows in the second and first stages of lactation showed the highest declines in milk yield on the first day (36.77±6.34 kg and 33.76±7.44 kg vs 28.14±7.00 kg and 25.50±8.20 kg; P<0.05). Cows in the late lactation stage came into the parlour later than the other cows, equally during morning and evening milkings (P<0.05). Relationships between the lactation stage and milking orders were positive and significant (0.3730*, 0.3946*, 0.4822**). We found that milk yield and behaviour at milking after relocation were influenced by the stage of lactation of the cows; however, the gestation stage had little long-term effect on the variables measured.

NĚKTERÉ SLOŽKOVÉ A ZDRAVOTNÍ UKAZATELE KVALITY MLÉKA DOJNIC S VYŠŠÍ UŽITKOVOSTÍ PŘI ZAŘAZENÍ VYBRANÝCH DRUHŮ OBILOVIN DO KRMNÉ DÁVKY

Because of economical reasons the substitution of maize by feed corn as wheat (Sulamit) and triticale (Kitaro) was revolved in concentrate part of dairy cow feeding rations. The design of mentioned replacement in feeding rations was carried out according to results of previous research (Pozdíšek and Vaculová, 2008) for nutrition experiment. The aim of this paper was to evaluate the possible effects of corn replacement in cow feeding rations on milk composition and properties. The expressively different variants of corn were selected for experiment in comparison to maize (reference). Dairy cows were fed by total mixed ration on the basis of maize and clover silage and hay. Otherwise the identical day feeding rations among cow groups differed only in concentrate portions ((K, control group) maize 1.5 kg, wheat (P1) 2.0 kg and triticale (P2) 2.0 kg (experimental groups)). Group feeding rations 1 (K), 2 (P1) and 3 (P2) had: NEL/kg dry (DM) matter (6.524, 6.512 and 6.491); NL % in DM (17.9, 18.2 and 17.9); fibre % in DM (15.96, 15.74 and 15.72); PDIN/PDIE (1.189, 1.189 and 1.191). The experiment took six weeks, there were included 8, 9 and 9 cows (n = 26) of Czech Fleckvieh breed. Feed groups were well balanced in terms of milk yield, days in milk and number of lactation. The tie stable and pipeline milking equipment were used in experiment. Animals were milked twice a day and sampled at morning milking in intervals about seven days approximately. Cows were relatively healthy in terms of occurrence of milk secretion disorders. Within groups the individual milk samples (in total 182 in experiment) were aggregated into bulk samples (n = 21 = 3 groups × 7 sampling periods), which were analysed on 45 milk indicators, 18 of them were evaluated in this paper. The differences in milk yield were significantly advantageous for K group (15.32 &gt; 14.07 (wheat) or 13.86 kg (triticale) at morning milking), while fat (3.27 &lt; 3.47 or 3.44 %) was lower (P &lt; 0.05). Lactose was not influenced. More important differences were in total dry matter, 12.09 (K) &lt; 12.23 (P1) or 12.40 % (P2). While for wheat was not for triticale was similar effect observed in crude protein (CP) of milk (3.08 (K) or 3.05 (P1) &lt; 3.23 % (P2)). Similar trend was also confirmed in casein (CAS; 2.43 or 2.44 &lt; 2.55 %; from P &lt; 0.05 to P &lt; 0.001 for CP and CAS). There were insignificant differences between groups for casein number, pH acidity, electrical conductivity, Mg and Cu (P &gt; 0.05). Milk specific weight was lowest in P1 (P &lt; 0.01), but this indicator is practically less important. More expressive differences were in somatic cell count (SCC) in geometric mean 249 (P2) &gt; 76 (K) or 72 103/ml (P1). Because of quite typical high SCC variability in tri­ti­ca­le P2 group (in opposite to this low variability in K and P1 groups) it could be caused by chance in animal selection for groups and all values met the standard demand for extra quality of milk. Therefore, it is not necessary to over estimate this result. Milk urea as metabolical indicator was higher in wheat group, significantly (P &lt; 0.05) versus triticale group (23.39 (P1) &gt; 20.80 (K) and 20.50 mg / 100ml (P2), but all values lay in respected physiological range (from 20 to 30 mg / 100ml). In the Ca case it was significantly higher (P &lt; 0.05 versus wheat) in triticale milk group by 5.7 and 4.0 % (1306 (P2) &gt; 1231 (K) or 1253 (P1) mg / kg). This increase could be interested in terms of milk nutritive value, but not for routine milk payment. The levels of P and Fe in milk were higher in K versus experimental groups (P &lt; 0.05). It is less interesting in terms of economy or nutrition. In general milk was a little different according to differences in corn portions of cow feeding rations and corn variant replacement. In terms of experiment the concrete corn replacement in concentrate portion of feeding ration could not have an essential impact on milk quality and it si possible to agree with such conception. However, the milk quality and yield were not overcome by replacement of maize by wheat (Sulamit) or triticale (Kitaro). At triticale the lower milk yield was compensated by higher levels of DM, fat, CP, CAS, Ca and also SCC as compared to maize and wheat. The used corn replacement variants were not expressively worse than maize.

Optimization and modeling of an electrolyzed oxidizing water based Clean-In-Place technique for farm milking systems using a pilot-scale milking system

Electrolyzed oxidizing (EO) water has been recommended to be used as a cleaning and sanitizing agent for Clean-In-Place (CIP) of on-farm milking systems. The CIP process for milking system with EO water was optimized using a pilot-scale pipeline milking system. The milking system was soiled using raw milk inoculated with four common microorganisms found in milk and cleaned using EO water. The cleaning effectiveness of the EO water treatment was evaluated by ATP bioluminescence test and microbiological analysis through enrichment culture. The effect of different temperatures of the alkaline EO water (45–75°C) and acidic EO water (25–45°C) were investigated. A generalized mathematical model was built and validated for the pilot scale milking system as well as compared with the conventional CIP technique. This study indicated that the EO water CIP outperformed the conventional CIP, indicating that it has a potential to be used in commercial dairy farms.

Mastitis control in Swedish dairy herds

The aim of this study was to investigate which preventive measures targeting mastitis are implemented in Swedish dairy herds with different housing and milking systems. Data were collected through a self-administered postal questionnaire sent to 898 dairy farmers, stratified by housing and milking system, in May 2011. The questionnaire contained general questions about the herd and the person responsible for the udder health of the cows, and specific questions about perceived udder health and the implementation of preventive measures. The response rate was 48%. The median herd size of participating herds was 80 cows, and the median herd average milk yield per cow was 9,586kg of milk. External validity was assessed by comparing participating herds with nonresponders in respect to key performance indicators in the Swedish official milk recording system; no significant differences were found. When herds with combined systems had been removed, 400 herds with tiestalls and pipeline milking, freestalls and parlor milking, and freestalls with an automatic milking system remained. Differences between herd types were analyzed using the Kruskal-Wallis test and Fisher’s exact test. The results showed that herd types differed in their rates of implementation of different preventive measures. Freestall herds with milking parlors implemented more preventive measures related to milking hygiene and milking routines than did tiestall herds. A milking order based on the udder health status of the cows was frequently implemented in tiestall herds, but not in most herds with an automatic milking system or most freestall herds with milking parlors. Irrespective of herd type, the proportion of herds in which cows were kept standing for at least 30min after milking was low. A substantial proportion of herds ignored the udder health status of lactating cows when grouping them, and few herds grouped dry cows according to udder health status, although this occurred more frequently in tiestall herds. A large proportion of herds, especially those with tiestalls, did not allow cows and heifers to calve in single pens that were cleaned between animal occupations. These findings can be used to tailor advice on mastitis specifically to different herd types and thus improve the efficiency of mastitis control.

Mastitis-Management in Schweizer Milchviehbetrieben mit Eutergesundheitsproblemen

The objective of this study was to describe the udder health management in Swiss dairy herds with udder health problems. One hundred dairy herds with a yield-corrected somatic cell count of 200'000 to 300'000 cells/ml during 2010 were selected. Data concerning farm structure, housing system, milking technique, milking procedures, dry-cow and mastitis management were collected during farm visits between September and December 2011. In addition, quarter milk samples were collected for bacteriological culturing from cows with a composite somatic cell count ≥ 150'000 cells/ml. The highest quarter level prevalence was 12.3 % for C. bovis. Eighty-two percent of the pipeline milking machines in tie-stalls and 88 % of the milking parlours fulfilled the criteria for the vacuum drop, and only 74 % of the pipeline milking machines met the criteria of the 10-l-water test. Eighty-five percent of the farms changed their milk liners too late. The correct order of teat preparation before cluster attachment was carried out by 37 % of the farmers only. With these results, Swiss dairy farmers and herd health veterinarians can be directed to common mistakes in mastitis management. The data will be used for future information campaigns to improve udder health in Swiss dairy farms.

English

&nbsp; Bacterial contamination of pasteurized milk may originate from different sources: raw milk, process equipment surfaces and packaging materials. It is hypothesized that post-pasteurization contamination along the milk processing lines is responsible of reducing shelf life of Algerian pasteurized milk. This assumption was investigated through assessment of both the microflora of biofilms in milk pipeline systems at five dairy plants of Northwestern Algeria and the effectiveness of a quaternary ammonium based compound used for the disinfection of the plant equipment. Samples were collected before and after cleaning-in-place (CIP) systems from different segments of pasteurization lines with sterile cotton swabs. Quantitative assessment showed little reduction of the total bacteria count after CIP. On the average bacterial numbers were 5.6 &times; 103, 1.2 &times; 104, 5.1 &times; 104, 2.5 &times; 105&nbsp;and 9.7 &times; 107&nbsp;cfu/cm2, respectively, in the different units. Phenotypic identification of isolates revealed predominance of Gram-positive bacilli belonging to&nbsp;Bacillus&nbsp;and notably the&nbsp;Bacillus cereus&nbsp;group,&nbsp;at maximal levels of 72 and 21% respectively. The other Gram-positive microflora included&nbsp;Staphylococcus&nbsp;(30%) andMicrococcus&nbsp;(10%). In contrast, the incidence of the Gram-negative bacteria was relatively low. Two genera, identified as&nbsp;Pseudomonas&nbsp;(9%) and&nbsp;Enterobacter&nbsp;(6%), were found only in two dairies. Three dairies were Gram-negative bacteria-free. That should be the result of common contamination sources or highly environmental selective pressure. Further studies have to address these hypotheses. Treatment of experimental&nbsp;Bacillus cereus&nbsp;sensu lato&nbsp;strains biofilms with a 50, 100 and 150 ppm of quaternary ammonium disinfectant, showed a significant resistance of biofilms to this product even after long exposure time (15 min). This study emphasized the importance of aerobic spore-forming bacteria in dairy-processing equipment as they are able to built recalcitrant biofilms&nbsp;on the inside equipment surfaces&nbsp;with subsequent resistance to conventional CIP system and potential transfer to pasteurized milk. Therefore, in order to reduce the contamination levels of spore-forming bacteria and improve the quality and shelf life of the product, these dairies have, besides improvement in the hygienic status of the plant equipments, also to monitor either the pasteurization process or the contamination from raw material (that is, milk powder). &nbsp; Key words:&nbsp;Milk contamination, pasteurization, biofilm, cleaning-in-place (CIP).

Content of free fatty acids, lipolytic bacteria and somatic cells in relation to milking technology

Content of free fatty acids, lipolytic bacteria and somatic cells in relation to milking technologyThe contents of free fatty acids (FFA) and counts of total bacteria, psychrotrophic lipolytic bacteria (PLiBC) and somatic cells were determined in 150 samples of cow's bulk raw milk on 20 farms with three different milking technologies in South Bohemia during 2008-10. FFA were determined using an extraction-titration method. Within the compared technologies, the highest mean values of FFA (3.88 mmol 100 g-1; P&lt;0.001) and PLiBC (696 CFU ml-1) were observed on farms with pipeline milking in stalls. The lowest mean FFA level (1.54 mmol 100 g-1) was determined on farms with an automatic milking system. Medium values were determined on farms with parlour milking.

Aerobic and Media Filter Treatment Systems for Milk House Wastewater on Small Dairy Operations

Four different aerobic treatment systems were installed downstream of one or more septic tanks to treat milk house wastewater on nine dairy farms with between 41 and 130 cows. Seven farms had pipeline milking systems, one farm had a flat parlor and one had a milking parlor where parlor wash water entered the milk house wastewater treatment system. Two Biomicrobics FAST systems, two NCS Nibbler systems, three Pirana units, and two Reactor Dynamics, Inc. DYNO2 units were installed. System performance was monitored over 1 to 2 years by measuring water use and collecting wastewater samples.

The effect of keeping technology on the microbiological status of raw milk

The 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 thereforeequipment 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.

Associations Between Herd Characteristics and Reproductive Efficiency in Dairy Herds

Dairy herds worldwide are experiencing a decline in reproductive efficiency at the same time as management methods are changing. This study aimed to investigate the extent to which herd-level characteristics were associated with reproductive performance. Data from herds using artificial insemination (AI) in the Swedish Official Milk Recording Scheme that had more than 45 cows were included in the study (total of 2,728 herds). Reproductive performance was measured as the average for each herd for the calving interval, calving to first AI interval, calving to last AI interval, number of AI per animal submitted for AI, and culling attributed to reproductive problems. Herds with mainly Swedish Holstein cows had longer calving intervals, calving to first AI, and calving to last AI compared with herds with mainly Swedish Red and White cows. Large herds had shorter calving to first AI but a greater number of AI than small herds, whereas small herds had greater culling attributed to reproductive problems than large herds. Low-yielding herds had longer calving intervals, calving to first AI, and calving to last AI and had greater culling attributed to reproductive problems than high-yielding herds, whereas herds with high milk yields had a greater number of AI than low-yielding herds. Herds with automatic milking systems had shorter calving intervals, calving to first AI, and calving to last AI and had lesser odds for culling attributed to reproductive problems when compared with herds with ordinary pipeline milking systems. Herds that used Advanced Feed Advisory Services had shorter calving to first AI but a greater number of AI and greater culling attributed to reproductive problems. Herds using TMR had longer calving intervals and calving to last AI than herds that did not. Herds with tie stalls had longer calving intervals, calving to first AI, and calving to last AI, and organic herds had shorter calving intervals, calving to first AI, and calving to last AI compared with conventional herds. We found that herds with do-it-yourself inseminations had longer calving intervals and calving to first AI. Our study showed numerous associations between herd characteristics and reproductive performance. When allocating advisory service resources to improve reproductive performance, the focus should be on herd characteristics that are easy to influence, such as TMR and do-it-yourself inseminations.

The milkability and somatic cell counts of milk cows in various systems of keeping and milking

A high milk production, time limited milking and healthy udders are priority tasks at milking farms. The aim of our research was to study how different ways of keeping (free rang and tying) and milking (milking parlour, bucket machine and pipeline milking) influence on the mentioned cattle characteristics. Investigation was conducted at four milking farms and 382 Holstein cows in eastern Croatia. The variance analysis has shown significant difference (P&lt;0,05) among researched farms for the milk yield per milking (MYM), the somatic cell count (LSCC) and the maximum milk flowing rate (MFR). Farms at which cows were kept and milked bound up in stables had more problems with udder health than farms at which milking was conducted at milking places. Also at these farms (at which cows were kept and milked bound up in stables) the maximum milk flowing rate was uneven, what was caused by uneven vacuum and obsoletes milking equipment. Keeping cows free at the stable and milking at a milking place have appeared to be more appropriate for cow?s udder health, what finally influences a higher milking production. Such farms should be the future of modern milking production in Croatia.

Soil Nutrient Load and Drain Water Quality in Seepage Fields Receiving Milk House Wastewater

The large volume of wastewater generated on dairy farms from the cleaning of milk pipelines and milking equipment contains nutrients and microorganisms that could pollute waterways if discharged without treatment. The objective of this study was to evaluate a modified septic tank-seepage field system for disposing of milk house wastewater, by measuring the accumulation of nutrients in the soil and monitoring the water drained from the seepage field. The study was conducted on two small dairy farms (40–50 milking cows) in south-west Quebec, Canada. After passing through a sediment and milk fat trap and then the septic tank, the milk house wastewater was drained into a 0.45 ha experimental seepage field under pasture or arable cropped land. Much larger than a conventional seepage bed (0.025 ha), the experimental seepage field was designed to remain recycle the wastewater nutrients and water, while preventing soil saturation. Annual nutrient loading from milk house wastewaters were, on average, 60 kg total N ha−1, 50 kg total P ha−1 and 80 kg total K ha−1. The concentrations of plant-available nutrients increased when milk house wastewater entered the seepage field, but the magnitude of change was farm-specific, due to the unique topography and soil characteristics offered by each farm. For instance, the P concentration was unchanged on one farm, but there was rapid and significant accumulation of P in the 20–60 cm depth of the soil profile on the second farm. There was an increase in Ca and Mg concentrations in the soil profile on both farms, but soil salinity remained <4 dS m−1 during this study. Water drained from the experimental seepage fields was similar in quality to that drained from a control area, indicating that the seepage fields were sufficiently large to adsorb and treat the nutrients contained in milk house wastewater in the short-term. Assessment of the cation and anion adsorption capacity of soils on these farms will be necessary to verify the treatment capacity and effective lifespan of the seepage fields.

Microbiological quality of goat's milk obtained under different production systems

In order to determine the safety of milk produced by smallholder dairy goat farms, a farm-based research study was conducted on commercial dairy goat farms to compare the microbiological quality of milk produced using 3 different types of dairy goat production systems (intensive, semi-intensive and extensive). A survey of dairy goat farms in and around Pretoria carried out by means of a questionnaire revealed that most of the smallholder dairy goat farms surveyed used an extensive type of production system. The method of milking varied with the type of production system, i.e. machine milking; bucket system machine milking and hand-milking, respectively. Udder half milk samples (n=270) were analysed, of which 31.1% were infected with bacteria. The lowest intra-mammary infection was found amongst goats in the herd under the extensive system (13.3%), compared with 43.3% and 36.7% infection rates under the intensive and semi-intensive production systems, respectively. Staphylococcus intermedius (coagulase positive), Staphylococcus epidermidis and Staphylococcus simulans (both coagulase negative), were the most common cause of intramammary infection with a prevalence of 85.7% of the infected udder halves. The remaining 14.3% of the infection was due to Staphylococcus aureus. Bacteriology of bulk milk samples on the other hand, showed that raw milk obtained by the bucket system milking machine had the lowest total bacterial count (16,450 colony forming units (CFU)/ml) compared to that by pipeline milking machine (36,300 CFU/ml) or hand-milking (48,000 CFU/ml). No significant relationship was found between the somatic cell counts (SCC) and presence of bacterial infection in goat milk In comparison with the herds under the other 2 production systems, it was shown that dairy goat farming under the extensive production system, where hand-milking was used, can be adequate for the production of safe raw goat milk.

Response surface modelling for cleaning and disinfecting materials used in milking systems with electrolysed oxidizing water

Electrolysed oxidizing (EO) water is produced by passing a DC current through a weak sodium chloride solution, resulting in alkaline and acidic EO water. The goal of this research was to determine whether EO water could be used as an acceptable cleaning and disinfecting agent for materials used in pipeline milking systems. Small pieces of materials commonly used in milking systems were soiled using raw milk inoculated with a cocktail of four bacterial cultures similar to those commonly found in raw milk, and then cleaned by soaking in alkaline EO water followed by soaking in acidic EO water at various treatment times and temperatures. Effective treatment time and temperature combinations were determined by response surface design for a temperature range of 25–60°C and a time range of 5–20 min. Treated materials were evaluated by aerobic plate counts and ATP bioluminescence to assess the disinfecting and cleaning effectiveness of EO water. Most of the treatments at 60°C and several treatments at lower temperatures successfully removed all detectable bacteria and ATP. Overall, the results of this study indicated that EO water has the potential to be used as a cleaning and disinfecting agent for materials used in milking systems.

CLEANING MILKING SYSTEMS USING ELECTROLYZED OXIDIZING WATER

Electrolyzed oxidizing (EO) water is a novel cleaning and disinfecting agent, produced by separating a weak sodium chloride solution into alkaline and acidic components. A pilot-scale pipeline milking system was soiled using raw milk inoculated with common microorganisms. The milking system was then washed with alkaline EO water followed by acidic EO water. After cleaning, the effectiveness of the EO water treatment was evaluated by ATP bioluminescence and microbiological analysis. A 10 min wash with 60°C alkaline EO water followed by a 10 min wash with 60°C acid EO water successfully removed all detectable bacteria and ATP from the non-porous milk contact surfaces. Shorter treatment times (5 and 7.5 min) with EO water were also evaluated, along with a control treatment using conventional dairy cleaning chemicals. There were no significant differences between the 10 min and 7.5 min EO water treatments and the conventional treatment. In a longer-term soiling-washing simulation, only the 7.5 min EO water treatment was evaluated after ten soiling and cleaning cycles, and it was