Teat Cup Application Research Articles

Pre-milking mechanical teat stimulation and milking performance of dairy buffaloes in early lactation

The objective of the present study was to investigate the effect of pre-milking mechanical teat stimulation on milk yield and milking performance of dairy buffaloes in early lactation. For this purpose, twenty-two healthy Italian Mediterranean buffaloes in their first to third lactation and in early lactation (<120 days in milk) were subjected to two treatments of teat stimulation: i) washing of the teats with water for about 5 s and attaching of the milking unit within 60 s, without any pre-milking massage (farm milking routine); ii) fast pulsation (FP), achieved by increasing pulsation rate to 120 pulsations per min during the first 60 s after application of teat cups. Each treatment lasted for 10 days and the following parameters were measured: milk yield (kg/milking), milk yield at 2 min after unit attachment (kg), time between milking unit attachment and its automatic removal (min), peak milk flow rate (kg/min), and milking time to reach peak flow rate (min). The average milk flow rate (kg/min) was calculated by dividing milk yield by the actual milking time. Milk yield was not affected by mechanical pre-stimulation and during the first 2 min of milking 20.2% and 19.6% of total milk yield were milked respectively when treatments 1 and 2 were applied. The time elapsed from attachment of the milking cluster until its automatic removal was less than 8 min both for buffaloes subjected to FP, and for buffaloes subjected just to washing of the teats before attaching the milking unit. FP stimulation did not show an enhancing effect on peak and average milk flow rates and on milking time to reach peak flow rate.

Effect of human-animal relationship and management on udder health in Swiss dairy herds

In a cross-sectional study, we investigated the effects of human-animal interactions and management factors on udder health in 46 Swiss dairy herds living in loose-housing systems on farms that participated in the Swiss dairy farm network “pro-Q.” The human-animal relationship was measured by observing milkers’ behavior, cows’ behavior during milking, and cows’ avoidance distance in the barn. Management factors were assessed by questionnaire-guided interviews and observations. Udder health was evaluated using indicators that were calculated from milk recording data over a period of 1 yr before assessment: (1) average somatic cell scores (SCS) per herd and (2) incidence of new infections per herd (NEWINF); and indicators that were calculated from quarter milk samples of all lactating cows at the time of assessment: (3) prevalence of quarters with elevated somatic cell counts (>100,000 cells/mL; %Q>100) and (4) prevalence of mastitis quarters (>100,000 cells/mL and culturally positive; %Qmast). After univariate preselection of associated factors, multivariable linear regression models were calculated at the herd level and a multilevel regression model was calculated at the herd and cow levels for SCS. Among all of the human-animal relationship factors, the most dominant predictor for SCS, %Q>100, and %Qmast was the percentage of positive interactions of milkers with the cows in relation to all of their interactions during milking. Furthermore, a higher prevalence of fearful cows in the herd (with an avoidance distance >1m) was associated with a higher %Q>100. In herds with a higher NEWINF, incidents of cows kicking during milking occurred more frequently. Concerning management as well as farm and herd characteristics, the following mastitis risk factors were found: (1) breed, especially Holstein with regard to SCS, NEWINF, and %Qmast; (2) high age in terms of lactation number with regard to SCS and %Qmast; (3) high amount of new infections of a cow over 1 yr with regard to SCS; (4) air-adsorption during application of teat-cups with regard to NEWINF; (5) lack of separation of diseased cows with regard to NEWINF; and (6) ample dimensions of lying places with regard to %Qmast. The results suggest that the human-animal relationship is relevant for udder health, especially for cows’ reactions to infections expressed as somatic cell count levels. Risk of infection itself appears to be mainly influenced by management factors. Hence, the human-animal relationship may be considered in extension concerning preventive mastitis control.

Introduction of electronics into milking technology

In countries, like the former German Democratic Republic (GDR), where ‘industrialized’ milk production in large herds was the goal to be reached, research on automation of machine milking was started more than 30 years ago. Initially, the main goal was to mechanize operations at the end of the milking process. This work finally resulted in milking devices that do not apply uniform parameters to all cows, but operate according to the milk flow obtained from the cow actually to be milked. This evolution towards ‘controlled milking’ would not have been possible without application of electricity and electronic components for sensors and control units. Also depending on the technical evolution of electronic control systems are devices for recording milk yield and for taking samples for milk analysis, which were available around the year 1980. At that time initial projects for automatic milk recording were evaluated, which had an obvious influence on further development of milk meters. The most demanding step of application of electronic control systems up to now was the introduction of automatic milking systems. Here not only application of teat cups has to be executed, it also is necessary to enable automatic checks of udder condition, milk quality and other operations which may be challenging even for trained human operators. Further evolution of electronic measurement procedures may be important for the milk-producing farmer too, especially when on-line milk analysis is to be introduced within the near future.

Epidemiological Analyses of the Associations between bovine udder health and milking machine and milking management

This paper presents data from 158 dairy herds in northern Norway. The influence of the milking machine and milking management on the prevalence of subclinical mastitis and herd cell counts was calculated from a least squares model by a backward elimination procedure. It was shown that 16–45% of the herd udder health variation found at the start of the programme could be associated with milking machine and milking management variables. The following variables were found to be of significance: number of clusters in the herd, vaccum, function and vaccum regulator, undulation of pipeline, limping of pulsator, rate of pulsator, type of claw-piece, hygienic/-technical condition of liner, preparation time, air admission during application of teat cups, overmilking and machine-on time.

Safety considerations for automatic milking systems

Successful introduction of fully automatic milking systems requires safety measures to avoid cow and equipment damage due to the behaviour of cows and due to collisions of animals and milking equipment. Investigations are reported on parameters which could be used to solve this problem and on possibilities to prevent accidents by appropriate treatment of cows. It was found that the activity of eating concentrates and variations of load on the hind legs were related to the frequency of leg lifting. As expected, leg lifting was observed to be mainly caused by collisions of milking equipment with different parts of the cow, especially with her legs. A considerable reduction of cow leg activity during the application of teat cups was observed after previous stimulation. Suitable sensors for recording the behavioural parameters of cows are weighing devices to measure mechanical loads on hind legs and on the manger to measure concentrate consumption. Leg activity also can be monitored by pressure sensitive plates or mats, commonly used by industry. To avoid collisions during automatic milking operations, capacitive and ultrasonic proximity sensors have been used successfully.

Milk Ejection in Cows Mechanically Stimulated During Late Lactation

Twelve Holstein cows in late lactation were divided into three groups by previous milk production. The average time in lactation for all cows was 223 days. Cows were subjected to four treatments of teat stimulation: 1) no stimulation, 2) manual stimulation for 60s, 3) positive pressure pulsation (during first 60s after teat cup application), and 4) fast pulsation for the first 60s after teat cup application. Each treatment lasted for 1 wk. On the last 3 days of each treatment, flow rate curves were recorded twice daily. Milk yield, milking time, and milk flow dynamics were determined from these curves. Absolute peak and average milk flow rate exhibited by cows subjected to manual stimulation were only 3 and 10% higher than those of unstimulated cows. Manually stimulated cows required 30s less machine-on time than unstimulated cows. This was less than sufficient to offset the 60s stimulation routine. The total time required to stimulate and milk each cow, i.e., the procedure time, was longer for manually stimulated cows than for unstimulated cows but not different from that for stimulation by fast pulsation. Milk flow patterns for cows stimulated by positive pressure pulsation and for unstimulated cows were similar. Flow patterns for cows given manual stimulation, when corrected for procedure time, were similar to those of cows given fast pulsation stimulation. Milk, fat, and protein yields were not different across treatments.

Udder Washing and Teat Disinfection

In the mechanization of milking least progress has been made in tasks involving direct contact with cows' teats and udders, namely fore-milk examination, udder and teat cleaning, application of teat cups and teat disinfection after milking. It is not surprising that this is so, since cows' udders and teats vary widely in size and shape and cows often object to mechanical interference with these organs. The tasks listed constitute the major manual labour of milking and thus limit milking performance. Applying the teat cups is inescapable but the other tasks are frequently omitted by milkers to reduce labour.

Release of Oxytocin in the Cow During Milking

Jugular vein oxytocin concentrations were determined at 15-s intervals on 10 Holstein cows during milking. Oxytocin ranged from .5 μU/ml plasma prior to udder washing to 652.7 μU/ml plasma at 1min after application of teat cups. The results indicate a gradually increasing release of oxytocin after stimulation and a maximal oxytocin release 1.5min after start of udder washing and 1min after teat cup application.

Epinephrine Inhibiting Milk Ejection in Lactating Cows

Blood oxytocin was determined on 10 Holstein cows during normal milking and during milking when epinephrine was injected intravenously before or after udder stimulation. The average peak oxytocin concentration during normal milking was 399.7μU/ml plasma and was reached at 1min after teat cup application. Oxytocin concentration in blood plasma declined rapidly after peak concentration and dropped to 30.5μU/ml plasma within 4min after the start of milking. By 5min after removal of the teat cups, it had declined to less than 4μU/ml plasma.The administration of epinephrine, either before or after udder washing, inhibited milk ejection as indicated by milk production and oxytocin concentrations. Peak oxytocin concentrations were 1.05μU/ml plasma 1min after teat cup application when epinephrine was injected before udder washing and 8.6μU/ml plasma at teat cup application when epinephrine was injected after udder washing. These results and the use of a beta receptor blocker to inhibit the effect of epinephrine at the myoepithelial cell level indicated that epinephrine inhibited release of oxytocin from the neurohypophysis.

A PROPOSAL FOR A CONSTANTLY ROTATING CAROUSEL FOR SHEEP MILKING

A proposal for sheep milking using a constantly rotating carousel is outlined. The system is operated by a single milker. The only operation carried out by hand is teat cup application. All other operations (ewe entry, feeding, cup removal, teat spraying, ewe exit, cleaning of the machine, milk recording, etc.) are activated by the rotation of the carousel. Details of design and estimated performance are given. The system incorporates a milking machine capable of removing the total yield without machine stripping. Such a machine is, however, not yet available. The inadequacy of existing sheep milking machines in this respect is described and an interim design incorporating these inefficient machines in a semi-automated system is proposed.

Milk Flow Rates of Individual Quarters of Dairy Cows

Twenty-four lactating Holstein cows were used to obtain milk flow rates at 60-second intervals for an adjustment of 7 days and an experimental period for 21 days. Treatments consisted of (a) controls which were milked by recommended milking practices; (b) a 5min delay between milk letdown and application of teatcups; (c) removal of the teatcups 4 minutes after application; and (d) intramuscular injection of 20 USPU of oxytocin prior to teatcup application.A 5-minute delay between stimulation of the udder and application of the milking machine decreased maximum flow rates during 60 seconds at which maximum flow occurred and quarter milk yields. The 4-minute milking reduced time to reach maximum flow and quarter milk yields, and post-treatment residual milk yields were greatly increased. Twenty USPU of oxytocin injected intramuscularly reduced maximum flow rates and times at which maximum flow occurred, and decreased post-treatment residual milk yields.For all treatments correlation coefficients were positive between maximum flow rates and milk yields.

Changing Machine Pulsation Rates and Ratios during Milking

Sixteen Holstein cows were in a counter-balanced design to study effects on milking rate with changing pulsation rates and ratios during milking. There were two experiments, each consisting of four periods (replications), four days per period, four treatments and 16 cows (four cows per group). Both experiments involved changing pulsation rates or ratios or both after 1.5 minutes of milking. There was no significant difference in rate of milk flow when pulsation ratios were changed from 60:40 to 50:50 or when pulsation rates were changed from 66 to 55 after 1.5 minutes of milking.Likewise, there was no significant effect on rate of milk flow when both pulsation ratios and rates were changed simultaneously. Milking rate was faster (P<.05) during the first 1.5 minutes of milking for the 60:40 pulsation ratios. The fastest rate of milk flow was at the one minute interval following application of teat cups. Neither total amount of milk produced nor total milking time were influenced by changes of pulsation ratios or rates.

Oxytocin Levels in the Plasma of Holstein-Friesian Cows During Milking with and without a Premilking Stimulus

Blood oxytocin concentrations were determined on 9 Holstein-Friesian cows during normal milking and during milking without a premilking stimulation at 1 to 2, 5 to 6, and 15 to 16 weeks postpartum. The average peak oxytocin concentration during normal milking was 139.2μU per milliliter plasma and during milking without premilking stimulation was 122.9. The difference was not statistically significant. The premilking stimulation caused an earlier release of oxytocin from the neurohypophysis into the blood and this resulted in a shorter machine-on time. The elimination of the premilking stimulation did not decrease milk production. The afternoon milk yield during normal milking was 9.89kg and that during milking without premilking stimulation was 9.95kg. The stimulus from the application of the milking machine apparently caused an adequate release of oxytocin for maximum milk ejection and a normal milk yield. The oxytocin concentration in the blood plasma declined rapidly after the peak concentration. By 5 minutes after teat cup application all values were below 2.5μU per milliliter plasma. By 5 minutes after the end of milking all values had dropped to less than 0.01μU. There was a tendency for the peak levels of oxytocin concentration to decrease with advancing lactation; however, the differences were not statistically significant.