Lelia Murgia

Effects of the working vacuum level on mechanical milking of buffalo.

Mechanized milking has become widely used for buffaloes in Italy in recent years, thus improving the management and the productivity of farms. The apparent similarities between buffalo and cattle have often resulted in applying the same milking systems and techniques currently used for dairy cows. Considering the effect of mechanical milking on animal health, productivity, and welfare in intensive livestock farming, this study compares the effects of milking at low vacuum (36 kPa) and medium vacuum (42 kPa) on milk emission characteristics and milking system performance. Individual milk flow curves were registered to analyze milk yield, average flow rate, and milking time, and milking operations were recorded to evaluate the system performances. When using 36 kPa vacuum, a significant increase in milking time and in the lag time before milk ejection occurred, as well as a decrease in average flow rate and residual milk. However, the vacuum level did not influence both milk yield and milk ejection time. As a consequence of decreasing the vacuum level to 36 kPa, the milking system throughput was decreased at most by 5 buffalo/h.

Dry Tests of Vacuum Stability in Milking Machines with Conventional Regulators and Adjustable Speed Vacuum Pump Controllers

A survey of vacuum control, noise levels and energy savings was performed on 15 farms in Lombardia, Italy comparing conventional vacuum regulation systems with variable speed drive (VSD) control systems on each milking machine. The data showed that if VSD controllers are set up properly they are able to meet or exceed the vacuum stability of conventional regulators. The reduction in noise levels achieved by VSD control systems averaged about 12 dB with up to 24 dB reductions in some locations. The energy saved by using VSD controllers was considerable, averaging 56%, with up to 87% savings observed on larger systems. VSD controllers also reduce the starting current of large electric motors, which may be a significant advantage when operated on some rural power distribution systems.

Dairy Energy Prediction (DEP) model

A population of 285 dairy cow farms located in the south of Italy was involved.Linear regression models for predicting diesel and electricity use were developed.A tool (DEP) was developed to predict direct energy related emission and costs.DEP tool is available online at this link: http://bit.ly/DEPTOOL. The need of reducing energy consumption in agriculture through more efficient working methods came first into focus in the 1970s as a consequence of oil crisis and the sharp increase of the energy price. Today, besides the economic issues, other aspects connected to a large use of fossil energies are becoming prominent: the depletion of nonrenewable resources and the pollution of the environment. The consumption of direct energy, as fuels and electricity, in dairy farming is a source of greenhouse gas emissions and contributes significantly to increasing the carbon footprint of milk.The objectives of this study were: (a) to build linear models to estimate the consumption of diesel fuel and electricity in dairy farms; (b) to develop a calculation tool in order to assess efficiency indicators associated to energy consumption, emissions of carbon dioxide and energy costs in dairy farms.Data used in the model development were collected from 285 dairy farms located in southern Italy. Two linear regression models were developed using total fuel (TF, kgyear1) and electricity consumption (TE, kWhyear1) as responses and total number of heads, total number of lactating cows, milk produced, and cultivated land as primary independent variables. Models parameters were then implemented in a spread sheet to develop the Dairy Energy Prediction (DEP) tool. Entering some basic information about dairy farms characteristics, DEP is able to predict diesel fuel and electricity consumptions, to list several Energy Utilization Indices (EUIs), to estimate carbon dioxide emissions from energy uses (kg CO2-eq), to evaluate the costs of energy purchase. DEP may be used by farmers, to evaluate the energy performances of their farms, and by researchers and stakeholders to compare the impact of different energy scenarios (i.e. LCA studies, economic evaluation, environmental assessment, etc.). DEP tool is available online at this link: http://bit.ly/DEPTOOL.

Effect of vacuum level on milk flow traits in Mediterranean Italian buffalo cow

The aim of this study was to determine the effects of six different working vacuum levels (range 37–52 kPa) on the milk production, milk flow rate and milking times of Mediterranean Italian buffalo. A total of 801 milk flow curves of 450 animals of different parity and at different stages of lactation were recorded at random by electronic milk flow meters (Lactocorder®) over a period of 12 weeks. The vacuum level did not significantly affect the individual milk production per milking (average 4.02±0.06 kg). Lower vacuum level resulted in a decrease in average and peak flow rate (P<0.001), and an increase in effective milking time between attaching the teat cup and reaching the value of 0.20 kg/min at the end of milking (P<0.001). Vacuum levels of 37 and 40 kPa provided good milkability conditions, in which the plateau phase was longer than the decline phase while lag time was not affected by vacuum level.

Evaluation of the performance of the first automatic milking system for buffaloes

The objective of this study was to evaluate the response of buffaloes to automatic milking, examining the relationships between milking interval, milk production, and milking time for this species. A total of 7,550 milking records from an average of 40 buffaloes milked by an automatic milking system (AMS) were analyzed during a 3-mo experimental period at a commercial farm with Italian Mediterranean buffaloes in southern Italy. Date and time of animal identification, milk yield, milking duration, milking interval, and average milk flow rate were determined for each milking. The results were also used to predict the maximum number of milkings per day and the optimal number of buffaloes per AMS for different levels of milk production. The average interval period between 2 consecutive milkings was 10.3 h [standard deviation (SD) 3.3]. Overall, 3.4 and 25.7% of the milkings had an interval of ≤ 6 h or >12 h, respectively. Milking duration averaged 8.3 min per buffalo per milking (SD 2.7). The average milk flow rate was 1.3 kg/min (SD 0.5) at a milk yield of 2.8 kg per milking (SD 1.4). Assuming that the milking station is occupied 80% of the time, the number of milkings ranged from 136 to 152 per day and the optimal number of buffaloes per AMS ranged from 59 to 66 when the production level increased from 2 to 5 kg of milk per milking. Automatic milking systems are suitable for buffalo, opening new options for the management of dairy buffalo farms.

Comparison of Upper Limb Muscle Activity among Workers in Large-Herd U.S. and Small-Herd Italian Dairies

Objectives Commercial cow milking tasks, regardless of dairy size, have been documented in many regions of the world as strenuous work requiring high muscular effort, awkward positions, and task repetition. Large-herd dairies are common in the U.S., while Europe historically has mostly small-herd dairies. The objective of this study was to compare the upper limb muscle activity during milking tasks between workers at large-herd U.S. dairies and small-herd Italian dairies. This is the first international study directly comparing upper limb muscle activity among dairy workers from different countries using identical methods. Methods Data were collected at 6 large-herd dairies in the U.S. region of Colorado and at 21 small-herd Italian dairies in the Lombardy region. Surface electromyography (sEMG) from the trapezius, anterior deltoid, biceps brachii, wrist flexors, and wrist extensors muscles was recorded from all participating workers (N = 65). Electromyography data were normalized to functional maximum voluntary contractions. Anthropometric measurements were also recorded. Results Upper limb muscle activity was generally greater among workers in the large-herd U.S. dairies compared with small-herd Italian dairies. The amount of muscular rest as a percent of the work time was significantly greater among large-herd U.S. dairy workers. Conclusion The differences revealed in sEMG and percent muscular rest among workers from the U.S. and Italy are likely due in part to differences in work processes adopted by fast-paced industrialized large-herd dairies compared with the slower, but sustained work processes performed at small-herd dairies.

Carpal tunnel syndrome among ewe dairy farmers in Sardinia, Italy

BACKGROUND The region of Sardinia, Italy is known internationally for the production of cheeses made from ewes milk. Although the use of automated milking equipment is available in ewe dairy operations, traditional hand milking is still performed on many ewe farms. The purpose of this study was to evaluate the prevalence of carpal tunnel syndrome (CTS) among farmers that manually milk ewes. METHODS Worker demographics, upper limb symptoms, and electrophysiologic studies were obtained on 76 ewe farmers recruited from a random sample of 109 in northern Sardinia. Characteristic hand symptoms and electrophysiologic studies were used in the case definition of CTS. RESULTS Of the 76 farmers evaluated, 42 (55.3%) fit the case definition of CTS in at least one hand. Assuming that all non-respondents did not have CTS, the CTS prevalence ratio would have been 38.5% (42/109) among the randomized sample of ewe farmers. CONCLUSIONS These findings suggest that CTS is a significant occupational health issue for ewe farmers that continue the traditional methods of manual milking. The recent trend in automated ewe milking machines may help reduce the prevalence of CTS among the next generation of Italian ewe farmers.

Effects of low vacuum levels on vacuum dynamics during milking

Abstract One of critical points of the milking unit is the short milk tube. Here milk plugs can cause abrupt variations in vacuum which are stressful for the animals. Our trials allowed us to define the effects of the operational vacuum and pulsation on vacuum stability in the short milk tube. Reducing the vacuum from 42 to 28 kPa did not produce appreciable variations in vacuum fluctuation. It was 9.2 kPa for the low vacuum and 9.8 kPa for the standard vacuum. Changing the pulsation rate from 150 to 120 cycles/min did not modify the vacuum stability in the short milk tube. By contrast, raising the pulsation ratio from 50% to 60% significantly increased the amplitude of vacuum fluctuation in the short milk tube.

Effects of a low vacuum level on vacuum stability and milking parlor performance for sheep.

In line with the current interest in animal welfare in animal husbandry, this study of two groups of 24 sheep compares milking performances at a low vacuum level (28 kPa) and at a standard level (42 kPa) that is normally used for sheep. The two working vacuum levels were tested with three different combinations of pulsator rate and pulsator ratio. Each of the experiments lasted 21 days, of which 11 were for adaptation and 10 were for collecting data. The milking machine used was a low line with 24 stalls, 12 milking units controlled by two operators, a milk line 74 mm in diameter, and a cluster with a total mass of 490 g. The measurements performed were the dynamics of the vacuum level in the short milk tube and the milk line during milking, and the time duration for each individual milking. There were no significant differences in fluctuations in vacuum in either the short tube or the milk line at the two vacuum levels used. By contrast, there was a significant increase in vacuum fluctuations in the short milk tube when the pulsator ratio changed from 50% to 60%. The milk flow time for each sheep increased on average by 17% with low vacuum, while the throughput of the system was reduced by some 4%, from 333 to 321 sheep/h.

Development and test of a portable device to monitor the health status of Sarda breed sheep by the measurement of the milk electrical conductivity

Abstract The electrical conductivity (EC) of milk is a parameter which is often used for identifying sub-clinical mastitis in dairy animals. It is widely used for cattle, and is measured either by means of probes integrated into the milking machine or by means of portable devices. However this is not the case for small ruminants, where the available devices are few. The aim of this study is to deepen the knowledge of about the relationship between EC and certain constituents of Sarda sheep milk, and thus to develop a portable device specifically designed for on-site measurement of conductivity and to estimate the somatic cell count (SCC) of Sarda sheep milk. Therefore, the device allows a rapid test for checking the acceptability of milk to monitor the effects of udder infection. The receiver operating characteristic (ROC) method was used to evaluate how efficacious EC was in discriminating between animals with a somatic cell level higher or lower of a threshold value previously defined. The cut-off values, sensitivity, specificity and the area under the ROC curve for EC were, respectively, 4.835 mS/cm, 73.08, 75.46 and 0.804, using a threshold of 700 000 cells/ml. Our results gave a positive evaluation of the portable device that we had designed for estimating the SCC in sheep milk. Only 8.8% of the samples were incorrectly identified as negative. A portable device for EC measurement is a useful tool for monitoring the somatic cell level individually, and allows early and efficacious action to contrast new intramammary infections.