Milk Flow Rate Research Articles

Increased pulsation ratio in rear quarters reduces machine-on time and milking on empty teats

Dairy cows usually store more milk in rear than in front quarters. At conventional machine milking this leads to an earlier cessation of milk flow in front than in rear quarters and hence unavoidable milking on empty front teats. We tested the hypothesis that an increased pulsation ratio in rear quarters reduces both milking on empty front teats and machine-on time. We have also tested if the different amplitude of cyclic vacuum fluctuations during milking with simultaneous vs. alternate pulsation within front and rear quarters, respectively, impacts milking characteristics. Ten Holstein dairy cows were milked twice daily at 14-h and 10-h milking intervals. Pulsation ratio in front quarters was 65:35, but was either set at 65:35, 70:30, 75:25 or 80:20 in rear quarters. Whole udder milk flow, claw vacuum, and mouthpiece chamber vacuum of all 4 quarters were recorded during milking. Teat tissue thickness of all 4 teats was measured with a cutimeter at 5 and 30 min after cluster detachment. Total milk yield did not differ among treatments, indicating complete udder emptying. The time of quarter milk flow (tQMF) of front quarters did not differ among treatments but decreased with increasing pulsation ratio in rear quarters. In addition, the faster milking of rear quarters at higher pulsation ratio caused higher peak and average milk flow rates, a shorter duration of milk flow decline, and a reduced machine-on time. The increased milk flow at a higher pulsation ratio did not cause a significant reduction of the claw vacuum at the used sample size. Teat tissue thickness did not significantly differ among treatments, likely because milking on empty teats did almost not occur in the rear quarters, and treatment settings did not differ in front quarters. Simultaneous pulsation caused higher amplitudes of cyclic vacuum fluctuation than alternate pulsation. However, milking characteristics did not differ between simultaneous and alternate pulsation. In conclusion, an increased pulsation ratio in rear quarters reduces machine-on time, increases milking performance, and reduces the time of milking on empty teats in front quarters, without an increased impact on teat tissue thickness.

Association between automatic milking system parameters and intramammary infections in dairy cows at dry-off

IntroductionThe current global concern over increasing antimicrobial resistance among animal and human pathogens has motivated efforts to reduce antimicrobial drug use in food animals and its impact on antimicrobial resistance. One such strategy is to use selective dry cow therapy (SDCT) in dairy cows, which involves treating only cows with intramammary infection (IMI) at dry-off. However, efficient methods are needed to identify cows with IMI at dry-off to implement SDCT. Automatic Milking Systems (AMS) data may help farmers identify cows with IMI when individual Somatic Cell Count (SCC) is not routinely tested. This study assessed the correlation between cow-level and quarter-level AMS parameters and IMI at dry-off.Methods & ResultsA total of 733 udder quarters (comprising both Primiparous [PRIM] and Multiparous [MULT] cows) were sampled and categorized for IMI based on bacterial growth and SCC. Data were aggregated both daily and into 7-day and 15-day intervals preceding dry-off. The quarter-level prevalence of bacterial growth at dry-off was 24.28% overall. When stratified by parity, logistic regression analysis at 15 days to dry-off revealed that the average difference in mastitis detection index (MDi) in PRIM, MDi, and standard deviation milk flow rate in MULT were associated with increased odds of IMI at dry-off. Similarly, data from 7 days to dry-off revealed that average peak milk flow rate in PRIM, and MDi in MULT were associated with increased odds of IMI at dry-off. However, an increase in average milk yield was associated with decreased odds of IMI.Discussion & ConclusionOur findings underscore the significance of MDi, milk flow rate, peak milk flow rate, and milk yield in predicting IMI at dry-off. Notably, stronger associations were observed with data collected 7 days preceding dry-off. Further research is warranted to refine and validate algorithms amalgamating these variables for precise IMI prediction in cows at dry-off.

Geometry of milk liners affects milking performance in dairy cows.

The geometry of milk liners may affect milking performance and cow comfort as the milk liner is the only part of the milking machine that comes into contact with the teat. To determine the effect of alternative shape of milk liners we compared square (SQR) vs. the conventional round (RND) teat cup liner on milking performance and comfort of dairy cows. Treatment milk liners were randomly allocated to clusters within each side of the 12 a side double up-herringbone dairy shed in a complete randomised block design over two periods. Milking performance data from a total of 10 065 (late stage of lactation and once-a-day milking frequency, LATE) and 18 048 (early stage of lactation and twice-a-day milking frequency, EARLY) milking events were automatically recorded by a DeLaval milk meter, and separately analysed for LATE and EARLY, respectively. In EARLY, cow comfort behaviour was also recorded during afternoon milking sessions. Across the two study periods, average milk flow rate, milk flow rate during 0-15, 15-30 and 30-60 s after cluster attachment, and milk flow rate at cluster take-off were higher in SQR compared to RND treatment. Proportion of time in a milking session with low milk flow rate and duration of milking session were less in SQR compared to RND treatment. However, effect of geometry of milk liner on peak milk flow rate was inconsistent across the two-study periods. Peak milk flow rate was higher (P < 0.001) in SQR than RND in LATE, but higher (P < 0.001) in RND than SQR in EARLY. Stomping and kicking behaviours of cows were similar between treatments. Results of this study suggest that square milk liners potentially improve milking performance, without adverse effect on cow comfort compared to conventional round liners. Long-term, multi-site studies are required to confirm potential teat-end health benefits associated with square milk liners and further verify these results.

The effect of flow-responsive vacuum and pulsation with early attachment of milking unit on teat tissue condition and milking performance in Holstein dairy cows

The objectives of this study were to assess the effect of flow-responsive vacuum and pulsation, in conjunction with the early attachment of the milking unit (TRT), on teat tissue conditions and milking characteristics in dairy cows. In a switch-back trial, 5,235 Holstein cows milked 3 times daily in a rotary parlor were assigned to the TRT or control (CON) group. The trial lasted 84 d and was comprised of 4 alternating 3-week periods of TRT and CON. For both groups, premilking udder preparation consisted of teat brushing, forestripping and predipping, and wiping of teats, resulting in a stimulation time of 4 s. In the TRT group, the preparation lag time was 58 s, and in the CON group, it was 91 s for early- and mid-lactation cows and 105 s for late-lactation animals. Upon milking unit attachment, the TRT cows were milked at a lower vacuum (37.6 kPa) and pulsation (50 cycles/min, pulsation ratio of 30:70). The vacuum and pulsation settings were changed to milking mode when the milk flow reached 0.5 kg/min (pulsation switch-point) and 1.6 kg/min (vacuum switch-point). For milking mode, the vacuum setting was 47.7 kPa, and the pulsation rate was 60 cycles/min at a ratio of 65:35. The CON cows were milked with a flow-responsive vacuum, using the same vacuum settings as the TRT group. We assessed machine milking-induced short-term teat tissue changes and teat-end hyperkeratosis by palpation and visual inspection postmilking. Electronic on-farm milk meters were used to assess milking characteristics. Generalized linear mixed models were used to analyze the effect of treatment on the outcome variables. Compared with cows in group CON, the odds ratios (95% confidence interval; 95% CI) of short-term teat-tissue changes in early-, mid-, and late lactation cows in group TRT were 0.62 (0.52-0.76), 0.61 (0.48-0.77), and 0.93 (0.76-1.14), respectively. The least squares means [LSM, (95% CI)] for milking unit-on time in early-, mid-, and late lactation animals, respectively, were 251 (248-253), 236 (234-238), and 220 (218-222) s for group TRT and 247 (245-249), 232 (230-234), and 214 (213-216) s for the CON group. The LSM (95% CI) of peak milk flow rate in early-, mid-, and late lactation animals, respectively, were 5.75 (5.68-5.82), 5.77 (5.70-5.84), and 5.54 (5.48-5.59) kg/min for the TRT cows and 5.65 (5.58-5.72), 5.74 (5.68-5.81), and 5.45 (5.40-5.51) kg/min for the CON cows. The odds ratios (95% CI) of forced take-off in group TRT for early-, mid-, and late lactation cows, respectively, were 0.39 (0.37-0.41), 0.32 (0.30-0.34), and 0.47 (0.44-0.52) compared with their respective CON groups. In this study, cows that were milked using flow-responsive vacuum and pulsation with early attachment of the milking unit had lower odds of short-term teat tissue changes and forced take-off, as well as a higher peak milk flow rate. Our data suggest that the application of flow-responsive vacuum and pulsation facilitates early attachment of the milking unit, improves teat tissue condition, and has the potential to improve parlor efficiency.

The Association of Delayed Milk Ejection with Milking Performance in Holstein Cows in a Large Dairy Herd with Suboptimal Premilking Teat Stimulation.

The primary objective was to investigate the association between delayed milk ejection (DME) and the average milk flow rate, milking unit-on time, and duration in a low milk flow rate in Holstein dairy cows in a large dairy herd with suboptimal premilking teat stimulation. Our second objective was to study the association between peak lactation milk yield and the occurrence of DME. This longitudinal field study was conducted at a 4300-cow dairy farm with a thrice-daily milking schedule over a 1-week period. We analyzed data from 61,677 cow milking observations from 2937 cows. Delayed milk ejection was defined as present if the 30-60 s milk flow rate was ≤3.1 kg/min. The mean average milk flow rate (MAMF, kg/min), mean milking unit-on time (MMUT, s), and mean duration of a low milk flow rate (MLMF, s) were calculated as the mean values from the 21 milking observations. General linear multivariable models revealed associations of DME with MAMF, MMUT, and MLMF. A multivariable ordinal logistic regression model revealed an association between peak lactation milk yield and DME. Cows with lower peak lactation milk yield had greater odds of exhibiting a higher frequency level of DME. The observed associations between DME and milking performance indices suggest that DME can negatively affect milking and parlor efficiency. Peak lactation milk yield may serve as a proxy to estimate cows' risk of recurrent DME. Future research is warranted to test if alleviating DME through, for example, a modified milking routine influences the milking performance indices described herein.

Evaluating milk flow patterns using the high flow rate period during breast pumping

ProblemBreast pumping practices have scope for improvement. BackgroundBreast milk weight measurement can be used to evaluate milk flow pattern dynamics during breast pumping. AimTo determine inter-individual differences in milk flow patterns and their practical implications based on high milk flow rate period (HFP) data among Japanese women expressing breast milk using an electric pump. MethodsThis cross-sectional, observational study analysed data from 19 women (33.0 ± 3.9 years) nursing 1–6-month-old infants and with previous breast milk expression experience. Breast milk was weighed continuously during a 15-min single-breast electric pumping session. The HFP features and flow rate time (≥0.1 g/s) were analysed to determine each individual's milk flow pattern. FindingsThe total expressed breast milk was 69.8 ± 42.5 g with a maximum individual flow rate of 0.5 ± 0.2 g/s. The breast milk yielded during the HFPs was 43.1 (34.4–81.3) g, accounting for 82.5 % (69.9–89.5 %) of the total expressed breast milk. HFP occurred 0–3 times during the 15-min session. Multiple discrete and continuous milk flow patterns were observed. Among those with discrete HFP, the HFP interval was 221 (68–371) s. Breast milk fat content changes and subjective residual milk measurements implied sufficient milk removal. A strong positive correlation was noted between HFP length and total breast milk expression volume. DiscussionIndividual differences in milk flow patterns were observed among the women using HFP. Milk flow patterns were consistent with previous reports. ConclusionMilk flow pattern data can be used to guide individualised lactation support.

Randomized-controlled study assessing the effect of milking permission settings and concentrate supplementation on milking frequency and milk yield in a pasture-based automatic milking system

This study aimed to verify the impact of milking permission (MP) and concentrate supplementation (CS) on milking frequency (milkings per cow/day) and milk yield (kg per cow/day) in a farm using a pasture-based automatic milking system (AMS). Sixty-eight cows milked using this AMS unit were randomly assigned to one of 4 groups homogeneous for parity, days in milk and milk yield. Treatments used were: Frequent (F) or Restricted (R) MP, that granted cows permission to milk after 6 to 8 h or 9.6 to 14 h of the previous milking, respectively; and low (LC) or high (HC) CS of 0.5 kg or 3.5 kg per cow/day, respectively. The combination of the 2 levels of MP and the 2 levels of CS resulted in the 4 treatment combinations (FHC, RHC, FLC, RLC). This study was designed as a 2 X 2 factorial arrangement with treatment crossover: each of the 4 cow-groups was randomly assigned to one of the 4 treatment combinations for a 5-week experimental period (one pre-treatment week and 4 treatment weeks), and after each 5-week period groups crossed over to another treatment combination until they experienced all. Statistical analysis assessed the impact of MP, CS and their interaction on milk yield, milking frequency, box time, milking time and average milk flow rate. This was done using a mixed model analysis with repeated measures to account for repeated observations on the experimental unit (cow). Milk yield per cow/day and milkings per cow/day were significantly higher with the Frequent compared with the Restricted MP (1.5 kg and 0.65 respectively). Milk yield per cow/day and milkings per cow/day were significantly higher with the HC compared with the LC CS (3.1 kg and 0.25 respectively). Additionally, milk yield per cow/day was affected by the interaction of MP and CS and it was highest with the FHC (20.1 kg) treatment combination, followed by RHC (18.2 kg) treatment combination. The number of milkings per cow/day were also affected by the interaction of MP and CS. The highest estimated number of milkings per cow/day was recorded for the FHC (2.12) and the FLC (1.77) treatment combinations, followed by the RHC (1.38) and RLC (1.23) treatment combinations. Similarly, milking interval was 2.5 h longer for the RLC treatment combination compared with RHC. The shortest milking interval/milking was observed for the FHC (11 h) and FLC (12.8 h) treatment combinations. In conclusion, the study showed that allowing access to the robot between 6 to 8 h after the previous milking was sufficient (even with a minimal level of CS) to achieve acceptable milk production and milking performance in a pasture-based AMS.

Effects of flow-responsive pulsation on teat tissue condition and milking performance in Holstein dairy cows

The objectives of this study were to assess the effect of a reduced liner-open phase applied through flow-responsive pulsation (FRP), as a method to provide supplemental stimulation, on teat tissue conditions and milking characteristics in dairy cows. In 2 switch-back trials, 156 Holstein cows milked 3 times daily were assigned to the FRP or conventional (CON) group in alternating sequences. Trial 1 lasted for 35 d and was split into 5 alternating 1-wk periods of FRP and CON. The duration of trial 2 was 84 d, consisting of 4 alternating 3-wk periods of FRP and CON. Premilking udder preparation for both groups consisted of predipping, forestripping, and wiping the teats. Upon milking unit attachment, the FRP cows were milked at a pulsation rate of 50 cycles/min and a pulsation ratio of 30:70 until the preset milk flow threshold of 0.5 kg/min was reached. When the threshold value of 0.5 kg/min was reached, the pulsation was automatically switched to milking mode, which consisted of a pulsation rate of 60 cycles/min and a pulsation ratio of 70:30. Cows in the CON group were milked by milking mode (pulsation rate, 60 cycles/min; pulsation ratio, 70:30) immediately after attachment of the milking unit. We assessed machine milking-induced short-term changes to the teat tissue by palpation and visual inspection during trial 1, and we assessed teat-end hyperkeratosis in trial 2. Electronic on-farm milk meters were used to assess milking characteristics: milk yield (kg/milking session), milking unit-on time (s), 2-min milk yield (kg), peak milk flow rate (kg/min), and duration of low milk flow rate (s). Generalized linear mixed models were used to analyze the effects of treatment on the outcome variables. The odds of machine milking-induced short-term changes to the teat tissue were lower for cows in the FRP group than for those in the CON group: odds ratio (95% CI) = 0.41 (0.31-0.55). There were no meaningful differences in the odds of teat-end hyperkeratosis between the FRP and CON groups: odds ratio (95% CI) = 1.05 (0.38-2.89). The LSM (95% CI) of milking characteristics in the FRP and CON groups were 14.3 (13.8-14.7) and 14.3 kg (13.8-14.7) for milk yield, respectively; 272 (264-281) and 270 s (262-278) for milking unit-on time, respectively; and 5.0 (4.8-5.1) and 4.9 kg/min (4.7-5.1) for peak milk flow rate, respectively. The FRP group had lower odds of bimodality than the CON group: odds ratio (95% CI) = 0.67 (0.61-0.74). In reference to CON, the odds ratios (95% CI) in FRP were 1.05 (0.76-1.46) for kick-off and 1.02 (0.85-1.23) for milking unit reattachment. In this study, cows that were milked using FRP had lower odds of postmilking short-term changes to the teat tissue and lower odds of bimodal milk flow. We conclude that FRP may foster adequate teat stimulation in cows before the initiation of milk harvest and has the potential to improve teat tissue conditions.

Pathogen-specific patterns of milking traits in automatic milking systems

Early detection of intramammary infection (IMI) can improve animal health and welfare in dairy herds. The implementation of sensors and automatic milking systems (AMS) in dairy production inherently increases the amount of available data and hence also the potential for new approaches to mastitis management. To utilize the full potential of data from AMS and auxiliary sensors, a better understanding of physiological and pathological changes in milking traits associated with different udder pathogens may be imperative. This observational study aimed to investigate pathogen-specific patterns in milking traits recorded in AMS. The milking traits included; online somatic cell count (OCC), electrical conductivity (EC), milk yield (MY), and average milk flow rate (AMF). Data were collected for a study period of 2 years and included 101 492 milkings from 237 lactations in 169 cows from one farm. Measurements of OCC were recorded at cow-level and data on EC, MY, and AMF were obtained at quarter-level. In addition to the data obtained from the AMS, altogether 5756 quarter milk samples (QMS) were collected. Milk samples were obtained monthly for bacteriological culturing. We included findings of 13 known mastitis pathogens to study pathogen-specific patterns in milking traits. These patterns were compared with those in a baseline group consisting of cows that did not have any positive milk culture results throughout the lactation period. Patterns of the milking traits are described for all positive samples both across 305 d in milk (DIM), and in the 15-d period before a positive bacteriological sample. The association between a positive sample and the milking traits (ln(OCC), EC-IQR; the ratio between the quarter with the highest and the quarter with the lowest level of EC, and MY) for the 15 d before the detection of a pathogen was assessed using mixed effects linear regression models. All pathogens were associated with alterations in the level and variability of ln(OCC) relative to lactations with no positive bacteriological samples. A positive sample for Staph. aureus was associated with increased values for MY during the 15 d before a positive diagnosis. It is biologically plausible to interpret changes in OCC and EC-IQR as consequences of an intramammary infection (IMI), while higher MY in bacteriologically-positive cows is most likely linked to the increased risk of infection in high-yielding cows. In this study, the most notable changes in the traits (OCC and EC-IQR) were observed for Staph. aureus and Strep. dysgalactiae, followed by Strep. simulans, Strep. uberis, and Lactococcus lactis. Even if we did not detect significant associations between positive bacteriology and EC-IQR, visual assessment and descriptive statistics indicated that there might be differences suggesting that it could be an informative trait for detecting infection when combined with OCC and possibly other relevant traits using machine learning algorithms.

The association between teat shape and bimodal milk ejection in Holstein dairy cows

Our objectives were to investigate the association of teat shape with (1) bimodality (2) incremental milk flow rates (average flow rates during the first 15 s, 15-30 s, 30-60 s, and 60-120 s of milking), and (3) peak milk flow rate in Holstein dairy cows milked 3 times per day. In this prospective cohort study, we analyzed 220,928 milking observations that were collected from 2,520 cows from a single dairy herd over a period of 31 d. Teat shape was visually assessed and classified into 1 of 4 categories as follows: (1) triangular barrel and pointed teat end (TP), (2) square barrel and round teat end (SR), (3) square barrel, round teat end, and flat in the area of the teat orifice (SRF), and (4) square barrel and flat teat end (SF). Individual cow-level milk flow rates were obtained using electronic on-farm milk meters. We considered bimodality to be present if any of the incremental milk flow rates (flow rates during 15-30 s, 30-60 s, or 60-120 s) were lower than any of the previous rates (flow rates during the first 15 s, 15-30 s, or 30-60 s). The frequency distribution of cows with different teat shapes was as follows: TP, 96 (3.8%); SR, 1,751 (69.5%); SRF, 617 (24.5%); and SF, 56 (2.2%). A generalized linear mixed model revealed differences in the odds of bimodality among cows with different teat shapes. Compared with cows in category SR, the odds (95% confidence interval) of bimodality of cows in other categories were as follows: TP, 0.68 (0.48-0.97); SF, 1.96 (1.21-3.19); and SRF, 1.46 (1.23-1.72). General linear mixed models indicated an association between teat shape and all incremental milk flow rates, with higher milk flow rates being present for cows with teat shapes in the SRF and SF categories. The general linear mixed model for the dependent variable peak milk flow rate indicated an association between teat shape and peak milk flow rate. Least squares means and 95% confidence intervals were 5.1 (4.9-5.3) kg/min for TP, 5.8 (5.5-6.1) kg/min for SF, 5.6 (5.5-5.7) for SRF, and 5.3 (5.3-5.4) for SR, respectively. We conclude that in this study cohort, bimodality is more likely to occur in cows with flat teat ends compared with those with a round teat ends. We attribute this relationship to the difference in milking speed across cows with different teat shapes. Teat shape may serve as a useful phenotype to identify cows that are more likely to exhibit bimodality. Because our study population was unique, future studies considering different circumstances such as breed, milking system, and milking routine are needed before results can be extrapolated.

Measurement of cow comfort during milking on different cluster removal settings through the use of leg-mounted accelerometers

Increasing levels of data are routinely collected on modern dairy farms. These include multiple variables measured by milking machine sensors and software and cow-attached sensor data, used predominantly for fertility and health monitoring. Following milking efficiency principles, including milking gently, quickly, and completely, there is utility in investigating how various milking machine settings affect gentleness of milking through a proxy measurement of cow comfort during milking. The use of leg-mounted accelerometers was investigated as a noninvasive labor-efficient means of estimating cow comfort on different automatic cluster remover (ACR) milk flow-rate switch-point settings. Accelerometer step count measurements during milking were collected from 37 cows divided into 2 groups allocated to either an ACR milk flow-rate switch-point setting of 0.2 kg/min or 0.8 kg/min for a 2-wk period and then crossed over to the other setting. Significantly more rear leg stepping occurred during daily milking (combined step count during a.m. and p.m. milkings) where the ACR activated at 0.2 kg/min (11.7 steps) compared with 0.8 kg/min (10.1 steps). Shorter milking interval between a.m. and p.m. milkings resulted in lower udder fill and reduced milk flow-rate. Under these lower udder fill conditions, rear leg movement, as an indicator of cow comfort, reduced when milk flow-rate switch-point for cluster removal increased from 0.2 kg/min (5.75 steps) to 0.8 kg/min (4.96 steps). There was no significant difference between stepping rates on both cluster removal settings during a.m. milkings. Similarly, no significant differences were noted in assessed postmilking teat condition, which was conducted after a.m. milking. The 0.2 kg/min setting extended total daily milking time by 70 s, resulting in lower mean flow-rates while producing similar milk yield. Higher vacuum levels at the teat-end were also recorded on this milking setting. This provides further incentive to consider cluster removal settings above 0.2 kg/min.

The Effect of Phenotypic and Genotypic Factors on Some Yield Traits in Holstein Friesian Cows with High Milk Yield Reared in Türkiye

This study was carried out to determine the effects and phenotypic relationships of some environmental factors (first calving age, calving year, and calving season) on Lactation period, dry period, milk yield and Milkability traits. The material of the study was the lactation records of 1079 Holstein cows raised in a private dairy farm. As a result of analyses, the values of 305-DMY yield (305 DMY), the lactation period (LP), dry period (DP), time to reach peak yield (Tmax), peak yield (Ymax), average daily milk yield (ADMY), total lactation milk yield (ATMY) and age at first calving (AFC) were determined as 9926.3±178.1 kg, 318.1±1.4 days, 60.05±0.9 days, 95.2±2.1 days, 42.3±0.3 kg, 32.2±0.3 kg, 10248.7±94.1, and 26.7±0.2 months, respectively. The study found the average milk flow rate (MFR) and the average milking time (MT) as 2.0±0.0 kg min-1 and 360.9±4.7 seconds, respectively. In addition, estimates of the 305-day mature equivalent milk yield (ME 305-d) and MFR were also found to be 0.41±0.24 and 0.51±0.30, respectively. As a result, this dairy farm can be recommended as an example to breeders who have just started their dairy farm in Türkiye and countries with similar environmental conditions and are looking for a model.

Topology Study of Milking Machine Based Parametric Modeling

The large market for cow's milk makes the order capacity for cow's milk high and will increase the milking process. In the production process, especially the milking process, people still manually use their hands, so fatigue often occurs, especially in people with more than 2 livestock. This causes the production process to be ineffective and the production results are also limited. Creating an automatic milking machine equipped with a milk can, a vacuum tube and a hose. Besides, a topology study will also be carried out based on the model of the machine. The three-unit component will affect the performance of the Milking Machine, especially the milk collector and milk can. Their size needs to be analyzed to get the optimum one. Optimization results for the topology of the milk collector bore diameter showed that the milk flow rate in the milk collector at a bore diameter of 9mm was 6,154 ltr/min, at a bore diameter of 14 mm was 26,566 ltr/min and at a bore diameter of 19mm was 66,128 ltr/min (conditions without being connected to hose). The shape of a milk can with a reduction of 30% from the initial weight, which is 3,358 kg to 2,350 kg, is owned by a milk can with the most optimal cone-dome tube shape. The difference in weight with the tube is generally 1,008 kg. The quantity flow when installed with a 2m long hose is 6,729 ltr/min

Incomplete milking before drying off does not impair the udder health of cows infected with minor pathogens.

When implementing the transition from regular milk production to the dry period, drying off is mostly conducted simply by abrupt cessation of milking. Efforts to reduce milk synthesis before cessation of milking aim to reduce stress in cows as well as to lower the risk of mastitis. A previous study demonstrated that incomplete milking during the last ten days of lactation gradually reduced the milk yield of healthy, high-yielding cows. However, a reduction period of ten days might be too long for cows with lower yields. Therefore, a follow-up study was conducted on an organic dairy research farm with a lower average milk yield. We investigated whether automated incomplete milking can reduce milk synthesis within one week without impairing the health status of udder quarters infected with minor pathogens. Before drying off, 15 German-Holstein cows with 58 lactating quarters, 21 of which were infected with minor pathogens (coagulase-negative Staphylococci (CNS) and Corynebacterium bovis), were milked twice daily using the software module AutoDry (GEA Farm Technologies) with the 5%-step-down-per-day-program. The level of udder emptying was gradually reduced over 8-10 milkings beginning at a mean milk yield of 17.2 ± 4.4 kg d-1. During the last three milkings before drying off, milking clusters were automatically removed when a milk flow rate of 0.3 kg min-1 was reached. Quarter fore-milk samples were collected at two time points (14 d before and at the date of the last milking, ie drying off) and were analysed for mastitis pathogens and somatic cell count. The gradual reduced emptying of the udder induced a clear decline in milk yield by 0.8 ± 0.3 kg d-1. Within the reduction period, the somatic cell count of quarter foremilk did not change regardless of the infection status. Furthermore, no cow suffered from clinical mastitis. Thus, a reduction in milk synthesis could be achieved within less than one week before drying off without any impairment in udder health of cows, even when infected with minor mastitis pathogens.

Relationship of Temperament during Milking with Milking Behavioural Features, Milk Yield and Udder Health of Crossbred Jersey Cows in Tropical Climate

Background: Milking behaviour of milch cows has notable impacts on their production efficiency. The present investigation is designed to explore the relationship of temperament while milking with other milking behavioural features, milk yield and udder health in crossbred Jersey cows. Methods: The study was done on crossbred Jersey cows (N=94) kept at ICAR-National Dairy Research Institute, Eastern Regional Station, Kalyani, West Bengal. The cows’ temperament score (TS) was judged on 5 points scale (1-docile, 5-aggressive). Calmer cows (TS-1 and 2) covered relatively higher (75.24%) proportions and no observation had shown for TS-5. Result: The temperament score was positively associated (P less than 0.01) with stepping/milking (0.72), flight speed (0.43) and exit score (0.33), while it was negatively associated (P less than 0.01) with milk yield (-0.64), milking duration (-0.61) and milk flow rate (-0.65). It was concluded from the above study that milking behavioural features are directly correlated with each other and production parameters. Dairy animals of calmer temperament were significantly high-yielders. The temperament of dairy animals did not significantly impact udder health as assessed through MCMT and somatic cell counts in milk.

The effect of 2 different premilking stimulation regimens, with and without a latency period, on teat tissue condition and milking performance in Holstein dairy cows

The objectives of this study were to assess the effect of 2 different premilking stimulation regimens, with and without a latency period between tactile stimulation and the attachment of the milking unit, on the teat tissue condition and milking performance of dairy cows. In a randomized controlled crossover study, 145 Holstein cows milked 3 times daily were assigned to treatment (TRT) or control (CON) groups. Premilking udder preparation for the TRT group consisted of the application of a latency period resulting in a preparation lag time of 90 s. The only difference in the premilking udder preparation of the CON group was the absence of latency period; the milking unit was attached immediately after completion of the tactile stimulation. The average duration of total tactile stimulation in TRT and CON group was 8 ± 2 and 9 ± 2 s, respectively. The study lasted for 14 d and was split into 2 periods, each consisting of a 2-d adjustment period followed by 5 d of data collection. We assessed machine milking-induced short-term changes to the teat tissue by palpation and visual inspection postmilking. Electronic on-farm milk meters were used to assess milking characteristics (milk yield [kg/milking session], machine-on time [s], 2-min milk yield [kg], and duration of low milk flow rate [s]). Generalized linear mixed models were used to analyze the effect of treatment on the outcome variables. The odds of machine milking-induced short-term changes to the teat tissue were lower for cows that received a 90-s preparation lag time (TRT cows) compared with cows in the CON group (odds ratio [95% confidence interval; 95% CI] = 0.13 [0.08-0.20]). The least squares means (95% CI) values of cows in the TRT and CON groups were 15.4 (14.9-15.9) and 15.3 (14.8-15.8) kg, respectively, for milk yield, and 246 (239-253) and 253 (247-260) s for machine-on time. The 2-min milk yield was higher for the TRT compared with CON group cows at all the parity levels. The 2-min milk yields of animals in lactation 1, 2, and ≥3 were 5.7, 5.7, and 6.5 kg, respectively, in the TRT group and 4.6, 5.0, and 5.9 kg in the CON group. The TRT cows spent less time in low milk flow rate compared with CON cows at all parity levels. The durations of low milk flow rate of cows in lactation 1, 2, and ≥3 in the TRT group were 19, 17 and 13 s, respectively, and those in the CON group were 31, 22, and 15 s. In this study, cows that received a latency period, and thus were subjected to a 90-s preparation lag time had lower odds of exhibiting short-term changes to the teat tissue after machine milking, shorter machine-on time, higher 2-min milk yields, and lower durations of low milk flow rates. We conclude that consideration of latency period leading to a 90-s preparation lag time in the premilking stimulation regimen facilitated cows' milk-ejection reflex. This latency period can alleviate the adverse effects of vacuum-induced forces on teat tissue during machine milking, improve udder health, and promote animal well-being.

The impact of automated, constant incomplete milking on energy balance, udder health, and subsequent performance in early lactation of dairy cows

Incomplete milking (IM) is one way of mitigating the negative energy balance (NEB) that is characteristic for early lactation and may increase the risk for disease. Our objectives were to test the effects of IM in early lactation on energy balance (EB), metabolic status, udder health, and subsequent performance. To facilitate the practical application, an automated system was used to remove the milking clusters once a predefined amount of milk is withdrawn. Forty-six Holstein cows were equally allocated to either the treatment (TRT, starting on 8 d in milk) or the control group (CON; conventional cluster removal at milk flow rate <0.3 kg/min). Milk removal in the TRT group was limited to the individual cow's milk yield 1 d before IM started and held constant for 14 d. Thereafter, all cows were conventionally milked and records related to EB, performance, and udder health were continued up to 15 wk of lactation. During the 14 d of IM, on average 11.1% less milk was obtained from the TRT cows than from the CON cows. Thereafter, milk yield increased in the TRT group, eliminating the group difference throughout the remaining observation period until wk 15 of lactation. The TRT cows tended to have less dry matter intake and also water intake than the CON cows. The extent of the NEB and the circulating concentrations of fatty acids, β-hydroxybutyrate, insulin-like growth factor-1, and leptin mostly did not differ between the groups. The IM did not affect body condition. Udder health was maintained over the entire observation period in all cows. Our results demonstrate the applicability of the automated cluster removal for limiting milk withdrawal to a defined amount in early lactation. However, it remains to be determined whether the absent effect on energy metabolism was due to the relatively stable energy status of the cows or to the relatively mild IM setting used herein.

Effect of milk flow-rate switch-point settings on milking duration and udder health throughout lactation

The objective of this study was to quantify the effects of different milk flow-rate switch-point settings on milking duration, SCC, strip milk, teat condition and milk yield in a grass based system in a long-term experiment. Much work has already been conducted providing strong support for significant reduction in milking duration without impact on yield through increasing the flow-rate switch-point at which vacuum to the milking cluster ceases and the cluster is removed from the cow by means of a retracting cord. However, in practice many farms have not adopted this labor saving technology on the basis that it may increase milk SCC. Recent research on commercial Irish dairy herds identified the contagious mastitis causing pathogen Staph. aureus as the most prevalent pathogen detected. Staph. aureus could have a cyclical shedding pattern which would inhibit detection at certain time points. Therefore, to reliably assess the effect of milk flow-rate switch-points on SCC, a long-term study was required, consisting of multiple observations on cow level SCC. The present study filled this gap in knowledge by informing on any impact that ceasing milking at different flow-rates may have on milking duration and SCC levels, particularly with regard to spring calving grass based systems. Four treatments, consisting of milk flow-rate switch-points increasing from 0.2 kg/min to 0.8 kg/min in steps of 0.2 kg/min, were deployed for 31 weeks to cows at the Teagasc Research Centre at Moorepark, Ireland. The effect of treatment on daily milking duration was significant (P < 0.001). The milking duration for a milk flow-rate switch-point of 0.8 kg/min was 95 s (14%) shorter than for 0.2 kg/min. We did not find a significant effect of increasing the milk flow-rate switch-point from 0.2 to 0.8 kg/min on milk yield or SCC in this long-term study. We did find a significant effect of week of experiment on milk SCC, whereby the SCC of the cows on the experiment increased similarly among treatment groups as lactation progressed. A significant reduction in Dead Time (time from cluster attachment to reach a milk flow-rate of 0.2 kg/min) was also noted as the milk flow-rate switch-point increased. On average reductions in Dead Time contributed 12% to the overall reductions in Milking Duration. Similarly, reductions in Low Flow Time (time from a flow-rate of 0.2 kg/min to cluster detachment at the end of milking) contributed 26% to the overall reductions in Milking Duration. Reductions in Dead Time and Low Flow Time played a greater role in reducing PM Milking Duration rather than AM Milking Duration due to the milking interval practiced on the research farm.

Exploring Alternative Methods to Reduce Milk Flow Rate From Infant Bottle Systems: Bottle Angle, Milk Volume, and Bottle Ventilation.

Modifying milk flow rate is a common pediatric dysphagia treatment. Though past investigations have demonstrated how this can be achieved using bottle nipples, little is known about the impact of other bottle modifications. The objective of this investigation is to demonstrate how bottle vent, bottle position, and volume of milk alter bottle pressures and milk flow. A Dr. Brown's bottle filled with formula was secured to a retort stand and inverted to allow milk to free flow from a Level 1 nipple. Milk flow rate and bottle pressures were calculated under three conditions: (a) with and without a vent in place; (b) with varying volumes of milk (1-4 oz); and (c) in horizontal, semi-inverted, and completely inverted positions. Differences between flow rates under the conditions were tested using repeated-measures analysis of variance. Upon inversion, milk dripped from both vented and unvented bottles. Dripping continued throughout the 20-min testing period in the vented bottle; however, as air pressure and hydrostatic pressure declined (p < .01) in the unvented bottle, milk flow slowed and eventually ceased (p < .001). As angle of bottle inversion increased, hydrostatic pressure and milk flow rate had corresponding increases as well (p < .001). Hydrostatic pressure increased an average of 1.4 ± 0.12 mm Hg per additional ounce of formula that was added to the bottle, with corresponding increases in milk flow rate observed (p < .001). Milk flow rate can be altered by feeding conditions outside of bottle nipples alone. Future work examining the clinical significance of these modifications is warranted to determine optimal interventions.

Nipple properties affect sensorimotor integration during bottle feeding in an infant pig model.

Infant feeding is a critical neurological milestone in development defined by the coordination of muscles, peripheral nerves, and brainstem nuclei. In infants, milk flow rate is often limited to improve feeding performance without treating the underlying deficiencies in the sucking and swallowing processes. Modification of the neuromotor response via sensory information from the nipple during bottle feeding is an unexplored avenue for physiology-based interventions. In this study, we assessed how differences in nipple hole size and nipple stiffness affect sucking muscle activation and subsequent movement. We fabricated four bottle nipples of varying hole size and stiffness to determine how variation in nipple properties affects the sucking behavior of infant pigs. Our results demonstrate that sensory information from the nipple affects sucking motor output. Nipple hole sizes and stiffnesses with a larger milk flow rate resulted in greater muscle activity and kinematic movement. Additionally, our results suggest that sensorimotor interventions are better directed towardmodulating tongue function rather than the mandible movementsdue to a greater response to sensory information. Understanding how sensory information influences infant feeding is instrumental in promoting effective infant feeding.