Dynamic responses of the dairy cow's teat to step changes in pressure

1979 ◽  
Vol 46 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Sybren Y. Reitsma ◽  
Norman R. Scott

SUMMARYDynamic responses of the teat end, measured as changes in external diameter and milk flow-rate, due to step changes in pressure, uniformly applied to the whole teat, are presented. The experiment involved a front and a rear teat of each of 6 Holstein–Friesian cows. The measured variables were: (1) step change in pressure, (2) milk flow-rate, (3) step change in external teat end diameter, (4) rise times of pressure and teat end diameter changes, (5) fall times of pressure and teat end diameter changes, and (6) delay times between pressure and teat end diameter changes both at start of rise and of fall times. A statistical analysis showed that front teats expanded more than rear teats (P < 0·05). Several other findings of importance to any system of milk removal through the streak canal of the teat are discussed.

1991 ◽  
Vol 58 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Janthea A. Newman ◽  
Robert J. Grindal ◽  
M. Clare Butler

SummaryThree types of liner (wide bore tapered, wide bore and narrow bore) were compared in a change-over design experiment comprising three 3-d periods and using six lactating Holstein Friesian cows with a wide range in milk flow rate and teat dimensions. Vacuum levels measured within the liner showed a characteristic pattern of three distinct phases: 1, a mouthpiece chamber (MPC) vacuum that fluctuated with vacuum beneath the teat; 2, a stable MPC vacuum that coincided with the period of peak milk flow and 3, a MPC vacuum that fluctuated with pressure changes in the pulsation chamber and coincided with the period of no or reduced flow. Of the three liners examined, the Gascoigne 1030A (wide bore tapered) induced the highest MPC vacuum (29·4 ± 2·23 kPa, mean ± s.e.m), significantly higher (P < 0·01) than the Alfa-Laval 960000–01 wide bore (23·5 ± 2·32), regardless of teat size and milk flow rate. The Alfa-Laval 7275737–01 (narrow bore) gave a significantly lower value (16·5 ± 1·96) than either of the others (P < 0·001). It was not possible to link absolutely raised MPC vacuum to cow discomfort and teat trauma but circumstantial evidence encourages this view. Narrow teats in combination with slow flow rate appeared to exacerbate MPC vacuum and, because milking time for such animals was protracted, teats were exposed for longer periods.


2013 ◽  
Vol 80 (3) ◽  
pp. 344-348 ◽  
Author(s):  
J Paul Edwards ◽  
Bernadette O'Brien ◽  
Nicolas Lopez-Villalobos ◽  
Jenny G Jago

The objective of the study was to determine the effect of varying degrees of overmilking on teat-end hyperkeratosis, milk production variables and indicators of udder health during late lactation. This was examined by assessing the effect of four end-of-milking criteria on 181 spring-calving, mixed-age Holstein-Friesian cows, at an average 217±24 d in milk, over a six-week period. The four treatments were: remove cluster once milk flow rate fell to 0·2 kg/min plus 5 s (Ovr0), plus 120 s (Ovr2), plus 300 s (Ovr5), and plus 540 s (Ovr9). Daily measurements included individual cow milk yield, milking duration, overmilking duration, maximum milk flow rate, milk flow rate at cluster removal and the number of cluster re-attachments. Individual cow bulk milk samples were collected weekly at AM and PM milkings to determine composition (fat, protein and lactose) and somatic cell count (SCC; AM only). Teat-end hyperkeratosis score was assessed at weeks 0, 3, 5 and 6. At week 6 mean teat-end hyperkeratosis score of the Ovr2 treatment was not greater than Ovr0, whilst Ovr5 was greater than Ovr2 and Ovr9 was greater than Ovr5 and Ovr2. Milk production, milking characteristics and SCC were not different between treatments, except milking duration and milk flow rate at cluster removal. However, higher teat-end hyperkeratosis scores may have a longer-term impact on indicators of udder health if teat-end condition reaches severe levels. Results indicate that to minimise changes in teat-end condition overmilking should be limited to 2 min, which has implications for milking management in large parlours not fitted with automatic cluster removers.


1981 ◽  
Vol 61 (2) ◽  
pp. 493-501 ◽  
Author(s):  
R. K. MOORE ◽  
SUSAN HIGGINS ◽  
B. W. KENNEDY ◽  
E. B. BURNSIDE

Teat conformation characteristics, udder height, total milking yield, 2-min yield, 2-min yield adjusted for the linear and quadratic effects of total milking yield, and 305-day milk and fat yields were recorded on 377 Holstein-Friesian cows in 18 herds. Simple relationships of teat conformation measures and udder height to milk flow rate and production traits which were significant (P < 0.05) were as follows. Mean 2-min, total milking, and 305-day milk yields were lower for plumb front teats than for front teats that were not plumb. Cows with plumb rear teats also had lower total milking yields. Cows with cylindrical teats, both front and rear, had lower total milking yields than cows with funnel teats. Teat length was positively correlated with total milking, 305-day milk and 305-day fat yields. Teat diameter measures taken at proximal, medial and distal locations of the teat were positively correlated with all production traits, and rear teat diameter measures were positively correlated with 2-min yield. Udder height was positively correlated with adjusted 2-min yield and negatively correlated with total milking, 305-day milk and 305-day fat yields. Least squares analyses, which corrected for the effects of herd, age of cow at calving, and stage of lactation, were conducted, and significant (P < 0.05) effects were as follows. Cows with cylindrical teats produced 0.7–0.8 kg less total milk at milking than cows with funnel teats. Rear teat diameter was more highly related to milk production than front teat diameter. Proximal and distal diameter of the rear teat was positively associated with all three production traits, and medial rear teat diameter was positively associated with total milking and 305-day milk yields. Also, proximal diameter of the rear teat had a positive relationship with 2-min yield. Total milking yield was positively influenced by front teat proximal and medial diameters, but medial diameter had a negative effect on adjusted 2-min yield. Udder height influenced all traits. High udders had relatively higher milk flow rates but lower milk and fat production. Each centimetre increase in udder height was associated with a 46-kg decrease in 305-day milk. Heritabilities of 2-min yield, adjusted 2-min yield, 305-day milk yield and 305-day fat yield were 0.17, 0.27, 0.18, and 0.50, respectively.


2019 ◽  
Vol 15 (2) ◽  
pp. 23-30
Author(s):  
Sonia Hiller ◽  
Inga Kowalewska-Łuczak ◽  
Ewa Czerniawska-Piątkowska

The aim of this study was to identify SNPs mutations in the CATHL2 gene and determine their potential association with dairy performance traits in Polish Black-and-White Holstein-Friesian (phf) cows. Genotypes of individuals were identified by PCR-RFLP. The frequencies of CATHL2/DdeI alleles were C ‒ 0.693 and T ‒ 0.307, and for CATHL2/HhaI polymorphisms, G ‒ 0.763 and C ‒ 0.237. The statistical analysis showed that cows with the CC (CATHL2/DdeI) and CG (CATHL2/HhaI) genotype produced higher milk yield than the other cattle genotypes. In the case of CATHL2/DdeI and CATHL2/HhaI polymorphisms, the highest somatic cell count was found in heterozygous CT and CG cows.


Author(s):  
Andrea Szentléleki ◽  
Jeremy Hervé ◽  
Ferenc Pajor ◽  
Daniel Falta ◽  
János Tőzsér

The aim of this study was to evaluate the change of temperament of Holstein cows scored before and during milking during the entire lactation and to calculate correlation between temperament measured in the two moments as well as milk production traits and temperament. Observations were carried out on 17 primiparous Holstein Friesian cows starting their lactation within 85 days. Measurements of temperament and milk production traits were taken once in each month of the lactation, during the morning milking, in a milking parlour. Temperament was assessed in a 5-point scale during udder preparation and milking procedure (1: very nervous, 5: very quiet). Data of milk yield and milk flow were collected individually on each test day morning. Results showed changes during the lactation in temperament of cows scored directly before milking (P < 0.01), however, temperament during milking did not alter with months (P > 0.10). By correlation coefficients, behaviour assessed in the two moments cannot be regarded as the same. In addition loose, significant relations were found only between milk traits and temperament before milking.


2003 ◽  
Vol 2003 ◽  
pp. 26-26
Author(s):  
H.C.F. Wicks ◽  
A.F. Carson ◽  
M.A. McCoy

During the transition period (defined as three weeks prior to calving to three weeks post-calving) heifers are exposed to physiological, nutritional, management, and social changes as they enter the dairy herd. One obvious change is the introduction of heifers to the milking parlour. Previous work has shown that when mature cows were milked in unfamiliar surroundings, milk yield, milk flow rate and milking duration were affected due to increased stress (Rushens, et al. 2001). The objective of the current study was to investigate the effects of habituating heifers to the milking parlour pre-calving on the subsequent performance of Holstein-Friesian and Norwegian dairy herd replacements.


2002 ◽  
Vol 45 (4) ◽  
pp. 341-348
Author(s):  
P. Mijić ◽  
I. Knežević ◽  
M. Domaćinović ◽  
M. Baban ◽  
D. Kralik

Abstract. The aim was to investigate the distribution of milk flow rate in Holstein Friesian and Fleckvieh cattle. Researches were made in four farms in Eastern Croatia with 534 cows. 2594 tests were made with computer milking equipment, Alfa-Laval and with digital milk flow counter made by Tru-Test Company. The measuring of milk flow rates was done from 50th to 180th day of lactation. Tests showed as expected better results among Holstein Friesian then Fleckvieh cows. The optimal distribution of milk flow rate of Holstein Friesian type was 56.58 % and Fleckvieh was only 38.91 %. The results of the investigation are discussed. The milk flow rate represents an essential performance trait and should be included into the breeding program.


1979 ◽  
Vol 46 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Sybren Y. Reitsma ◽  
Norman R. Scott

SUMMARYA frequency response of the cow's teat has been determined by applying sinusoidal changes in vacuum level to the teat. Twelve frequencies were applied ranging from 0.06 to 12 Hz. The responses investigated were the external teat end diameter and the teat milk flow-rate. The measured variables were: (1) frequency of applied pressure and teat end diameter, (2) peak-to-peak pressure and teat end diameter, (3) average vacuum level and teat end diameter, (4) time delay between maxima of vacuum level and teat end diameter, (5) time delay between minima of vacuum level and teat end diameter, and (6) teat milk flow-rate. The results showed that within the range of the investigation milk flow-rates were lower between 0.8 and 2.5 Hz than at frequencies both below and above this range. A statistical analysis of the flow rate and teat end diameter data supports the common practice of applying the same frequency to both front and rear teats during milking. Other findings show good agreement with results reported previously on dynamic responses of the teat to step changes in pressure.


2011 ◽  
Vol 54 (4) ◽  
pp. 360-373 ◽  
Author(s):  
A. B. Müller ◽  
S. Rose-Meierhöfer ◽  
C. Ammon ◽  
R. Brunsch

Abstract. This study was carried out to investigate a new quarter-individual milking system called MultiLactor® (Siliconform GmbH, Türkheim, Germany). The MultiLactor enables milking on quarter level basis with low vacuum (37 kPa), sequential pulsation and periodic air inlet. Within the same dairy farm, the influence of this quarter-individual milking system (MULTI) on milkability traits was compared with a conventional milking system (CON). CON was equipped with a conventional milking cluster and used alternating pulsation. Vacuum level was adjusted to 40 kPa. For the study, 84 Holstein Friesian cows were randomly selected and uniformly divided into two herds. During the 30-week survey, the milk flow curves were recorded every other week by using a LactoCorder (WMB, Balgach, Switzerland). Significant differences (P<0.05) between both milking systems were found for all milk flow traits, except for milk yield and decline phase. Concerning the incline (tAN) and plateau (tPL) phase, large differences existed between MULTI and CON. The estimated value of tAN calculated for MULTI (29.4 s) took only half of the time when calculated for CON (56.4 s). The estimated value of tPL at CON was reduced by 1.43 min (35 %) compared to MULTI. Milking process at MULTI (8.49 min) took longer time than for CON (7.43 min). From the study, it was concluded that the effect of shorter tAN in the quarter-individual milked cows may be related to additional prestimulation by an actuator. In contrast, the longer milking time in MULTI is possibly caused by lower vacuum level and periodic air inlet.


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