Changes in the sites of milk storage over the lactation cycle of primiparous and multiparous dairy cows.

1993 ◽  
Vol 1993 ◽  
pp. 38-38
Author(s):  
R.J. Dewhurst ◽  
C.H. Knight
Keyword(s):  
Management Practices ◽  
Regulatory Mechanism ◽  
Milk Secretion ◽  
Site Of Action ◽  
Sources Of Variation ◽  
Secretory Tissue ◽  
Milking Frequency ◽  
Lactation Cycle ◽  
Milk Storage ◽  
Storage Characteristics

Work at The Hannah Research Institute has demonstrated the effects of an inhibitory (autocrine) protein, within the whey fraction of milk, on the efficiency of milk secretion and responses to changes in milking frequency. The regulatory mechanism involves both the concentration of the inhibitor and the site of milk storage (relative to its site of action, the secretory tissue). Milk storage characteristics influence responses to a number of management practices, most notably changes in milking frequency (Dewhurst and Knight, 1992; Knight and Dewhurst, 1992). There is, therefore, a need to understand phenotypic sources of variation in the sites of milk storage in order to define standard conditions and procedures for making cistern measurements.

Once daliy milking of dairy cows: relationship between yield loss and cisternal milk storage

1994 ◽  
Vol 61 (4) ◽  
pp. 441-449 ◽  
Author(s):  
Christopher H. Knight ◽  
Richard J. Dewhurst
Keyword(s):  
Milk Yield ◽  
Once Daily ◽  
A Value ◽  
Total Milk ◽  
Alveolar Tissue ◽  
Milking Frequency ◽  
Rate Of Decline ◽  
Milk Storage ◽  
Storage Characteristics ◽  
Degree Of Recovery

SummaryThe proportions of milk stored in the gland cistern (cisternal) and within secretory alveolar tissue (alveolar) were determined for a group of ten cows in mid lactation, yielding ∼ 20 kg milk/d. As a proportion of total milk, cisternal milk, measured at 8 h after milking, ranged from 0·09 to 0·53. Milking frequency was then reduced from twice daily to once daily on two occasions, first for 1 week and then, 2 weeks later, for 2 weeks. Milk yield was reduced during once daily milking in all cows, by an average of 22·8% during the first week (P < 0·001). The amount of decrease varied among cows in a way that was unrelated to pretreatment yield, but the immediate decrease was significantly and inversely correlated with cisternal milk proportion (r = 0·81, P < 0·01). When milking reverted to twice daily, yield recovered to a value not significantly different from pretreatment, and the degree of recovery was inversely related to cisternal milk proportion (r = 0·74, P < 0·01). With the exception of one cow, yield decreases correlated well between the two periods of once daily milking. When treatment weeks were disregarded, lactation persistency (the rate of decline in yield with time) was unaffected by once daily milking. The results show that the ability of individual cows to tolerate once daily milking is related to their cisternal storage characteristics; yield is reduced less in cows that store a greater proportion of their total milk production within the cistern. Once daily milking for up to 2 weeks had no lasting effect on milk yield or lactation persistency, suggesting that there had been no detrimental effect on udder development.

Udder characteristics and relationship to efficiency of milk production

1995 ◽  
Vol 19 ◽  
pp. 79-85 ◽  
Author(s):  
C. H. Knight ◽  
J. R. Brown ◽  
R. J. Dewhurst
Keyword(s):  
Secretion Rate ◽  
Secretory Cells ◽  
Selection Strategies ◽  
Fine Control ◽  
Feedback Inhibitor ◽  
Secretory Tissue ◽  
Highly Correlated ◽  
Milk Storage ◽  
Storage Characteristics ◽  
Autocrine Mechanism

AbstractMilk yield is ultimately constrained by the number of mammary secretory cells and the amount produced by each cell; increasing yield during early lactation is associated with increased output per cell, whilst decreasing yield during declining lactation correlates with reduced number of cells. Overall, yield is highly correlated with mass of secretory tissue but strategic control of lactation involves a galactopoietic complex of hormones including GH, prolactin and oxytocin acting to ensure efficient milk ejection and maintenance of secretion. Fine control, on the other hand, is achieved locally within the mammary gland by an autocrine mechanism which matches supply of milk to demand. The feedback inhibitor of lactation (FIL) is a milk protein which is inhibitory to secretion, so as milk accumulates between milkings, secretion rate gradually falls. The more frequently FIL is removed by milking, the greater the overall secretion rate. Storage of milk occurs within secretory tissue (alveolar milk) but also in the cistern (cisternal milk); FIL is effective in alveolar milk but not in cisternal milk, because it is then remote from its site of action. Therefore predictions would be that for a given mass of secretory tissue, large-cisterned cows should produce more milk, be more tolerant of infrequent milking but be less responsive to frequent milking. Methods developed by us for determining cisternal and alveolar milk storage spaces have obtained statistically proven support for the latter two predictions in dairy cows; the first prediction has been proven in goats. It has been shown that cisternal milk fraction increases during the course of lactation and with increasing parity. It is now intended to investigate the feasibility of incorporating storage characteristics into future selection strategies.

Preliminary Performance of the Computerized Inventory-Monitoring System for Pine Seed Orchards

1985 ◽  
Vol 9 (3) ◽  
pp. 173-176
Author(s):  
Scott A. Merkle ◽  
Peter P. Feret ◽  
David L. Bramlett
Keyword(s):  
Pinus Taeda ◽  
Monitoring System ◽  
Loblolly Pine ◽  
Management Practices ◽  
Predictive Accuracy ◽  
Predictive Performance ◽  
Seed Orchard ◽  
Productivity Data ◽  
Orchard Management ◽  
Sources Of Variation

Abstract A seed orchard Inventory-Monitoring System (IMS) and companion computer program were tested for predictive accuracy and monitoring effectiveness in an operational loblolly pine (Pinus taeda) seed orchard. The IMS was used to predict 1980 and 1981 cone harvests by tracking the survival of strobili on sample trees representing each producing clone in the orchard. The 1980 cone harvest was substantially overestimated, possibly due to the use of generalized cone efficiency estimates. Predictions for the 1981 cone harvest, made with the benefit of clonal cone efficiency estimates from the 1980 crop, were much more accurate, under-estimating the actual harvest by as little as 5%.Predictive performance of the IMS is expected to improve with accumulation of productivity data for each clone and with the reduction of nonclonal sources of variation resulting from improved orchard management practices. Seed orchard-to-nursery efficiency (SO-NE) data from the system's monitoring function showed that low SO-NE values for the orchard of 22 % in 1980 and 24 % in 1981 were due mainly to low cone efficiency and low seed efficiency.2

Studies on milk yield and calf suckling behaviour in Kenyan camels (Camelus dromedarius)

1996 ◽  
Vol 1996 ◽  
pp. 105-105 ◽  
Author(s):  
S.P. Simpkin ◽  
P. Rowlinson
Keyword(s):  
Milk Yield ◽  
Literature Survey ◽  
Camel Milk ◽  
Human Consumption ◽  
Milk Secretion ◽  
Experimental Conditions ◽  
Short Period ◽  
The World ◽  
Total Milk ◽  
Milking Frequency

Estimates of camel lactation yields in the literature vary from less than 1000kg to more than 12000 kg, with mean daily yields from 0.1 to 35kg (Simpkin 1985). Suckling or milking frequency and strength of the milk letdown reflex are just two of many factors that affect milk secretion rate in camels. Most of the 18 million camels in the world are kept in nomadic pastoral herds where estimation of milk yield is particularly difficult and the large variation in reported camel milk yields could be attributed to the methodology used to estimate yields. A literature survey shows most articles are based on infrequent observations on small numbers of animals over a short period of lactation and fail to state the experimental conditions or whether figures represent milk offtake for human consumption or total milk yield.

Relationship between milk storage characteristics and the short-term response of dairy cows to thrice-daily milking

1994 ◽  
Vol 58 (2) ◽  
pp. 181-187 ◽  
Author(s):  
R. J. Dewhurst ◽  
C. H. Knight
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Short Term ◽  
Additional Time ◽  
Lactating Dairy Cows ◽  
Total Milk ◽  
Milk Storage ◽  
The Relationship ◽  
Storage Characteristics ◽  
Term Response

AbstractTwenty lactating dairy cows were used to investigate the relationship between the site of milk storage in the udder and the short-term response to thrice-daily milking. Cisternal and alveolar milk volumes were measured 8 h after an ordinary morning milking by catheter drainage and machine milking with oxytocin respectively. The response to thrice-daily milking was assessed using a half-udder technique and the relative milk yields quotient (RMYQ). Over the first 7 days, both halves were milked twice daily (8/16 h intervals) and milk yields over the final 4 days of this period were higher for left fore/right hind (LF/RH) (12·4 (s.e. 0·85) kg/day) than for RF/LH (10·5 (s.e. 0·63) kg/day) which was milked after LF/RH throughout the experiment. Over the following week, LF/RH quarters were milked an additional time (8/8/8 h intervals) and yields over the final 4 days were increased (15•7 (s.e. 0·95) kg/day) compared with control quarters (9·8 (s.e. 0·73) kg/day). In a final 4-day period, animals were milked twice daily and half udder yields were 13·1 (s.e. 0·89) kg/day and 10•6 (s.e. 0·77) kg/day respectively. Differences between yields from the two halves of the udders were highly significant in all 3 weeks of the experiment (P < 0·001). Cistern milk yield as a proportion of total milk yield at 8 h (cistern proportion) averaged 0·170 (s.e. = 0·0275; range 0·020 to 0·334) and tended to be greater for multiparous (0·215, s.e. 0·0279) than for primiparous animals (0·118, s.e. 0·0437; P = 0·076). During the periods of twice-daily milking, the proportion of milk yielded from LF/RH quarters was not significantly related to cistern proportion (P = 0·70 and 0·43 for weeks 1 and 3 respectively). However the response to thrice-daily milking, assessed as RMYQ, was significantly related to cistern proportion both when changing up to, and down from, thrice-daily milking (P < 0·01). Animals with low cistern proportions showed larger responses to thrice-daily milking. There was a significant relationship (P < 0·05) between the responses on changing up to, and down from, thrice-daily milking. Primiparous animals tended to exhibit smaller declines on returning to twice-daily milking than multiparous animals with equivalent responses to thrice-daily milking.

Measurement of functional udder capacity in lactating Jersey cows

1988 ◽  
Vol 39 (6) ◽  
pp. 1163 ◽  
Author(s):  
SR Davis ◽  
GA Hughson
Keyword(s):  
Milk Production ◽  
Functional Capacity ◽  
Milk Secretion ◽  
Tissue Volume ◽  
Milking Frequency ◽  
Capacity Data ◽  
Jersey Cows ◽  
Serial Measurements ◽  
Rate Of Accumulation

Serial measurements of udder volume in 11 multiparous and 4 primiparous Jersey cows in mid-lactation were used to establish the time of cessation of milk production after a period of milk accumulation. Udder volume was determined from measurements of udder height, length and width. Functional udder capacity (defined as the litres of contained milk in the udder when milk secretion ceased) was greater in cows (15.5 � 0.8 litres) than heifers (9.3 � 0.7 litres). Expressed as hours-worth of secretion, on average, heifers possessed 25.9 � 1.5 and cows 33.6 � 2.9 hours-worth of capacity - data which indicate some potential for reduction in milking frequency without loss of production. Functional udder capacity (l.) was correlated with empty udder volume (tissue volume), and was greater in cows showing high residual milk volumes. The data show that once functional capacity is reached the shut down in milk secretion is rapid, occurring over a 2-4 h period, the rate of accumulation of secretion being constant up to this time.

Use of ultrasonography to estimate cistern size and milk storage at different milking intervals in the udder of dairy cows

2003 ◽  
Vol 70 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Moez Ayadi ◽  
Gerardo Caja ◽  
Xavier Such ◽  
Christopher H Knight
Keyword(s):  
Dairy Cows ◽  
Blocking Agent ◽  
Non Invasive ◽  
Milk Volume ◽  
Invasive Method ◽  
Highly Correlated ◽  
Milk Storage ◽  
Transducer Probe ◽  
Storage Characteristics

Four lactating Holstein cows (average milk yield: 20±3 l/d) were used to develop and validate a method for estimating the size of udder cisterns (Sinus lactiferi) using ultrasonography. A sectorial transducer probe of 5 MHz, placed in contact with the teat in a parallel cranial position, was used to obtain vertical scans of the udder in two perpendicular planes with the teat canal axis as reference. Udder scans for each udder quarter were taken randomly at intervals of 4, 8, 12, 16, 20 and 24 h after milking. Glandular parenchyma (echogenic) and lumen of the cisterns full of milk (anechogenic) were evident in the scans, the calculated area of the anechogenic portion being defined as cistern area. Cistern areas measured in perpendicular scans were highly correlated. Immediately after each measurement, cisternal milk was removed from each quarter using a teat cannula after i.v. injection of an oxytocin-receptor blocking agent. Alveolar milk from each quarter was then obtained by machine milking after i.m. injection of oxytocin. Cistern area and cisternal milk volume increased with length of milking interval showing a curvilinear pattern with a plateau after 16 h. Correlations between cistern area and cisternal milk volume were positive and significant (P<0·001) at all intervals but showed the highest values with the smallest residual standard deviations at 8 h (r=0·88) and 12 h (r=0·84). Since 8 h has previously been identified as a suitable time at which to determine cisternal milk volume for the purposes of defining suitability for different milking strategies, we conclude that ultrasonography provides a satisfactory, non-invasive method for determination of milk storage characteristics in dairy cows.

The effect of pregnancy on lactation persistency and milk composition in dairy cows

1996 ◽  
Vol 1996 ◽  
pp. 3-3
Author(s):  
J.B. Coulon ◽  
B. Rémond ◽  
L. Pérochon
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Late Pregnancy ◽  
Milk Composition ◽  
Milk Secretion ◽  
Lactation Cycle

In dairy cows, effect of pregnancy on milk production is acknowledged but little documented, and with conflicting data. Weak during the « normal » lactation, this effect becomes important in late pregnancy. To precisely model milk secretion, and to adjust novel management of the lactation cycle, it is important to specify this effect.

Effect of unilateral once or twice daily milking of cows on milk yield and udder characteristics in early and late lactation

1997 ◽  
Vol 64 (4) ◽  
pp. 487-494 ◽  
Author(s):  
KERST STELWAGEN ◽  
CHRISTOPHER H. KNIGHT
Keyword(s):  
Milk Yield ◽  
Control Period ◽  
Mammary Epithelium ◽  
Cell Loss ◽  
Once Daily ◽  
Secretion Efficiency ◽  
Milking Frequency ◽  
Positive Correlations ◽  
Milk Storage ◽  
Friesian Cows

Twelve multiparous British Friesian cows in early (40±23 d in milk; n=6) or late (216±17 d in milk; n=6) lactation were used to study the effects of milking frequency on yield, udder volume and milk storage within the udder. After a 2 week control period of twice daily milking, diagonally opposed udder halves within a cow were milked once or twice daily for 3 weeks. Milk yield was 28–38% lower from the halves that were milked once daily than from halves that were milked twice daily. The loss of milk yield, expressed as a decrease in the relative milk yield quotient (an index that accounts for pretreatment differences), was greater for cows in early than in late lactation (0·59 v. 0·68). Empty udder-half volume was not decreased by once daily milking, suggesting that no cell loss occurred. Instead, once daily milking reduced the secretion efficiency (units of milk per unit of empty udder-half volume) by 46 and 27% respectively in early and late lactation; thus, at least part of the loss was due to reduced metabolic activity of the mammary epithelium. There were positive correlations between the relative milk yield quotient and the proportion (r=0·804) or volume (r=0·644) of cisternal milk in the glands that were milked once daily. These results confirm that, during extended milking intervals, milk loss was smallest for cows that stored a larger proportion of milk in the gland cistern.

scholarly journals Systematic Review and Meta-Analysis: Identification of Factors Influencing Milking Frequency of Cows in Automatic Milking Systems Combined with Grazing

Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 913
Author(s):  
Françoise Lessire ◽  
Nassim Moula ◽  
Jean-Luc Hornick ◽  
Isabelle Dufrasne
Keyword(s):  
Management Practices ◽  
Meta Analysis ◽  
Principal Component ◽  
Mitigation Strategies ◽  
Production Costs ◽  
Management Options ◽  
Milking Frequency ◽  
Automatic Milking ◽  
Automatic Milking Systems ◽  
The Relationship

More dairy farms (up to more than one in four in some countries) are equipped with automatic milking systems (AMS) worldwide. Because of the positive impacts of grazing, e.g., on animal welfare or on production costs, numerous researchers have published papers on the combination of AMS with grazing. However, pasture-based AMS usually causes a reduction in milking frequency (MF) compared to indoors systems. The objectives of this meta-analysis were to review publications on the impacts of pasture-based AMS on MF and mitigation strategies. First, data from 43 selected studies were gathered in a dataset including 14 parameters, and on which a Principal Component Analysis (PCA) was performed, leading to the description of four clusters summarizing different management practices. Multiple pairwise comparisons were performed to determine the relationship between the highlighted parameters of MF on milk yield (MY). From these different analyses, the relationship between MF and MY was confirmed, the systems, i.e., Clusters 1 and 2, that experienced the lowest MF also demonstrated the lowest MY/cow per day. In these clusters, grazed grass was an essential component of the cow’s diet and low feeding costs compensated MY reduction. The management options described in Clusters 3 and 4 allowed maintenance of MF and MY by complementing the cows’ diets with concentrates or partial mixed ration supplied at the AMS feeding bin or provided at barn. The chosen management options were closely linked to the geographical origin of the papers indicating that other factors (e.g., climatic conditions or available grasslands) could be decisional key points for AMS management strategies.

Sign in / Sign up

Export Citation Format

Share Document