A quantitative evaluation of some factors affecting the non-fatty solids of cow's milk

1960 ◽  
Vol 27 (1) ◽  
pp. 19-32 ◽  
Author(s):  
W. H. Alexander ◽  
F. B. Leech

SummaryTen farms in the county of Durham took part in a field study of the effects of feeding and of udder disease on the level of non-fatty solids (s.n.f.) in milk. Statistical analysis of the resulting data showed that age, pregnancy, season of the year, and total cell count affected the percentage of s.n.f. and that these effects were additive and independent of each other. No effect associated with nutritional changes could be demonstrated.The principal effects of the factors, each one freed from effects of other factors, were as follows:Herds in which s.n.f. had been consistently low over a period of years were compared with herds in which s.n.f. had been satisfactory. Analysis of the data showed that about 70% of the difference in s.n.f. between these groups could be accounted for by differences in age of cow, stage of lactation, cell count and breed.There was some evidence of a residual effect following clinical mastitis that could not be accounted for by residual high cell counts.The within-cow regression of s.n.f. on log cell count calculated from the Durham data and from van Rensburg's data was on both occasions negative.The implications of these findings are discussed, particularly in relation to advisory work.

1983 ◽  
Vol 36 (3) ◽  
pp. 335-339 ◽  
Author(s):  
P. D. P. Wood ◽  
J. M. Booth

ABSTRACTA survey was carried out of 1 640 British Friesian heifers calving predominantly in the autumn of 1979. The monthly samples of 1 055 animals showing no reported evidence of udder infection were used to evaluate the parameters of a lactation curve in milk cell count. The model wasC = 190 n−0.4880exp(0·178n)where C is the monthly cell count in millions per 1 during the nth month of lactation. The cell count varied from 230 × 106 in week 1 and 190 × 106 in week 11 to 400 × 106 in week 44 of lactation.On applying the model to the whole sample, milk sampled within a month before or after antibiotic treatment for clinical mastitis contained more than 200 × 106 cells per 1 above the level suggested by the lactation curve. Lactation mean cell counts of treated cows were 400 × 106 cells per 1 higher than those of untreated cows. It was not possible to identify periods in which cows required treatment, or those with high cell counts, by reference to the lactose concentration in the milk samples. Among the untreated cows, the cell count at the third monthly test-day was lower than at any other time, and was more highly correlated with the lactation mean cell count.


1997 ◽  
Vol 1997 ◽  
pp. 25-25
Author(s):  
R A Mrode ◽  
G J T Swanson

Mastitis remains a costly health problem to dairy farmers despite a significant reduction in both clinical and sub-clinical mastitis over the last 25 years. This reduction has been due predominantly to the success of management control programmes. The continuing losses have raised the interest in breeding as a means to reduce mastitis incidence. Somatic Cell Counts (SCC) have been used since 1977 as an indirect means of monitoring mastitis within dairy herds. Since 1991 an optional individual cell count service has been offered by Milk Recording Organisations in the UK. The result is that 0.80 of recorded cows have SCC records. The Animal Data Centre has analysed the SCC data to establish genetic parameters and produced preliminary evaluations on bulls and cows (Mrode et al, 1996). As a forerunner to launching SCC evaluations it is important to determine whether SCC evaluations in the UK agree with similar evaluations overseas.


Author(s):  
Laura Jerpseth ◽  
Ketan Thakare ◽  
Zhijian Pei ◽  
Hongmin Qin

Abstract In bioprinting, biomaterials are deposited layer-by-layer to fabricate structures. Bioprinting has many potential applications in drug screening, tissue engineering, and regenerative medicine. Both animal cells and plant cells can be used to synthesize bioinks. Green bioprinting uses bioinks that have been synthesized using plant cells. Constructs fabricated via green bioprinting contain immobilized plant cells, with these cells arranged at desired locations. The constructs provide scaffolds for cell growth. Printing parameters affecting the growth of cells in green bioprinted constructs include print speed, needle diameter, extrusion temperature, and extrusion pressure. This paper reports a study to examine effects of extrusion pressure on cell growth (measured by cell count) in bioprinted constructs, using bioink containing Chlamydomonas reinhardtii algae cells. Three levels of extrusion pressure were used: 3, 5, and 7 bar. Cell counts in the bioprinted constructs were measured on the third and sixth days after bioprinting. It was found that, as extrusion pressure increased, cell count decreased on both the third and sixth days after bioprinting. Furthermore, the difference in cell counts between the third and the sixth days decreased as extrusion pressure increased. These trends suggest that increasing extrusion pressure during green bioprinting negatively affects cell growth. A possible reason for these trends is physical damage to or death of cells in the bioprinted constructs when extrusion pressure became higher.


1979 ◽  
Vol 46 (3) ◽  
pp. 453-462 ◽  
Author(s):  
Amer M. A. Salih ◽  
Malcolm Anderson

SummaryThe effect that changes in composition which occur in milks possessing high cell counts have on milk lipolysis has been investigated. High cell counts were produced either by intramammary infusion of Escherichia coli endotoxin or Streptococcus agalactiae or by addition of washed cells which were isolated from milk obtained from quarters infused with endotoxin. Free fatty acid levels in milk were measured in terms of acid degree value (ADV) either as initial ADV measured immediately after milking or ADV developed after a prescribed incubation period.There was an increase in initial ADV after the infusion either of endotoxin or of Str. agalactiae relative to a control quarter. This increase appeared to be associated with changes in cell count, but in absolute terms the influence of cells on ADV became less as cell count increased. Neither type of infusion had any effect on lipoprotein lipase activity. The addition of washed cells to normal milk resulted in an increase in developed ADV, but the increment was not as large as that produced by the addition of 1% blood serum. When cream and skim-milk from endotoxin-treated quarters and control quarters were mixed in different combinations with and without additional cells, developed ADV was higher in those samples containing endotoxin cream and those with added cells. Milk from a quarter treated with endotoxin was diluted with its own skim-milk to produce different cell counts and ADV was determined after various time intervals at 4 and 37 °C. Lipolysis increased with increasing cell count, but a depression in lipolytic rate was noted after incubation for 6 h at 4 °C and 20 min at 37 °C.The proportion of skim-milk lipoprotein lipase activity in milk serum was larger both in milks possessing high cell counts and in normal milk adjusted to between 5 and 20 mM-NaCl by addition of solid NaCl. These levels of NaCl inhibited lipolysis.The possible direct and indirect effects of high cell count on milk lipolysis are discussed.


2009 ◽  
Vol 76 (4) ◽  
pp. 490-496 ◽  
Author(s):  
Jan Lievaart ◽  
Herman W Barkema ◽  
Henk Hogeveen ◽  
Wim Kremer

Bulk milk somatic cell count (BMSCC) is a frequently used parameter to estimate the subclinical mastitis prevalence in a dairy herd, but it often differs considerably from the average SCC of all individual cows in milk. In this study, first the sampling variation was determined on 53 dairy farms with a BMSCC ranging from 56 000 to 441 000 cells/ml by collecting five samples on each farm of the same bulk tank. The average absolute sampling variation ranged from 1800 to 19 800 cells/ml. To what extent BMSCC represents all lactating cows was evaluated in another 246 farms by comparing BMSCC to the average herd SCC corrected for milk yield (CHSCC), after the difference was corrected for the sampling variation of BMSCC. On average BMSCC was 49 000 cells/ml lower than CHSCC, ranging from −10 000 cells/ml to 182 000 cells/ml, while the difference increased with an increasing BMSCC. Subsequently, management practices associated with existing differences were identified. Farms with a small (<20%) difference between BMSCC and CHSCC administered intramuscular antibiotics for the treatment of clinical mastitis more often, used the high SCC history when cows were dried off more frequently and had a higher number of treatments per clinical mastitis case compared with farms with a large (⩾20%) difference. Farms feeding high-SCC milk or milk with antibiotic residues to calves were 2·4-times more likely to have a large difference. Although sampling variation influences the differences between BMSCC and CHSCC, the remaining difference is still important and should be considered when BMSCC is used to review the average herd SCC and the subclinical mastitis prevalence.


1980 ◽  
Vol 60 (2) ◽  
pp. 231-239 ◽  
Author(s):  
SUSAN HIGGINS ◽  
R. K. MOORE ◽  
B. W. KENNEDY

Teat conformation characteristics were measured on 402 Holstein-Friesian cows in 18 dairy herds in western Quebec and eastern Ontario. The purpose of the study was to determine the effects of heridity on teat conformation traits as well as to examine phenotypic relationships between the traits and somatic cell count as a measure of udder health. Maximum likelihood estimates of heritabilities of teat conformation traits and cell count, transformed to a log scale, were low; usually less than 0.10. Exceptions were length of front teat (h2 = 0.44) and distance of udder to the floor (h2 = 0.41). Significantly higher cell counts were associated with teats that were long, wide, not plumb and bottle (as opposed to cylindrical or funnel) shaped. The most highly correlated trait with cell count was distance of udder to the floor (r = − 0.24). However, many of the significant gross relationships observed were jointly related with age of cow, and when the effects of age of cow at calving, stage of lactation and herd were removed, only length of rear teat and front and rear teat medial diameters had significant influences on cell count.


10.5219/1336 ◽  
2020 ◽  
Vol 14 ◽  
pp. 744-749
Author(s):  
Vladimí­r Tančin ◽  
Šimon Mikláš ◽  
Maroš Čobirka ◽  
Michal Uhrinčať ◽  
Lucia Mačuhová

Under the practical conditions, it is important to evaluate the factors affecting milk performance. Data from test day yield and milk components should be useful for such evaluation. The aim of the experiment was to study the effect of season, udder health (by somatic cell counts SCC), parity, stage of lactation on milk production, milk components, and SCC under the practical conditions. Also, the frequency of incidence of high SCC during the season was observed. The experiment was realized on one dairy farm in dairy practice. The experiment lasted from December 2015 to October 2017. We examined 481 Holstein dairy cows (6910 milk samples). Milk samples were collected once per month – performed by recording test day. Only cows with 9 – 11 test days were evaluated. The effect of season, parity, stage of lactation, and SCC influenced most of the studied traits. The milk yield was highest at 2nd lactation. In the following lactations, the milk yields were decreasing. The SCC significantly increased with advanced parity. The elevated SCC was found in the beginning and in the final part of lactation. SCC as a factor significantly reduced milk yield, lactose content but increased fat and protein content. In conclusion, under practical conditions, the management should use the data from test days and analyze them for a better understanding of the performance efficiency at the farm level and for implementing more sophisticated decision making in farming.


1983 ◽  
Vol 50 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Anthony T. Andrews

SummaryMilk obtained from cows which were either infected by clinical mastitis or had been subjected to intramammary infusion of Escherichia coli endotoxin possessed high counts of somatic cells and very high levels of proteinase activity which hydrolysed the caseins almost completely in a few hours at 37 °C. The rate of hydrolysis of β-casein was slightly greater than that of αs1-casein, but in both cases hydrolysis was enhanced by 6 cycles of freezing and thawing to disrupt somatic cell membranes. A study of the relationship between proteinase activity and cell count suggested that only some of the proteinase activity originated in the somatic cells and also that the identity of the cells making up the total cellular population was important. Maximum proteolysis occurred at 50–60 °C, but the temperature-activity curve was a broad peak. Likewise the pH versus activity plot was very broad and was almost flat over the pH range 6–9. Experiments with a number of inhibitors of proteinases failed to give a clear cut pattern of inhibition. All evidence obtained was consistent with the view that several different enzymes with different pH and temperature optima and different specificities contributed to the overall hydrolysis of caseins in these milks. From electrophoretic band patterns one of these enzymes was clearly plasmin, but in high cell count milks other proteinases also became significant.


1995 ◽  
Vol 1995 ◽  
pp. 128-128 ◽  
Author(s):  
R A Mrode ◽  
G J T Swanson ◽  
M S Winters

Mastitis constitutes a major source of economic loss in the national dairy herd. Although good management practices can produce a major reduction in mastitis, there is considerable interest in the reduction of mastitis through breeding. Somatic cell counts (SCC) have been used as a way of indirectly measuring sub-clinical mastitis within a herd. Since 1991, average cell count is obtained for all herds and this is used to adjust milk payments.Milk recording organisations introduced a cow cell count service in 1990. The data are now available for the preliminary analysis of the usefulness of somatic cell counts. The objective of this study was to estimate genetic parameters for SCC for three major breeds in the UK.


1958 ◽  
Vol 25 (1) ◽  
pp. 52-59 ◽  
Author(s):  
D. A. McKenzie ◽  
Elizabeth M. K. Booker ◽  
W. Moore

Tests over a 2-year period of milk from an Ayrshire herd showed that there was a greater incidence of low S.N.F. samples from milk with a high cell count compared with samples from that of a low cell count.While a wide variation in S.N.F. was found at any particular cell count level, there was a broad correlation between cell count and S.N.F., the average S.N.F. for cows in the same lactation being lower for those animals with high cell counts in the milk.It is suggested that a cell count > 100,000/ml. in bulk milk should be regarded as significant.Bacteriological examination of the high cell count samples showed that in a large proportion of cases no typical mastitis-producing organism could be isolated.The authors wish to thank their colleagues in the Bacteriology, Chemistry and Veterinary Investigation Departments for assistance in this work.


Sign in / Sign up

Export Citation Format

Share Document