Economic Losses f r o m and the National Research Program on Mastitis in the United States T. H. BLOSSER Agricultural Research Service U.S. Department of Agriculture Behsville, MD 20705
ABSTRACT Scientific papers estimating economic losses from mastitis were reviewed. Reduced milk production from cows with subclinical mastiffs was responsible for the largest losses. Losses from mastiffs in the Unite d States in 1976 were estimated by usable responses to a survey from 33 states representing 9.5 million cows or 86% of the dairy cow population. Losses of milk yields caused by mastiffs were 386 kg/cow per yr and losses of discarded milk 62 kg/cow per yr. Annual losses per cow from mastitis were a) reduced milk production, $81.32; b) discarded milk, $12.88; c) cost of veterinary services, $1.97; d) cost of drugs, $3.86; e) increased labor, $2.28; f) decreased sale value, $5.72; g) increased replacement costs, $9.32; h) total, $117.35. For the 11 million cows in the United States 1976 losses from mastiffs were $1.294 billion. Mastiffs research was supported publicly at 22 locations under 43 projects. Approximately 24 scientist years were involved and $2.7 million of public funds were expended annually. If economic losses from mastiffs were reduced 2% per year for 10 yr by research and expenditures for mastiffs research remained the same, the benefit to cost ratio from mastiffs research would be approximately 9.6 to 1. INTRODUCTION Mastitis is recognized worldwide as one of the most costly diseases afflicting dairy cows. Many dairymen do not recognize fully the tremendous losses sustained through unrealized milk production. At the subclinical level dairymen could be unaware of the problem.
Received September 19, 1977. 1979 J Dairy Sci 62:119--127
Identifiable mastiffs losses are not dramatic. Dairymen are more likely to become concerned about diseases that obviously affect the cow's health, even though such diseases may be of short duration and have less effect than mastitis on income from the herd. A well-documented continued research and educational effort is necessary to increase producer awareness of costs of mastitis to the dairy enterprise. LITERATURE REVIEW The types and extent of economic losses sustained by the dairy industry due to mastiffs were described in a number of papers (7, 23). Major losses from mastiffs have been identified (7, 16) in the following categories: a) realized (clinical) and unrealized (subclinical) reduced milk production; b) milk discarded because it contained antibiotics or was of abnormal composition; e) cost of veterinary services to treat acute and chronic mastiffs; d) cost of drugs purchased by dairymen for intramammary infusion; e) cost of increased labor to care for mastitic cows; f) decreased sale value of cows sold for dairy purposes; g) increased herd replacement costs when cows were culled because of mastiffs. Reduced Milk Production The largest of these losses was that caused by reduced milk production. Investigators have attempted to quantify these losses by establishing the milk production of cows and concurrently measuring the somatic cell count (SCC) of milk. Investigators have compared milk production on a between-cow and a betweenquarter within-cow basis. After a sizable number of cows or quarters have been compared in this way, reduced milk production can be estimated from the SCC. In a review o f mastiffs literature, Janzen (16) cited losses of milk per quarter per day in mastitic cows of .34 to 2.66 kg (9.0 to 43.3%). Gray and Schalm (13) collected information on 119
120
BLOSSER
milk production and the California Mastits Test (CMT) from 1,243 cows in 10 commercial herds over 305 days of lactation. When lactation yields between CMT-negative and CMTpositive groups were compared, the average losses were 6.0, 10.0, 16.0, and 24.5% for CMT-positive grotlps with scores of trace (T), 1, 2, and 3. Forster et al. (10) compared 1,258 opposite quarter milkings from 763 cows in 30 dairy herds. Cahforma Mastitis Test reactions (in total quarter milk) of T, 1, 2, and 3 were associated with average decreases of milk production of .42 (9.0%), .95 (19.5%), 1.72 (31.8%), and 2.33 (43.4%) kg/quarter per day. Natzke et al. (24) calculated milk losses of production from quarters with various CMT scores compared with production of opposite negative quarters on 384 quarter samples from 48 cows. Losses of milk production from CMT 1, 2, and 3 quarters were .19, .29, and .67 kg/quarter per milking. Philpot (27) found that milk production was reduced by 2.8, 11.4, 25.6, and 45.5% in quarters of 178 Jersey cows with CMT reactions of T, 1, 2, and 3. His data showed that CMT-negative quarters compensated (to a limited extent) for losses in production in CMT-positive quarters. In a 3-yr study of 108 lactations of Holstein cows from the New Mexico State University herd, Miller (21) reported that clinical mastitis reduced milk production more than 20% for the total lactation. Cows producing milk with over 500,000 SCC/ml were considered to have clinical mastitis. Ward and Schultz (33) examined milk from 874 quarters with the Filter-DNA method. A quadratic regression based on these data indicated losses of 15% from quarters with SCC of 2 million/ml and more than 25% from quarters with SCC of 4 million/ml. Schultz (31) compared milk production for full lactations of cows whose milk gave varying reactions to monthly test by the Filter-DNA method. Cows whose milk averaged less than 500,000 somatic cells/ml produced 572 kg more milk and 25 kg more fat per lactation than cows whose average lactation SCC was more than 1 million/ml. King (20) cited a Milk Marketing Board study in Great Britain in 1971 which attributed losses of 164, 289, 661, and 770 kg of milk/ Journal of Dairy Science Vol. 62, No. 1, 1979
cow per yr to SCC ranges of 250,000 to 499,000; 500,000 to 749,000; 750,000 to 999,000; and 1,000,000 and over/ml. Discarded Milk Losses
When cows are treated with antibiotics, milk must be withheld from the market until it is antibiotic free. This milk normally is discarded or fed to calves. In addition, some milk is discarded because of" altered composition prior to treatment. Natzke (23)estimated discarded milk losses as 27 kg/day for 5 days for each clinical case and 1 to 1.5 clinical cases/cow per yr in herds without teat dip and dry cow therapy programs. Dobbins (7) estimated the losses from discarded milk as 34 kg or $7.72/ cow per yr in 31 random herds involved in the Georgia Quality Milk Program. Cost of Veterinary Services
Natzke (23) stated that veterinary services for a 200-cow herd not involved in teat dip and dry cow therapy programs were $125 annually or $.62/cow. Dobbins (7) estimated average cost per cow of veterinary fees for cows not involved in a milking hygiene program at $7.20/cow per yr. Cost of Drugs
Natzke (23) stated that antibiotics used to treat mastitis in a 200-cow herd cost the owner $500/yr or $2.50/cow per yr. Dobbins (7) found a cost of $2.16/cow per yr for 31 Georgia herds. Cost of Increased Labor
Dobbins (7) stated that because of mastitis additional labor was required to change units, discard milk, wash extra equipment, and treat cows, and more time was needed to handle each cow. He estimated that this cost was $1.50/cow per yr. Natzke (23) estimated that extra labor required to care for clinical mastitis cases averaged 250 h or $1,000 in a 200-cow herd (5.00/cow per yr). Deceased Sale Value and Increased Replacement Costs
When cows offered for sale for dairy purposes have unbalanced quarters or evidence of subclinical mastitis, their sale value is reduced.
SYMPOSIUM: BOVINE MASTITIS
No estimate of losses from this cause appeared in the literature. Bonewitz (4) found that 17% of the cows culled in Kansas DHIA herds were culled because of udder trouble. Gaunt (11) reported that mastitis accounted for 9% of the culling in 42 Massachusetts dairy herds. Natzke (23) suggested an average culling rate of 12% due to mastitis, which, in a 200-cow herd, converts to $2,202 annually or $11.01/cow. Dobbins (7) estimated a replacement cost due to mastitis of $39.00/cow per yr in Georgia herds.
Total Economic Losses f r o m Mastitis in the United States
Dobbins (7) reported that national estimates of losses from mastitis ranged from $35 to $60/cow per yr but felt that a more reasonable figure was $90 to $ 2 5 0 / c o w per yr. The Georgia study based on 31 herds suggested a loss of $294/cow per yr. Natzke (23) commented that estimates of losses vary from $25 to $150/cow per yr. On the basis of estimates by Natzke, losses in herds not using teat dip and dry cow therapy programs were $206/cow per yr. Philpot (28) suggested that total losses from mastitis could be divided: reduced milk production, 70%; death and premature culling, 14%; discarded milk, 8%; treatment and veterinary expenses, 8%. A USDA handbook published in 1965 (15) suggested a loss of $411 million annually in the United States from mastitis. Janzen (16) stated in 1970 that the total annual economic losses attributable to mastitis have been estimated at $400 to $500 million. Nielsen (25) commented on earlier studies of economic losses from mastitis and estimated the annual loss in the United States in 1976 as $600 to $800 million. Information is available in the literature concerning the effect of mastitis on milk cornposition (10, 16, 31). Schultz (31) reported decreases in lactose, fat, and casein and increases in whey proteins, chloride, sodium, and pH associated with an increased SCC. Janzen (16) indicated that decreases in the composition of milk have been recorded for fat, .1 to .45%; solids-not-fat, .1 to .57; lactose, .1 to .77%; and total solids, 1.07%. These alternations in composition significantly affected the yield and quality of dairy products.
121
Losses Reported from Mastitis in Other Countries
Losses from mastitis have been reported from several countries. Jaartsveld (17, 18) reported a total loss in the Netherlands of 140 million guilders ($57 million)/yr or a loss of 75 guilders ($31.00)/cow per yr in 1974. Hamann (14) stated that milk producers lost an estimated 370 to 450 million deutsche mark ($158 to $192 million) in 1970 in the German Federal Republic due to subclinical mastitis and indicated that 24 to 27% of all quarters were mastitic. Plommet and leLouedec (30) reported a French national herd of 9.7 million dairy cows in 1967 with a mean annual milk production of 3,000 liters/head and milk selling at .5 francs/liter. The financial loss due to mastitis was estimated between 644 ($131 million) and 1,244 million francs ($253 million). Giesecke et al. (12) stated that the total value of annual milk losses due to mastitis in South Africa have been estimated at 29.68 million rands ($34.3 million) (a third of the total annual milk production) or 24 rands ($27.60)/ cow per yr. A report from the Milk Marketing Board in England (1) in 1971 to 1972 reported 160,000 samples of herd milk counted and a national geometric mean SCC of 468,000 per ml. Brander (5) stated that losses in Britain from mastitis (1972) were 20 million pounds sterling ($34.4 million) from reduced milk production alone. He stated further that in the United Kingdom approximately 50% of milking cows in dairy herds were subclinically infected, an average of 50 cases of clinical mastitis occurred annually in a herd of 50 cows, and over 10 million tubes of antibiotics were used annually to treat 3 million dairy cows. Finally, Brander stated that the incidence of mastitis in Great Britain had not changed in the last 25 yr. Morris (22) reported that in Australia mastitis affected over 30% of the quarters. Ellis and Asby (9) reported annual losses from mastitis in Denmark as 125 to 150 million kroner ($21 to $26 million). These authors also pointed out that statistics that indicated increased income to producers due to mastitis reduction must be treated with caution because of the depression effect an increased national milk supply would have on milk prices. Journal of Dairy Science Vol. 62, No. 1, 1979
122
BLOSSER
Current Status of Mastitis in the United States
The best information on the current status of mastitis in the United States comes from milk quality tests conducted as part of the National Cooperative Dairy Herd Improvement Program and from tests run by regulatory agencies. A recent report by Jones and Patterson (19) indicated 35% of Virginia herds participating in a SCC testing program had an average SCC over 500,000/ml, and 13.8% of the 113,735 cows had a SCC over 800,000/ml. Stadler et al. (32) examined 23,173 cows in Connecticut and found 16.67% quarters infected. Sendelbach et al. (32) reported data from 3,277 complete lactations in Wisconsin herds with 28.4% (lactation 1) to 62.0% (lactation 4) average SCC over 500,000 ml and 8.5% (lactation 1) to 35.3% (lactation 4) average SCC over 750,000/ ml. Wesen (34) reported CMT screening test data from 200 North Carolina herds which indicated 59% of herds had 11% or more cows with CMT scores of 2 and 3. Barr (3) indicated 13% of DHIA cows in Ohio with mastitis screening test information had CMT scores of 2 and 3. Results in Arizona (2) indicated 4.7% of cows had CMT scores of 2 and 3 in 1976. Philpot (27) stated that 40 to 50% of all dairy cows are infected with mastitis in one or more quarters.
SURVEY TO ESTIMATE LOSSES FROM MASTITIS IN THE UNITED STATES
In an effort to gain more information on current losses from mastitis, based on the judgment of competent individuals in the United States, a questionnaire was sent to one person in each of the 50 states requesting that he or a person whom the questionnaire recipient considered better qualified respond. Seven questions related to economic losses from mastitis in 1976 were asked. Additional questions related to other mastitis losses, evidence of mastitis reduction, and mastitis research. Thirty seven responses were received. Usable responses representing 9.5 million cows or 86% of the United States dairy cow population were received from 33 states. The summary of the responses is an average of estimates, and no accuracy should be implied. Estimates were by well-qualified persons Journal of Dairy Science Voi. 62, No. 1, 1979
familiar with mastitis in that state. The results of the survey are recorded in Table 1. The statistics provided on losses per cow by individual respondents from the various states were variable. This variability is reflected by the large standard deviations. It is not known to what extent variations in responses are due to actual differences between states or to differences between respondents in assessing mastitis losses. Responses from reporting states substantiated the view that milk production losses from cows with subclinical mastitis were responsible for the largest dollar loss per COW.
Many respondents indicated their estimate of milk production losses per cow were based on experiments such as those by Forster et al. (1) and Gray and Schalm (13) and an estimate of the current mastitis status in the states based on an estimated SCC. Average losses per cow in the United States were calculated as a) a simple arithmetic average of the individual values submitted by each respondent and b) a weighted average by the number of cows/state. The latter value is listed in Tables 1 and 2 as "weighted average." Total dollar losses at the farm in the United States in 1976 and percentages of the total loss were estimated: a) decreased milk production, $897 million (69.3%); b) discarded milk, $142 million (11.0%); c) veterinary fees, $22 million (1.7%); d) drug costs, $42 million (3.2%); e) increased labor, $25 million (1.9%); f) decreased sale value, $63 million (4.9%); and g) increased replacement costs, $103 million (8.0%) (Table 2). The total annual loss from mastitis was estimated $1.3 billion. This represents 11% of 1976 receipts from farm sales of milk. Procedures in this survey to estimate losses from mastitis are subject to questions and reservations. A question was raised by one respondent (26) concerning the validity of basing mastitis losses on milk production and SCC data from opposite quarters because of possible compensator)' increases in production from normal quarters opposite mastitis-infected quarters. In addition, estimates of economic losses from decreased milk production based on assumptions in this paper are subject to criticism because increases in national milk production that occur as a result of mastitis-free cows could depress milk prices. The economic losses
TABLE 1. Summary of annual losses per cow and total losses from mastitis, U.S., 1976. a In-
Item
.= o
No. of states reporting No. of cows in states reporting, million Loss per cow, average of respondents SD Loss per cow, weighted average b $ Loss per cow, average o f respondents SD $ Loss per cow, weighted average b $ Loss, states reporting, million $ Loss, projected to total U.S. cow population, millionb, c
Annual losses Veterinary Drug fees costs
Decreased sale value
Increased labor
31 9.1 . . . . . .
32 9.3 32.9 min 38.7
24 6.7
creased replacement costs
Reduced milk production
Discarded milk
33 9.5 371 kg 202 386 kg 82.02 49.03 81.32 771
33 9.5 64 kg 83 62 kg 15.31 21.16 12.88 122
"2128 2.07 1.97 18
;115 3.80 3.86 36
1.82 2.05 2.28 21
ii162
"1;54
14.95 5.72 39
21.20 9.32 82
897
142
22
42
25
63
© 33 9.3 . .
. .
. .
31 8.8 ©
103
aBased on responses from 33 states, representing 9.5 million cows, May 1977. bweighted average values give consideration to the numbers of cows in each state. CTotal dairy cow population in 1976, approximately 11 million. < o
Z o
t~
124
BLOSSER
TABLE 2. Dollar losses per cow and total dollar losses from mastitis, U.S., 1976. $ Losses per cow Average of reWeighted pondents averagea
Item Reduced milk production Discarded milk Cost of veterinary services Cost of drugs Increased labor Decreased sale value Increased replacement costs Total
Total $ losses U.S. (million)
Losses for each item (%)
82.02 15.31 2.28 4.15 1.82 11.62 15.54
81.32 12.88 1.97 3.86 2.28 5.72 9.32
897 142 22 42 25 63 103
69.3 11.0 1.7 3.2 1.9 4.9 8.0
132.74
117.35
1,294
100.0
aweighted average values give consideration to the numbers of cows in each state. from mastitis could be less than the estimates indicate. No evidence is available to indicate whether subclinical mastitis reduces feed consumption as well as milk production. Recipients of the questionnaire were asked to identify losses from mastitis not included in the seven items for which responses were solicited. Some of the other losses mentioned were: a) loss of genetic potential due to early culling; b) cost of milking hygiene programs; e) extra time spent milking cows that have responded to treatment but have slow milking quarters requiring more machine stripping; d) extra time spent with mastitic cows with reduced time available for clean cows and herd management; e) purchase of unnecessary equipment or excessive use of invalid "treatments" and "preventions"; f) reduced milk consumption; and g) losses from treated milk in "dead" cheese vats. In response to the question whether losses from mastitis had been reduced in the last 10 yr, 15 respondents indicated there was evidence of reduced losses; 12 respondents indicated no evidence of reduced losses. Evidence of reduced losses included SCC information from Dairy Herd Improvement Associations, state milk quality test programs, and bulk milk tank tests run by processors. M A S T I T I S RESEARCH IN T H E U N I T E D STATES
Mastitis research historically has been supported rather modestly as compared with the economic losses caused by mastitis. Journal of Dairy Science Vol. 62, No. 1, 1979
Pilchard (29) reviewed mastitis research in the United States in 1972. He emphasized the complexity of mastitis research and the importance of increasing support for research on mastitis. A computer search was made through the Current Research Information System (CRIS) of the publicly supported research by ARS and the state agricultural experiment stations (8). Information obtained from this source and similar data from Pilchard (29) are recorded in Table 3. Mastitis research was (1976) conducted in the United States at 22 locations under 43 projects. Approximately $.9 million ARS and $1.8 million state agricultural experiment station funds were being used for mastitis research for a national total of $2.7 million. Approximately 24 scientist years were involved in mastitis research in the United States. The scientist years involved in mastitis research have changed little since 1968. Funds expended for mastitis research since 1968 have more than doubled. In terms of percentage cash receipts from milk sales expended for mastitis research, the percentages for 1968, 1970, and 1976 were .022, .024, and .024%. An examination of the stated objectives available for each project from the CRIS summary provided some information on research emphasis. Some projects had several objectives. Project objectives, with the number of projects listing each objective were: management factors, 17; diagnostic procedures, 8; pathogenesis, 9; resistance (including immune response and phagocytosis, 9; mastitis therapy,
TABLE 3. United States regional data on farm income from dairy products, total dairy cows, and status of mastitis research 1968, 1970, and 1976.
Regions and years a
Northeast 1968 a 1970 a 1976 b South 1968 a 1970 a 1976 b North Central 1968 a 1970 a 1976 b
Farm income from milk sales
No. of dairy cows
(million $)
(thousand)
Research expenditures SAES b
ARS c
Scientist years
Total
SAES b
Projects
ARS c
Total
SAES b
ARS c
Total
(thousand $)
1,308 1,538 2,487
2,892 2,785 2,249
216 205 367
137 317 612
353 522 979
5.0 3.8 3.4
2.4 2.5 4.9
7.4 6.3 8.3
7 7 11
1 3 5
8 10 16
979
3,008 2,829 2,060
213 228 697
1 5 0
214 233 697
4.9 4.1 6.5
0 0 0
4.9 4.1 6.5
11 13 11
1 1 0
12 14 11
© 1,188
1,969
© < 2,454 2,804 5,023
7,017 6,550 5,201
182 301 477
238 367 275
420 668 752
3.6 4.2 3.6
4.0 7.3 2.5
7.6 11.5 6.1
9 11 10
3 4 4
12 15 14
789 992 1,947
1,745 1,711 1,540
211 146 305
11 11 42
222 157 347
4.2 2.8 2.5
0 0 .3
4.2 2.8 .3
9 9 1
1 1 1
10 10 2
5,530 6,522 11,426
14,662 13,874 11,050
822 880 1,803
387 700 929
1,209 1,580 2,732
17.7 14.9 16.0
6.4 9.8 7.7
24.1 24.7 23.7
36 40 33
6 9 10
42 49 43
West
1968 a 1970 a 1976 b United States 1968 a 1970 a 1976 b o_ t~
Z O
aData for 1968 and 1970 are from Pilchard (29); data for 1976 are from Dopkowski (8). b s t a t e Agricultural Experiment Stations. C
Agricultural Research Service, USDA.
t~ >
126
BLOSSER
10; basic p h y s i o l o g y and b i o c h e m i s t r y o f mastitis, 6 ; heritability, 1. Regional research p r o j e c t NE-112 entitled, " R e s i s t a n c e to Mastitis in Dairy C a t t l e , " (6) b e c a m e effective J a n u a r y 1, 1977. Investigators at 12 research locations were p a r t i c i p a t i n g in this project. The objectives o f this p r o j e c t were t o a) characterize t h e factors and m e c h a n i s m s t h a t c o n t r i b u t e to the resistance o f t h e m a m m a r y gland t o i n f e c t i o u s mastitis; b) characterize mastitis m i c r o o r g a n i s m s , virulence factors, and m e c h a n i s m s t h a t p e r m i t t h e s e m i c r o o r g a n isms t o invade t h e bovine m a m m a r y gland and p r o d u c e mastitis; c) characterize resistance o f the bovine m a m m a r y gland t o mastitis; d) d e t e r m i n e the e c o n o m i c and practical feasibility of field i m p l e m e n t a t i o n o f p r o c e d u r e s t o increase resistance to bovine mastitis. Scientists and agricultural research administrators are r e q u e s t e d to j u s t i f y research areas and research proposals f r o m a b e n e f i t to cost s t a n d p o i n t with increasing f r e q u e n c y . If e c o n o m i c losses f r o m mastitis were r e d u c e d 2% ($26 m i l l i o n ) / y r for 10 y r as a result o f research, and e x p e n d i t u r e s for mastitis research r e m a i n e d the same ($2.7 million), the b e n e f i t to cost ratio o f mastitis research w o u l d be 9.6 to 1. If losses f r o m mastitis were r e d u c e d 4 % / y r for 10 yr and research e x p e n d i t u r e s r e m a i n e d t h e same, the b e n e f i t to cost ratio w o u l d be 19.2 t o 1.
9
10
11
12
13 14 15 16 17 18 19
20 REFERENCES
1 Anonymous. 1973. Report of the breeding and production organization 1971-72. Milk Marketing Board, Thomas Dutlin, Surrey. 158 pp. 2 Anonymous. 1976. Arizona~ herd improvement summaries. January to December 1976. 3 Barr, H. L. 1976. Herd CMT performance related to milk produced. Ohio Herd Improvement Observer 8:1. 4 Bonewitz, E. R. 1976. Annual summary Dairy Herd Improvement Association 1975--76. Kansas State University Ext. PubL, Dairy Sci. 6, 27 pp. 5 Brander, G. C. 1972. The control ofmastitis. Brit. Vet. J. 128:58. 6 Carroll, E. J., L. D. Williams, J. Simon, W. Pankey, M. Gershman, A. J. Guidry, S. N. Gaunt, R. P. Natzke, N. L. Norcross, K. L. Smith, R. J. Eberhart, A. Zarkower, W. Bolton, and E. D. Erickson. 1977. Resistance to mastitis in dairy cattle. Cooperative Regional Project NE-112. Cooperative State Research Service, USDA. 7 Dobbins, C. N., Jr. 1977. Mastitis losses. J. Amer. Vet. Med. Ass. 170-1129. 8 Dopkowski, P. 1977. Unpublished information from computer search of Current Research InforJournal of Dairy Science Vol. 62, No. 1, 1979
21
22 23
24
25
26 27 28
marion System, Cooperative States Research Service, USDA, April 21, 1977. Ellis, P. R., and C. B. Asby. 1975. The economics of mastitis control. Page 453 in Proc. IDF Seminar on Mastitis Control. Reading University. Forster, T. L., U. S. Ashworth, and L. O. Luedecke. 1967. Relationship between California Mastitis Test reaction and production and composition of milk from opposite quarters. J. Dairy Sci. 50:675. Gaunt, S. N. 1976. Annual summary of mastitis laboratory activity, 1975. Dairy Digest, University of Mississippi Coop. Ext. Serv., October 15, 1976. Giesecke, W. H., L. W. van den tteever, and I. J. du Toit. 1971. Bovine mastitis in the Republic of South Africa. Bulletin de l'Office International des Epizooties 76:621. Gray, D. M., and O. W. Schalm. 1962. The mastitis variable in milk yield as estimated by the California Mastitis Test. Amer. J. Vet. Res. 32:541. Hamann, J. 1975. Mastitis is still the main problem in dairy farming. An appraisal of control measures. Tierzuchter 27:237. Irving, G. W., Jr. 1965. Losses in agriculture. USDA, ARS, Agr. Hand. 291, p. 73. Janzen, J. J. 1970. Economic losses resulting from mastitis. A review. J. Dairy Sci. 53:1151. Jaartsveld, F. H. J. 1974. Some figures on bovine mastitis in the Netherlands. Tijdschrift voor Diergeneeskunde 99:605. Jaartsveld, F. H. J. 1975. Some figures for the year 1974 concerning bovine mastitis in the Netherlands. Tijdschrift voor Diergeneeskunde 100:1273. Jones, G. M., and W. N. Patterson. 1977. Monitor the herd mastitis status with the Fossomatic somatic cell counts. Dairy Guidelines, Virginia Polytechnic Institute and State University. Ser. 229, 4 pp. King, J. O. L. 1972. Mastitis as a production disease. Vet. Rec. 91:325. Miller, D. D. 1973. Relation of clinical and subclinical mastitis to milk production and composition. New Mexico Agr. Exp. Sta. Bull. 605, pp. 28. Morris, R. S. 1971. Economic aspects of disease control programs for dairy cattle. Austr. Vet. J. 47:358. Natzke, R. P. 1976. The economics of mastitis control. Proc. Large Herd Management Symposium, University of Florida, January 1976. Natzke, R. P., L. H. Schultz, G. R. Barr, and W. B. Holtmann. 1965. Variation in mastitis screening tests and milk composition of udder quarters under normal conditions and following omission of a milking. J. Dairy Sci. 48:1295. Nielsen, V. H. 1976. Why processors should concern themselves with bovine mastitis infection, economic losses. Amer. Dairy Rev. 38:16. Pelissier, C. L. 1977. Personal communication. University of California, Davis. Philpot, W. N. 1967. Influence of subclinical mastitis on milk production and milk composition. J. Dairy Sci. 50:978. Philpot, W. N. 1976. Mastitis controlled yield increased profits. Page 80 in Proc. Ruakura Far-
SYMPOSIUM: BOVINE MASTITIS mers Conf., Hamilton, New Zealand, June 1976. 29 Pilchard, E. I. 1972. Economic importance of mastitis research in the United States. Agri. Sci. Rev. 10:30. 30 Plommet, M., and C. leLouedec. 1972. Bovine mastitis. Centre de Recherches de Tours, INRA, 37-Nouzilly, France. Regards sur la France. Spec. No. 16. 31 Schultz, L. H. 1977. Somatic cells in milk physiological aspects and relationship to a m o u n t and composition of milk. J. Food Prot. 40:125.
127
32 Stadler, R. J., A. Mandirola, L. J. Williams, and W. H. Daniels. 1976. Activity report o f the Connecticut Mastitis Control Program. Report presented at Northeastern Mastitis Conf., September 30 and October 1, 1976. 33 Ward, G. E., and L. H. Schultz, 1972. Relationships of somatic ceils in quarter milk to type of bacteria and production. J. Dairy Sci. 55:1428. 34 Wesen, D. P. 1975. Mastitis screening tests through DHIA, Texas Dairy Herd Improvement Ass., Inc. S u m m a r y , 12 pp.
Journal of Dairy Science Vol. 62, No. 1, 1979
ABSTRACT Scientific papers estimating economic losses from mastitis were reviewed. Reduced milk production from cows with subclinical mastiffs was responsible for the largest losses. Losses from mastiffs in the Unite d States in 1976 were estimated by usable responses to a survey from 33 states representing 9.5 million cows or 86% of the dairy cow population. Losses of milk yields caused by mastiffs were 386 kg/cow per yr and losses of discarded milk 62 kg/cow per yr. Annual losses per cow from mastitis were a) reduced milk production, $81.32; b) discarded milk, $12.88; c) cost of veterinary services, $1.97; d) cost of drugs, $3.86; e) increased labor, $2.28; f) decreased sale value, $5.72; g) increased replacement costs, $9.32; h) total, $117.35. For the 11 million cows in the United States 1976 losses from mastiffs were $1.294 billion. Mastiffs research was supported publicly at 22 locations under 43 projects. Approximately 24 scientist years were involved and $2.7 million of public funds were expended annually. If economic losses from mastiffs were reduced 2% per year for 10 yr by research and expenditures for mastiffs research remained the same, the benefit to cost ratio from mastiffs research would be approximately 9.6 to 1. INTRODUCTION Mastitis is recognized worldwide as one of the most costly diseases afflicting dairy cows. Many dairymen do not recognize fully the tremendous losses sustained through unrealized milk production. At the subclinical level dairymen could be unaware of the problem.
Received September 19, 1977. 1979 J Dairy Sci 62:119--127
Identifiable mastiffs losses are not dramatic. Dairymen are more likely to become concerned about diseases that obviously affect the cow's health, even though such diseases may be of short duration and have less effect than mastitis on income from the herd. A well-documented continued research and educational effort is necessary to increase producer awareness of costs of mastitis to the dairy enterprise. LITERATURE REVIEW The types and extent of economic losses sustained by the dairy industry due to mastiffs were described in a number of papers (7, 23). Major losses from mastiffs have been identified (7, 16) in the following categories: a) realized (clinical) and unrealized (subclinical) reduced milk production; b) milk discarded because it contained antibiotics or was of abnormal composition; e) cost of veterinary services to treat acute and chronic mastiffs; d) cost of drugs purchased by dairymen for intramammary infusion; e) cost of increased labor to care for mastitic cows; f) decreased sale value of cows sold for dairy purposes; g) increased herd replacement costs when cows were culled because of mastiffs. Reduced Milk Production The largest of these losses was that caused by reduced milk production. Investigators have attempted to quantify these losses by establishing the milk production of cows and concurrently measuring the somatic cell count (SCC) of milk. Investigators have compared milk production on a between-cow and a betweenquarter within-cow basis. After a sizable number of cows or quarters have been compared in this way, reduced milk production can be estimated from the SCC. In a review o f mastiffs literature, Janzen (16) cited losses of milk per quarter per day in mastitic cows of .34 to 2.66 kg (9.0 to 43.3%). Gray and Schalm (13) collected information on 119
120
BLOSSER
milk production and the California Mastits Test (CMT) from 1,243 cows in 10 commercial herds over 305 days of lactation. When lactation yields between CMT-negative and CMTpositive groups were compared, the average losses were 6.0, 10.0, 16.0, and 24.5% for CMT-positive grotlps with scores of trace (T), 1, 2, and 3. Forster et al. (10) compared 1,258 opposite quarter milkings from 763 cows in 30 dairy herds. Cahforma Mastitis Test reactions (in total quarter milk) of T, 1, 2, and 3 were associated with average decreases of milk production of .42 (9.0%), .95 (19.5%), 1.72 (31.8%), and 2.33 (43.4%) kg/quarter per day. Natzke et al. (24) calculated milk losses of production from quarters with various CMT scores compared with production of opposite negative quarters on 384 quarter samples from 48 cows. Losses of milk production from CMT 1, 2, and 3 quarters were .19, .29, and .67 kg/quarter per milking. Philpot (27) found that milk production was reduced by 2.8, 11.4, 25.6, and 45.5% in quarters of 178 Jersey cows with CMT reactions of T, 1, 2, and 3. His data showed that CMT-negative quarters compensated (to a limited extent) for losses in production in CMT-positive quarters. In a 3-yr study of 108 lactations of Holstein cows from the New Mexico State University herd, Miller (21) reported that clinical mastitis reduced milk production more than 20% for the total lactation. Cows producing milk with over 500,000 SCC/ml were considered to have clinical mastitis. Ward and Schultz (33) examined milk from 874 quarters with the Filter-DNA method. A quadratic regression based on these data indicated losses of 15% from quarters with SCC of 2 million/ml and more than 25% from quarters with SCC of 4 million/ml. Schultz (31) compared milk production for full lactations of cows whose milk gave varying reactions to monthly test by the Filter-DNA method. Cows whose milk averaged less than 500,000 somatic cells/ml produced 572 kg more milk and 25 kg more fat per lactation than cows whose average lactation SCC was more than 1 million/ml. King (20) cited a Milk Marketing Board study in Great Britain in 1971 which attributed losses of 164, 289, 661, and 770 kg of milk/ Journal of Dairy Science Vol. 62, No. 1, 1979
cow per yr to SCC ranges of 250,000 to 499,000; 500,000 to 749,000; 750,000 to 999,000; and 1,000,000 and over/ml. Discarded Milk Losses
When cows are treated with antibiotics, milk must be withheld from the market until it is antibiotic free. This milk normally is discarded or fed to calves. In addition, some milk is discarded because of" altered composition prior to treatment. Natzke (23)estimated discarded milk losses as 27 kg/day for 5 days for each clinical case and 1 to 1.5 clinical cases/cow per yr in herds without teat dip and dry cow therapy programs. Dobbins (7) estimated the losses from discarded milk as 34 kg or $7.72/ cow per yr in 31 random herds involved in the Georgia Quality Milk Program. Cost of Veterinary Services
Natzke (23) stated that veterinary services for a 200-cow herd not involved in teat dip and dry cow therapy programs were $125 annually or $.62/cow. Dobbins (7) estimated average cost per cow of veterinary fees for cows not involved in a milking hygiene program at $7.20/cow per yr. Cost of Drugs
Natzke (23) stated that antibiotics used to treat mastitis in a 200-cow herd cost the owner $500/yr or $2.50/cow per yr. Dobbins (7) found a cost of $2.16/cow per yr for 31 Georgia herds. Cost of Increased Labor
Dobbins (7) stated that because of mastitis additional labor was required to change units, discard milk, wash extra equipment, and treat cows, and more time was needed to handle each cow. He estimated that this cost was $1.50/cow per yr. Natzke (23) estimated that extra labor required to care for clinical mastitis cases averaged 250 h or $1,000 in a 200-cow herd (5.00/cow per yr). Deceased Sale Value and Increased Replacement Costs
When cows offered for sale for dairy purposes have unbalanced quarters or evidence of subclinical mastitis, their sale value is reduced.
SYMPOSIUM: BOVINE MASTITIS
No estimate of losses from this cause appeared in the literature. Bonewitz (4) found that 17% of the cows culled in Kansas DHIA herds were culled because of udder trouble. Gaunt (11) reported that mastitis accounted for 9% of the culling in 42 Massachusetts dairy herds. Natzke (23) suggested an average culling rate of 12% due to mastitis, which, in a 200-cow herd, converts to $2,202 annually or $11.01/cow. Dobbins (7) estimated a replacement cost due to mastitis of $39.00/cow per yr in Georgia herds.
Total Economic Losses f r o m Mastitis in the United States
Dobbins (7) reported that national estimates of losses from mastitis ranged from $35 to $60/cow per yr but felt that a more reasonable figure was $90 to $ 2 5 0 / c o w per yr. The Georgia study based on 31 herds suggested a loss of $294/cow per yr. Natzke (23) commented that estimates of losses vary from $25 to $150/cow per yr. On the basis of estimates by Natzke, losses in herds not using teat dip and dry cow therapy programs were $206/cow per yr. Philpot (28) suggested that total losses from mastitis could be divided: reduced milk production, 70%; death and premature culling, 14%; discarded milk, 8%; treatment and veterinary expenses, 8%. A USDA handbook published in 1965 (15) suggested a loss of $411 million annually in the United States from mastitis. Janzen (16) stated in 1970 that the total annual economic losses attributable to mastitis have been estimated at $400 to $500 million. Nielsen (25) commented on earlier studies of economic losses from mastitis and estimated the annual loss in the United States in 1976 as $600 to $800 million. Information is available in the literature concerning the effect of mastitis on milk cornposition (10, 16, 31). Schultz (31) reported decreases in lactose, fat, and casein and increases in whey proteins, chloride, sodium, and pH associated with an increased SCC. Janzen (16) indicated that decreases in the composition of milk have been recorded for fat, .1 to .45%; solids-not-fat, .1 to .57; lactose, .1 to .77%; and total solids, 1.07%. These alternations in composition significantly affected the yield and quality of dairy products.
121
Losses Reported from Mastitis in Other Countries
Losses from mastitis have been reported from several countries. Jaartsveld (17, 18) reported a total loss in the Netherlands of 140 million guilders ($57 million)/yr or a loss of 75 guilders ($31.00)/cow per yr in 1974. Hamann (14) stated that milk producers lost an estimated 370 to 450 million deutsche mark ($158 to $192 million) in 1970 in the German Federal Republic due to subclinical mastitis and indicated that 24 to 27% of all quarters were mastitic. Plommet and leLouedec (30) reported a French national herd of 9.7 million dairy cows in 1967 with a mean annual milk production of 3,000 liters/head and milk selling at .5 francs/liter. The financial loss due to mastitis was estimated between 644 ($131 million) and 1,244 million francs ($253 million). Giesecke et al. (12) stated that the total value of annual milk losses due to mastitis in South Africa have been estimated at 29.68 million rands ($34.3 million) (a third of the total annual milk production) or 24 rands ($27.60)/ cow per yr. A report from the Milk Marketing Board in England (1) in 1971 to 1972 reported 160,000 samples of herd milk counted and a national geometric mean SCC of 468,000 per ml. Brander (5) stated that losses in Britain from mastitis (1972) were 20 million pounds sterling ($34.4 million) from reduced milk production alone. He stated further that in the United Kingdom approximately 50% of milking cows in dairy herds were subclinically infected, an average of 50 cases of clinical mastitis occurred annually in a herd of 50 cows, and over 10 million tubes of antibiotics were used annually to treat 3 million dairy cows. Finally, Brander stated that the incidence of mastitis in Great Britain had not changed in the last 25 yr. Morris (22) reported that in Australia mastitis affected over 30% of the quarters. Ellis and Asby (9) reported annual losses from mastitis in Denmark as 125 to 150 million kroner ($21 to $26 million). These authors also pointed out that statistics that indicated increased income to producers due to mastitis reduction must be treated with caution because of the depression effect an increased national milk supply would have on milk prices. Journal of Dairy Science Vol. 62, No. 1, 1979
122
BLOSSER
Current Status of Mastitis in the United States
The best information on the current status of mastitis in the United States comes from milk quality tests conducted as part of the National Cooperative Dairy Herd Improvement Program and from tests run by regulatory agencies. A recent report by Jones and Patterson (19) indicated 35% of Virginia herds participating in a SCC testing program had an average SCC over 500,000/ml, and 13.8% of the 113,735 cows had a SCC over 800,000/ml. Stadler et al. (32) examined 23,173 cows in Connecticut and found 16.67% quarters infected. Sendelbach et al. (32) reported data from 3,277 complete lactations in Wisconsin herds with 28.4% (lactation 1) to 62.0% (lactation 4) average SCC over 500,000 ml and 8.5% (lactation 1) to 35.3% (lactation 4) average SCC over 750,000/ ml. Wesen (34) reported CMT screening test data from 200 North Carolina herds which indicated 59% of herds had 11% or more cows with CMT scores of 2 and 3. Barr (3) indicated 13% of DHIA cows in Ohio with mastitis screening test information had CMT scores of 2 and 3. Results in Arizona (2) indicated 4.7% of cows had CMT scores of 2 and 3 in 1976. Philpot (27) stated that 40 to 50% of all dairy cows are infected with mastitis in one or more quarters.
SURVEY TO ESTIMATE LOSSES FROM MASTITIS IN THE UNITED STATES
In an effort to gain more information on current losses from mastitis, based on the judgment of competent individuals in the United States, a questionnaire was sent to one person in each of the 50 states requesting that he or a person whom the questionnaire recipient considered better qualified respond. Seven questions related to economic losses from mastitis in 1976 were asked. Additional questions related to other mastitis losses, evidence of mastitis reduction, and mastitis research. Thirty seven responses were received. Usable responses representing 9.5 million cows or 86% of the United States dairy cow population were received from 33 states. The summary of the responses is an average of estimates, and no accuracy should be implied. Estimates were by well-qualified persons Journal of Dairy Science Voi. 62, No. 1, 1979
familiar with mastitis in that state. The results of the survey are recorded in Table 1. The statistics provided on losses per cow by individual respondents from the various states were variable. This variability is reflected by the large standard deviations. It is not known to what extent variations in responses are due to actual differences between states or to differences between respondents in assessing mastitis losses. Responses from reporting states substantiated the view that milk production losses from cows with subclinical mastitis were responsible for the largest dollar loss per COW.
Many respondents indicated their estimate of milk production losses per cow were based on experiments such as those by Forster et al. (1) and Gray and Schalm (13) and an estimate of the current mastitis status in the states based on an estimated SCC. Average losses per cow in the United States were calculated as a) a simple arithmetic average of the individual values submitted by each respondent and b) a weighted average by the number of cows/state. The latter value is listed in Tables 1 and 2 as "weighted average." Total dollar losses at the farm in the United States in 1976 and percentages of the total loss were estimated: a) decreased milk production, $897 million (69.3%); b) discarded milk, $142 million (11.0%); c) veterinary fees, $22 million (1.7%); d) drug costs, $42 million (3.2%); e) increased labor, $25 million (1.9%); f) decreased sale value, $63 million (4.9%); and g) increased replacement costs, $103 million (8.0%) (Table 2). The total annual loss from mastitis was estimated $1.3 billion. This represents 11% of 1976 receipts from farm sales of milk. Procedures in this survey to estimate losses from mastitis are subject to questions and reservations. A question was raised by one respondent (26) concerning the validity of basing mastitis losses on milk production and SCC data from opposite quarters because of possible compensator)' increases in production from normal quarters opposite mastitis-infected quarters. In addition, estimates of economic losses from decreased milk production based on assumptions in this paper are subject to criticism because increases in national milk production that occur as a result of mastitis-free cows could depress milk prices. The economic losses
TABLE 1. Summary of annual losses per cow and total losses from mastitis, U.S., 1976. a In-
Item
.= o
No. of states reporting No. of cows in states reporting, million Loss per cow, average of respondents SD Loss per cow, weighted average b $ Loss per cow, average o f respondents SD $ Loss per cow, weighted average b $ Loss, states reporting, million $ Loss, projected to total U.S. cow population, millionb, c
Annual losses Veterinary Drug fees costs
Decreased sale value
Increased labor
31 9.1 . . . . . .
32 9.3 32.9 min 38.7
24 6.7
creased replacement costs
Reduced milk production
Discarded milk
33 9.5 371 kg 202 386 kg 82.02 49.03 81.32 771
33 9.5 64 kg 83 62 kg 15.31 21.16 12.88 122
"2128 2.07 1.97 18
;115 3.80 3.86 36
1.82 2.05 2.28 21
ii162
"1;54
14.95 5.72 39
21.20 9.32 82
897
142
22
42
25
63
© 33 9.3 . .
. .
. .
31 8.8 ©
103
aBased on responses from 33 states, representing 9.5 million cows, May 1977. bweighted average values give consideration to the numbers of cows in each state. CTotal dairy cow population in 1976, approximately 11 million. < o
Z o
t~
124
BLOSSER
TABLE 2. Dollar losses per cow and total dollar losses from mastitis, U.S., 1976. $ Losses per cow Average of reWeighted pondents averagea
Item Reduced milk production Discarded milk Cost of veterinary services Cost of drugs Increased labor Decreased sale value Increased replacement costs Total
Total $ losses U.S. (million)
Losses for each item (%)
82.02 15.31 2.28 4.15 1.82 11.62 15.54
81.32 12.88 1.97 3.86 2.28 5.72 9.32
897 142 22 42 25 63 103
69.3 11.0 1.7 3.2 1.9 4.9 8.0
132.74
117.35
1,294
100.0
aweighted average values give consideration to the numbers of cows in each state. from mastitis could be less than the estimates indicate. No evidence is available to indicate whether subclinical mastitis reduces feed consumption as well as milk production. Recipients of the questionnaire were asked to identify losses from mastitis not included in the seven items for which responses were solicited. Some of the other losses mentioned were: a) loss of genetic potential due to early culling; b) cost of milking hygiene programs; e) extra time spent milking cows that have responded to treatment but have slow milking quarters requiring more machine stripping; d) extra time spent with mastitic cows with reduced time available for clean cows and herd management; e) purchase of unnecessary equipment or excessive use of invalid "treatments" and "preventions"; f) reduced milk consumption; and g) losses from treated milk in "dead" cheese vats. In response to the question whether losses from mastitis had been reduced in the last 10 yr, 15 respondents indicated there was evidence of reduced losses; 12 respondents indicated no evidence of reduced losses. Evidence of reduced losses included SCC information from Dairy Herd Improvement Associations, state milk quality test programs, and bulk milk tank tests run by processors. M A S T I T I S RESEARCH IN T H E U N I T E D STATES
Mastitis research historically has been supported rather modestly as compared with the economic losses caused by mastitis. Journal of Dairy Science Vol. 62, No. 1, 1979
Pilchard (29) reviewed mastitis research in the United States in 1972. He emphasized the complexity of mastitis research and the importance of increasing support for research on mastitis. A computer search was made through the Current Research Information System (CRIS) of the publicly supported research by ARS and the state agricultural experiment stations (8). Information obtained from this source and similar data from Pilchard (29) are recorded in Table 3. Mastitis research was (1976) conducted in the United States at 22 locations under 43 projects. Approximately $.9 million ARS and $1.8 million state agricultural experiment station funds were being used for mastitis research for a national total of $2.7 million. Approximately 24 scientist years were involved in mastitis research in the United States. The scientist years involved in mastitis research have changed little since 1968. Funds expended for mastitis research since 1968 have more than doubled. In terms of percentage cash receipts from milk sales expended for mastitis research, the percentages for 1968, 1970, and 1976 were .022, .024, and .024%. An examination of the stated objectives available for each project from the CRIS summary provided some information on research emphasis. Some projects had several objectives. Project objectives, with the number of projects listing each objective were: management factors, 17; diagnostic procedures, 8; pathogenesis, 9; resistance (including immune response and phagocytosis, 9; mastitis therapy,
TABLE 3. United States regional data on farm income from dairy products, total dairy cows, and status of mastitis research 1968, 1970, and 1976.
Regions and years a
Northeast 1968 a 1970 a 1976 b South 1968 a 1970 a 1976 b North Central 1968 a 1970 a 1976 b
Farm income from milk sales
No. of dairy cows
(million $)
(thousand)
Research expenditures SAES b
ARS c
Scientist years
Total
SAES b
Projects
ARS c
Total
SAES b
ARS c
Total
(thousand $)
1,308 1,538 2,487
2,892 2,785 2,249
216 205 367
137 317 612
353 522 979
5.0 3.8 3.4
2.4 2.5 4.9
7.4 6.3 8.3
7 7 11
1 3 5
8 10 16
979
3,008 2,829 2,060
213 228 697
1 5 0
214 233 697
4.9 4.1 6.5
0 0 0
4.9 4.1 6.5
11 13 11
1 1 0
12 14 11
© 1,188
1,969
© < 2,454 2,804 5,023
7,017 6,550 5,201
182 301 477
238 367 275
420 668 752
3.6 4.2 3.6
4.0 7.3 2.5
7.6 11.5 6.1
9 11 10
3 4 4
12 15 14
789 992 1,947
1,745 1,711 1,540
211 146 305
11 11 42
222 157 347
4.2 2.8 2.5
0 0 .3
4.2 2.8 .3
9 9 1
1 1 1
10 10 2
5,530 6,522 11,426
14,662 13,874 11,050
822 880 1,803
387 700 929
1,209 1,580 2,732
17.7 14.9 16.0
6.4 9.8 7.7
24.1 24.7 23.7
36 40 33
6 9 10
42 49 43
West
1968 a 1970 a 1976 b United States 1968 a 1970 a 1976 b o_ t~
Z O
aData for 1968 and 1970 are from Pilchard (29); data for 1976 are from Dopkowski (8). b s t a t e Agricultural Experiment Stations. C
Agricultural Research Service, USDA.
t~ >
126
BLOSSER
10; basic p h y s i o l o g y and b i o c h e m i s t r y o f mastitis, 6 ; heritability, 1. Regional research p r o j e c t NE-112 entitled, " R e s i s t a n c e to Mastitis in Dairy C a t t l e , " (6) b e c a m e effective J a n u a r y 1, 1977. Investigators at 12 research locations were p a r t i c i p a t i n g in this project. The objectives o f this p r o j e c t were t o a) characterize t h e factors and m e c h a n i s m s t h a t c o n t r i b u t e to the resistance o f t h e m a m m a r y gland t o i n f e c t i o u s mastitis; b) characterize mastitis m i c r o o r g a n i s m s , virulence factors, and m e c h a n i s m s t h a t p e r m i t t h e s e m i c r o o r g a n isms t o invade t h e bovine m a m m a r y gland and p r o d u c e mastitis; c) characterize resistance o f the bovine m a m m a r y gland t o mastitis; d) d e t e r m i n e the e c o n o m i c and practical feasibility of field i m p l e m e n t a t i o n o f p r o c e d u r e s t o increase resistance to bovine mastitis. Scientists and agricultural research administrators are r e q u e s t e d to j u s t i f y research areas and research proposals f r o m a b e n e f i t to cost s t a n d p o i n t with increasing f r e q u e n c y . If e c o n o m i c losses f r o m mastitis were r e d u c e d 2% ($26 m i l l i o n ) / y r for 10 y r as a result o f research, and e x p e n d i t u r e s for mastitis research r e m a i n e d the same ($2.7 million), the b e n e f i t to cost ratio o f mastitis research w o u l d be 9.6 to 1. If losses f r o m mastitis were r e d u c e d 4 % / y r for 10 yr and research e x p e n d i t u r e s r e m a i n e d t h e same, the b e n e f i t to cost ratio w o u l d be 19.2 t o 1.
9
10
11
12
13 14 15 16 17 18 19
20 REFERENCES
1 Anonymous. 1973. Report of the breeding and production organization 1971-72. Milk Marketing Board, Thomas Dutlin, Surrey. 158 pp. 2 Anonymous. 1976. Arizona~ herd improvement summaries. January to December 1976. 3 Barr, H. L. 1976. Herd CMT performance related to milk produced. Ohio Herd Improvement Observer 8:1. 4 Bonewitz, E. R. 1976. Annual summary Dairy Herd Improvement Association 1975--76. Kansas State University Ext. PubL, Dairy Sci. 6, 27 pp. 5 Brander, G. C. 1972. The control ofmastitis. Brit. Vet. J. 128:58. 6 Carroll, E. J., L. D. Williams, J. Simon, W. Pankey, M. Gershman, A. J. Guidry, S. N. Gaunt, R. P. Natzke, N. L. Norcross, K. L. Smith, R. J. Eberhart, A. Zarkower, W. Bolton, and E. D. Erickson. 1977. Resistance to mastitis in dairy cattle. Cooperative Regional Project NE-112. Cooperative State Research Service, USDA. 7 Dobbins, C. N., Jr. 1977. Mastitis losses. J. Amer. Vet. Med. Ass. 170-1129. 8 Dopkowski, P. 1977. Unpublished information from computer search of Current Research InforJournal of Dairy Science Vol. 62, No. 1, 1979
21
22 23
24
25
26 27 28
marion System, Cooperative States Research Service, USDA, April 21, 1977. Ellis, P. R., and C. B. Asby. 1975. The economics of mastitis control. Page 453 in Proc. IDF Seminar on Mastitis Control. Reading University. Forster, T. L., U. S. Ashworth, and L. O. Luedecke. 1967. Relationship between California Mastitis Test reaction and production and composition of milk from opposite quarters. J. Dairy Sci. 50:675. Gaunt, S. N. 1976. Annual summary of mastitis laboratory activity, 1975. Dairy Digest, University of Mississippi Coop. Ext. Serv., October 15, 1976. Giesecke, W. H., L. W. van den tteever, and I. J. du Toit. 1971. Bovine mastitis in the Republic of South Africa. Bulletin de l'Office International des Epizooties 76:621. Gray, D. M., and O. W. Schalm. 1962. The mastitis variable in milk yield as estimated by the California Mastitis Test. Amer. J. Vet. Res. 32:541. Hamann, J. 1975. Mastitis is still the main problem in dairy farming. An appraisal of control measures. Tierzuchter 27:237. Irving, G. W., Jr. 1965. Losses in agriculture. USDA, ARS, Agr. Hand. 291, p. 73. Janzen, J. J. 1970. Economic losses resulting from mastitis. A review. J. Dairy Sci. 53:1151. Jaartsveld, F. H. J. 1974. Some figures on bovine mastitis in the Netherlands. Tijdschrift voor Diergeneeskunde 99:605. Jaartsveld, F. H. J. 1975. Some figures for the year 1974 concerning bovine mastitis in the Netherlands. Tijdschrift voor Diergeneeskunde 100:1273. Jones, G. M., and W. N. Patterson. 1977. Monitor the herd mastitis status with the Fossomatic somatic cell counts. Dairy Guidelines, Virginia Polytechnic Institute and State University. Ser. 229, 4 pp. King, J. O. L. 1972. Mastitis as a production disease. Vet. Rec. 91:325. Miller, D. D. 1973. Relation of clinical and subclinical mastitis to milk production and composition. New Mexico Agr. Exp. Sta. Bull. 605, pp. 28. Morris, R. S. 1971. Economic aspects of disease control programs for dairy cattle. Austr. Vet. J. 47:358. Natzke, R. P. 1976. The economics of mastitis control. Proc. Large Herd Management Symposium, University of Florida, January 1976. Natzke, R. P., L. H. Schultz, G. R. Barr, and W. B. Holtmann. 1965. Variation in mastitis screening tests and milk composition of udder quarters under normal conditions and following omission of a milking. J. Dairy Sci. 48:1295. Nielsen, V. H. 1976. Why processors should concern themselves with bovine mastitis infection, economic losses. Amer. Dairy Rev. 38:16. Pelissier, C. L. 1977. Personal communication. University of California, Davis. Philpot, W. N. 1967. Influence of subclinical mastitis on milk production and milk composition. J. Dairy Sci. 50:978. Philpot, W. N. 1976. Mastitis controlled yield increased profits. Page 80 in Proc. Ruakura Far-
SYMPOSIUM: BOVINE MASTITIS mers Conf., Hamilton, New Zealand, June 1976. 29 Pilchard, E. I. 1972. Economic importance of mastitis research in the United States. Agri. Sci. Rev. 10:30. 30 Plommet, M., and C. leLouedec. 1972. Bovine mastitis. Centre de Recherches de Tours, INRA, 37-Nouzilly, France. Regards sur la France. Spec. No. 16. 31 Schultz, L. H. 1977. Somatic cells in milk physiological aspects and relationship to a m o u n t and composition of milk. J. Food Prot. 40:125.
127
32 Stadler, R. J., A. Mandirola, L. J. Williams, and W. H. Daniels. 1976. Activity report o f the Connecticut Mastitis Control Program. Report presented at Northeastern Mastitis Conf., September 30 and October 1, 1976. 33 Ward, G. E., and L. H. Schultz, 1972. Relationships of somatic ceils in quarter milk to type of bacteria and production. J. Dairy Sci. 55:1428. 34 Wesen, D. P. 1975. Mastitis screening tests through DHIA, Texas Dairy Herd Improvement Ass., Inc. S u m m a r y , 12 pp.
Journal of Dairy Science Vol. 62, No. 1, 1979
