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Prevalence of intramammary infections in primigravid Brazilian dairy heifers
PREVENTIVE
VETERINARY ELSEVIER
MEDICINE heventive VeterinaryMedicine29 ( 1996) I5 I- 15.5
Prevalence of intramammary infections in primigravid Brazilian dairy heifers E.O. da Costa aTb’* , P.A. Melville b, A.R. Ribeiro b, E. Watanabe b, F.C. Viani a, C.R. White a aDepartment of Preventive Veterinary Medicine, Faculdade de Medic&a Veterinciria e Zootecnia, Universidade de Silo Paula, Au. Corijeu de Azevedo Marques, 2720-Butantan, Cep: 05340-000 Siio Paula, SP, Brazil b Nucleus on Mammary Gland and Milk Production (NAP GAMA) Faculdade de Medicinn Veterinhria e Zootecnia Universidade de Siio Paula, Au. Cortfeu de Azevedo Marques, 2720-Butantan, Cep: 05340-000 silo Paula, SP. Brazil Accepted28 March I996
Abstraci Mammary-gland secretions from 467 quarters of 120 primigravid purebred and crossbred Holstein heifers from six dairy herds were collected; 96 (80%) of the heifers had intramammary infections and 57% of the quarters were infected. Sru~hylococcus spp. were isolated from 230 (49%) quarters. Other microorganisms commonly isolated from secretion samples were: Corynebtzcterium sp. (33 quarters, 7%) and Streptococcus (21 quarters, 4%). Enterobacteriaceae (Escherichiu coli, Klebsiella spp.) were isolated from eight (2%) samples. Keywords: Heifer; Primigravid;
Intramammwy
infection
1. Introduction Currmt practices for the control of mastitis in mature cows include postmilking teat antisepsis, dry-cow therapy, proper treatment of clinical mastitis, functionally adequate milking machines, and culling of chronically infected cows. Unbred and primigravid heifers are generally regarded as uninfected; therefore, mastitis control is not considered as a management practice in nulliparous heifers. Mammary glands from these animals are not observed until the first milking. The presence of mammary inflammation in
* Corresponding
author. Tel.: (011) 818-7651;
0167-5877/96/$15.00 Copyright PII SO167-5877(96)01072-O
fax: (011) 210-2224.
0 1996 Elsevier Science B.V. All rights reserved.
152
E.O. da Costa et al./Preventive
Veterinary Medicine 29 (1996) 151-155
young dairy animals may be deleterious to future milk production, since mammary tissue development is at its peak during the first gestation, and the presence of intramammary infections (IMI) may adversely affect secretory-cell differentiation (Trinidad et al., 1990a). Palmer et al. (1941) isolated Stu~hyZococcus spp. from 24 heifers in three herds. Oliver and Mitchell (1983) studied 32 primigravid heifers and found that 68.8% of them were infected at the time of parturition and that coagulase negative Sfu~hylococcus spp. were the main cause of IMI. In research conducted in Vermont, Pankey (1990) isolated Stu~hylococcus spp. from mammary gland secretions from 23 heifers. In Louisiana (USA), Trinidad et al. (199Oa) reported the occurrence of IMI in 37% of the 116 heifers examined. The purpose of this investigation was to determine the prevalence of IMI in primigravid heifers on six Brazilian dairy farms and the distribution of the microorganisms isolated. 2. Materials and methods There were no substantial differences in management practices among the six herds examined. However, in one of the farms the calves were separated from their dams shortly after birth and were fed with stored colostrum instead of nursing the dam. On all farms the calves remained in individual pens until about 10 days after weaning, at which time they were moved from individual housing to a group pen where they had access to good quality hay. In some of the herds (n = 5) calves also had access to pasture. In general, the calves were kept in good sanitation conditions. The heifers were kept on pastures where they also received the highest fibre, lowest energy forages and sufficient concentrates to supply nutritional requirements. Four hundred and sixty seven samples were collected from the mammary glands of 120 heifers (bred by AI), approximately 15 days (15 _t 2 days, ?= 8) before calving. During a routine visit to the herds, heifers were selected for sampling according to the stage of gestation. The secretion samples were always aseptically collected by the same people who conducted the laboratory work. Teats were dried with individual paper towels and swabbed with cotton soaked in 70% alcohol (or alcohol-iodine) before a milk sample was collected in a separate vial
Table 1 Frequency of intramammary Paula, Brazil in 1994 No. of quarters infected
0 1 2 3 4
infection observed from 120 prim&avid
dairy heifers in a study conducted
Animals No.
%
24 20 17 25 34
20.0 16.7 14.2 20.8 28.3
at SBo
E.O. da Costa et al./Preventive
Veterinary Medicine 29 (1996) 151-155
153
Table 2 Results of the microbiological examination of 467 secretion samples from 120 primigravid study conducted at SZo Paulo, Brazil in 1994
dairy heifers in a
Microbiological
results
Staphylococcus spp. ’ Streptococcus sp. Corynebacterium
Enterobacteriaceae Contaminations Negatives Associate :,amples
sp.
Quarters a
Heifers b
No.
%
No.
%
230 21 33 08 13 186 24
49.2 4.4 7.0 1.7 2.7 39.8 5.1
93 19 22 5
77.50 15.83 18.33 4.17
86
18.42
a A total 01’ 480 mammary glands (467 sampled and 13 blind quarters). b Heifers in which the microorganism was found in at least one quarter. ’ Of 102 kolated Staphylococcus spp. submitted to the tube coagulase test, 97 (95.0%) were coagulase-negative and five (4.9%) were coagulase-positive.
for each quarter. Milk samples were immediately put in an ice cooler, transported to the laboratory and streaked for initial isolation within 24 h after collection. A 0.01 ml sample was streaked for isolation on one quadrant of a sheep-blood-agar plate. Agar plates were incubated at 37°C and read at approximately 24 and 48 h. Colony morphology, haemolysis, catalase reaction and Gram stain were used for the first-level identification as described by the National Mastitis Council (1987). Confirmatory tests were used for final identification as described by Krieg and Holt (1984) and Lennette et al. (1985). Isolates identified as staphylococci were tested for coagulase production by the tube coagulase method. Milk samples yielding three or more different organisms were judged to have been contaminated at collection.
3. Results Intramammary infections were found in 57% of quarters and in 80% of heifers examined. Only 20% of heifers were completely free of infections and 28.3% had all four mammary quarters infected (Table 1). Sfu@zylococcus spp. were isolated from 49.2% of the samples but of the 102 isolated Sru@zylococc~~ spp. that were submitted to the coagulase tube test, only five (4.9%) were coagulase positive, and 97 (95.0%) were coagulase negative staphylococci (CNS). Microorganisms from the genera Corynebacterium (7.0%), Streptococcus (4.4%) and from the Enterobacteriaceae family (1.7%) were also isolated (Table 2).
4. Discussion Previously reported estimates of the prevalence of IMI at calving in first-lactation animals in heifers have ranged from 26 to 69% (Munch-Petersen, 1970; Meaney, 1981;
154
E.O. da Costa et al./ Preventive Veterinary Medicine 29 (1996) 151-155
Oliver and Mitchell, 1983). Meaney (1981) reported that the prevalence of IMI in heifers at calving ranged from 26 to 42%. Munch-Petersen (1970) reported that over 22% of 535 quarters of 134 first-calf heifers yielded microorganisms in the milk on the first day of lactation. Oliver and Mitchell (1983) sampled secretions from heifers 14 days prepartum and 7-14 days postpartum during a 4-year period in a herd and reported that 27% of quarters and 69% of heifers had IMI at parturition and 32.9% of quarters at prepartum. In our study most IMI were due to Sruphylococc~s spp. (49.2%) with 95% of these being CNS. These results are similar to those obtained by Oliver and Mitchell (19831, who found that 23.4% of IMI were due to Staphylococcus spp. and 94.9% of those were CNS. These data are consistent with previous studies conducted by Shearer and Harmon (1993) who pointed out the importance of the participation of CNS in the aetiology of IMI in heifers, although these are considered minor pathogens. Determination of the origin of IMI in these heifers was beyond the scope of this study. However, some management practices for lactating cows may help to decrease transmission of pathogens from mature cows to heifers (Trinidad et al., 1990a). Teat dipping after milking reduces the number of pathogens on teat surfaces and helps to minimise the possibility of transmission of microorganisms by flies from infected cows to heifers. However, the application of teat dips during the prepartum period was not effective in reducing the prevalence of mastitis at calving (Shearer and Harmon, 1993). Suckling among calves and heifers has been associated with mastitis (Schalm, 1942) and should be prevented, particularly if calves are fed mastitic milk (Roberson et al., 1990). Trinidad et al. (1990b) evaluated the influence of antibiotic therapy in heifers to reduce IMI at calving, and concluded that this practice was effective in reducing the prevalence of mastitis at calving. According to these authors, heifers treated during the second trimester of pregnancy had the greatest reduction in the prevalence of mastitis at parturition. The results obtained by these authors and those of Oliver et al. (1992) support prepartum therapy as an effective means to decrease the prevalence of mastitis in heifers during early lactation. However, Oliver et al. (1992) recommended the use of intramammary therapy during late gestation, i.e. prepartum administration of antibiotic formulations for lactating cows more than 14 days prior to expected parturition. Traditionally, mastitis control has been practised on lactating dairy cows. Replacement heifers had generally been considered mastitis-free. However, the results of this and other studies demonstrate that mastitis control in replacement heifers may be equally important to ensure the availability of IMI-free lactating cows, to enhance profitability and to improve milk quality.
Acknowledgements The authors thank Maria de Fatima Miranda Suzana for help with computing; Lilian S.M. Diniz, Nilson Roberti Benites, Marco Antonio Lazaro and Strgio Y. Abe. This project was funded by FAPESP (Funda@o de Amparo B Pesquisa do Estado de SZo Paulo).
E.O. da Costa et al./Preuentiue
Veterinary Medicine 29 (1996) 151-155
155
References Krieg, N.F!. and Holt, J.G. (Editors), 1984. Bergey’s Manual of Systematic Bacteriology. Williams and Wilkins, Baltimore, MD, 1600 pp. Lennette, E.H., Balows, A., Hausler, W. and Shadomy, H. (Editors), 1985. Manual of Clinical Microbiology, 4th edr. American Society for Microbiology, Washington, 1149 pp. Meaney, W.J., 1981. Mastitis level in spring-calving dairy heifers. Ir. Vet. J., 35: 205-209. Munch-Petersen, E., 1970. Mastitis in bovine primiparae. Vet. Rec., 87: 568-574. National Mastitis Council, 1987. Laboratory and Field Handbook on Bovine Mastitis. National Mastitis Council, Arlington, VA. Oliver, S.P. and Mitchell, B.A., 1983. Intramammary infections in primigravid heifers near parturition. J. Dairy !ki., 66: 11SO- 1184. Oliver, S.P., Lewis, M.J., Gillespie, B.E. and Dowlen, H.H., 1992. Influence of prcpartum antibiotic therapy on intmmammary infections in primigravid heifers during early lactation. J. Dairy Sci., 75: 406-414. Palmer, C.C., Kakavas, J.C. and Hay, J.R., 1941. Studies on bovine mastitis. Mastitis in heifers. Am. J. Vet. Res., 2: 18-34. Pankey, J.W., 1990. Prevalence of mastitis in first lactation cows. In: Int. Symp. on Bovine Mastitis, Indiana.polis, IN, pp. 108- 111. Roberson, J.R., Fox, L.K. and Hancock, D.H., 1990. Staphylococcus aweus intramammary infections (IMI): prevalence, sources and modes of transmission in dairy heifers. In: Int. Symp. on Bovine Mastitis, Indiana.polis, IN, pp. 112- 117. Schalm, O.W., 1942. Streptococcus agalactiae in the udder of heifers at parturition traced to suckling among calves. Cornell Vet., 34: 49-60. Shearer, J.K. and Harmon, R.J., 1993. Mastitis in heifers. Vet. Clin. North Am. Food Anim. Pratt., 9: 583-595. Trinidad, I’., Nickerson, S.C. and Alley, T.K., 1990a. Prevalence intramammary infection and teat canal colonization in unbred and primigravid dairy heifers. J. Dairy Sci., 73: 107-l 14. Trinidad, P., Nickerson, S.C. and Alley, T.K., 1990b. Efficacy of intramammary treatment in unbred and primigravid dairy heifers. J. Am. Vet. Med. Assoc., 197: 465-470.
VETERINARY ELSEVIER
MEDICINE heventive VeterinaryMedicine29 ( 1996) I5 I- 15.5
Prevalence of intramammary infections in primigravid Brazilian dairy heifers E.O. da Costa aTb’* , P.A. Melville b, A.R. Ribeiro b, E. Watanabe b, F.C. Viani a, C.R. White a aDepartment of Preventive Veterinary Medicine, Faculdade de Medic&a Veterinciria e Zootecnia, Universidade de Silo Paula, Au. Corijeu de Azevedo Marques, 2720-Butantan, Cep: 05340-000 Siio Paula, SP, Brazil b Nucleus on Mammary Gland and Milk Production (NAP GAMA) Faculdade de Medicinn Veterinhria e Zootecnia Universidade de Siio Paula, Au. Cortfeu de Azevedo Marques, 2720-Butantan, Cep: 05340-000 silo Paula, SP. Brazil Accepted28 March I996
Abstraci Mammary-gland secretions from 467 quarters of 120 primigravid purebred and crossbred Holstein heifers from six dairy herds were collected; 96 (80%) of the heifers had intramammary infections and 57% of the quarters were infected. Sru~hylococcus spp. were isolated from 230 (49%) quarters. Other microorganisms commonly isolated from secretion samples were: Corynebtzcterium sp. (33 quarters, 7%) and Streptococcus (21 quarters, 4%). Enterobacteriaceae (Escherichiu coli, Klebsiella spp.) were isolated from eight (2%) samples. Keywords: Heifer; Primigravid;
Intramammwy
infection
1. Introduction Currmt practices for the control of mastitis in mature cows include postmilking teat antisepsis, dry-cow therapy, proper treatment of clinical mastitis, functionally adequate milking machines, and culling of chronically infected cows. Unbred and primigravid heifers are generally regarded as uninfected; therefore, mastitis control is not considered as a management practice in nulliparous heifers. Mammary glands from these animals are not observed until the first milking. The presence of mammary inflammation in
* Corresponding
author. Tel.: (011) 818-7651;
0167-5877/96/$15.00 Copyright PII SO167-5877(96)01072-O
fax: (011) 210-2224.
0 1996 Elsevier Science B.V. All rights reserved.
152
E.O. da Costa et al./Preventive
Veterinary Medicine 29 (1996) 151-155
young dairy animals may be deleterious to future milk production, since mammary tissue development is at its peak during the first gestation, and the presence of intramammary infections (IMI) may adversely affect secretory-cell differentiation (Trinidad et al., 1990a). Palmer et al. (1941) isolated Stu~hyZococcus spp. from 24 heifers in three herds. Oliver and Mitchell (1983) studied 32 primigravid heifers and found that 68.8% of them were infected at the time of parturition and that coagulase negative Sfu~hylococcus spp. were the main cause of IMI. In research conducted in Vermont, Pankey (1990) isolated Stu~hylococcus spp. from mammary gland secretions from 23 heifers. In Louisiana (USA), Trinidad et al. (199Oa) reported the occurrence of IMI in 37% of the 116 heifers examined. The purpose of this investigation was to determine the prevalence of IMI in primigravid heifers on six Brazilian dairy farms and the distribution of the microorganisms isolated. 2. Materials and methods There were no substantial differences in management practices among the six herds examined. However, in one of the farms the calves were separated from their dams shortly after birth and were fed with stored colostrum instead of nursing the dam. On all farms the calves remained in individual pens until about 10 days after weaning, at which time they were moved from individual housing to a group pen where they had access to good quality hay. In some of the herds (n = 5) calves also had access to pasture. In general, the calves were kept in good sanitation conditions. The heifers were kept on pastures where they also received the highest fibre, lowest energy forages and sufficient concentrates to supply nutritional requirements. Four hundred and sixty seven samples were collected from the mammary glands of 120 heifers (bred by AI), approximately 15 days (15 _t 2 days, ?= 8) before calving. During a routine visit to the herds, heifers were selected for sampling according to the stage of gestation. The secretion samples were always aseptically collected by the same people who conducted the laboratory work. Teats were dried with individual paper towels and swabbed with cotton soaked in 70% alcohol (or alcohol-iodine) before a milk sample was collected in a separate vial
Table 1 Frequency of intramammary Paula, Brazil in 1994 No. of quarters infected
0 1 2 3 4
infection observed from 120 prim&avid
dairy heifers in a study conducted
Animals No.
%
24 20 17 25 34
20.0 16.7 14.2 20.8 28.3
at SBo
E.O. da Costa et al./Preventive
Veterinary Medicine 29 (1996) 151-155
153
Table 2 Results of the microbiological examination of 467 secretion samples from 120 primigravid study conducted at SZo Paulo, Brazil in 1994
dairy heifers in a
Microbiological
results
Staphylococcus spp. ’ Streptococcus sp. Corynebacterium
Enterobacteriaceae Contaminations Negatives Associate :,amples
sp.
Quarters a
Heifers b
No.
%
No.
%
230 21 33 08 13 186 24
49.2 4.4 7.0 1.7 2.7 39.8 5.1
93 19 22 5
77.50 15.83 18.33 4.17
86
18.42
a A total 01’ 480 mammary glands (467 sampled and 13 blind quarters). b Heifers in which the microorganism was found in at least one quarter. ’ Of 102 kolated Staphylococcus spp. submitted to the tube coagulase test, 97 (95.0%) were coagulase-negative and five (4.9%) were coagulase-positive.
for each quarter. Milk samples were immediately put in an ice cooler, transported to the laboratory and streaked for initial isolation within 24 h after collection. A 0.01 ml sample was streaked for isolation on one quadrant of a sheep-blood-agar plate. Agar plates were incubated at 37°C and read at approximately 24 and 48 h. Colony morphology, haemolysis, catalase reaction and Gram stain were used for the first-level identification as described by the National Mastitis Council (1987). Confirmatory tests were used for final identification as described by Krieg and Holt (1984) and Lennette et al. (1985). Isolates identified as staphylococci were tested for coagulase production by the tube coagulase method. Milk samples yielding three or more different organisms were judged to have been contaminated at collection.
3. Results Intramammary infections were found in 57% of quarters and in 80% of heifers examined. Only 20% of heifers were completely free of infections and 28.3% had all four mammary quarters infected (Table 1). Sfu@zylococcus spp. were isolated from 49.2% of the samples but of the 102 isolated Sru@zylococc~~ spp. that were submitted to the coagulase tube test, only five (4.9%) were coagulase positive, and 97 (95.0%) were coagulase negative staphylococci (CNS). Microorganisms from the genera Corynebacterium (7.0%), Streptococcus (4.4%) and from the Enterobacteriaceae family (1.7%) were also isolated (Table 2).
4. Discussion Previously reported estimates of the prevalence of IMI at calving in first-lactation animals in heifers have ranged from 26 to 69% (Munch-Petersen, 1970; Meaney, 1981;
154
E.O. da Costa et al./ Preventive Veterinary Medicine 29 (1996) 151-155
Oliver and Mitchell, 1983). Meaney (1981) reported that the prevalence of IMI in heifers at calving ranged from 26 to 42%. Munch-Petersen (1970) reported that over 22% of 535 quarters of 134 first-calf heifers yielded microorganisms in the milk on the first day of lactation. Oliver and Mitchell (1983) sampled secretions from heifers 14 days prepartum and 7-14 days postpartum during a 4-year period in a herd and reported that 27% of quarters and 69% of heifers had IMI at parturition and 32.9% of quarters at prepartum. In our study most IMI were due to Sruphylococc~s spp. (49.2%) with 95% of these being CNS. These results are similar to those obtained by Oliver and Mitchell (19831, who found that 23.4% of IMI were due to Staphylococcus spp. and 94.9% of those were CNS. These data are consistent with previous studies conducted by Shearer and Harmon (1993) who pointed out the importance of the participation of CNS in the aetiology of IMI in heifers, although these are considered minor pathogens. Determination of the origin of IMI in these heifers was beyond the scope of this study. However, some management practices for lactating cows may help to decrease transmission of pathogens from mature cows to heifers (Trinidad et al., 1990a). Teat dipping after milking reduces the number of pathogens on teat surfaces and helps to minimise the possibility of transmission of microorganisms by flies from infected cows to heifers. However, the application of teat dips during the prepartum period was not effective in reducing the prevalence of mastitis at calving (Shearer and Harmon, 1993). Suckling among calves and heifers has been associated with mastitis (Schalm, 1942) and should be prevented, particularly if calves are fed mastitic milk (Roberson et al., 1990). Trinidad et al. (1990b) evaluated the influence of antibiotic therapy in heifers to reduce IMI at calving, and concluded that this practice was effective in reducing the prevalence of mastitis at calving. According to these authors, heifers treated during the second trimester of pregnancy had the greatest reduction in the prevalence of mastitis at parturition. The results obtained by these authors and those of Oliver et al. (1992) support prepartum therapy as an effective means to decrease the prevalence of mastitis in heifers during early lactation. However, Oliver et al. (1992) recommended the use of intramammary therapy during late gestation, i.e. prepartum administration of antibiotic formulations for lactating cows more than 14 days prior to expected parturition. Traditionally, mastitis control has been practised on lactating dairy cows. Replacement heifers had generally been considered mastitis-free. However, the results of this and other studies demonstrate that mastitis control in replacement heifers may be equally important to ensure the availability of IMI-free lactating cows, to enhance profitability and to improve milk quality.
Acknowledgements The authors thank Maria de Fatima Miranda Suzana for help with computing; Lilian S.M. Diniz, Nilson Roberti Benites, Marco Antonio Lazaro and Strgio Y. Abe. This project was funded by FAPESP (Funda@o de Amparo B Pesquisa do Estado de SZo Paulo).
E.O. da Costa et al./Preuentiue
Veterinary Medicine 29 (1996) 151-155
155
References Krieg, N.F!. and Holt, J.G. (Editors), 1984. Bergey’s Manual of Systematic Bacteriology. Williams and Wilkins, Baltimore, MD, 1600 pp. Lennette, E.H., Balows, A., Hausler, W. and Shadomy, H. (Editors), 1985. Manual of Clinical Microbiology, 4th edr. American Society for Microbiology, Washington, 1149 pp. Meaney, W.J., 1981. Mastitis level in spring-calving dairy heifers. Ir. Vet. J., 35: 205-209. Munch-Petersen, E., 1970. Mastitis in bovine primiparae. Vet. Rec., 87: 568-574. National Mastitis Council, 1987. Laboratory and Field Handbook on Bovine Mastitis. National Mastitis Council, Arlington, VA. Oliver, S.P. and Mitchell, B.A., 1983. Intramammary infections in primigravid heifers near parturition. J. Dairy !ki., 66: 11SO- 1184. Oliver, S.P., Lewis, M.J., Gillespie, B.E. and Dowlen, H.H., 1992. Influence of prcpartum antibiotic therapy on intmmammary infections in primigravid heifers during early lactation. J. Dairy Sci., 75: 406-414. Palmer, C.C., Kakavas, J.C. and Hay, J.R., 1941. Studies on bovine mastitis. Mastitis in heifers. Am. J. Vet. Res., 2: 18-34. Pankey, J.W., 1990. Prevalence of mastitis in first lactation cows. In: Int. Symp. on Bovine Mastitis, Indiana.polis, IN, pp. 108- 111. Roberson, J.R., Fox, L.K. and Hancock, D.H., 1990. Staphylococcus aweus intramammary infections (IMI): prevalence, sources and modes of transmission in dairy heifers. In: Int. Symp. on Bovine Mastitis, Indiana.polis, IN, pp. 112- 117. Schalm, O.W., 1942. Streptococcus agalactiae in the udder of heifers at parturition traced to suckling among calves. Cornell Vet., 34: 49-60. Shearer, J.K. and Harmon, R.J., 1993. Mastitis in heifers. Vet. Clin. North Am. Food Anim. Pratt., 9: 583-595. Trinidad, I’., Nickerson, S.C. and Alley, T.K., 1990a. Prevalence intramammary infection and teat canal colonization in unbred and primigravid dairy heifers. J. Dairy Sci., 73: 107-l 14. Trinidad, P., Nickerson, S.C. and Alley, T.K., 1990b. Efficacy of intramammary treatment in unbred and primigravid dairy heifers. J. Am. Vet. Med. Assoc., 197: 465-470.