7.5 Discussioni
La presenza di mastite durante il periodo iniziale della lattazione, specialmente nei primi 90 giorni, è un occorrenza comune in tutti gli allevamenti di bovine da latte. Lo scopo della presente tesi è stato quello di dimostrare se la presenza di mastite in un allevamento di bovine da latte determinasse solamente una riduzione della produzione di latte associata ad un abbassamento della qualità dello stesso, oppure fosse in grado di ridurre contemporaneamente le performances riproduttive delle bovine colpite da infezione mammaria.
Per valutare ciò abbiamo eseguito i controlli tra i 20 e 60 giorni PP; questo intervallo di tempo è stato scelto perché nei primi 7-10 gg PP la CCS nel latte è fisiologicamente alta e potrebbe causare la diagnosi di falsi positivi per mastite (Sharma et al., 2011) ed inoltre l’esame ecografico assume un particolare interesse a partire dal 12° al 15° giorno PP in quanto permette di evidenziare quadri di metrite- endometrite (Gnemmi, 2005).
In letteratura è riportata una chiara associazione tra mastite e alterazione dei parametri riproduttivi. Lo studio di Schrick e collaboratori (2001) evidenzia un aumento del numero di giorni tra parto e prima inseminazione nelle vacche con mastite (clinica o subclinica) (75,7±1,8 gg) rispetto al gruppo di controllo (67,8±2,2 gg). Nel nostro studio non abbiamo trovato differenze statisticamente significative per questo parametro tra il gruppo di bovine affette da mastite rispetto al gruppo di controllo.
Nello studio di Schrick e collaboratori si evidenzia inoltre un aumento dei giorni open (143,5±11,4 gg) e un aumento degli interventi fecondativi necessari per un concepimento (3,1±0,3 interventi) nelle vacche mastitiche rispetto al gruppo di controllo (85,4±5,8 gg e 1,6±0,2 interventi, rispettivamente). Nel nostro studio, al contrario, non abbiamo trovato differenze statisticamente significative per questo parametro tra il gruppo delle sane vs le mastitiche. Questa differenza potrebbe essere legata al basso numero di animali inclusi nel presente lavoro. E’ stata, invece, evidenziata una differenza statisticamente significativa per il numero di inseminazioni necessarie per il concepimento tra il gruppo di animali pluripari (3,9±0,5 interventi) e primipari (1,7±0,3 interventi). Questo parametro trova concordanza in letteratura (Grohn e Rajala-Shultz, 2000; Balendran et al., 2008;
Siddiqui et al., 2012) dove viene dimostrato che la fertilità decrescerebbe all’aumentare della parità della bovina.
I nostri risultati relativi all’involuzione uterina mostrano una riduzione costante e significativa nel tempo del diametro uterino nelle vacche sane, primipare e pluripare, mentre questo non avviene nelle mastitiche. In particolare in questo gruppo l’involuzione sembra più lenta. I risultati relativi alle primipare, pluripare e sane concordano con la bibliografia relativa allo studio dell’involuzione uterina negli animali sani (Sheldon et al., 2004).
La mancata involuzione dell’utero nelle vacche mastitiche potrebbe essere legata a un’endometrite subclinica correlata o associata alla mastite (Barker et al., 1998; Schrick et al., 2001). Nel nostro studio non abbiamo mai diagnosticato endometrite perché tutte le vacche mastitiche non presentavano segni clinici ed ecografici compatibili con la patologia. E’ vero però che in corso di endometrite moderata o lieve l’unico segno potrebbe essere soltanto l’aumento delle dimensioni dell’utero (Sheldon e Noakes, 1998).
Le differenze riscontrate nell’andamento delle intercette calcolate per il gruppo sane vs mastitiche confermano l’involuzione fisiologica per le sane e il rallentamento dell’involuzione per le mastitiche (p<0,05). Lo stesso test applicato ai gruppi primipare vs pluripare non evidenzia differenze, confermando l’involuzione fisiologica in entrambi i gruppi.
CONCLUSIONI
Fra le numerose patologie che interessano l’allevamento del bovino da latte, la mastite bovina è senza dubbio una problematica ancora molto diffusa e che provoca ingenti perdite economiche per l’allevatore, sia attraverso una diminuzione della produzione di latte, correlata anche una riduzione della sua qualità, sia attraverso una riduzione delle performance riproduttive della bovina affetta da mastite.
Il numero degli animali presi da noi in esame non ci ha permesso di avere un quadro chiaro delle correlazioni esistenti riportate in letteratura fra mastite e le alterazioni delle performance riproduttive.
Dato importante riscontrato è l’interruzione dell’involuzione uterina da noi descritta nel gruppo degli animali mastitici, sicuramente una diagnosi di endometrite subclinica sarebbe stata necessaria per verificare la presenza/assenza della stessa. Ulteriori indagini, effettuate su un numero maggiore di animali, sono auspicate per poter correlare più significativamente alterazioni riproduttive derivanti dalla presenza della mastite.
BIBLIOGRAFIA:
Ahmadzadeh A., Frago F., Shafii B., Dalton J.C., Price W.J., McGuire, M.A. (2009). Effect of clinical mastitis and other diseases on reproductive performance of Holstein cows. Anim. Reprod. Sci., 112: 273-82.
Balendran A., Gordon M., Pretheeban T., Singh R., Perera R., Rajamahedran R.,(2008). Decreased fertility with increasing parity in lactating dairy cows Can. J. Animal Sci. 88: 425-8.
Barker A., Schrick F., Lewis M., Dowlen H., Oliver S. (1998). Influence of clinical mastitis during early lactation on reproductive performance of Jersey cows. J. Dairy Sci. 81: 1285–90.
Bertocchi L. (1999). Il conteggio delle cellule somatiche del latte: approccio diagnostico Atti della Società Italiana di Buiatria – Vol. XXXI 361-369
Beam S.W., Butler W.R. (1997). Energy balance and ovarian follicle development prior to the first ovulation postpartum in dairy cows receiving three levels of dietary fat. Biol. Reprod. 56: 133–42.
Blum J.W., Dosogne H., Hoeben D., Vangroenweghe F., Hammon H.M., Bruckmaier R.M., Burvenich C. (2000). Tumor necrosis factor-b and nitrite/nitrate responses during acute mastitis induced by Escherichia coli infection and endotoxin in dairy cows. Dom. Anim. Endocrinol. 19: 223.
Bouchard L., Blais S., Desrosiers C., Zhao X., Lacasse P. (1999). Nitric oxide production during endotoxin-induced mastitis in the cow. J. Dairy Sci. 82: 2574.
Bolzoni G., Benicchio S., Posante A., Boldini M., Peli M., Varisco G. (2006). Milk culture examination. Some valutations on execution, interpretation of results and frequence of isolation Large Animal Review, 12(5): 3-11.
BonDurant RH. (1999). Inflammation in the bovine reproductive tract. J. Dairy Sci. 82(S2): 101–10.
Borsberry S., Dobson H. (1989). Periparturient diseases and their effect on reproductive performance in five dairy herds. Vet. Rec. 124: 217–9.
Bradley A.J. (2002). Bovine mastitis: an evolving disease. Vet. J. 164: 116–28.
Brolund L. (1985). Cell count in bovine milk: Causes of variation and applicability for diagnosis of subclinical mastitis. Acta Vet. Scand. 80(Suppl): 1-123. (Thesis).
Buford W.I., Ahmad N., Schrick F.N., Butcher R.L., Lewis P.E., Inskeep E.K. (1996). Embryotoxicity of a regressing corpus luteum in beef cows supplemented with progesterone. Biol. Reprod. 54: 351.
Buttler W.R. (2000). Nutritional interactions with reproductive performance in dairy cattle. Anim. Reprod. Sci. 60: 449.
Cai T.Q., Weston P.G., Lund L.A., Brodie B., McKenna D.J., Wagner W.C. (1994). Association between neutrophil functions and periparturient disorders in cows. Am. J. Vet. Res. 55: 934–43.
Clarkson A.R. (1975). Milk leucocyte counts and their significance in mastitis control. N.Z. Vet. J. 23: 284.
Chebel R.C. (2007). Mastitis effects on reproduction in Proceedings NMC Regional Meeting; 43-55.
Chen, H.W., Jiang W.S., Tzeng C.R. (2001). Nitric oxide as a regulator in preimplantation embryo development and apoptosis. Fertil. Steril. 75: 1163.
Davidson J.A., Tiemann U., Betts J.G., Hansen P.J. (1995). DNA synthesis and prostaglandin secretion by bovine endometrial cells as regulated by interleukin-1. Reprod. Fertil. Dev. 7: 1037.
DesCoteaux L., Colloton J., Gnemmi G. (2010). Pratical atlas of ruminant and camelid reproductive ultrasonography. Wiley-Blackwell ed., p. 76.
Duffield T., Dingwell HP., Skidmore A., Weary D., Neuder L., Rapheal W., Millman S., Newby N., Leslie K. (2009). Effect of flunixin meglumine treatment following parturition on cow health and milk production. The AABP Proceedings, Omaha, Nebraska Sep.10-12 2009, 42: 188.
Edwards J.L., Hansen P.J. (1997). Differential responses of bovine oocytes and preimplantation embryos to heat shock. Mol. Reprod. Dev. 46: 138.
Esslemont D., Kossaibati M.A. (2002). Mastitis: how to get out of the dark ages. Vet. J. 164: 85-6.
Esslemont RJ. (2013). Consensus conference on breeding protocols. Zoetis Marsille 22-23/03/13.
Esslemont RJ., Kossaibati MA., Allcock J. (1999). Economics of fertility in dairy cows. Fertility in high-producing dairy cow. Br. Soc. Anim. Sci. Occasional Pubblication, 26: 19-29.
Eicker SW., Gröhn YT., Hertl JA. (1996). The association between cumulative milk yeald, days open and days to first breeding in New York Holstein cow. J. Dairy Sci. 79(2): 235-41.
Fazio RA., Buuck MJ., Schrick FN. (1997). Embryonic development of frozen- thawed bovine embryos cultured in vitro in response to elevated concentrations of prostaglandin F2α. Biol. Reprod. 56 (Suppl. 1): 187.
Fourichon C., Seegers H., Malher X., (2000). Effect of disease on reproduction in the dairy cow: a meta-analysis. Theriogenol. 53: 1729–59.
Frazer G.S. (2005). A rational basis for therapy in the sick postpartum cow. Vet. Clin. 70
North Am Food An. Pract. 21: 523–68.
Goff J.P., Horst R.L. (1997). Physiological changes at parturition and their relationship to metabolic disorders. J. Dairy Sci. 80. 1260–8.
Gunnink J.W. (1984). Pre-partum leucocytic activity and retained placenta. Vet. Quarterly 6: 52–54.
Ginther O.J., Kot K., Kulick L.J., Martin S., Wiltbank M.C. (1996). Relationships between FSH and ovarian follicular waves during the last six months of pregnancy in cattle. J. Reprod. Fert. 108: 271-9.
Gilbert,R.O., Grohn Y.T., Guard C.L., Surman V., Neilsen N.,Slauson D.O. (1993). Impaired neutrophil function in cows which retain fetal membranes. Res. Vet. Sci. 55: 15–9.
Giri S.N., Chen Z., Carroll E.J., Mueller R., Schiedt M.J., Panico L., (1984). Role of prostaglandins in pathogenesis of bovine mastitis induced by Escherichia coli endotoxin. Am. J. Vet. Res. 45: 586.
Gnemmi G. (2010). Pratical uses for transrectal ultrasonography in reproductive management of cattle. XXVI Worl Buiatric Congress. Santiago del Cile, Cile.
Gnemmi G. (2010). Ultrasonography in Bovine Reproduction. Jap. J. Vet. Med. 63(1): 435-438
Gnemmi G., Maraboli C., Colloton J. (2005). Ultrasonografia in ginecologia buiatrica. Summa 5: 11-6.
Goff J.P., Horst R.L. (1997). Physiological changes at parturition and their relationship to metabolic disorders. J. Dairy Sci. 80: 1260- 8.
Grohn Y.T., Erb H.N., McCullogh C.E., Saloniemi H.S. (1990). Epidemiology of reproductive disorders in dairy cattle: associations among host characteristics,
disease and production. Prev. Vet. Med. 8: 25–39.
Gröhn YT., Eicker AW., Ducrocq V., Hertl JA. (1998). Effect of disease on the culling of holstein dairy cow in New York State. J. Dairy Sci. 81(4): 966-78.
Gröhn YT., Rajala-Schultz P.J. (2000). Epidemiology of reproductive performance in dairy cows. An. Reprod. Sci. 60-61: 605-14.
Guidry A.J., Paape M. J., Pearson R. E. (1976). Effects of parturition and lactation on blood and milk cell concentrations, corticosteroids, and neutrophil phagocytosis in the cow. Am. J. Vet. Res. 37: 1195–200.
Hammon D.S., Evjen I.M., Dhiman T.R., Goff, J.P., Walters J.L. (2006). Neutrophil function and energy status in Holstein cows with uterine health disorders. Vet. Immunol. Immunopathol. 113: 21–9.
Harmon R.J., Reneau J.K. (1993). Factors affecting the somatic cell count in milk. National Mastitis Council Annual Meeting Proceedings, pp. 48-54.
Harmon R.J. (2001). Somatic cell counts: a primer National Mastitis Council Annual Meeting Proceedings; 3-9
Heuwieser W., Tenhagen BA., Tischer M., Luhr J, H. (2000). Effect of three programmes for the treatment of endometritis on the reproductive performance of a dairy herd. Vet. Rec. 146: 338-41.
Hertl J. A., Gröhn Y.T., Leach J.D., Bar D., Bennett G.J., González R.N., Rauch B.J., Welcome F.L., Tauer L.W., Schukken Y.H. (2010). Effects of clinical mastitis caused by grampositive and gram-negative bacteria and other organisms on the probability of conception in New York State Holstein dairy cows. J. Dairy Sci. 93: 1551–60.
Hertl J.A., Schukken Y.H., Welcome F.L., Tauer L.W., Gröhn T. (2014). Effects of pathogen-specific clinical mastitis on probability of conception in Holstein dairy cows J. Dairy Sci. 97 :1–13.
Hoeben D., Burvenich C., Trevisi E., Bertoni G., Hamann J., Bruckmaier R.M., Blum J.W. (2000). Role of endotoxin and TNF-b in the pathogenesis of experimentally induced coliform mastitis in periparturient cows. J. Dairy Res. 67: 503.
Hockett M.E., Hopkins F.M., Lewis M.J., Saxton A.M., Dowlen H.H., Oliver S.P., Schrick N. (2000). Endocrine profiles of dairy cows following experimentally induced clinical mastitis during early lactation. Anim. Reprod. Sci. 58: 241.
Ingvartsen K.L. (2006). Feeding- and management-related diseases in the transition cow. Physiological adaptations around calving and strategies to reduce feeding- related diseases. An. Feed Sci. Technol. 126: 175–213.
Joosten I., Sanders M.F., Hensen E.J. (1991). Involvement of major histocompatibility complex class I compatibility between dam and calf in the aetiology of bovine retained placenta. An. Genet. 22: 455–63.
Kasimanickam R., Duffield T., Foster R., Gartley C., Leslie K., Walton J., Johnson W. (2004). Endometrial cytology and ultrasonography for detection of subclinical endometritis in postpartum dairy cows. Theriogenol. 62: 9-23.
Kaidi R., Brown P.J., David J.S.E. (1991). Uterine involution in cattle. In Grunsell C.S.G, Raw M.E. (eds): The Veterinary Annual, Blackwell Scientific Publications, Oxford, UK, pp. 38–50.
Kennedy P.C., Miller R.B. (1993). The female genital system. In Jubb K.V.F., Kennedy P.C., Palmer N. (eds): Pathology of domestic animals. 4th ed., San Diego Academic Press, USA, pp. 378–87.
Kehrli M.E., Nonnecke B.J., Roth J.A. (1989). Alterations in bovine peripheral blood neutrophil function during the peripartum period. Am. J. Vet. Res. 50: 207–14.
Kehrli Jr.M.E., Kimura K., Goff J.P., Stabel J.R., Nonnecke B.J., Smith R.A. (1999). 73
Immunological dysfunction in periparturient cows – what role does it play in postpartum infectious diseases? Proc. 32nd AABP Congress Nashville, TN, USA, pp. 24–8.
Kehrli Jr.M.E., Nonnecke B.J., Roth J.A. (1989). Alterations in bovine lymphocyte function during the periparturient period. Am. J. Vet. Res. 50: 215–20.
Kimura K., Goff J.P., Kehrli Jr. M.E. (1999). Effects of the presence of the mammary gland on expression of neutrophil adhesion molecules and myeloperoxidase activity in periparturient dairy cows. J. Dairy Sci. 82: 2385–92.
Kimura K., Reinhardt T.A., Goff J.P., (2006). Parturition and hypocalcemia blunts calcium signals in immune cells of dairy cattle. J. Dairy Sci. 89: 2588–95.
Krininger C.E. III, Stephens S.H., Hansen P.J. (2002). Develpomental changes in inhibitory effects of arsenic and heat shock on growth of preimplantation bovine embryos. Mol. Reprod. Dev. 63: 335.
Hibbitt K.G., Craven N., Batten E.H. (2004). Anatomy, Physiology and Immunology of the Udder. In Andrews A.H. (ed): Bovine Medicine Diseases and Husbandry of Cattle. 2nd ed., Blackwell Science Ltd, Oxford OX42DQ, UK, 22: 311-325
Kelton D.F., Lissemore K.D., Martin R.E. (1998). Reccomandations for recording and calculating the incidence of selected clinical disease of dairy cattle.J. Dairy Sci. 81(9): 2502-9.
Lee L.A., Ferguson J.D., Galligan D.T. (1989). Effect of disease on days open assessed by survival analysis. J. Dairy Sci. 72(4): 1020-6.
Lewis G.S. (2003). Role of ovarian progesterone and potential role of prostaglandin F2α and prostaglandin E2 in modulating the uterine response to infectious bacteria in postpartum ewes. J. Anim. Sci. 81: 285–93.
Lewis G.S. (2004). Steroidal regulation of uterine immune defenses. Anim. Reprod. 74
Sci. 82–83: 281–94.
Lewis G.S. (1997). Uterine health and disorders. J. Dairy Sci. 80: 984–94.
Loeffler S., Vries M., Schukken Y. (1999). The effects of time of disease occurrence, milk yield, and body conditions on fertility of dairy cows. J. Dairy Sci. 82: 2589-604.
Li P.S., Wagner W.C. (1983). In vivo and in vitro studies on the effect of adrenocorticotropic hormone or cortisol on the pituitary response to gonadotropin releasing hormone. Biol. Reprod. 29: 25.
LeBlanc SJ., Duffield TF., Leslie KE., Bateman KG., Keefe GP., Walton JS. (2002). Defining and diagnosing postpartum scheclinical endometritis and its impact on reproductive performance in dairy cows. J. Dairy Sci. 85: 2223–36.
LeBlanc S.J., Herdt T., Seymour W., Duffield T., Leslie K. (2004). Factors associated with peripartum serum concentrations of vitamin E, retinol, and (-carotene in Holstein dairy cattle, and their associations with periparturient disease. J. Dairy Sci. 87: 609–19.
Mallard B.A., Dekkers J.C., Ireland M.J., Leslie K.E., Sharif S.,Vankampen C.L., Wagter L., Wilkie B.N. (1998). Alteration in immune responsiveness during the peripartum period and its ramification on dairy cow and calf health. J. Dairy Sci. 81, 585–95.
Maltz E., Devir S., Metz J.H.M., Hogeveen H. (1997). The body weight of the dairy cow. I. Introductory study into body weight changes in dairy cows as a management aid. Livest. Prod. Sci. 48: 175.
McCann S.M., Kimura M., Karanth S., Yu W.H., Mastronardi C.A., Rettori V. (2000). The mechanism of action of cytokines to control the release of hypothalamic and pituitary hormones in infection. Ann. N.Y. Acad. Sci. 917: 4.
Morin, D.W. (2009). Mammary Gland Health and Disorders. In Smith, B.P. (ed): 75
Large Animal Internal Medicine, 4th ed, Mosby Elsevier 11830 Westline Industrial Drive St. Louis, Missouri, USA, pp. 1112-42.
Moore D., Cullor J., Bondurant R., Sischo W. (1991). Preliminary field evidence for the association of clinical mastitis with altered interestrus intervals in dairy cattle. Theriogenol. 36: 257–65.
Murray RD., Allison JD., Gard RP. (1990). Bovine endometritis: comparative efficacy of alfaprostol and intrauterine therapies, and other factors influencing clinical success. Vet. Rec.127: 86–90.
Nakajima Y., Mikami O., Yoshioka M., Motoi Y., Ito T., Ishikawa Y., Fuse M., Nakano K., Yasukawa K. (1997). Elevated levels of tumor necrosis factor-b (TNF-b) and interleukin-6 (IL-6) activities in the sera and milk of cows with naturally occurring coliform mastitis. Res. Vet. Sci. 62: 297.
Newbould F.H.S. (1976). Phagocytic activity of bovine leukocytes during pregnancy. Can. J. Comp. Med. 40: 111–6.
Nagahata H., Makino S., Takeda S., Takahashi H., Noda H. (1988). Assessment of neutrophil function in the dairy cow during the perinatal period. J. Vet. Med. B 35:747–51.
Oltenacu P.A., Frick A., Lindhe B. (1990). Epidemiological study of several clinical diseases, reproductive performance and culling in primiparous Swedish cattle. Prev. Vet. Med. 9: 59–74.
Opsomer G., Grohn YT., Hertl J., Coryn M., Deluyker H., de Kruif A. (2000). Risk factors for post partum ovarian dysfunction in high producing dairy cows in Belgium: a field study. Theriogenol. 53: 841–57.
Padmanabhan V., Keech C., Convey E.M. (1983). Cortisol inhibits and adrenocorticotropin has no effect on luteinizing hormone-releasing hormone-induced release of luteinizing hormone from bovine pituitary cells in vitro. Endocrinol. 112:
1782.
Pampfer S., Wuu Y.D., Vanderheyden I., De Hertogh R. (1994). Expression of tumor necrosis factor-b (TNF-b) receptors and selective effect of TNFb on the inner cell mass in mouse blastocyst. Endocrinol. 134: 206.
Peter A.T., Bosu W.T.K. (1988). Relationship of uterine infections and folliculogenesis in dairy cows during early puerperium. Theriogenol. 30: 1045–51.
Roche J.F., Diskin M.G. (2000). Resumption of reproductive activity in the early postpartum period of cows. Fertility in the High-Producing Dairy Cow. Br. Soc. An. Sci. Occasional Pubblication, 6(1): 31-42.
Savio J.D., Boland M.P., Hyne N., Roche J.F. (1990). Resumption of follicular activity in the early postpartum period of dairy cows. J. Rep. Fert. 88: 569–79.
Saad A.M., Concha C., Astrom G. (1989). Alterations in neutrophil phagocytosis and lymphocyte blastogenesis in dairy cows around parturition. J. Vet. Med. 36: 337– 45.
Santos J., Cerri R., Ballou M., Higginbotham G., Kirk J. (2004). Effect of timing of first clinical mastitis occurrence on lactational and reproductive performance on Holstein dairy cows. Anim. Reprod. Sci. 80: 31–45.
Sartori R., Sartor-Bergfelt R., Mertens S.A., Guenther J.N., Parrish J.J., Wiltbank M.C. (2002). Fertilization and Early Embryonic Development in Heifers and Lactating Cows in Summer and Lactating and Dry Cows in Winter. J. Dairy Sci. 85: 2803.
Schrick F., Hockett M., Saxton A., Lewis M., Dowlen H., Oliver S. (2001). Influence of subclinical mastitis during early lactation on reproductive parameters. J. Dairy Sci. 84, 1407–12.
Schultze W.D. (1985). Development in the identification of diseased udder quarters 77
or cows. Proc. International Dairy Federation Seminar Progress in the Control of Bovine Mastitis. Kieler Milchwirtschaftliche Forschungsberichte, 37: 319–28.
Semambo D.K., Ayliffe T.R., Boyd J.S., Taylor D.J. (1991). Early abortion in cattle induced by experimental intrauterine infection with pure cultures of Actinomyces pyogenes. Vet. Rec. 129: 12–6.
Sheldon I.M., Dobson H. (2004) Postpartum uterine health in cattle. Anim. Reprod. Sci. 82–83: 295–306.
Sheldon I.M., Noakes D.E., Rycroft A.N., Dobson H. (2003). The effect of intrauterine administration of estradiol on postpartum uterine involution in cattle. Theriogenol. 59: 1357–71.
Sheldon I.M., Noakes D.E., Rycroft A.N., Pfeiffer D.U., Dobson H. (2002). Influence of uterine bacterial contamination after parturition on ovarian dominant follicle selection and follicle growth and function in cattle. Reprod. 123: 837–45.
Sheldon I.M., Barrett D.C., Boyd H. (2004). The postpartum period. In Andrews A.H. (ed): Bovine Medicine Diseases and Husbandry of Cattle. 2nd Ed. Blackwell Science Ltd, Oxford UK, 34: 508-29.
Sheldom I.M., Lewis G.S., Le Blanc S., Gilbert R.O. (2006). Defining postpartum uterine disease in cattle. Theriogenol. 65(8): 1516-30.
Sheldom I.M., Cronin J., Goetze L., Donofrio G., Shubert H.J. (2009). Defining postpartum uterine disease and the mechanism of infection and immunity in the female reproductive tract in cattle. Biol. Reprod. 81(6): 1025-32.
Sheldrake R.F., Hoare J.T., McGregor G. (1983). Lactation stage, parity and infection affecting somatic cell, electrical conductivity, and scrum albumin in milk. J. Dairy Sci. 66: 542.
Siddiqui M.A.R., Das Z.C., Bhattacharjee J., Rahman M.M., Islam M.M., Haque 78
M.A., Parrish J.J., Shamsuddin M. (2013). Factor Affecting the First Service Coonception Rate of Cows in Smallholder Dairy Farms in Bangladesh. Reprod. Dom. Anim. 42: 500-5.
Skarzynski D.J., Miyamoto Y., Okuda K. (2000). Production of prostaglandin F2α by cultured bovine endometrial cells in response to tumor necrosis factor β: cell type specificity and intracellular mechanisms. Biol. Reprod. 62: 1116.
Soto P., Natzke R.P., Hansen P.J. (2003). Identification of possible mediators of embryonic mortality cause by mastitis: actions of lipopolysaccharide, prostaglandin F2α, and the nitric oxide generator, sodium nitroprusside dihydrate, on oocyte maturation and embryonic development in cattle. Am. J. Reprod. Immunol. 50: 263.
Stoebel D.P., Moberg G.P. (1982). Effect of adrenocorticotropin and cortisol on luteinizing hormone surge and estrous behavior of cows. J. Dairy Sci. 65: 1016.
Wenz J.R., Barrington G.M., Garry F.B., McSweeney K.D., Dinsmore R.P., Goodell G., Callan R.J. (2001). Bacteremia associated with naturally occurring acute coliform mastitis dairy cows. J. Am. Vet. Med. Assoc. 219: 976.
Wuu Y.D., Pampfer S., Becquet P., Vanderheyden I., Lee K.H., De Hertogh R. (1999). Tumor necrosis factor b decreases the viability of mouse blastocyst in vitro and in vivo. Biol. Reprod. 60: 479.
Zecconi A., Zanirato G. (2013). Il controllo delle mastiti per un allevamento sostenibile. Filiera AQ DiVet, Budrio (BO), pp. 5-64.