Hostname: page-component-745bb68f8f-hvd4g Total loading time: 0 Render date: 2025-02-12T04:07:31.681Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of continuous lactation and short dry periods on mammary function and animal health

Published online by Cambridge University Press:  12 December 2011

R. J. Collier ,
E. L. Annen-Dawson  and
A. Pezeshki
R. J. Collier*
Affiliation:
Department of Animal Science, University of Arizona, Tucson 85719, USA
E. L. Annen-Dawson
Affiliation:
Oord Dairy, LLC, Sunnyside, WA 98944, USA
A. Pezeshki
Affiliation:
Physiology and Biometrics, Ghent University, Ghent, Belgium
*
†Email: rcollier@ag.arizona.edu
Get access

Abstract

The dry period is required to facilitate cell turnover in the bovine mammary gland in order to optimize milk yield in the next lactation. Traditionally, an 8-week dry period has been a standard management practice for dairy cows based on retrospective analyses of milk yields following various dry period lengths. However, as milk production per cow has increased, transitioning cows from the nonlactating state to peak milk yield has grown more problematic. This has prompted new studies on dry period requirements for dairy cows. These studies indicate a clear parity effect on dry period requirement. First parity animals require a 60-day dry period, whereas lactations following later parities demonstrate no negative impact with 30-day dry period or even eliminating the dry period when somatotropin (ST) is also used to maintain milk yields. Shortened dry periods in first parity animals were associated with reduced mammary cell turnover during the dry period and early lactation and increased numbers of senescent cells and reduced functionality of lactating alveolar mammary cells postpartum. Use of ST and increased milking frequency postpartum reduced the impact of shortened dry periods. The majority of new intramammary infections occur during the dry period and persist into the following lactation. There is therefore the possibility of altering mastitis incidence by modifying or eliminating the dry period in older parity animals. As the composition of mammary secretions including immunoglobulins may be reduced when the dry period is reduced or eliminated, there is the possibility that the immune status of cows during the peripartum period is influenced by the length of the dry period.

Keywords

dry periodmammary glandmammary cellhealthmilk yield
Type
Full Paper
Information
animal , Volume 6 , Issue 3: 61th EAAP Annual Meeting, 2010, Heraklion, Greece: 10th International Workshop on Biology of Lactation in Farm Animals (BOLFA) and Session “Evolution of mammary gland and milk secretion: consequences for lactation in farm animals” , 27 January 2012 , pp. 403 - 414
Copyright
Copyright © The Animal Consortium 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Accorsi, PAPacioni, B, Pezzi, C, Forni, M, Flint, DJ, Seren, E 2002. Role of prolactin, growth hormone and insulin-like growth factor 1 in mammary gland involution in the dairy cow. Journal of Dairy Science 85, 507–513.CrossRefGoogle ScholarPubMed
Andersen, JB, Madsen, TG, Larsen, T, Ingvartsen, KL, Nielsen, MO 2005. The effects of dry period versus continuous lactation on metabolic status and performance in periparturient cows. Journal of Dairy Science 88, 3530–3541.CrossRefGoogle ScholarPubMed
Annen, EL, Collier, RJ 2005. Modified dry periods in dairy cattle: Implications for milk yield and the transition period. Proceedings of the 20th Annual Southwest Nutrition and Management Conference, 24–25 February 2005, Tempe, AZ, USA, pp. 209–224.Google Scholar
Annen, EL, Collier, RJ, McGuire, MA, Vicini, JL, Ballam, JM, Lormore, MJ 2004a. Effect of modified dry period lengths and bovine somatotropin on yield and composition of milk from dairy cows. Journal of Dairy Science 87, 3746–3761.CrossRefGoogle ScholarPubMed
Annen, EL, Collier, RJ, McGuire, MA, Vicini, JL 2004b. Effects of dry period length on milk yield and mammary epithelial cells. Journal of Dairy Science 87, E66–E76.CrossRefGoogle Scholar
Annen, EL, Stiening, CM, Crooker, BA, Fitzgerald, AC, Collier, RJ 2008. Effect of continuous milking and prostaglandin E2 on milk production and mammary epithelial cell turnover, ultrastructure, and gene expression. Journal of Animal Science 86, 1132–1144.CrossRefGoogle ScholarPubMed
Annen, EL, Fitzgerald, AC, Gentry, PC, McGuire, MA, Capuco, AV, Baumgard, LH, Collier, RJ 2007. Effect of continuous milking and bST supplementation on mammary epithelial cell turnover. Journal of Dairy Science 90, 165–183.CrossRefGoogle ScholarPubMed
Athie, F, Bachman, KC, Head, HH, Hayen, MJ, Wilcox, CJ 1996. Estrogen administered at final milk removal accelerates involution of bovine mammary gland. Journal of Dairy Science 79, 220–226.CrossRefGoogle ScholarPubMed
Bachman, KC 2002. Milk production of dairy cows treated with estrogen at the onset of a short dry period. Journal of Dairy Science 85, 797–803.CrossRefGoogle ScholarPubMed
Bauman, DE, Vernon, RG 1993. Effects of exogenous bovine somatotropin on lactation. Annual Review of Nutrition 13, 437–461.CrossRefGoogle ScholarPubMed
Bradley, AJ, Green, MJ 2004. The importance of the nonlactating period in the epidemiology of intramammary infection and strategies for prevention. Veterinary Clinics of North America: Food Animal Practice 20, 547–568.Google ScholarPubMed
Brandon, MR, Lascelles, AK 1975. The effect of pre-partum milking on the transfer of immunoglobulin into mammary secretion of cows. Australian Journal of Experimental Biology and Medical Science 53, 197–204.CrossRefGoogle ScholarPubMed
Breau, WC, Oliver, SP 1986. Growth inhibition of environmental mastitis pathogens during physiologic transitions of the bovine mammary gland. American Journal of Veterinary Research 47, 218–222.Google ScholarPubMed
Burvenich, C, Bannerman, DD, Lippolis, JD, Peelman, L, Nonnecke, BJ, Kehrli, MEJ, Paape, MJ 2007. Cumulative physiological events influence the inflammatory response of the bovine udder to Escherichia coli infections during the transition period. Journal of Dairy Science 90, E39–E54.CrossRefGoogle ScholarPubMed
Bushe, T, Oliver, SP 1987. Natural protective factors in bovine mammary secretion following different methods of milk cessation. Journal of Dairy Science 70, 696–704.CrossRefGoogle ScholarPubMed
Butler, JE 1983. Bovine immunoglobulins: an augmented review. Veterinary Immunology and Immunopathology 4, 43–152.CrossRefGoogle ScholarPubMed
Capuco, AV, Akers, RM 1999. Mammary involution in dairy animals. Journal of Mammary Gland Biology and Neoplasia 4, 137–144.CrossRefGoogle ScholarPubMed
Capuco, AV, Akers, RM, Smith, JJ 1997. Mammary growth in Holstein cows during the dry period: quantification of nucleic acids and histology. Journal of Dairy Science 80, 477–487.CrossRefGoogle ScholarPubMed
Capuco, AV, Annen, EL, Fitzgerald, AC, Ellis, SE, Collier, RJ 2006. Mammary cell turnover: relevance to lactation persistency and dry period management. In Ruminant physiology, digestion, metabolism and impact of nutrition on gene expression, immunology and stress (ed. K Sejrsen, T Hvelplund and MO Nielsen), pp. 363–388. Wageningen Academic Publishers, Wageningen, the Netherlands.Google Scholar
Capuco, AV, Li, M, Long, E, Ren, S, Hrusk, KS, Schorr, K, Furth, PA 2002. Pregnancy retards mammary involution: effects on apoptosis and proliferation of the mammary epithelium after forced weaning of mice. Biology of Reproduction 66, 1471–1476.CrossRefGoogle ScholarPubMed
Capuco, AV, Ellis, SE, Hale, SA, Long, E, Erdman, RA, Zhao, X, Paape, MJ 2003. Lactation persistency: insights from mammary cell proliferation studies. Journal of Animal Science 81, 18–31.CrossRefGoogle ScholarPubMed
Collier, RJ, Annen, EL, Fitzgerald, AC 2004. Prospects for zero days dry. Veterinary Clinics of North America: Food Animal Practice 20 (Transition Cow Management Issue), 687–701.Google ScholarPubMed
Collier, RJ, McGrath, MF, Byatt, JC, Zurfluh, LL 1993. Regulation of bovine mammary growth by peptide hormones: involvement of receptors, growth factors and binding proteins. Livestock Production Science 35, 21–33.CrossRefGoogle Scholar
Collier, RJ, Byatt, JC, McGrath, MF, Eppard, PJ, Vicini, JL, Stiening, C 2002. Effect of growth factors and hormones on mammogenesis and lactogenesis. Journal of Dairy Science 85 (suppl. 1), 53.Google Scholar
Cousins, CL, Higgs, TM, Jackson, ER, Neave, FK, Dodd, FH 1980. Susceptibility of the bovine udder to bacterial infection in the dry period. Journal of Dairy Science 47, 11–18.Google ScholarPubMed
Craven, N, Williams, MR 1985. Defenses of the bovine mammary gland against infection and prospects for their enhancement. Veterinary Immunology and Immunopathology 10, 71–127.CrossRefGoogle ScholarPubMed
Crooker, BA, Collier, RJ, Vicini, JL, McGrath, MF, Weber, WJ 2003. Induced lactation: the need for enhanced mammary development and differentiation. Journal of Dairy Science 86 (suppl. 1), 155.Google Scholar
Detilleux, JC, Koehler, KJ, Freeman, AE, Kehrli, MEJ, Kelley, DH 1994. Immunological parameters of periparturient Holstein cattle: genetic variation. Journal of Dairy Science 77, 2640–2650.CrossRefGoogle ScholarPubMed
Dias, FM, Allaire, FR 1982. Dry period to maximize milk production over two consecutive lactations. Journal of Dairy Science 65, 136–145.CrossRefGoogle Scholar
Dickerson, GE, Chapman, AB 1939. The effect of age and dry period on production at different levels of producing ability. Journal of Animal Science 13, 73–76.CrossRefGoogle Scholar
Dix Arnold, PT, Becker, RB 1936. Influence of preceding dry period and mineral supplementation on lactation. Journal of Dairy Science 19, 257–266.CrossRefGoogle Scholar
Eckles, CH, Palmer, LS 1916. The influence of parturition on the composition and properties of milk and milk fat of the cow. Journal of Biological Chemistry 27, 313–326.CrossRefGoogle Scholar
Feng, Z, Marti, A, Jehn, B, Altermatt, HJ, Chicaiza, G, Jaggi, R 1995. Glucocorticoid and progesterone inhibit involution and programmed cell death in the mouse mammary gland. Journal of Cell Biology 131, 1095–1103.CrossRefGoogle ScholarPubMed
Fitzgerald, AC, Annen-Dawson, EL, Baumgard, LH, Collier, RJ 2007. Evaluation of continuous lactation and increased milking frequency on milk production and mammary cell turnover in primiparous Holstein cows. Journal of Dairy Science 90, 5483–5489.CrossRefGoogle ScholarPubMed
Fleet, IR, Goode, JH, Hamon, MH, Laurie, MS, Linzell, JL, Peaker, M 1975. Secretory activity of the goat mammary glands during pregnancy and the onset of lactation. Journal of Physiology 251, 763–773.CrossRefGoogle ScholarPubMed
Goff, JP, Horst, RL 1997. Physiological changes at parturition and their relationship to metabolic disorders. Journal of Dairy Science 80, 1260–1268.CrossRefGoogle ScholarPubMed
Goff, JP, Kimura, K, Horst, RL 2002. Effect of mastectomy on milk fever, energy, and vitamins A, E, and β-carotene status at parturition. Journal of Dairy Science 85, 1427–1436.CrossRefGoogle Scholar
Goodman, RE, Schanbacher, FL 1991. Bovine lactoferrin mRNA: sequence, analysis and expression in the mammary gland. Biochemical and Biophysical Research Communications 180, 75–84.CrossRefGoogle ScholarPubMed
Grummer, RR, Rastani, RR 2005. Strategies for shortening the dry period. Proceedings of the 7th Western Dairy Management Conference, 9–11 March 2005, Reno, NV, USA, pp. 129–140.Google Scholar
Gulay, MS, Hayen, MJ, Head, HH, Wilcox, CJ, Bachman, KC 2005. Milk production from Holstein half udders after concurrent thirty- and seventy-day dry periods. Journal of Dairy Science 88, 3953–3962.CrossRefGoogle ScholarPubMed
Gulay, MS, Hayen, MJ, Bachman, KC, Belloso, T, Liboni, M, Head, HH 2003. Milk production and feed intake of Holstein cows given short (30-d) or normal (60-d) dry periods. Journal of Dairy Science 86, 2030–2038.CrossRefGoogle ScholarPubMed
Gulay, MS, Hayen, MJ, Liboni, M, Belloso, TI, Wilcox, CJ, Head, HH 2004. Low doses of bovine somatotropin during transition period and early lactation improves milk yield, efficiency of production, and other physiological responses of Holstein cows. Journal of Dairy Science 87, 948–960.CrossRefGoogle ScholarPubMed
Guy, MA, McFadden, TB, Cockrell, DC, Besser, TE 1994. Regulation of colostrum formation in beef and dairy cows. Journal of Dairy Science 77, 3002–3007.CrossRefGoogle ScholarPubMed
Harmon, RJ 1994. Physiology of mastitis and factors affecting somatic cell counts. Journal of Dairy Science 77, 2103–2112.CrossRefGoogle ScholarPubMed
Hernandez, LL, Limesand, SW, Collier, JL, Horseman, ND, Collier, RJ 2009. The bovine mammary gland expresses multiple functional isoforms of serotonin receptors. Journal of Endocrinology 203, 123–131.CrossRefGoogle ScholarPubMed
Hernandez, LL, Stiening, CM, Wheelock, JB, Baumgard, LH, Parkhurst, AM, Collier, RJ 2008. Evaluation of serotonin as a feedback inhibitor of lactation in the bovine. Journal of Dairy Science 91, 1834–1844.CrossRefGoogle ScholarPubMed
Holst, BD, Hurley, WL, Nelson, DR 1987. Involution of the bovine mammary gland: histological and ultrastructural changes. Journal of Dairy Science 70, 935–944.CrossRefGoogle ScholarPubMed
Huguet, EL, Smith, K, Bicknell, R, Harris, AL 1995. Regulation of Wnt5a expression in human mammary epithelial cells by cell shape, confluence and hepatocyte growth factor. The Journal of Biological Chemistry 270, 12851–12856.CrossRefGoogle ScholarPubMed
Hurley, WL 1989. Mammary gland function during involution. Journal of Dairy Science 72, 1637–1646.CrossRefGoogle ScholarPubMed
Hurley, WL, Rejman, JJ 1986. β-lactoglobulin and α-lactalbumin in mammary secretions during the dry period: parallelism of concentration changes. Journal of Dairy Science 69, 1642–1647.CrossRefGoogle ScholarPubMed
Huxley, JN, Green, MJ, Green, LE, Bradley, AJ 2002. Evaluation of the efficacy of an internal teat sealer during the dry period. Journal of Dairy Science 85, 551–561.CrossRefGoogle ScholarPubMed
Kishimoto, TK, Jutila, MA, Berg, EL, Butcher, EC 1989. Neutrophil Mac-1 and MEL-14 adhesion proteins inversely regulated by chemotactic factors. Science 245, 1238–1241.CrossRefGoogle ScholarPubMed
Klusmeyer, TH, Fitzgerald, AC, Fabellar, AC, Ballam, JM, Cady, RA, Vicini, JL 2009. Effect of recombinant bovine somatotropin and a shortened or no dry period on the performance of lactating dairy cows. Journal of Dairy Science 92, 5503–5511.CrossRefGoogle ScholarPubMed
Knight, CH 1998. Extended lactation. In Hannah Research Institute Yearbook 1998 (ed. E Taylor), pp. 30–39. University of Glasgow, Glasgow, Scotland.Google Scholar
Lamote, I, Meyer, E, Massart-Leen, AM, Burvenich, C 2004. Review: sex steroids and growth factors in the regulation of mammary gland proliferation, differentiation, and involution. Steroids 69, 145–159.CrossRefGoogle ScholarPubMed
Lascelles, AK 1979. The immune system of the ruminant mammary gland and its role in the control of mastitis. Journal of Dairy Science 62, 154–160.CrossRefGoogle ScholarPubMed
Leitner, G, Anug, AM, Merin, U, Silanikove, N 2007. Pregnancy obstructs involution stage II of the mammary gland in cows: general biological implications. Nature Precedings, posted 3 September 2007, doi: hdl:10101/npre.2007.846.2.CrossRefGoogle Scholar
Lotan, E, Alder, JH 1976. Observations on the effect of shortening the dry period on milk yield, body weight, and circulating glucose and FFA levels in dairy cows. Tijdschrift voor Diergeneeskunde 101, 77–82.Google ScholarPubMed
Marquis, GS, Penny, ME, Diaz, JM, Marin, RM 2002. Postpartum consequences of an overlap of breastfeeding and pregnancy: reduced breast milk intake and growth during early infancy. Pediatrics 109, e56–e63.CrossRefGoogle ScholarPubMed
Marti, A, Lazar, H, Ritter, P, Jaggi, R 1999. Transcription factor activities and gene expression during mouse mammary gland involution. Journal of Mammary Gland Biology and Neoplasia 4, 145–152.CrossRefGoogle ScholarPubMed
Matsuda, M, Imaoka, T, Vomachka, AJ, Gudelsky, GA, Hou, Z, Mistry, M, Bailey, JP, Nieport, KM, Walther, DJ, Bader, M, Horseman, ND 2004. Serotonin regulates mammary gland development via an autocrine–paracrine loop. Developmental Cell 6, 193–203.CrossRefGoogle ScholarPubMed
Mayer, B, Doleschall, M, Bender, B, Bartyik, J, Bosze, Z, Frenyó, LV, Kacskovics, I 2005. Expression of the neonatal Fc receptor (FcRn) in the bovine mammary gland. Journal of Dairy Research 72, 107–112.CrossRefGoogle ScholarPubMed
McGrath, MF, Collier, RJ, Clemmons, DR, Busby, WH, Sweeny, CA, Krivi, GG 1991. The direct in vitro effect of insulin like growth factors (IGFs) on normal bovine mammary cell proliferation and production of IGF binding proteins. Endocrinology 129, 671–678.CrossRefGoogle ScholarPubMed
Neave, FK, Dodd, FH, Henriques, E 1950. Udder infection in the dry period. Journal of Dairy Research 17, 37–49.CrossRefGoogle Scholar
Nguyen, DD, Neville, MC 1998. Tight junction regulation in the mammary gland. Journal of Mammary Gland Biology and Neoplasia 3, 233–246.CrossRefGoogle ScholarPubMed
Oliver, SP, Smith, KL 1982a. Milk yield and secretion composition following intramammary infusion of colchicines. Journal of Dairy Science 65, 204–210.CrossRefGoogle Scholar
Oliver, SP, Smith, KL 1982b. Nonantibiotic approach in control of bovine mastitis during dry period. Journal of Dairy Science 65, 2119–2124.CrossRefGoogle ScholarPubMed
Oliver, SP, Sordillo, LM 1988. Udder health in the periparturient period. Journal of Dairy Science 71, 2584–2606.CrossRefGoogle ScholarPubMed
Oliver, J, Dodd, FH, Neave, FK 1956. Udder infections in the dry period. IV. The relationship between the new infection rate in the early dry period and the daily milk yield at drying-off when lactation was ended by either intermittent or abrupt cessation of milking. Journal of Dairy Research 23, 204–211.CrossRefGoogle Scholar
Ongsakul, M, Sirisinha, S, Lamb, AJ 1985. Impaired blood clearance of bacteria and phagocytic activity of vitamin A deficient rats. Proceedings of the Society for Experimental Biology and Medicine 178, 204–208.CrossRefGoogle ScholarPubMed
Pai, V, Horseman, ND 2008. Biphasic regulation of mammary epithelial resistance by serotonin through activation of multiple pathways. Journal of Biological Chemistry 283, 30901–30910.CrossRefGoogle ScholarPubMed
Pezeshki, A, Mehrzad, J, Ghorbani, GR, Rahmani, HR, Collier, RJ, Burvenich, C 2007. Effects of short dry periods on performance and metabolic parameters in Holstein dairy cows. Journal of Dairy Science 90, 5531–5541.CrossRefGoogle Scholar
Pezeshki, A, Mehrzad, J, Ghorbani, GR, De Spiegeleer, B, Collier, RJ, Burvenich, C 2008. The effect of dry period length reduction to 28 days on the performance of multiparous dairy cows in the subsequent lactation. Canadian Journal of Animal Science 88, 449–456.CrossRefGoogle Scholar
Pezeshki, A, Capuco, AV, De Spiegeleer, B, Peelman, L, Stevens, M, Collier, RJ, Burvenich, C 2010. An integrated view on how the management of the dry period length of lactating cows could affect mammary biology and defense. Journal of Animal Physiology and Animal Nutrition 94, e7–e30, doi: 10.1111/j.1439-0396.2010.00991.x.CrossRefGoogle Scholar
Quarrie, LH, Addey, CVP, Wilde, CJ 1996. Programmed cell death during mammary involution induced by weaning, litter removal, and milk stasis. Journal of Cellular Physiology 168, 559–569.3.0.CO;2-O>CrossRefGoogle ScholarPubMed
Rajala-Schultz, PJ, Hogan, JS, Smith, KL 2005. Short communication: association between milk yield at dry-off and probability of intramammary infections at calving. Journal of Dairy Science 88, 577–579.CrossRefGoogle ScholarPubMed
Rastani, RR, Del Rio, NS, Gressley, TF, Dahl, GE, Grummer, RR 2007. Effects of increasing milking frequency during the last 28days of gestation on milk production, dry matter intake, energy balance and metabolic profiles. Journal of Dairy Science 90, 1729–1739.CrossRefGoogle Scholar
Rastani, RR, Grummer, RR, Bertics, SJ, Gumen, A, Wiltbank, MC, Mashek, DG, Schwab, MC 2005. Reducing dry period length to simplify feeding transition cows: milk production, energy balance, and metabolic profiles. Journal of Dairy Science 88, 1004–1014.CrossRefGoogle ScholarPubMed
Remond, B, Bonnefoy, JC 1997. Performance of a herd of Holstein cows managed without the dry period. Annales de Zootechnie 46, 3–12.CrossRefGoogle Scholar
Remond, B, Ollier, A, Miranda, G 1992. Milking cows in late pregnancy: milk production during this period and during the succeeding lactation. Journal of Dairy Research 59, 233–241.CrossRefGoogle ScholarPubMed
Remond, B, Kerouanton, J, Brocard, V 1997a. Effets de la reduction de la duree de la periode seche ou de son omission sur les performances des vaches laitie′ras. INRA Productions Animales 10, 301–333.CrossRefGoogle Scholar
Remond, B, Rouel, J, Pinson, N, Jabet, S 1997b. An attempt to omit the dry period over three consecutive lactations in dairy cows. Annales de Zootechnie 46, 399–408.CrossRefGoogle Scholar
Rinaldi, M, Li, RW, Bannerman, DD, Daniels, KM, Evock-Clover, C, Silva M, VB, Paape, MJ, Van Ryssen, B, Burvenich, C, Capuco, AV 2010. A sentinel function for teat tissues in dairy cows: dominant innate immune response elements define early response to E. coli mastitis. Functional and Integrative Genomics 10, 21–38.CrossRefGoogle ScholarPubMed
Rukkwamsuk, T, Kruip, TA, Meijer, GAL, Wensing, T 1999. Hepatic fatty acid composition in periparturient dairy cows with fatty liver induced by intake of a high energy diet in the dry period. Journal of Dairy Science 82, 280–287.CrossRefGoogle ScholarPubMed
Schanbacher, FL, Goodman, RE, Talhouk, RS 1993. Bovine mammary lactoferrin: implications from messenger ribonucleic acid (mRNA) sequence and regulation contrary to other milk proteins. Journal of Dairy Science 76, 3812–3831.CrossRefGoogle ScholarPubMed
Schairer, ML 2001. Estrogen treatments for the initiation of dry off in dairy cows. Master thesis, University of Florida, Gainesville, FL, USA.Google Scholar
Schlamberger, G, Wiedemann, S, Viturro, E, Meyer, HHD, Kaske, M 2010. Effects of continuous milking during the dry period or once daily milking in the first 4 weeks of lactation on metabolism and productivity of dairy cows. Journal of Dairy Science 93, 2471–2485.CrossRefGoogle ScholarPubMed
Smith, A, Wheelock, JV, Dodd, FH 1967. Effect of milking throughout pregnancy on milk secretion in the succeeding lactation. Journal of Dairy Research 34, 145–150.CrossRefGoogle Scholar
Smith, KL, Todhunter, DA, Schoenberger, PS 1985a. Environmental mastitis: cause, prevalence, prevention. Journal of Dairy Science 68, 1531–1553.CrossRefGoogle ScholarPubMed
Smith, KL, Todhunter, DA, Schoenberger, PS 1985b. Lactoferrin and defense of the involuted mammary gland against infection by environmental pathogens. Kieler Milchwirtschaft Forschungsber 37, 477–481.Google Scholar
Sordillo, LM 1987. Physiological aspects of bovine mammary involution: a biochemical and morphological investigation. PhD thesis, Louisiana State University, Baton Rouge, LA.Google Scholar
Sordillo, LM, Nickerson, SC 1988. Morphologic changes in the bovine mammary gland during involution and lactogenesis. American Journal of Veterinary Research 49, 1112–1120.Google ScholarPubMed
Sordillo, LM, Streicher, KL 2002. Mammary gland immunity and mastitis susceptibility. Journal of Mammary Gland Biology and Neoplasia 7, 135–146.CrossRefGoogle ScholarPubMed
Sorensen, JT, Enevoldsen, C 1991. Effect of dry period length on milk production in subsequent lactation. Journal of Dairy Science 74, 1277–1283.CrossRefGoogle ScholarPubMed
Stull, MA, Pai, V, Vomachka, AJ, Marshall, AM, Jacob, GA, Horseman, ND 2007. Mammary gland homeostasis employs serotonergic regulation of epithelial tight junctions. Proceedings of the National Academy of Sciences of the United States of America 104, 16708–16713.CrossRefGoogle ScholarPubMed
Swanson, EW 1965. Comparing continuous milking with sixty-day dry periods in successive lactations. Journal of Dairy Science 48, 1205–1209.CrossRefGoogle ScholarPubMed
Swanson, EW, Pardue, FE, Longmire, DB 1967. Effect of gestation and dry period on deoxyribonucleic acid and alveolar characteristics of bovine mammary glands. Journal of Dairy Science 50, 1288–1292.CrossRefGoogle ScholarPubMed
Tatarczuch, L, Philip, C, Lee, CS 1977. Involution of sheep mammary gland. Journal of Anatomy 190, 405–416.CrossRefGoogle Scholar
Travers, MT, Barber, MC, Tonner, E, Quarrie, L, Wilde, CJ, Flint, DJ 1996. The role of prolactin and growth hormone in the regulation of casein gene expression and mammary cell survival: relationships to milk synthesis and secretion. Endocrinology 137, 1530–1539.CrossRefGoogle ScholarPubMed
Vangroenweghe, F, Lamote, I, Burvenich, C 2005. Physiology of the periparturient period and its relation to severity of clinical mastitis. Domestic Animal Endocrinology 29, 283–293.CrossRefGoogle ScholarPubMed
Watters, RD, Guenther, JN, Brickner, AE, Rastani, RR, Crump, PM, Clark, PW, Grummer, RR 2008. Effects of dry period length on milk production and health of dairy cattle. Journal of Dairy Science 91, 2595–2603.CrossRefGoogle ScholarPubMed
Wheelock, JV, Rook, JAF, Dodd, FH 1965. The effect of milking throughout the whole pregnancy on the composition of cow's milk. Journal of Dairy Research 32, 249–254.CrossRefGoogle Scholar
Wilde, CJ, Knight, CH, Flint, DJ 1999. Control of milk secretion and apoptosis during mammary involution. Journal of Mammary Gland Biology and Neoplasia 4, 129–136.CrossRefGoogle ScholarPubMed
Wilde, CJ, Addey, CVP, Li, P, Fernig, DG 1997. Programmed cell death in bovine mammary tissue during lactation and involution. Experimental Physiology 82, 943–953.CrossRefGoogle ScholarPubMed
Wilton, JW, Burnside, EB, Rennie, JC 1967. The effects of days dry and days open on the milk and butterfat production of Holstein Friesian cattle. Canadian Journal of Animal Science 47, 85–90.CrossRefGoogle Scholar
Zhang, CL, Chen, H, Wang, YH, Zhang, RF, Lan, XY, Lei, CZ, Zhang, L, Zhang, AL, Hu, SR 2008. Serotonin receptor 1B (HTR1B) genotype associated with milk production traits in cattle. Research in Veterinary Science 85, 265–268.CrossRefGoogle ScholarPubMed