Impact of Oxytocin-Milking Method on Lactation Performance and Lactation Length of Sheep

Document Type : Research Article


1 Arazdam Company, West Azarbaijan, Poldasht, Iran

2 Agriculture and Natural Resources Research Center, West Azerbaidjan, Urmia, Iran

3 Agriculture Jihad Organization of West Azerbaidjan, Urmia, Iran


Determination of milk yield potential using an accurate method is essential for assessing nutritional requirements, evaluation of genetic potential, lamb growth and survival, management decisions and improving performance traits of sheep flocks. Exogenous oxytocin injection is applied to estimate milk secretion rate in sheep. Oxytocin is a neurohormone produced in the hypothalamo-neurohypophysial system, which is released into the blood in response to teat stimulation. It has a galactopoietic effect and plays an important role in lactation acting on milk ejection via the secretory activity and contraction of myoepithelial cells. One hundred singleton-bearing and rearing Makui breed ewes were assigned into two treatments: group I (hand milking and stripping following the intramuscular injection of 2.5 IU of oxytocin) and group II (hand milking and stripping). The study aimed to examine the effect of exogenous oxytocin injection on milk yield, milk composition and lactation length of ewes during the entire lactation period. Data were recorded at fortnightly intervals from post-partum day 14 onward. Oxytocin treatment group produced significantly more average daily milk yield (562.3 vs. 301.4 g) and total milk yield (93.6 vs. 38.5 kg) compared with non-treated animals (P<0.05). Lactation length was 145.7 days and 115.2 days for the oxytocin and the control group, respectively (P=0.038). Oxytocin injection increased milk peak yield and lactation persistency (P<0.05) while shorter peak time (34.1 vs. 39.2 days) was observed for oxytocin group (P=0.043). Oxytocin administration increased milk fat percentage (6.73 vs. 5.86) in treated compared to control ewes (P=0.029). However, no difference was detected in the percentage of protein and lactose associated to the oxytocin injection (P>0.05). The development of milk ejection inhibition throughout lactation during the exclusively sucklingperiod, followed by hand-stripping, entails the need for oxytocin to sustain mammary cells and lactation persistency in ewes. Itfurther confirms that oxytocin allows overcoming the negative feedback mechanisms exerted on milk ejection, enhancing the intracellular transfer of secretory vesicles and contraction of myoepithelial cells and thereby increasing milk production and lactation length, which is a useful technique to ensure complete alveolar milk let-down and optimum milk withdrawal from the cistern.


Aboul-Naga A.M., El-Shobkshy A.S. and Moustafa M.A. (1981). Milk production from subtropical non-dairy sheep. 2. Method of measuring. J. Agric. Sci. 79, 303-308.
Antonic J., Tancin V., UhrincatM., Macuhová L., Macuhová J. and Jackuliaková L. (2013). The effect of exogenous oxytocin on milkability and milk composition in ewes differed in milk flow pattern. Small Rumin. Res. 113, 254-257.
Awoniyi K.A. (2003). Effect of oxytocin on milk yield of west African Dwarf (WAD) sheep. MS Thesis. Federal Univ. Agric., Nigeria.
Banda J.W., Steinbach J. and Zerfas H.P. (1992). Composition and yield of milk from non-dairy goats and sheep in Malawi. Pp. 461-483 in Proc. 1st Biennial Conf. African Small Rumin. Res. Nairobi, ILCA, Addis Ababa Ethiopia.
Belgin O.C., Esenbuga N. and Davis E.M. (2010). Comparison of models for describing the lactation curve of Awassi, Morkaraman and Tushin sheep. Arch. Tierz. 53, 447-456.
Bencini R. (1995). Use of intramuscular oxytocin injections to measure milk output in nondairy sheep and its effect on milk composition. Australian J. Exp. Agric. 35, 563-565.
Bencini R., knight T.W. and Hartmann P.E. (2003). Secretion of milk and milk components in sheep. Australian J. Exp. Agric. 43, 529-534.
Boutinaud M., Guinard-Flament J. and Jammes H. (2004). The number of activity of mammary epithelial cells, determining factors for milk production. Reprod. Nutr. Dev. 44, 499-508.
Braidwood L.S., Braidwood R.J., Howe B., Reed C.S. and Watson P.J. (1983). Prehistoric archaeology along zagros flank. University of Chicago press, USA.
Bruckmaier R.M., Paul G., Mayer H. and Schams D. (1997). Machine milking of Ostfriesian and Lacaune dairy sheep: udder anatomy, milk ejection and milk characteristics. J. Dairy Res. 64, 163-172.
Burgoyne R.D. and Wilde C.J. (1994). Control of secretory function in mammary epithelial cells. Cell. Signal. 6, 607-616.
Capuco A., Ellis S., Hale S., Long E., Erdman R., Zhao X. and Paape M.J. (2003). Lactation persistency: insights from mammary cell proliferation studies.J. Anim. Sci. 81(3), 18-28.
Capuco A.V., Wood D.L., Baldwin R., Mcleod K. and Paape M.J. (2001). Mammary cell number, proliferation and apoptosis during a bovine lactation: relation to milk production and effect of bST. J. Dairy Sci. 84, 2177-2187.
Carretero A., Ruberte J., Caja G., Perez-Aparicio F.J., Such X., Peris S., Mansse M. and Navarro M. (1999). Study on the structure and the development of the canalicular system of the mammary gland during lactation in Manchega and Lacaune dairy sheep. Pp. 35-40 in Milking and Milk Production of Dairy Sheep and Goats. D.F. Barillet and N.P. Zervas Eds. Wageningen, Netherland.
Da Costa T.H.M., Taylor K., Ilic V. and Willaimson D.H. (1995). Regulation of milk lipid secretion: effects of oxytocin, prolactin and ionomycin on triacylglycerol release from rat mammary gland slices. Biochem. J. 308, 975-981.
Doney J.M., Peart J.N., Smith W.F. and Louda F. (1979). A consideration of the techniques for estimation of milk yield by suckled sheep and a comparison of estimates obtained by two methods in relation to the effect of breed, level of production and stage of lactation. J. Agric. Sci. 92, 123-132.
Dove H. (1988). Estimation of the intake of milk by lambs, from the turnover of deuterium or tritium labelled water. Br. J. Nutr. 60, 375-387.
FAO. (2012). Food and Agriculture Organization of the United Nations the State of Food Insecurity in the World.
Fernandez G., Alvarez P., San Primitivo F. and De la Fuente L.F. (1995). Factors affecting variation of udder traits of dairy ewes. J. Dairy Sci. 78, 842-849.
Fernandez N., Balasch S., Pérez I., Rodríguez M. and Peris C. (2013). Milk yield estimation during suckling using the double oxytocin injection-milking and the double weighing-suckling methods in dairy goats. Small Rumin. Res. 112, 181-185.
Geenty K.G. (2010). Lactation and lamb growth. Pp. 259-276 in International Sheep and Wool Handbook. D. Cottle, Ed. Nottingham University press, United Kingdom.
Gorewit R.C., Svennersten K., Butler W.R. and Uvnas-Moberg K. (1992). Endocrine responses in cows milked by hand and machine. J. Dairy Sci. 75, 443-448.
Haenlein G.F.W. (2001). Past, present and future perspectives of small ruminant dairy research. J. Dairy Sci. 84, 2097-2115.
Heesom K.J., Souza P.F., Ilic V. and Williamson D.H. (1992). Chain-length dependency of interactions of medium-chain fatty acids with glucose metabolism in acini isolated from lactating rat mammary glands. A putative feed-back to control milk lipid synthesis from glucose. Biochem. J281, 273-278.
Hernandez L.L., Stiening C.M., Wheelock J.B., Baumgard L.H., Parkhurst A.M. and Collier R.J. (2008). Evaluation of serotonin as a feedback inhibitor of lactation in the bovine. J. Dairy Sci. 91, 1834-1844.
Hesse B. (1978). Evidence for husbandry from the early neolithic site of Ganj Dareh in western Iran. Ph D. Thesis. Columbia Univ., USA.
ICAR. (2010). International Committee for Animal Recording. Guidelines Approved by the General Assembly held in Cork, Ireand.
Iniguez L., Hilali M., Thomas D.L. and Jesry G. (2009). Udder measurements and milk production in two Awassi sheep genotypes and their crosses. J. Dairy Sci. 92, 4613-4620.
Keskin I. and Dag B. (2006). Comparison of different mathematical models for describing the complete lactation of Akkaraman ewes in Turkey. Asian-australas J. Anim. Sci. 19, 1551-1555.
Kuchtík J., Šustová K., Urban T. and Zapletal D. (2008). Effect of the stage of lactation on milk composition, its properties and the quality of rennet curdling in east Friesian ewes. Czech J. Anim. Sci. 53, 55-63.
Lefcourt A.M. and Akers R.M. (1983). Is oxytocin really necessary for efficient milk removal in dairy cows? J. Dairy Sci. 66, 2251-2259.
Lollivier V., Guinard-Flament J., Ollivier-Bousquet M. and Marnet P.G. (2002). Oxytocin and milk removal: two important sources of variation in milk production and milk quality during and between milkings. Reprod. Nutr. Dev. 42, 173-186.
Lollivier V., Marnet P.G., Delpal S., Rainteau D., Achard C., Rabot A. and Ollivier-Bousquet M. (2006). Oxytocin stimulates secretory processes in lactating rabbit mammary epithelial cells. J. Physiol. 570, 125-140.
María G. and Gabiña D. (1993). Non-genetic effects on milk production of Latxa ewes. Small Rumin. Res. 12, 61-67.
Marnet P.G. and McKusik B.C. (2001). Regulation of milk ejection and milkability in small ruminants. Livest. Prod. Sci. 70, 125-133.
Marnet P.G., Negrao J.A. and Labussiere J. (1998). Oxytocin release and milk ejection parameters during milking of dairy ewes in and out natural season of lactation. Small Rumin. Res. 28, 183-191.
Morgan J., Fogarty N.M. and Nicol H. (2000). Oxytocin administration and its effect on ewe milk composition. Asian-australas J. Anim. Sci. 13, 206-208.
Novotná L., Kuchtík J., Šustová K., Zapletal D. and Filipík R. (2009). Effects of lactation stage and parity on milk yield, composition and properties of organic sheep milk. J. Appl. Anim. Res. 36, 71-76.
NRC. (2007). Nutrient Requirements of Small Ruminants: Sheep, Goats, Cervids and New World Camelids. National Academy Press, Washington, DC, USA.
Ollivier-Bousquet M. (2002). Milk lipid and protein traffic in mammary epithelial cells: joint and independent pathways. Reprod. Nutr. Dev. 42, 149-162.
Peaker M. and Taylor E. (1994). Inhibitory effect of milk fat on milk secretion in the mouse: a reexamination. Exp. Physiol. 79, 561-64.
Ploumi K., Belibasaki S. and Triantaphyllidis G. (1998). Some factors affecting daily milk yield and composition in a flock of Chios ewes. Small Rumin. Res. 28, 89-92.
Ribeiro L.C., Pérez J.R.O., Carvalho P.H.A., Fonseca e Silva F., Muniz J.A., de Oliveira Júnior J.M. and Vilela de Souza N. (2007). Effects of oxytocin on milk yield and composition of Santa Inês ewes. Rev. Brasileira Zootec. 36, 438-444.
Sapino A., Macri L., Tonda L. and Bussolati G. (1993). Oxytocin enhances myoepithelial cell differentiation and proliferation in the mouse mammary gland. Endocrinology. 133, 838-842.
SAS Institute. (2009). SAS®/STAT Software, Release 9.1.3. SAS Institute, Inc., Cary, NC. USA.
Sharp J.A., Lefevre C. and Nicholas K.R. (2008). Lack of functional α-lactalbumin prevents involution in Cape fur seals and identifies the protein as an apoptotic milk factor in mammary gland involution. BMC Biol. 6, 48-52.
Silanikove N., Leitner G., Merin U. and Prosser C.G. (2010). Recent advances in exploiting goat’s: quality, safety and production aspects. Small Rumin. Res. 89, 110-124.
Unal N., Atasoy F., Akcapinar H., Kocak S., Yakan A., Erol H. and Ugurlu M. (2007). Milk yield measured by oxytocin plus hand milking and weigh-suckle-weigh methods in ewes originating from local crossbred in Turkey. Rev. Med. Vet. 158, 320-325.
Wagner K.U., Young W.S., Liu X., Ginns E.I., Li M., Furth P.A. and Hennighausen L. (1997). Oxytocin and milk removal are required for post-partum mammary-gland development. Genes. Funct. 1, 233-244.
Wallin L.A, Fawcett C.P. and Rosenfeld C.R. (1989). Oxytocin stimulates glucagon and insulin secretion in fetal and neonatal sheep. Endocrinology. 125, 2289-2296.
Zamiri M.J., Qotbi A. and Izadifard J. (2001) Effect of daily oxytocin injection on milk yield and lactation length in sheep. Small Rumin. Res. 40,179-185.
Zeder M.A., Bradley D.G., Emshwiller E. and Smith B. (2006). Documenting domestication: new genetic and archaeological paradigsm. University of California press, Ltd.