Short communication: Bovine milk sampling efficiency for pregnancy-associated glycoproteins (PAG) detection test

Helen K. da Silva, Laerte D. Cassoli, José C. F. Pantoja, Pedro H. R. Cerqueira, Tatiane B. Coitinho, Paulo F. Machado

Abstract


Two experiments were conducted to verify whether the time of day at which a milk sample is collected and the possible carryover in the milking system may affect pregnancy-associated glycoproteins (PAG) levels and, consequently, the pregnancy test results in dairy cows. In experiment one, we evaluated the effect of time of day at which the milk sample is collected from 51 cows. In experiment two, which evaluated the possible occurrence of carryover in the milk meter milking system, milk samples from 94 cows belonging to two different farms were used. The samples were subjected to pregnancy test using ELISA methodology to measure PAG concentrations and to classify the samples as positive (pregnant), negative (nonpregnant), or suspicious (recheck). We found that the time of milking did not affect the PAG levels. As to the occurrence of carryover in the milk meter, the PAG levels of the samples collected from Farm-2 were heavily influenced by a carryover effect compared with the samples from Farm-1. Thus, milk samples submitted to a pregnancy test can be collected during the morning or the evening milking. When the sample is collected from the milk meters, periodic equipment maintenance should be noted, including whether the milk meter is totally drained between different animals’ milking and equipment cleaning between milking is performed correctly to minimize the occurrence of carryover, thereby avoiding the effect on PAG levels and, consequently, the pregnancy test results. Therefore, a single milk sample can be used for both milk quality tests and pregnancy test.

Keywords


pregnancy test; milk samples; morning milking; evening milking; carryover; milk meter

Full Text:

PDF HTML XML

References


Fava LW, Guimarães TG, Pinto AT, 2011. Efeito de três ordenhas diárias na composição do leite de vacas da raça Holandês. Acta Sci Vet 39 (4): pub. 998. http://www.ufrgs.br/actavet/39-4/PUB%20998.pdf.

Forsback L, Lindmark-Månsson H, Andrén A, Åkerstedt M, Andrée L, Svennersten-Sjaunja K, 2010. Day-to-day variation in milk yield and milk composition at the udder-quarter level. J Dairy Sci 93: 3569-3577. https:/doi.org/10.3168/jds.2009-3015

Friedrich M, Holtz W, 2010. Establishment of an ELISA for measuring bovine pregnancy-associated glycoprotein in serum or milk and its application for early pregnancy detection. Reprod Domest Anim 45: 142-146. https:/doi.org/10.1111/j.1439-0531.2008.01287.x

Gajewski Z, Sousa NM, Beckers JF, Pawlinski B, Olszewska M, Thun R, Kleczkowski M, 2008. Concentration of bovine pregnancy associated glycoprotein in plasma and milk: its application for pregnancy diagnosis in cows. J Physiol Pharmacol 9: 55-64.

Green JA, Parks TE, Avalle MP, Telugu BP, McLain AL, Peterson AJ, McMillan W, Mathialagan N, Hook RR, Xie S, Roberts RM, 2005. The establishment of an ELISA for the detection of pregnancy-associated glycoproteins (PAGs) in the serum of pregnant cows and heifers. Theriogenology 63: 1481-1503. https:/doi.org/10.1016/j.theriogenology.2004.07.011

Green JC, Volkmann DH, Poock SE, McGrath MF, Ehrhardt M, Moseley AE, Lucy MC, 2009. A rapid enzyme-linked immunosorbent assay blood test for pregnancy in dairy and beef cattle. J Dairy Sci 92: 3819-3824. https:/doi.org/10.3168/jds.2009-2120

Han RX, Kim HR, Diao YF, Lee MG, Jin D, 2012. Detection of early pregnancy-specific proteins in Holstein milk. J Proteomics 75: 3221-3229. https:/doi.org/10.1016/j.jprot.2012.03.029

Lawson BC, Shahzad AH, Dolecheck KA, Martel EL, Velek KA, Ray DL, Lawrence JC, Silvia WJ, 2014. A pregnancy detection assay using milk samples: Evaluation and considerations. J Dairy Sci 97: 1-10. https:/doi.org/10.3168/jds.2014-8233

LeBlanc SJ, 2013. Field evaluation of a pregnancy confirmation test using milk samples in dairy cows. J Dairy Sci 96: 2345-2348. https:/doi.org/10.3168/jds.2012-6414

Lollivier V, Guinard-Flament J, Ollivier-Bousquet M, Marnet P, 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. https:/doi.org/10.1051/rnd:2002016

Løvendahl P, Bjerring MA, 2006. Detection of Carryover in automatic milk sampling equipment. J Dairy Sci 89: 3645-3652. https:/doi.org/10.3168/jds.S0022-0302(06)72404-3

Løvendahl P, Chagunda MGG, 2011. Covariance among milking frequency, milk yield, and milk composition from automatically milked cows. J Dairy Sci 94: 5381-5392. https:/doi.org/10.3168/jds.2010-3589

Pavel ER, Gavan C, 2011. Seasonal and milking-to-milking variations in cow milk fat, protein and somatic cell counts. Not Sci Biol 3: 20-23.

Quist MA, LeBlanc SJ, Hand KJ, Lazenby D, Miglior F, Kelton DF, 2008. Milking-to-milking variability for milk yield, fat and protein percentage, and somatic cell count. J Dairy Sci 91: 2412-3423. https:/doi.org/10.3168/jds.2007-0184

R CORE TEAM, 2015. R: A language and environment for statistical computing. R Foundation for Statistical Computing. Vienna, 2015. https://www.R-project.org [10 oct. 2015].

Reis GL, Alves AA, Lana ÂMQ, Coelho SG, Souza MR, Cerqueira MMOP, Penna CFAM, Mendes EDM, 2007. Procedimentos de coleta de leite cru individual e sua relação com a composição físico-química e a contagem de células somáticas. Cienc Rural 37: 1134-1138. https:/doi.org/10.1590/S0103-84782007000400035

Silva E, Sterry RA, Kolb D, Mathialagan N, McGrath MF, Ballam JM, Fricke PM, 2007. Accuracy of a pregnancy-associated glycoprotein ELISA to determine pregnancy status of lactating dairy cows twenty-seven days after timed artificial insemination. J Dairy Sci 90: 4612-4622. https:/doi.org/10.3168/jds.2007-0276

Szenci O, Beckers JF, Humblot P, Sulon J, Sasser G, Taverne MAM, Varga J, Baltusen R, Schekk G, 1998. Comparison of ultrasonography, bovine pregnancy-specific protein B, and bovine pregnancy-associated glycoprotein 1 tests for pregnancy detection in dairy cows. Theriogenology 50: 77-88. https:/doi.org/10.1016/S0093-691X(98)00115-0

Watson PF, Petrie A, 2010. Method agreement analysis: A review of correct methodology. Theriogenology 73: 1167-1179. https:/doi.org/10.1016/j.theriogenology.2010.01.003

Whitlock BK, Maxwell HS, 2008. Pregnancy-associated glycoproteins and pregnancy wastage in cattle. Theriogenology 70: 550-559. https:/doi.org/10.1016/j.theriogenology.2008.05.003




DOI: 10.5424/sjar/2016144-9923