32. HAJURKA,J., HURA,V., BÍRES,J., KACMÁRIK,J., CSICSAI,G., VALOCKÝ,I.: Evaluation of calcium content in mares prepartum mammary secretion. (A kanca ellés elõtti tejmirigy-váladékának Ca-tartalma)
32. Hajurka
érk: 97.10.16.
UVL, 04101 Kosice, Komenského 73. Slovak Republic
SUMMARY
Parturition in the mare is a rapid process, and any pathology can have serious consequence. The gestation length can vary considerably, as can the signs of impending parturition. Much time, effort and money can be expended waiting for the mare to foal.
Seventeen Thoroughbred multiparous mares were allowed to foal spontaneously and the calcium content of their mammary secretions was measured over last four days before foaling. Measurement of mammary secretion calcium by atomic absorbent spectrofotometry (Perkin Elmer 306 and 1100) show tendency gradually increasing to foal. Tw0enty four hours before foal the calcium content more than 6 mg/l-1 had 77% of mares. The results indicate that calcium content in udder secretions are not particu-larly acurate in predicting time of parturition. Evening measurement by simple method may be more helpful by indicating when is not necessary to attend mares at night.
INTRODUCTION
Parturition in mares is a critical moment in stud management and considerable expense and effort are devoted to "sitting up". It is a well - known fact that the gestation length can vary considerably, as can the signs of impending parturition. Much time, effort and money can be expended waiting for the mare to foal.
Changes in mammary sland size, constituent of mammary secretions and hormones involved in lactogenesis have been subjects of intesive study in dairy animals (COWIE, FORSYTH and HAST, 1980). The changes in electrolyte content of prefoaling udder secretions are related to fetal maturity and viability, and thus readiness for birth (CASH, OUSEY and ROSSDALE, 1985, OUSEY, DELCLAUX and ROSSDALE, 1989).
This paper study the calcium content in mammary secretions in normal spontaneously foaling mares and retrospectively to assess readiness for birth.
MATERIALS AND METHODS
Animals
Seventeen Thoroughbred multiparous mares from two stud farms were studied over the expected last ten days of gestation. The mares was allowed to foal spontaneously. The mean gestation age at delivery was 340,6 11,8 days.
Sampling procedures
Mammary gland secret was collected daily over the expected last ten days of gesta-tion. Samples were milked into clean plastic vials and immedialy was frozen and kept at -18°C until assayed.
Calcium assays
Calcium was measured by atomic absorbent spectrofotometry using a Perkin Elmer 306 and 1100.
RESULTS AND DISCUSION
All mares delivered spontaneously and the resulting foals were full term and normal. Table 1 shows calcium content in prefoaling mammary secretion.
Tab 1. Descriptive statistics for, prefoaling mammary secretion of calcium (mg/l-1)
Student t test a-a, a-b P<0.05
a-c, P<0.001
From our study we can clearly demontrate increas udder secretions calcium content.
Approximately a day before the parturition in 77% of mares calcium contents was over 6 mg/l. Fifty four percent of mares had the level of over 7 mg/l and over 8 mg/l was in 39% of mares. Minimum calcium concentration on the day of the parturition was 8.2 mg/l but the day before only 2.3 mg/l. The result is that the highest increasing of calcium in milk secret occurred in the last hours before the parturition. The practical use of determination will be in introducing a simple stable examination although the forecast of the expected parturition is uncertain. Examination of calcium contents in milk secret together with other phenomena of the approaching parturition in the evening hours can help the stable personnel to eliminate parturition during the following night, which corresponds to the conclusions of the authors OUSEY, DERCLAUX and ROSSDALE /1989/.
REFERENCES
1. CASH, R.S.G.; OUSEY, J.C.; ROSSDALE, P.D.: Rapid strip test method to assist management of foaling mares. Equine Vet. J. 17, 1985,: 61-62.
2. COWIE, A.T.; FORSYTH, I.A.; HART, I.: Hormonal control of lactation. Monogr. Endocr. 15, 1980,: 146-165.
3. OUSEY, J.C.; DELCLAUX, M.; ROSSDALE, P.D.: Evaluation of thre Strip tests for measuring electrolytes in mares' pre-partum mammary secretions and for predicting parturition. Equine Vet. J. 21, 1989,: 196-200.