title: [Activities of the enzymes LDH, gamma-GT, GOT, GPT and lactoperoxidase in the milk of breeding mares during the course of lactation].
abstract: Milk samples were collected from 44 mares (trotters, warm blood horses, quarter horses) during lactation between the 1st and 90th day p.p. at 20 defined days. The activity of the enzymes LDH, gamma-GT, GOT, GPT and lactoperoxidase was investigated. The aim of this study was to find out the changes of these parameters during lactation and whether an influence of race, conception, date of foaling, age and number of lactations existed on the enzyme activities in mare's milk. The following results were obtained: In mare's milk the LDH-activity was highest (xg = 629 x 1.5 +/- 1 U/l) on the 1st day p.p. and showed a marked decrease on the 3rd day p.p. followed by a slight decrease until the 20th day p.p. It remained then at a constant level of about 80 U/l. The lowest activity (xg = 65.2 x 1.51 +/- 1 U/l) was measured on the 76th day p.p. The influence of conception and date of foaling time were statistically significant. The gamma-GT-activity was highest on the 3rd day p.p. (xg = 143.4 x 1.45 +/- 1 U/L) and decreased during lactation. The lowest activity was measured on the 90th day p.p. (xg = 23.2 x 1.51 +/- 1 U/L). The influence of race and conception--time were statistically significant. The GOT-activity of the 1st day p.p. (xg = 38.3 x 1.77 +/- 1 U/L) was higher than in mature milk. After the 3rd day p.p. activities between 15.5 x 1.38 +/- 1 U/l and 11.9 x 1.38 +/- 1 U/L were measured. The GPT-activity was highest on the 1st day p.p. (xg = 37.5 x 1.81 +/- 1 U/L) and decreased on the following days. After the 9th day p.p. activities between 9.1 x 1.37 +/- 1 U/l and 8.5 x 1.32 +/- 1 U/l were found. The influence of age, race, race (time, date of foaling (time and conception (time were significant. No Lactoperoxidase activity could be found in mare's milk. The origin and importance of the mare's milk enzymes are discussed.
authors.affiliation: Institut für Anatomie, Physiologie und Hygiene, Haustiere der Universität Bonn.
authors.forename: E
authors.initials: E
authors.lastname: Rieland
authors.forename: A
authors.initials: A
authors.lastname: Hatzipanagiotou
authors.forename: S
authors.initials: S
authors.lastname: Jahnecke
authors.forename: H
authors.initials: H
authors.lastname: Enbergs
mesh_terms: D000410:Alanine Transaminase / Q000378:metabolism; D000818:Animals; D001219:Aspartate Aminotransferases / Q000378:metabolism; D005260:Female; D006736:Horses; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007774:Lactation / Q000502:physiology*; D007784:Lactoperoxidase / Q000378:metabolism; D008892:Milk / Q000201:enzymology*; D013997:Time Factors; D005723:gamma-Glutamyltransferase / Q000378:metabolism
chemical_list: D007770:L-Lactate Dehydrogenase; D007784:Lactoperoxidase; D005723:gamma-Glutamyltransferase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase