Changes in some blood indices during copulation in the boar.

Klumbies & Kleinsorge (1950) and Fox & Fox (1969) recorded blood pressure, heart rate and respiratory changes during ejaculation elicited by masturbation and natural coitus. Jakubowski (1966) reported that a rise in the heart rate occurred and Wierzcho\l=s'\(1970) observed a rise in blood pressure, heart rate and respiratory rate during copulation in the boar. According to W\l=o'\jcik(1969), the blood in copulating rams contains substances which induce incomplete contractions of the isolated vas deferens. Gudat & Schnell (1970) found that the levels of erythrocytes, leucocytes, haemoglobin, plasma glucose and transaminases, GOT and GPT, were higher in boars immediately after copulation than before it. Changes in the blood constituents of the male during copulation do not, however, appear to have been described until now. Since copulation in the boar is a relatively prolonged process, it affords favourable conditions for studying such changes. Observations were carried out on four Polish Large White boars of 150 to 200 kg body weight. Semen was collected by manual technique using a dummy sow. The time and course of the successive fractions of ejaculate were noted. Ejaculates followed by control blood samples were collected for 4 consecutive days from each boar. Blood samples (2 to 3 ml) obtained from the coccygeal artery after tail-lopping were collected into tubes containing heparin or ammonium oxalate. According to Spincer, Rook & Towers (1969), in sows the levels of constituents in the arterial blood and in the blood collected from the tail are similar. Four to six blood samples were collected in the stall and then the boar was introduced to the dummy. Blood was collected continuously throughout the period of sexual excitement and copulation and for 5 to 7 min after ejaculation. Further samples were collected thereafter every 2 to 4 min. The total blood loss during each copulation did not exceed 100 ml. For control estimations, blood was collected in the stall for a period similar to that of the semen collection. The heparinized blood was used for filling the haematocrit capillary and for preparing the basic dilution to determine the leucocyte count. Plasma glucose was estimated with glucose oxidase and peroxidase (Bergmeyer & Bernt, 1962), and the concentration of lactic acid in the blood samples was measured by the method of Barker & Summerson (1941). Blood and plasma sodium and blood potassium were determined by flame photometric analysis. Leucocytes were counted in Celloscope 101, AB Lars Ljungberg and Co., Sweden.