[Induced preovulatory discharge of LH during the seasonal anoestrus of the goat (author's transl)]. / La décharge préovulatoire de LH induite chez la Chèvre en période d'anoestrus saisonnier.

Preovulatory LH surges were induced and synchronized in 12 Alpine goats during the anoestrus season using a progestagen-PMSG treatment. Onsets of oestrus, plasma LH levels and numbers of ovulations were recorded. During the preovulatory surge, frequencies of blood sampling were such (1 per hour in 8 goats and 1 each 4 min. in 4 other goats) as to allow for the first time a precise description of this biological event in the goat. Results may be summarized as follows: (1) Plasma LH levels were low (less than 1 ng/ml) and constant during the hours preceding the surge, (2) the onset of LH surge preceded by 2 hrs, on the average, that of oestrus behaviour, (3) preovulatory surges presented a definite pulsatility when maximum levels were reached, (4) no positive relationship was found between the magnitude of the surge and the corresponding number of ovulation, (5) in two animals, the LH surge was definitely biphasic, each peak presenting serveral pulses of secretion.

[Role of seminal plasma in the in vitro survival of goat sperm]. / Rôle du plasma séminal dans la survie in vitro des spermatozoïdes de bouc.

The in vitro survival of ejaculated and epididymal goat sperm was measured in a milk diluent while being incubated at + 37 degrees C and after having been exposed to seminal plasma or to its components. Non-breeding season seminal plasma had a negative effect on sperm survival whether the cells were cooled to + 20 degrees C, chilled to + 4 degrees C or deep-frozen (- 196 degrees C) before being incubated at + 37 degrees C. Bulbo-urethral gland secretions also had a deleterious effect on the survival of washed ejaculated and epididymal sperm cooled to + 20 degrees C. The deleterious effect of the bulbo-urethral secretions on sperm survival and motility was significantly inhibited by the vesicular secretions. Non-breeding season seminal plasma contained bulbo-urethral but little or no vesicular secretions. The non-inhibition of their negative effect(s) may explain that of non-breeding season seminal plasma. Breeding season and non-breeding season washed ejaculated sperm had a better survival and a better motility than those incubated with breeding season seminal plasma. The mild washing procedure used may be responsible for the incomplete removal of seminal plasma from the sperm environment, namely that of the negative factors of the bulbo-urethral secretions. Breeding season seminal plasma would thus simply inhibit the effect of these negative factors or the factors themselves. This hypothesis is supported by the fact that breeding season seminal plasma had no effect on the survival of epididymal sperm.

[Effects of seminal plasma on the survival and fertility of spermatozoa kept in vitro]. / Effets du plasma séminal sur la survie et la fertilité des spermatozoïdes conservés in vitro.

In sperm cell populations kept in vitro, the profiles of motile cell number and motility are always influenced by the seminal plasma. The non-epididymal fraction of the seminal plasma first enhanced and then depressed bull, ram and goat sperm motility or immediately depressed that of horses and rabbits. The secretions of Cowper's gland (male goat) or of the seminal vesicles (boar) were implicated in the depressive effect of the non-epididymal plasma fraction on the maintenance of sperm motility. These secretions were responsible for variations in motility correlated with variations in sperm fertility. The level and significance of these correlations indicated that the seminal plasma might be involved in sperm fertility, perhaps owing to a type A lecithinase secreted by Cowper's gland (bull, ram and male goat) or by a protein of vesicular origin (boar).