Testosterone plasma profiles, as a function of age in young bulls from the bovine double-muscled Belgian White Blue breed

Poster (1982)

Biochemical and immunological studies on the Bovine Leukemia Virus (BLV).

in Yohn, D.; Blakeslee, J. (Eds.) Advances in Comparative Leukemia Research 1981 (1982)

Testostérone (T), Hormone lutéinisante (LH), prolactine (P) et hormone de croissance (GH) chez les bovins de race Blanc Bleu Belge soumis au performance test

in Bulletin des Recherches Agronomiques de Gembloux (1982), 17

A bovine thymic lymphosarcoma case showing a negative serological response to bovine leukemia virus antigens, in a herd with high incidence of enzootic bovine leukosis.

in Zentralblatt für Veterinarmedizin. Reihe B = Journal of Veterinary Medicine. Series B (1981), 28

Mesure de profils nycthéméraux de prolactine et d'hormone de croissance chez le bovin mâle Blanc Bleu Blege et Pie Noire, âgés de 3 à 10 mois

in Bulletin des Recherches Agronomiques de Gembloux (1981), 16

Detection by immunodiffusion tests and radioimmunoassay of antibodies to bovine leukemia virus antigens in sera of experimentally infected sheep and cattle.

in Markson, L. M. (Ed.) CEC Scientific workshop on bovine leucosis (1980)

Genomic integration of bovine leukemia provirus and lack of viral RNA expression in the target cells of cattle with different responses to BLV infection.

in Leukemia Research (1980), 4

Fertilite male chez les bovins et taux sanguin d'hormone luteinisante et de testosterone.

in Bulletin des Recherches Agronomiques de Gembloux (1980), 15(4), 333-348

We determined blood plasma testosterone (T) values in bulls from the Friesian (N) and the Belgian White Blue (BBB) breeds, between 1 and 12 months of age. The BBB breed is divided into 2 sub-breeds: one ... [more ▼]

We determined blood plasma testosterone (T) values in bulls from the Friesian (N) and the Belgian White Blue (BBB) breeds, between 1 and 12 months of age. The BBB breed is divided into 2 sub-breeds: one is highly specialized for meat production (BBB-V); the other has mixed zootechnic characteristics (BBB-M). The results obtained show that T values in PN are significantly higher than in BBB-V, for at least, the first 5 months of life. In a second experiment, we followed T profiles for 12 or 24 hours in PN, BBB-M and BBB-V bulls. Every 20 minutes, blood was withdrawn from the jugular vein through a catheter, in order to minimized stress. Data observes are as follows: (1) Luteinizing hormone (LH) plasma levels are comparable in all animals at 130 and 180 days. From then on, average LH values slightly decreased in BBB-V whilst they increase in PN. As early as 130 days, LH secretion shows successive pulses in BBB-V, a similar pulsatile profile appearing later on in PN. (2) Average T values are significantly higher in PN and BBB-M than in BBB-V. T profiles are flat but of increasing average level up to 140 days in PN and 170 days in BBB-V. Thereafter, pulses develop. (3) 24 hour profiles show no influence of daylight upon LH or T parameters. (4) T peaks follow LH peaks by a delay of 60 to 100 minutes. (5) Frequency and amplitude of LH and T peaks differ, on the same day, among two monozygous twins. A third experiment showed that LH and T profiles were similar in two adult BBB-V bulls with significantly different fertility grades. We hypothesize that the delay of sexual maturing frequently observed in sub-breeds highly selected for meat production (BBB-V, for exemple) is related to the delay shown by animals of these breeds to develop T pulsatile profiles with peaks of adequate frequency and amplitude. [less ▲]

Large scale serological detection in Belgium of enzootic bovine leucosis.

in Zentralblatt für Veterinarmedizin. Reihe B = Journal of Veterinary Medicine. Series B (1978), 25

Detection of complement-dependent lytic antibodies in sera from bovine leukemia virus-infected animals.

in Annales de Recherches Vétérinaires = Annals of Veterinary Research (1978), 9(4), 667-674