[Impotentia coeundi and penile extension in steers]. / Impotentia coeundi en emissio penis bij stieren.

Penis extension (emissio penis) depends on the length of the penis and on the relaxation of the retractor muscle of the penis. When the relaxation is insufficient, penis extension is at its smallest just before intromission takes place. In severe cases this can lead to impotence (impotentia coeundi). Whether this occurs depends on the animal's libido and mating behaviour and on external factors. Genetic factors play a role in emissio penis.

Changes in the composition of cervical mucus of the cow during the estrous cycle as parameters for predicting potential fertility.

Four experiments were conducted to test the hypothesis that the composition of cervical mucus can be used as an indicator of reproductive efficiency in the cow. In Experiment 1, biochemical changes were studied in cervical mucus during the estrous cycle. Sorbitol concentration was observed to be highest at 1 to 3 days prior to estrus and lowest on Days 6 to 12 (P<0.001) of the estrous cycle. Cholesterol and protein concentrations were highest at Day 6 of the estrous cycle and lowest on the day of estrus (P<0.001). In Experiment 2, the relationships between the biochemical characteristics of cervical mucus and fertility were studied. It was shown that the embryo transfer recipients which exhibited a high concentration of sorbitol (>1.5 mMol/l) at 1 to 3 days before estrus; a low concentration of protein (< 2 units); and a low concentration of cholesterol (<0.1 mMol/l) on the day of estrus had a higher level of fertility than their counterparts. The predictive ability of these criteria was tested using embryo transfer recipients (n=294) in Experiment 3. Significantly more of the animals predicted to have high potential fertility became pregnant than those predicted to have low potential fertility (70.7 vs 45.6%; P<0.001). A similar difference in pregnancy rate for cows (n=56) presented for artificial insemination was observed in Experiment 4 (59.1 vs 27.2%; P<0.10). These results suggest that the composition of cervical mucus may be a useful indication of potential fertility in cattle.

[Blood titers of the bovine respiratory syncytial virus]. / Bloedtiter ten aanzien van het bovine respiratoire syncitiaal virus.

The variations in titre of the bovine respiratory syncytial virus were determined in young calves. As soon as maternal immunity was no longer detectable, the calves were inoculated. Inoculations in animals which were less than four months of age gave rise to only a slight increase in titres. The increases in titre in calves over this age varied markedly.

[Fertilization results of insemination with deep frozen sperm with various numbers of spermatozoa per dosage in Meuse-Rhine-Ijsel cattle]. / Bevruchtingsresultaten van inseminaties met diepvriessperma met verschillende aantallen spermatozoa per dosis bij het MRIJ-vee.

Four groups of cows, each group comprising from 5,000 to 5,500 animals, were inseminated with 7.5, 10, 15 and 20 millions of living and dead spermatozoa respectively. This was deep frozen semen in 0.25 ml straws. The fertilisation rates of the groups did not differ significantly, even when the fertility levels of the twenty-eight bulls involved were taken into account.

[Congenital flexure of the forelimbs in calves]. / Aangeboren kromme voorpoten bij kalveren.

The incidence of congenital multiple arthrogryposis in newborn calves during the period from September 1982 to September 1983 was studied by conducting a questionnaire on 2,204 dairy farms in the province of Overijssel. This entity was observed on 19 per cent of the farms with Meuse-Rhine-IJssel breed and on 12 per cent of those with the Friesian-Dutch or Friesian-Dutch/Dutch-Friesian breed of cattle. Bull-calves showing normal or heavy birth weights following a normal period of gestation were mainly affected. There was a considerable difference in incidence between sires.

[Progesterone in mare's milk: suitable for early pregnancy detection?]. / Progesteron in melk van merries: geschikt voor een vroege drachtigheidsbepaling.

The concentrations of progesterone in milk were determined in twenty-one mares to establish a diagnosis of pregnancy in an early stage (15-19 days). Progesterone levels varied from 0.0 to 4.2 ng/ml in nine non-pregnant mares and from 6.7 to 30.0 ng/ml in twelve pregnant mares. Progesterone levels were determined by an enzyme-linked immunosorbent assay (ELISA).

[Progesterone determination in milk]. / Progesteronbepaling in melk.

Samples of milk were taken every sixty minutes in ten cows for a period of ten hours to determine the concentrations of progesterone. The concentrations recorded were related to those in the strippings. All these samples furnished adequately reliable evidence of the presence of an active corpus luteum, with the possible exception of those taken during the last hours prior to milking in some cases.

[Improvement of fertility status in dairy farms by using the milk progesterone test]. / Verbetering van de fertiliteitsstatus op melkveebedrijven door toepassing van de melk-progesterontest.

On nine farms comprising a total number of 370 cows, studies were done for two years to determine whether the reproductive status (RS) could be improved by systematic performance of the milk progesterone test. Milk samples were taken on the day of insemination (day 0), day 8 and day 21 to verify oestrus detection, the observation of ovarian dysfunction and the early diagnosis of (non-)pregnancy. The RS on these nine farms increased from thirty-six to fifty-four, which was mainly due to the reduction of the number of inseminations required for each conception (from 2.1 to 1.7). On ten farms selected by a similar method, on which reproduction was supervised by the veterinary practitioner, the RS increased from forty-seven to fifty-five, which increase was particularly due to inseminations carried out sooner after calving. The RS of ten herds which served as controls, increased from forty-one to forty-seven. An analysis of costs showed that the costs using the progesterone test were estimated to be equivalent to the expense of supervising a reproductive dairy herd health programme. A diagnosis negative for pregnancy based on three milk samples tested was correct in 98 per cent of the cases. A diagnosis positive for pregnancy was correct in 90 per cent of the cases. When a death rate of 8 per cent of the embryos within three weeks after conception is taken into account, the proportion will also be 98 per cent. Summarizing, it is concluded that systematic performance of the milk progesterone test provides an attractive method of improving reproduction on those farms which do not take part in veterinary supervision of reproductive dairy herd health programmes.

[Inability to have erections in male swine (author's transl)]. / Impotentia erigendi bij de beer

There are three degrees of impotence or diminished ability to have an erection: (a) there is no erection at all; (b) erection only occurs prior to ejaculation; (c) there is a short-lived erection at the beginning of ejaculation and occasionally also during the final stage of ejaculation. There are differences of degree in erection, ranging from the absence of erection to normal erection. When abnormalities such as those referred to under (b) and (c) are observed in young male swine, the mating pattern may be restored to normal as time goes on.