Results and evaluation of thirty years of health recordings in the Norwegian dairy cattle population.

The results are based on the Norwegian Cattle Health Recording System, which has been in place for the entire country since 1975. The dairy breeds in Norway consist of 94% Norwegian Red and 4% crossbreeds with Norwegian Red. No other breed consists of more than 0.5% of the total population. During the past 30 yr, there have been 11,563,692 dairy cows within the recording system, corresponding to 8,633,532 cow-years and 8,632,516 calvings. This population consisted of 3,038,675 first-calving cows. Altogether, 8,435,704 different diagnoses were recorded from 4,444,485 different cows each year. The general trend for all recordings was an increase in the incidence rate of all cases from 0.74 per 365 d at risk (cow-year) in 1976 to 1.36 in 1990, and then a decrease to 0.62 in 2002. The corresponding figures for cows treated per cow-year were 0.44 up to a maximum of 0.82, and then a decrease to 0.46 per cow-year in 2002. The most common diseases were acute (severe to moderate) clinical mastitis, chronic (mild) clinical mastitis, ketosis, milk fever, teat injuries, retained placenta, silent heat or anestrous, indigestion, cystic ovaries, and metritis. Clinical mastitis increased from 0.15 cows treated per cow-year in 1975 to 0.44 in 1994, and then decreased to 0.23 in 2002. Ketosis began at 0.10 in 1975, increased to 0.24 in 1985, and then decreased to 0.05 in 2005. For several of the most common diseases, there was a reduction of more than 50% from the 1990s to the years after 2000. Validation processes confirmed that this fluctuation reflected the general trend in the population. The disease recording system also reflected the known outbreaks of bovine respiratory syncytial virus during 1976, 1989 to 1990, and 1995. A marked increase in malformation diagnoses could be seen in 1986 and in 1989 and 1990. These could be related to the Chernobyl nuclear power plant accident in April 1986. The diagnosis that showed the most stability throughout these 30 yr was retained placenta. The 3 main reasons for the large fluctuation for many of the diseases could be the following: a breeding effect, an effect of preventive work, and an effect of changing the therapeutic attitude. Many of the actions taken to bring about improvements would not have been possible without a functioning and practical recording system. Our experience is that an organ-related diagnosis system with up to 60 or 70 different diagnoses will meet the needs of the dairy industry.

A sperm midpiece defect in a Hereford bull with variable semen quality and freezability.

A midpiece sperm defect with a frequency of 25-35% in ejaculates obtained from a Hereford bull with a 60 d non-return rate of 76.4% after careful pre- and post-freeze semen selection was studied in light microscope and by transmission electron microscopy. The defect consisted in a folding and coiling of the distal midpiece characterized by disorganization and irregularity of mitochondria surrounding the axial fiber bundle, combined with retraction of doublet fibers and dislocation and fracturing of these elements and the corresponding dense fibers. Based on examination of the spermatogenic epithelium it was concluded that the alterations in the axial fiber bundle were secondary to those in the mitochondrial sheath. The abnormality appeared to be related to the "Dag-like" defect earlier observed in different breeds.

[Opiate-related deaths among drug addicts. Autopsy findings, circumstances and forensic toxicologic analyses regarding deaths]. / Opiatrelaterte dødsfall hos stoffmisbrukere. Obduksjonsfunn, omstendigheter og rettstoksikologiske analyser ved dødsfallene.

The study is based on autopsies of 86 drug addicts who died during the period 1986-88 after an opiate ingestion. The average postmortal concentration of morphine after ingestion of heroin was 0.88 mumol/l blood, ranging from 0.0 to 3.1 mumol/l, which is substantially lower than values that have been reported from patients receiving morphine intravenously as an analgetic. Postmortal blood concentrations of morphine were significantly lower among deceased with only fresh needle marks than among deceased with both old and fresh needle marks, suggesting that a pause in the drug abuse may have led to a decrease in opiate tolerance. There was no relationship between the detected organ pathology finding of other ingested substances and the postmortal concentration of morphine. In 20% (n = 17) of the deceased the HIV-antibody test was positive and the average blood concentration of morphine was higher in this sub-population than in the rest of the cases.

Semen production in artificial insemination bulls in Norway.

Semen production data from 792 Norwegian Red AI bulls, of 46 sires, were analyzed. Semen production was affected by AI center, year and season of collection, number of months the bull had been collected, and sire (each P < 0.01). Heritability for produced accepted doses was estimated to be 0.34 (+/-0.13). This should allow a successful phenotypic selection for this trait. A negative correlation between number of accepted and number of discarded doses (-0.82+/-0.11) was found. Selection based on number of accepted doses per bull will therefore result in improvement of semen quality.

[Repeated freezing of bull semen (author's transl)]. / Dobbeltfrysing av oksesaed.

Repeated freeze-thaw cycles have been used as a mean to predict the viability and fertility of bull semen. In order to investigate the level of fertility of bull semen that has been frozen, thawed and refrozen again, two split sample field trials were performed. 25 bulls were used in the trial, and inseminations were performed by 30 technicians. The semen was diluted to 27 million spermatozoas per dose in a skimmilk-fructose extender, and filled in the french mini-straw. The straws were coded by use of a batch number system. The one half of the straws was fixed to the freezing rampes. After freezing and transfering of the rampes to liquid nitrogen, the rampes were placed in a water-bath at + 35 degree C in 7 seconds. Immediately after thawing the straws they were transferred to a refrigidaire room at + 5 degree C, dried, remounted on the rampes and frozen again in the ordinary way. The other half of the straws were frozen according to the normal routine. The semen from the two treatments were distributed in equal numbers to the technicians who were not informed of the trial. The motility after refreezing had decreased and the percentage of intravital eosin spermatozoas after refreezing increased by 23, as an average. Fertility results were estimated as 60 days non returns after 1st inseminations. Single frozen semen: 1488 1st ins. 493 ret. 66,86 N.r.-% Refrozen semen: 1511 1st ins. 500 ret. 65,30 N.R.-% The trials indicate that further investigation should be performed to see if semen might be frozen concentrated, rediluted after thawing and refrozen for distribution to the technicians.

The occurrence of a "SME"-defect-like abnormality in the head of spermatozoa from a Norwegian Landrace boar.

A spermhead-defect appearing in 15-20 per cent of the spermatozoa from a Norwegian Landrace boar with a slightly impaired fertility was studied in light and electron microscope. The defect had the shape of a circumferential, somewhat elevated area containing a cystic structure located within the nucleus. In some of the sections observed in electron microscope a communication could be found between the cyst and the acrosome, indicating that a deviating development of the latter could be involved in the formation of the defect. In some spermatozoa the occurrence of the cyst was combined with the presence of an apical defect of the acrosome. From ultrastructural studies of spermatids the development of the cystic defect was found to have reached a rather advanced stage early in the acrosome-phase of the spermateliosis. As a whole the observations correspond very well with those made in connection with the socalled "SME"-defect first found in a Danish Landrace boar.