[Death of pregnant heifers at a dairy farm due to fatty liver disease]. / Sterfte van drachtige pinken op een melkveebedrijf door leververvetting.

Fatty liver disease usually occurs in periparturient dairy cows. However, this case study describes the occurrence of the disease in maiden heifers on a dairy farm during late gestation. It resulted in the death of 5 heifers (21-25 months of age) within 31 days after turning them out to grass. The diagnosis was confirmed by blood testing and gross pathology findings. Housing the animals and providing them with good quality grass silage prevented further clinical cases.

Relationships between fatty liver and fertility and some periparturient diseases in commercial Dutch dairy herds.

Declining fertility in dairy cows is frequently suggested to arise from the occurrence of a more negative energy balance and/or the concomitant increased accumulation of triacylglycerol in the liver. Therefore, we performed a field study to assess the clinical effects of postpartum fatty liver in dairy cows on fertility and reproductive disease. Data were collected from 360 cows from nine dairy herds on fertility, diseases, and the liver triacylglycerol content on two occasions during lactation: 6 to 17 days and 38 to 50 days postpartum. The mean concentration of triacylglycerol in the liver was 54.6 mg/g from 6 to 17 days and 38.4 mg/g from 38 to 50 days postpartum. The probability of pregnancy was 30% lower for cows with higher contents of triacylglycerol in the liver compared to the probability for cows with low liver triacylglycerol (P = 0.049). The probability of estrus was also 35% lower for the cows with high triacylglycerol in the liver. This resulted in larger intervals between parturition and first heat and parturition and pregnancy for these cows. There was no effect observed on the first insemination conception rate. Given a certain level of triacylglycerol, recorded milk production had a positive effect on time to pregnancy. The incidences of endometritis, lochiometra and cystic ovarian follicles were not higher in cows with higher liver triacylglycerol contents. Endometritis was associated with a lower first insemination conception rate and more days open (chi2 = 4.26, P = 0.03 and T-test = -2.02, P= 0.04 respectively). We concluded that our results support the idea that differences in the negative energy balance or the accumulation of triacylglycerol in the liver of postpartum dairy cows affect fertility performance. The data also indicate that an increase in milk production has no negative impact on fertility as long as the amount of triacylglycerol in the liver remains the same.

[An overview of fertility statistics and milk production data of 15 dairy operations in southeast Friesland]. / Een overzicht van vruchtbaarheidskengetallen en melkproductiegegevens van 15 melkveebedrijven in zuidoost-Friesland.

In 1988 the collection of data on fertility and milk production was initiated by the veterinary practice in Oosterwolde in the context of a veterinary herd health programme. An automated management and production control programme, VAMPP, was used for this purpose. Although it is not possible to give the precise effect of veterinary herd health programmes on technical farm results, because a control group is lacking, it is possible to discern trends in data collected over 10 years. The field data, show that the first insemination pregnancy rate decreased by 10.1%, from 55.5% to 45.4% (p = 0.002). The number of cows showing first heat decreased by 1.3% (p = 0.46) between 0-15 days post partum, 2.6% (p = 0.41) between 15-30 days post partum, by 4.9% (p = 0.07) between 30-50 days post partum and by 11.4% (p = 0.008) between 50-70 days post partum. In the same period, the milk production increased from 7558 kg 4% fat corrected milk in 305 days to 8744 kg (p = 0.0004). These data may be useful for veterinarians working in veterinary herd health on dairy farms. Furthermore, the described trends and especially the discussed differences between farms may be a stimulus for both farmers and veterinarians to continue with herd health programmes.

[Veterinary supervision of dairy facilities in the Netherlands: what do veterinarians think about participating and non-participating cattle owners?]. / Veterinaire begeleiding van melkveebedrijven in nederland: hoe denkt de dierenarts over deelnemende en niet-deelnemende veehouders?

Dairy herd health and production management programmes are being used increasingly more often, also in the Netherlands. However, little is known about the rationale behind the farmers' decision to participate or not to participate. This paper reports the results of a questionnaire survey among cattle practitioners about why they thought farmers did or did not participate in these programmes, the perceived advantages and disadvantages of such programmes, the extent to which the respective farming areas were represented in the programmes, and the reasons why farmers stopped participation in the programme. Furthermore, the ways in which the practitioners try to convince the non-participating farmers to join the programme were addressed. The future of dairy herd health programmes in the context of quality assurance programmes and the way the farmers think about these developments were discussed by the practitioners.

[The setting up of an integrated veterinary business approach in dairying]. / Het opzetten van geïntegreerde veterinaire bedrijfsbegeleiding bij melkveebedrijven.

In addition to the continuous provision of veterinary care, another important aspect of a veterinarian's work is his or her advisory function in farm management. Too few veterinarians fulfil this function. This can only be done successfully if the dairy farmer and veterinarian solve a number of problems. An integrated management plan incorporation a step-by-step approach should make this possible.

[Production management on dairy farms: the road to the future]. / Bedrijfsbegeleiding op melkveebedrijven: de weg naar de toekomst.

In this paper the developments in the field of bovine herd health and production management are illustrated. The current use of herd health and production management methods in veterinary practices are illustrated, and a uniform concept for execution of herd health and production management programs is given. The expected future developments and the critical points in these developments are discussed. The changing role of the veterinarian in bovine practice with the application of herd health is outlined.

[Determination of the excretion time of oxytetracycline and lugol in milk of intrauterine treated cows]. / Bepaling van de uitscheidingsduur van oxytetracycline en lugol in de melk van intra-uterien behandelde koeien.

Sixteen dairy cows with chronic puerperal endometritis between 3 and 8 weeks post partum were treated with intra-uterine applied oxytetracycline (OTC) and lugol. OTC was rapidly removed from plasma and was not detectable after 48 hours. The concentration of OTC in milk did not exceed 40 micrograms/kg, and it was still detectable in milk 34 hours after treatment. The concentration of OTC in milk was always lower than the limit of 50 micrograms/kg used by milk-testing stations and the European limit (MRL) of 100 micrograms/kg. Milk from cows treated with lugol did not cause inhibition in the plate test.