Swiss College of Agriculture, Zollikofen

Project Opti-Milk: Cows health and fertility

With a contribution of 30 – 50 %, fertility problems and mammary infections are the major cause for the preliminary elimination of cows in dairy production worldwide. Fertility and health therefore also were important indicators to compare the high yield (HL) and the full grazing (VW) strategy in the Opti-Milk project. For both strategies, no drastic decrease of the body condition score was observed during the first 100 das of the lactation. No serious fluctuations were detected and most animals reached their initial state towards the end of the lactation, at the latest. Most VW farms realised calving intervals well below 400 days in the second year after the introduction of the new strategy. Mean annual veterinary costs were lower for the VW farms than for the HL farms and for both strategies they were higher in 2001 (HL 216.6 CHF, VW 141.1 CHF) than in 2002 (HL 222.1 CHF, VW 128.9 CHF). Per kilogram of milk produced, they were 2.1 – 3.0 Swiss cents for both strategies. For both strategies fertility problems and mammary infections were the major cause for the preliminary elimination of cows. The project results demonstrate that as far as animal health and fertility are concerned, comparable results can be attained by both strategies. They clearly contradict the claim that the full grazing strategy with seasonal calving is not possible in Switzerland for animal health reasons.

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