Effect of keeping system on fertility and milk production in small dairy farms (<100 cows) in Switzerland and a large scale dairy farm (>500 cows) in Hungary

Due to the higher milk yield and thus shorter estrus and lower fertility, the heat of the Hungarian Holstein cow is more difficult to detect and needs a higher amount of AI/ pregnancy as the Swiss dairy cows. Contributing to the higher number is also the heat management/detection itself, which could be optimized. Also does the Hungarian feeding system (Total Mixed Ration) compared to the Swiss feeding system (Partly Mixed Ration plus individual concentrate adaption) contribute to the negative energy balance of some dairy cows of the herd, especially the high yielding ones of the production group. The food quality/ adequate supply are important factors to contribute to good fertility. Management could be optimized in these 2 branches to get a shorter inter-calving intervals and a higher fertility over all. The influence of the herd size is also negative correlated to the length/ strength of the estrus. What makes the heat detection even more difficult as it already is in large herds. Also the still occurring diseases (like BVD, IBR, Leptospira, Ketosis, Metritis…) may play a not to underestimate role in low fertility. Eradication and vaccination programs should be enhanced for that. Also should one emphasis in general a good herd health, and enhance general hygiene and individual animal health