Silage or hay: does feeding regime affect health related traits of primiparous dairy cows?

Summary

In this study, we aimed to assess health related traits of first lactating cows that were kept in farms, mostly organic or low-input, with or without silage feeding of heifers in Austria (AT; 392 farms, 10,736 Fleckvieh), France (FR; 20 farms, 2,360 Holstein and Montbéliarde), Germany (DE; 34 farms, 1,566 Brown Swiss and Fleckvieh) and Slovenia (SI; 18 farms, 1269 Brown Swiss, Fleckvieh, Holstein and crosses). Cows calved between 2010 and 2019. Data originated from routine performance recording and on-site data collection. As data structure differed, analyses were performed within country. Traits analysed using the logistic regression methodology were the percentage of elevated cell counts (>100,000 cells/ml; SCC100P) during the cow’s 305-day standard lactation, fat-protein-ratio (FPR), defined as binary trait whether it was or was not >1.4 or <1.1 at least once during the cow’s first 120 days in milk, and mastitis, metabolic and fertility disorders. SCC100P was higher in DE silage feeding farms. In AT no differences were found, while in FR and SI results significantly differed between breeds. In AT and DE silage feeding farms, FPR>1.4 during the first 120 days in milk was higher, while no significant differences between feeding regimes were found in FR and SI. However, FPR<1.1 was significantly lower in AT silage feeding farms; no differences were found in the other countries. Disease frequencies were generally low; no significant differences could be found between silage and non-silage feeding farms in any of the countries involved. The rearing and feeding regime of replacement stock is complex and influenced by numerous factors. Differences between countries with regard to geographical location and management could have led to the partly contradicting results.