Mineral content of hay harvested in Bavarian and Swiss horse farms. Predictive value of cutting time, number of cut, botanical composition, origin and fertilization.

Hay samples from 29 horse farms in Southern Upper Bavaria and 31 horse farms in Switzerland were taken and analysed for minerals such as calcium, magnesium, phosphorus and potassium. The content of herbs and legumes in the hay was determined and the Weende analysis was performed. Comparison between Bavaria and Switzerland resulted in comparable calcium contents of approximately 4 g Ca/kg dry matter (DM) in grass hay. Hay with more than 10% of herbs and legumes found only in Switzerland showed higher Ca contents of >7 g Ca/kg DM in hay. The mineral contents of phosphorus and potassium were lower in hay from Switzerland (P: 1.8 +/- 0.7 g/kg DM, K: 15.4 +/- 5.1 g/kg DM) than from Bavaria (P: 3.8 +/- 0.6 g/kg DM, K: 20.0 +/- 6.0 DM), whereas the magnesium content of the hay showed no difference between the regions ( approximately 1.5 g Mg/kg DM). Very late first grass hay cuts showed low magnesium and calcium (<4 g/kg DM) contents. Further minerals in the hay for horses differed from those in dairy cattle in the same region. Fertilization showed only small effects on the mineral contents of the hay produced for horses. Therefore, in calculation of ration and production of supplements for horses, these differences should be taken into account.

Judgement of hygienic quality of roughage in horse stables in Switzerland.

In 46 horse farms all over Switzerland, the hygienic quality of the roughage (including silages) was investigated. Therefore, a macroscopic examination as well as the microbial counts (bacteria, yeasts and moulds) was carried out. Further, the contents of lipopolysaccharides (LPS) and the contamination with deoxynivalenol (DON) were determined. In all roughages, the dry matter (DM) content was measured and in silages additionally the pH was measured. Predominantly, the straw showed a lower hygienic quality than hay and silages. The LPS contents were significantly higher in straw than those in hay samples. The macroscopic examination and the microbial counts showed a tendency in the same direction. Eight straw samples and one hay sample with DON contamination were found. The silages showed a DM content with a median of 65.8%. The pH of those silages was between 4.3 and 5.9. Despite the high values of DM and pH, the silages showed mainly a high hygienic quality. In total, the hygienic standard of straw was worse than that of hay. This should be taken into account also in straw used as bedding as much as the hygienic quality of hay.

[Nutrient content and adequacy of roughage for horse nutrition: an investigation under Swiss conditions]. / Nährstoffgehalte und Eignung des Grundfutters zur Pferdefütterung: Eine Erhebung unter schweizerischen Bedingungen.

For horses no special tables related to nutrients for Swiss roughage exist. For this reason samples of hay, straw, silage/haylage and green forage were taken from 46 horse keeping farms in 22 cantons. The samples were judged by sense and following the nutrient--and macromineral--content as well as the content of fructans were analysed. Regarding its quality no sample was totally inadequate for horses. The mean contents of crude protein in Swiss hay for horses were clearly lower than in hay for ruminants and in German hay for horses. The mineral contents (calcium, magnesium, phosphorus) showed a wide range. On average they were also lower than the values provided in tables for ruminants. Except for one sample the silages/haylages showed a dry matter content of more than 40 %. No nutrient tables for silage or haylage, which are such high in dry matter contents, were found in the literature. The contents offructans in silage/haylage and green forage also showed a wide range with a maximum of 94 g/kg DM fructan.