Norway spruce is a wide-spread food resource and its utilisable biomass exceeds the needs of herbivores. Needles seem to be a generally ignored food component in temperate forests that is consumed only when there are no better food sources. It is used especially during winters with deep snow cover. The aim of this study was to test presumption of needles as nutritive poor component of ungulate diets through botanical diet analyses and chemical nutrition estimation (content of crude protein and metabolizable energy volume in faeces) and elaborate the calibration curve on indirect estimation of quality food resources for ungulates in environment (NIRS needle content in faeces). High content of spruce needles corresponded well with a low quality winter diet of wild ungulates and may reflect animal nutritional constraints. As a consequence, the content of spruce needles may be used as an easy index of animal performance in a particular environment in forested area with coniferous forests in temperate zone. Needle content can be determined from the faeces by near infrared spectrophotometer and this easy technique can be recommended as indicator of the food resources quality for ungulates.
An experiment was conducted to monitor the effect of the length of environmental exposure of faeces on the content of nitrogen and diaminopimelic acid. We used samples of the droppings of wild red deer and examined them for the content of N and DAPA upon exposure to field conditions for 0–7 days during the growing season and for 0–30 days in winter, and after a year of storage in dried and frozen state. In relation to nitrogen level, there were no differences between the samples of fresh droppings and those after different lengths of exposure to ambient conditions before analysis and no differences between fresh and stored samples. As to DAPA level, there were no differences between the samples of fresh droppings and those after exposure. Nitrogen and DAPA levels in the droppings were stable and can be measured in both fresh samples and samples that have been exposed to ambient conditions for one week in summer or one month in winter.