A 7-Year Survey on corn silage nutrient composition in Po Valley (Italy)

Corn is the primary crop in the plain of Northern Italy, a region characterized by intensive cropping and dairy farming activities. In particular corn silage is predominantly used as a base ingredient in dairy farms. Thus, monitoring the variability in the nutrient content of this primary ingredient is mandatory to meet animal requirements. Typically, drought-stressed corn silage is lower in energy overall (from 80–90% of a normal crop); 2022 was the hottest, driest year in Italy. Accordingly, the objective of this paper is to bring to light a significant volume of data on corn silage nutritional composition in Northern Italy. The Regional Breeders Association of Lombardy has been conducting a survey program to monitor corn silage nutritional composition over the last seven years (2017-2023). Nutritional composition was determined by NIRs while dry matter was also determined by oven drying. Mean values recorded over the experimental survey period were dry matter 34.6%, neutral detergent fibre (NDF) 45%, acid detergent fibre (ADF) 26.2%, acid detergent lignin (ADL) 2.7%, starch 29.1%, crude protein 7.3%, crude fat 2.4%, ash 3.9%, and forage unit (UF q.le) 29.6. Average values observed for nutritional composition were in line with literature results. However, considering the starch content, lower values were observed for the 2022 silage crop, furtherly numerous samples were below the 2nd quartile, indicating numerous samples with reduced content in starch. Concluding the present survey study provided information on the major effects of drought-stressed corn silage with a focus on a dairy dedicated area.