## 1 Introduction  
Whole-plant corn silage (WPCS) is typically harvested and chopped from the end of milk ripening to the early wax ripening stage, packed into the cellar layer by layer, suppressed, and sealed. WPCS has become a key component in dairy cow diets worldwide [1] because of its high fiber digestibility [2] and nutritional value [3]. The high adoption of WPCS can improve the economic utilization of crops and effectively solve the problem of balanced feed supply in spring and winter in northern regions [4]. At the same time, it optimizes the feed structure for large-scale livestock farms, reduces costs, and increases efficiency in healthy livestock farming. A major challenge for dairy and corn farmers today is the need to produce larger quantities of WPCS to meet the nutritional demands of high-yielding cows [5]. However, variations in fermentation processes and preservation conditions can lead to significant differences in silage flavor. The formation of unique odors in silage is believed to result from the dynamic relationship between different microorganisms, which influence the metabolic pathways that lead to the accumulation of small molecules [6]. For example, corn stalk silage with Lactobacillus brucei added has a reduced butyric acid taste, a fresh fruit aroma, and a high-quality green fruit color [7]. [PERSON] et al. found that sweet sorghum silage, rich in starch, protein, fat, and tannins, enhances the flavor of fragrant wine, producing an ethyl acetate aroma and increasing the ethanol content through anaerobic fermentation by brewing yeast [8]. Meanwhile, different microbial populations and contamination by exogenous pathogenic bacteria can lead to variations in silage quality, including differences in flavor compounds [9]. [PERSON] et al. discovered that the outer surface of the bale that comes into contact with air has a higher probability of emitting pungent moldy odors in haylage [10]. Silage fermented predominantly by anaerobic spoilage bacteria, such as Butyricicoccus species, can decompose proteins to produce ammonia or amines, resulting in unpleasant odors [6]. This demonstrates that VOCs are formed through interactions between microbial populations or non-biochemical processes. We found that, among various animal management factors, diet is considered to be the most important and sensitive factor influencing the flavor of milk and dairy products [11]. There are three primary ways in which raw milk flavor compounds are synthesized. Firstly, flavor compounds in the diet can be directly absorbed through the digestive tract, enter the bloodstream, and reach peripheral tissues (such as the mammary glands) [12]. Secondly, nutrients such as carbohydrates, fats, and proteins in the diet can influence the formation of flavor substances in milk through rumen metabolism [13]. Some studies have highlighted the potential for direct transfer of compounds from the diet to raw milk. An important finding was that the flavor intensity of cheeses made from milk of indoor green-fed cows was more similar to that of cheeses made from milk of cows fed conserved forage rather than that of cheeses made from milk of cows that graze on pasture [14]. Often, artisanal hard and semi-hard cheese producers often avoid milk from silage-fed farms to prevent late swelling and off-flavors during ripening, which can occur if butyric acid bacteria spores from silage are present [15]. VOCs may be a key factor in reducing DMI to some extent. A study on the effect of fermentation products and VOCs on dry matter intake found that silage with higher levels of biogenic amines (histamine, tyramine, tryptamine, phenylethylamine) and aldehydes (formaldehyde, acetaldehyde, propanal, butyraldehyde) was less favored by ruminants [16]. Additionally, when formic acid and histamine were added to the feed with formaldehyde, cows completely rejected it. In a study, DMI in a 600 kg cow decreased by 0.48 kg/d as the AcA concentration in the diet increased from 10 to 30 g/kg DM [17].