Valorization of Citrus Pulp Wastes on Improving the Silage Quality of Alfalfa (Medicago sativa L.): Effects on Chemical Composition, Fermentation, Gas Production, and Aerobic Stability Properties

This study was carried out to evaluate the effect of the pulps obtained from citrus on the quality properties of alfalfa (Medicago sativa L.) silage, which has low water-soluble carbohydrates (WSC) and high protein content. The alfalfa was harvested in the pre-blooming period and chopped into 1-3 cm lengths, added 0%, 5% and 10% fresh orange, tangerine, grapefruit and lemon pulps, then siled in vacuum bags for 90 days with 3 replications. At the end of the ensiling period, chemical analyses, gas production (GP), and other calculations were performed. Citrus pulp addition increased the dry matter (DM), crude ash (CA), crude protein (CP), and Flieg Score (FS) of the silages, and reduced the pH, net GP, and methane (CH4). The addition of 10% tangerine pulp increased the FS of silages more than 50%. While the control group silages were graded "low", the addition of 10% tangerine pulp increased the quality grades of the silages to "good". With the addition of 5% grapefruit pulp, a 27% decrease in the CH4 on a per-mL basis of the silages was determined. When silages were compared with the control group, only the silages with %5 tangerine pulp addition had anti-methanogenic properties due to their percentage. With the addition of citrus pulp, excessive degradation of proteins occurring in alfalfa silage was prevented. Silage quality and environmental pollution can be addressed to some extent by using citrus pulp waste to ensile alfalfa, which improves both the nutritional and fermentation characteristics of the silage.