Assessment of Silage Quality and In Vitro Digestibility in Alfalfa and Pomegranate Pomace Based Silages

Abstract

This study evaluated the effects of pomegranate pomace supplementation on silage quality and in vitro digestibility of alfalfa, a forage crop that is challenging to ensile. For this purpose, three groups were formulated: the alfalfa silage group (A) without pomegranate pomace, a mixed group (APP) containing 50% alfalfa and 50% pomegranate pomace, and a pomegranate pomace silage group (PP) without alfalfa. Each group was ensiled in six jars for 45 days. Based on physical characteristics, the silages were classified as ‘satisfactory’ (A) and ‘excellent–good’ (APP and PP). In the APP group, pomegranate pomace supplementation increased the dry matter content (p<0.001) and Flieg score (p<0.001) of alfalfa silage, while significantly reducing ammonia nitrogen (p<0.05) and pH (p<0.05) levels. The crude ash contents of the A, APP, and PP groups were 11.33%, 7.94%, and 4.72%, respectively, while the ether extract contents were 3.58%, 2.74%, and 1.08%. Statistically significant differences were found among the groups in terms of neutral detergent fiber (p<0.001), acid detergent fiber (p<0.001), acid detergent lignin (p<0.01), and crude cellulose (p<0.001) contents. The in vitro dry matter digestibility values of A, APP, and PP silages were determined as 69.79%, 64.23%, and 61.13%, respectively, while in vitro organic matter digestibility values were 66.75%, 59.94%, and 59.77%, respectively. In conclusion, pomegranate pomace supplementation significantly enhanced fermentation characteristics and overall silage quality. These findings suggest that tannin-rich pomegranate pomace could be a promising additive in high-protein forage silages such as alfalfa, and its effects should be further evaluated at different inclusion levels in animal feeding trials.

Yonca ve Nar Posası Silajlarında Silaj Kalitesinin ve İn Vitro Sindirilebilirliğin Değerlendirilmesi

Abstract

Bu çalışma, silolanması güç olan yoncaya nar posası ilavesinin silaj kalitesi ve in vitro sindirilebilirlik üzerine etkilerini değerlendirmek amacıyla yürütülmüştür. Bu kapsamda üç grup oluşturulmuştur: nar posası içermeyen yonca silajı grubu (A), %50 yonca + %50 nar posası içeren silaj grubu (APP) ve yalnızca nar posası silajı grubu (PP). Her grup altışar kavanozda 45 gün süreyle silolanmıştır. Fiziksel özelliklere göre yapılan sınıflandırmada A grubu ‘tatmin edici’, APP ve PP grupları ise ‘çok iyi’ kalite olarak belirlenmiştir. APP grubunda nar posası ilavesi, yonca silajının kuru madde içeriğini (p<0.001) ve Flieg skorunu (p<0.001) artırırken, amonyak azotu (p<0.05) ve pH (p<0.05) düzeylerini önemli ölçüde azaltmıştır. A, APP ve PP gruplarının ham kül düzeyleri sırasıyla %11.33, %7.94 ve %4.72; ham yağ düzeyleri ise %3.58, %2.74 ve %1.08 olarak belirlenmiştir. Nötral deterjan lifi (p<0.001), asit deterjan lifi (p<0.001), asit deterjan lignini (p<0.01) ve ham selüloz (p<0.001) içerikleri bakımından gruplar arasında istatistiksel olarak anlamlı farklılıklar tespit edilmiştir. A, APP ve PP gruplarının in vitro kuru madde sindirilebilirlik değerleri sırasıyla %69.79, %64.23 ve %61.13; organik madde sindirilebilirlik değerleri ise %66.75, %59.94 ve %59.77 olarak bulunmuştur. Sonuç olarak, nar posası ilavesi silajın fermantasyon özelliklerini ve genel kalitesini önemli ölçüde iyileştirmiştir. Bu bulgular, tanen açısından zengin nar posasının yüksek proteinli yem bitkilerinden elde edilen silajlarda umut verici bir katkı maddesi olduğunu ve farklı düzeylerde hayvan denemeleriyle daha ayrıntılı olarak değerlendirilmesi gerektiğini ortaya koymaktadır.

Keywords

• İn Vitro Sindirilebilirlik
• Nar Posası
• Silaj Kalitesi
• Yonca Silajı

References

1. ANKOM. (2020). Ankom Technology Method 3: In-vitro true digestibility using the DAISYII Incubator. Retrieved February 2, 2020, from https://www.ankom.com/sites/default/files/document-files/Method_3_Invitro_D200_D200I.pdf
2. AOAC. Official Methods of Analysis, 18th Edition, Association of Official Analytical Chemists, Gaithersburg, MD. 2006.
3. Bağuç, Y., & Aksu, T. (2021). Elma (Malus pumila) katkısının yaş şeker pancarı posası silajı kalitesine etkisi. Atatürk Üniversitesi Veteriner Bilimleri Dergisi, 16(1), 49-56.
4. Bai, J., Xu, D., Xie, D., Wang, M., Li, Z., & Guo, X. (2020). Effects of antibacterial peptide-producing Bacillus subtilis and Lactobacillus buchneri on fermentation, aerobic stability, and microbial community of alfalfa silage. Bioresource Technology, 315, 123881. https://doi.org/10.1016/j.biortech.2020.123881
5. Başaran, U., Gülümser, E., Mut, H., & Doğrusöz, M. Ç. (2018). Determination of silage yield and quality of grasspea + cereal intercrops. Turkish Journal of Agriculture – Food Science and Technology, 6(9), 1237–1242. https://doi.org/10.24925/turjaf.v6i9.1237-1242.2022
6. Besharati, M., Maggiolino, A., Palangi, V., Kaya, A., Jabbar, M., Eseceli, H., De Palo, P., & Lorenzo, J. M. (2022). Tannin in ruminant nutrition: Review. Molecules, 27(23), 8273. https://doi.org/10.3390/molecules27238273
7. Bingöl, N. T., Karslı, M. A., Bolat, D., & Akca, I. (2008). The effects of molasses and formic acid addition in sainfoin silage harvested at different maturities on silage quality and digestibility. Van Veterinary Journal, 2, 61–66.
8. Canbolat, Ö., Kalkan, H., Karaman, Ş., & Filya, İ. (2010). Üzüm posasının yonca silajlarında karbonhidrat kaynağı olarak kullanılma olanakları. Kafkas Üniversitesi Veteriner Fakültesi Dergisi, 16(2), 269–276. https://doi.org/10.9775/kvfd.2009.679

9. Canbolat, Ö., Kamalak, A., & Kara, H. (2014). Nar posası silajına (Punica granatum L.) katılan ürenin silaj fermantasyonu, aerobik stabilite ve in vitro gaz üretimi üzerine etkisi. Veterinary Journal of Ankara University, 61, 217-223. https://doi.org/10.1501/vetfak_0000002632
10. Erişci, D., Bingöl, T., & Avci, A. (2022). Elma (Malus Pumila) katkısının yonca silaj kalitesi üzerine etkisi. Van Veterinary Journal, 33(3), 135-140. https://doi.org/10.36483/vanvetj.1185934
11. Gerçekcioğlu, R., Sönmez, A., & Atasever, Ö. Ö. (2015). Kuytucak yöresi bazı nar (Punica granatum L.) çeşitlerinin bitkisel ve pomolojik özellikleri. Tarım Bilimleri Araştırma Dergisi, 8(2), 32-34.
12. Hoque, M. B., Tanjila, M. J., Hosen, M. I., Hannan, M. A., Haque, P., Rahman, M. M., & Hasan, T. (2025). A comprehensive review of the health effects, origins, uses, and safety of tannins. Plant and Soil, 507(1), 221-240. https://doi.org/10.1007/s11104-024-06768-7
13. Huang, J., Zaynab, M., Sharif, Y., Khan, J., Al-Yahyai, R., Sadder, M., Ali, M., Alarab, S. R., & Li, S. (2024). Tannins as antimicrobial agents: Understanding toxic effects on pathogens. Toxicon, 247, 107812. https://doi.org/10.1016/j.toxicon.2024.107812
14. İflazoğlu Mutlu, S., & Güler, T. (2021). The effect of ellagic acid on performance, digestibility, egg quality, cecal bacterial flora,antioxidant activity, and some blood parameters in laying quails reared at different temperatures. Turkish Journal of Veterinary & Animal Sciences, 45 (1): 101-112. https://doi.org/10.3906/vet-2002-58
15. Iqbal, N., & Poór, P. (2025). Plant protection by tannins depends on defence-related phytohormones. Journal of Plant Growth Regulation, 44(1), 22-39. https://doi.org/10.1007/s00344-024-11291-1
16. Jalal, H., Giammarco, M., Lanzoni, L., Akram, M. Z., Mammi, L. M. E., Vignola, G., Chincarini, M., Formigoni, A., & Fusaro, I. (2023). Potential of fruits and vegetable by-products as an alternative feed source for sustainable ruminant nutrition and production: a review. Agriculture, 13(2), 286. https://doi.org/10.3390/agriculture13020286
17. Jung, J. S., Wong, J. W. C., Soundharrajan, I., Lee, K. W., Park, H. S., Kim, D., Choi, K. C., Chang, S. W., & Ravindran, B. (2024). Changes in microbial dynamics and fermentation characteristics of alfalfa silage: a potent approach to mitigate greenhouse gas emission through high-quality forage silage. Chemosphere, 362, 142920. https://doi.org/10.1016/j.chemosphere.2024.142920
18. Kamalak, A., Şahin, M., & Canbolat, Ö. (2014). The effect of tannin extract (Artutan) as a silage additive on the quality characteristics of clover silage and its effects on feed consumption, digestion, and rumen fermentation in sheep (Project No: 111 O 821). TÜBİTAK. https://search.trdizin.gov.tr/tr/yayin/detay/613964/silaj-katki-maddesi-olarak-mese-tanen-ekstraktinin-artutan-yonca-silajinin-kalite-ozellikleri-ile-koyunlarda-yem-tuketimi-sindirim-derecesi-ve-rumen-fermentasyonu-uzerine-etkisi
19. Kara, K. (2016). Effect of dietary fibre and condensed tannins concentration from various fibrous feedstuffs on in vitro gas production kinetics with rabbit faecal inoculum. Journal of Animal and Feed Sciences, 25(3), 266-272. https://doi.org/10.22358/jafs/65563/2016
20. Kara, K., Guclu, B. K., Baytok, E., Aktug, E., Oguz, F. K., Kamalak, A., & Atalay, A. I. (2018). Investigation in terms of digestive values, silages quality and nutrient content of the using pomegranate pomace in the ensiling of apple pomace with high moisture contents. Journal of applied animal research, 46(1), 1233-1241. https://doi.org/10.1080/09712119.2018.1490300
21. Kirchgessner, M., Kellner, R. J., & Roth, F. X. (1977). Zur schätzung des futterwertes mittels rohfaser und der zellwandfraktionen der detergentien-analyse. Landwirtschaftliche Forschung, 30, 245–250.
22. Köksal, Y., Bölükbaş, B., & Selçuk, Z. (2021). An in vitro evaluation of the silage mixtures containing different levels of white mulberry pomace and meadow grass. Kocatepe Veterinary Journal, 14(3), 309-315. https://doi.org/10.30607/kvj.923403
23. Leon-Tinoco, A. Y., Garcia, M., Stonoha-Arther, C. M., Brito, A. F., & Romero, J. J. (2025). Factors influencing protein utilisation in legume silage and hay for ruminants. Grass and Forage Science, 80(2). https://doi.org/10.1111/gfs.12729
24. Malhatun Çotuk, G., & Soycan Önenç, S. (2017). Yonca silajına kepek ve puding ilavesinin silaj fermantasyonu, aerobik stabilite ve in vitro sindirilebilirlik üzerine etkileri. Hayvansal Üretim, 58, 13–19.
25. Ogunade, I. M., Jiang, Y., Pech Cervantes, A. A., Kim, D. H., Oliveira, A. S., Vyas, D., Weinberg, Z. G., Jeong, K. C., & Adesogan, A. T. (2018). Bacterial diversity and composition of alfalfa silage as analyzed by Illumina MiSeq sequencing: effects of Escherichia coli O157: H7 and silage additives. Journal of Dairy Science, 101(3), 2048-2059. https://doi.org/10.3168/jds.2017-12876
26. Paydaş, E. (2019). Mısır silajına farklı oranlarda antep fıstığı (Pistacia vera L.) dış kabuğu ilavesinin silaj kalitesi ve in vitro metan gazı oluşumu üzerine etkisinin araştırılması. Erciyes Üniversitesi Veteriner Fakültesi Dergisi, 16(1), 16-22. https://doi.org/10.32707/ercivet.538026
27. Şakalar, B., & Kamalak, A. (2016). Use of dried molasses beet pulp in ensiling of alfalfa plant. Anadolu Journal of Agricultural Sciences, 31, 157–164.
28. Schmidt, R. J., Hu, W., Mills, J. A., & Kung Jr, L. (2009). The development of lactic acid bacteria and Lactobacillus buchneri and their effects on the fermentation of alfalfa silage. Journal of Dairy Science, 92(10), 5005-5010. https://doi.org/10.3168/jds.2008-1701
29. Shi, J., Zhang, G., Ke, W., Pan, Y., Hou, M., Chang, C., & Lu, Q. (2023). Effect of endogenous sodium and potassium ions in plants on the quality of alfalfa silage and bacterial community stability during fermentation. Frontiers in Plant Science, 14, 1295114. https://doi.org/10.3389/fpls.2023.1295114
30. Sun, L., Jiang, Y., Ling, Q., Na, N., Xu, H., Vyas, D., Adesogan, A. T., & Xue, Y. (2021). Effects of adding pre-fermented fluid prepared from red clover or lucerne on fermentation quality and in vitro digestibility of red clover and lucerne silages. Agriculture, 11(5), 454. https://doi.org/10.3390/agriculture11050454
31. Sun, Y., Wu, C., Zu, X., Wang, X., Yu, X., Chen, H., Xu, L., Wang, M., & Li, Q. (2023). Effect of mixing peanut vine on fermentation quality, nitrogen fraction and microbial community of high-moisture alfalfa silage. Fermentation, 9(8), 713. https://doi.org/10.3390/fermentation9080713
32. Tabacco, E., Borreani, G., Crovetto, G. M., Galassi, G., Colombo, D., & Cavallarin, L. (2006). Effect of chestnut tannin on fermentation quality, proteolysis, and protein rumen degradability of alfalfa silage. Journal of Dairy Science, 89, 4736–4746. https://doi.org/10.3168/jds.S0022-0302(06)72524-0
33. Tatlı Seven, P., Çiçek, M. S., İflazoğlu Mutlu, S., Dadan, F. M., & Aktaş, N. Y. (2025). Assessing the nutritional value, fermentation quality, and in vitro degradability of mulberry pomace silage ensiled with sumac additive. Revista Científica De La Facultad De Ciencias Veterinarias, 35(2), 8. https://doi.org/10.52973/rcfcv-e35608
34. Tatlı Seven, P., Yıldırım, E. N., Seven, İ., Kaya, C. A., & İflazoğlu Mutlu, S. (2024). An evaluation of the effectiveness of sumac and molasses as additives for alfalfa silage: Influence on nutrient composition, in vitro degradability and fermentation quality. Journal of Animal Physiology and Animal Nutrition, 108(4), 1096-1106. https://doi.org/10.1111/jpn.13955
35. Tilley, J. M. A., & Terry, D. R. (1963). A two-stage technique for the in vitro digestion of forage crops. Grass and Forage Science, 18(2), 104–111. https://doi.org/10.1111/j.1365-2494.1963.tb00335.x
36. Ülger, İ., & Özdemir, M. (2023). Atık kırmızı ve beyaz üzüm posalarının alternatif kaba yem kaynağı olarak silolanmasının besin madde kompozisyonu ve silaj kalite özellikleri üzerine etkileri. Osmaniye Korkut Ata Üniversitesi Fen Bilimleri Enstitüsü Dergisi, 6(1), 792-805. https://doi.org/10.47495/okufbed.1160833
37. Ünver, E., Okur, A. A., Tahtabiçen, E., Kara, B., & Şamlı, H. E. (2014). Tannins and their impacts on animal nutrition. Turkish Journal of Agriculture - Food Science and Technology, 2(6), 263–267. https://doi.org/10.24925/turjaf.v2i6.263-267.125
38. Van Soest, P. J., Robertson, J. D., & Lewis, B. A. (1991). Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. Journal of Dairy Science, 74(10), 3583–3597. https://doi.org/10.3168/jds.S0022-0302(91)78551-2
39. Zarei, M., Azizi, M., & Bashir-Sadr, Z. (2011). Evaluation of physicochemical characteristics of pomegranate (Punica granatum L.) fruit during ripening. Fruits, 66(2), 121-129. https://doi.org/10.1051/fruits/2011021