100 © 2025 by the authors; licensee Asian Online Journal Publishing Group Agriculture and Food Sciences Research Vol. 12, No. 2, 100-109, 2025 ISSN(E) 2411-6653/ ISSN(P) 2518-0193 DOI: 10.20448/aesr.v12i2.7312 © 2025 by the authors; licensee Asian Online Journal Publishing Group Effects of additives and ensiling period on groundnut shell silage and in sacco rumen degradability characteristics Abba Ibrahim Abubakar1 Abubakar Masud2 Muktar Umar Muktar3 Bilkisu Ahmad4 Tukur Sani Tajo5 Sani Ibrahim6 Mahmud Suraj Abdullahi7 ( Corresponding Author) 1,2,3,4Department of Animal Health and Production Technology, Federal Polytechnic, Kabo, Kano State, Nigeria. 1Email: abbamusa35@yahoo.com 2Email: masudabk79@gmail.com 3Email: muktarumarmuktar91@gmail.com 4Email: ummanabba122@gmail.com 5Department of Science Laboratory Technology, Federal Polytechnic, Kabo, Kano, State, Nigeria. 5Email: sanitajo88@gmail.com 6Department of Animal Health Technology, Audu Bako College of Agriculture Dambatta, Kano State, Nigeria. 6Email: ibrahimsanirogo@gmail.com 7Department of Animal Science, Bayero University Kano, Nigeria. 7Email: mahmudsuraj70@gmail.com Abstract This study evaluated the effects of additives and ensiling periods on the chemical composition and in sacco rumen degradability of groundnut shell (GNS). In phase one, a 3 × 5 factorial CRD was used with three ensiling periods (3rd, 5th, and 7th weeks) and five additives (control, urea, yeast, molasses, and NaOH). In phase two, in sacco degradability was determined using a 3 × 3 switch- over design. Chemical composition was analyzed following AOAC procedures, and data were subjected to ANOVA. pH decreased with longer ensiling periods, reaching desirable levels (3.8– 5.0). Additives, period, and their interactions significantly (p<0.05) influenced proximate constituents and fibre fractions but not dry matter (DM) degradability. Urea and yeast increased crude protein (8.97% and 7.15%, respectively), while dry matter (DM) and crude fibre decreased after ensiling with additives. Crude protein rose and crude fibre declined with longer ensiling. The highest crude protein (9.58%) was from urea-treated GNS at 7 weeks. After 48 hours of incubation, DM disappearance peaked at 7 weeks for all additives, with urea and yeast yielding the highest potential degradability (100%). It is concluded that urea- or yeast-treated GNS ensiled for 7 weeks improves nutrient quality and degradability, presenting a practical feed option for farm animals. Keywords: Additives, Ensiling, Degradability, Groundnut shell, Silage, In sacco, Rumen. Citation | Abubakar, A. I., Masud, A., Muktar, M. U., Ahmad, B., Tajo, T. S., Ibrahim, S., & Abdullahi, M. S. (2025). Effects of additives and ensiling period on groundnut shell silage and in sacco rumen degradability characteristics. Agriculture and Food Sciences Research, 12(2), 100–109. 10.20448/aesr.v12i2.7312 History: Received: 28 March 2025 Revised: 8 August 2025 Accepted: 19 August 2025 Published: 26 August 2025 Licensed: This work is licensed under a Creative Commons Attribution 4.0 License Publisher: Asian Online Journal Publishing Group Funding: This study received no specific financial support. Institutional Review Board Statement: Not applicable. Transparency: The authors confirm that the manuscript is an honest, accurate, and transparent account of the study; that no vital features of the study have been omitted; and that any discrepancies from the study as planned have been explained. This study followed all ethical practices during writing. Competing Interests: The authors declare that they have no competing interests. Authors’ Contributions: All authors contributed to the conception and design of the study. All authors have read and agreed to the published version of the manuscript. Contents 1. Introduction .................................................................................................................................................................................... 101 2. Materials and Methods ................................................................................................................................................................. 101 3. Results and Discussion ................................................................................................................................................................. 102 4. Conclusion ....................................................................................................................................................................................... 108 References ............................................................................................................................................................................................ 108 mailto:abbamusa35@yahoo.com mailto:masudabk79@gmail.com mailto:muktarumarmuktar91@gmail.com mailto:ummanabba122@gmail.com mailto:sanitajo88@gmail.com mailto:ibrahimsanirogo@gmail.com mailto:mahmudsuraj70@gmail.com https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://www.doi.org/10.20448/aesr.v12i2.7312 https://orcid.org/0000-0001-9763-4795 https://orcid.org/0009-0009-4312-1156 https://orcid.org/0009-0008-6397-3877 https://orcid.org/0009-0004-5235-6348 https://orcid.org/0009-0001-2792-863X https://orcid.org/0009-0001-0514-4172 https://orcid.org/0009-0000-6132-4680 Agriculture and Food Sciences Research, 2025, 12(2): 100-109 101 © 2025 by the authors; licensee Asian Online Journal Publishing Group Contribution of this paper to the literature This work provides novel evidence that urea- or yeast-treated groundnut shells, when ensiled for seven weeks, significantly improve crude protein content and rumen degradability. It establishes an efficient, low-cost method or technique for upgrading an underutilized agro- industrial by-product into a high-quality ruminant feed. 1. Introduction Processing crops to obtain desired products typically generates large amounts of residues as by-products. In ruminant nutrition, many of these residues are valuable because they supply nutrients to animals, especially during periods of feed scarcity [1]. One such crop residue is the groundnut shell (GNS), which is produced in large quantities in many communities. An average of 1018 kg/ha of groundnut shell (GNS) is produced annually in Nigeria [2]. With the exception of a small quantity used as fuel or mulching material, most are discarded as waste. It is common practice in Nigeria to either burn or leave them on the farm to decompose. Burning GNS contributes to global warming; therefore, there is a need to convert it into a useful feed resource [3]. However, one of the disadvantages of crop residues as feed is generally low palatability, low degradability, and low nutrient content [4]. Improved management of crop residues enables their efficient utilization as valuable feed resources. One important way of achieving protein self-sufficiency for the growing Nigerian population is through enhanced utilization of crop residues [5]. Improving the digestibility of poor-quality forages using physical, biological, or chemical methods contributes greatly to this goal [6]. Physical, biological, and chemical treatments disrupt the bonds between cellulose, hemicellulose, and lignin in plant cell walls. This disruption increases the surface area available for microbial attachment, thereby improving digestibility [7, 8]. The in sacco technique of feed evaluation was developed to enable the routine assessment of different feeds. Rumen degradability is commonly determined using this method, which involves incubating feed samples in nylon bags placed in the rumen. The in sacco technique is a robust tool widely applied in ruminant nutrition studies [9]. It is particularly valuable for describing the degradability characteristics of proteins and other feed fractions in forages, as well as in rumen simulation studies [10]. The in-situ method is the most frequently used approach for estimating the degradability of dry matter (DM), organic matter (OM), protein, fiber, and other nutrients [11]. The rate and extent of DM fermentation in the rumen are critical factors influencing nutrient availability to ruminants [12]. 2. Materials and Methods 2.1. Study Area The experiment was conducted at the Laboratory and Research Farm of the Department of Animal Science, Bayero University, Kano. The facilities are located at the new site campus of the university, about 13 km from Kano metropolis, in Ungogo Local Government Area of Kano State. Kano State lies between longitude 9°30′ and 12°30′ East, and latitude 8°42′ and 9°30′ North, within the semi-arid region of northern Nigeria [13]. The state occupies a total land area of 24,400 km² [14] with mean annual rainfall ranging from 600 to 1000 mm [15]. The climate is characterized by 4–8 months of dry season, with average maximum and minimum temperatures of 33.0°C and 15.2°C, respectively. 2.2. Experimental Design The experiment was laid out in a 3 x 5 factorial arrangement in a completely randomized design, with five (5) different additives (Control, Molasses, Sodium hydroxide, Urea, and Yeast) and three ensiling periods (3rd, 5th, and 7th week). In sacco degradability was laid out in a 3 x 3 switch-over design. 2.3. Ensiling Procedure Before ensiling, 31.5 kg of groundnut shells were ground into smaller pieces of about 1 cm using a medium crusher with a 2 mm size. Five combinations of groundnut shell, treated with molasses, urea, laboratory yeast, sodium hydroxide, and untreated groundnut shell were used. Forty-five bottles were employed, each filled with either treated or untreated groundnut shell, compressed using a wooden stick to remove air and tightly closed. Grease was applied at the brim to ensure an airtight condition after filling with silage materials and compression. Each bottle was replicated three times and divided into three ensilage periods of 3rd, 5th, and 7th weeks, stored under shade. At the end of each ensilage period, samples were sun-dried and prepared for chemical analysis and degradability studies. An untreated (Control) groundnut shell was prepared by adding 3000 ml of distilled water to 1 kg of groundnut shell and ensiling it. Molasses at 5% of groundnut shells was diluted in 3000 ml of water (50 ml of molasses was diluted in 3 liters of water to treat 1 kg of GNS) and mixed with groundnut shells. Good silages have been reported when molasses is applied at 3-5% [16]. Urea at a level of 2% of groundnut shell was dissolved in 3000 ml of distilled water (20 g of urea was dissolved in 3 liters of water to treat 1 kg of GNS) and mixed with groundnut shell as described in the procedure Roy and Rangnekar [17]. Yeast at 1% of groundnut shell was dissolved in 3000 ml of distilled water (10 g of yeast was dissolved in 3 liters of water to treat 1 kg of GNS) and mixed with groundnut shell as described in the procedure of Gattass et al. [18]. Sodium hydroxide at 1% of groundnut shell was dissolved in 3000 ml of distilled water (10 g of NaOH was dissolved in 3 liters of water to treat 1 kg of GNS) and thoroughly mixed with groundnut shell. 2.4. Quality Determination of Ensiled Groundnut Shell Ensiled materials were opened at the 3rd, 5th, and 7th weeks after ensiling. At opening, pH, colour, and aroma were determined, and quality characteristics were assessed according to Babayemi et al. [19]. Immediately after Agriculture and Food Sciences Research, 2025, 12(2): 100-109 102 © 2025 by the authors; licensee Asian Online Journal Publishing Group opening, a laboratory thermometer was inserted to determine the temperature. The pH was measured by adding 100 ml of distilled water to 25 g of each treatment in a beaker, and a pH meter was used to determine the pH. Colour and aroma were assessed by descriptive statistics. The conditions were scored for aroma and colour by three independent panelists on a scale of 1-4 (Table 1). Table 1. Description of colour and aroma rating used as indices of silage quality. Rating Colour Aroma 1 Dark or deep brown Putrid or rancid 2 Light brown Pleasant 3 Pale yellow Sweet 4 Yellowish green Very sweet Source: Muhammad, et al. [20]. 2.5. In Sacco Degradability Study Degradability study of groundnut shell was carried out using three fistulated Kano Brown bucks with an average age of 48 months, according to the nylon bag technique described by Ørskov et al. [21]. The animals were given a ten-day period for adaptation to the new feed and housing conditions prior to the suspension of bags. Samples were shade-dried and ground through a 2 mm sieve before rumen incubation. Duplicate samples of about 5 g each were placed in nylon bags (bag size 80 mm x 140 mm; pore size 45 μm) and suspended in the rumen of three fistulated bucks for 8, 12, 18, 24, 36, and 48 hours as outlined by Ørskov and McDonald [22]. After removal from the rumen, the bags were immediately dipped into cold water to stop microbial activity, then washed under running water to remove rumen contents from the outside of the bags. They were subsequently rinsed for 30 minutes to ensure thorough cleaning. Zero-hour samples were prepared by washing the bags containing test samples for 30 minutes without rumen incubation. The residues remaining in the bags were oven- dried at 60°C for 48 hours, following the procedure of Nocek [23]. The bags were then cooled, weighed, and the data obtained were used to calculate the percentage dry matter loss. The results from the in sacco study were fitted to the model of Ørskov and McDonald [22] (P = a + b (1 – e^(-ct))) to determine the degradation characteristics of the incubated samples. Where, P = Potential degradability after time ‘t’. a = Water Soluble Fraction (Zero hour). b = Insoluble but degradable fraction after time ‘t’. c = Rate of degradation of the slowly degradable fraction b. t = Incubation length, i.e. 8, 12, 18, 24, 36, and 48 hrs. e = exponential. 2.6. Statistical Analysis Descriptive statistics were used to assess silage quality. For in sacco data, analysis of variance (ANOVA) was performed using the General Linear Model procedure of SPSS (SPSS Version 21.0). Differences among means were separated using LSD at a 95% probability level. 2.7. Chemical Composition of Groundnut Shell Samples ensiled (GNS) were analyzed for proximate composition (CP, CF, EE, DM, Nitrogen-free extract and Ash) according to procedures of AOAC (Association of Official Analytical Chemists) [24]. Neutral detergent Fibre (NDF) and acid detergent Fibre (ADF) were determined according to procedures outlined by Van Soest and Robertson [25]. 3. Results and Discussion 3.1. Results 3.1.1. Effects of Additives on Groundnut Shell Silage Characteristics The result of additives on GNS characteristics is shown in Table 2. The pH values ranged from 5.63 – 3.87 and there was a significant (p<0.05) difference among the treatments. The silage made with NaOH had a higher pH value (5.63), while the lowest value was recorded in yeast treatments. The silage treated with additives had pH values less than 6.0. Table 2. Effects of additives on groundnut shell silage characteristics. Parameter Treatment Ph Colour Aroma Untreated GNS 4.67b Light brown Pleasant Urea+GNS 4.55b Pale yellow Sweet Yeast+GNS 3.87c Pale yellow Sweet Molasses+GNS 4.55b Pale yellow Sweet NaOH+GNS 5.63a Light brown Pleasant SEM 0.043 - - Note: Means with different superscripts (a, b, c) within the same column are significantly different (P<0.05). 3.1.2. Effect of Ensiling Period on Groundnut Shell Silage Characteristics The results of the ensiling period on GNS silage characteristics are presented in Table 3. The pH values of silages were significantly affected (P<0.05) by the ensiling period. The pH values ranged from 4.39 at 7 weeks, 4.58 at 5 weeks, and 4.98 at 3 weeks. In terms of colour and aroma, all silage produced at different periods was light brown with a pleasant aroma at 3 weeks, and pale yellow with a sweet aroma at 5 and 7 weeks, respectively. Agriculture and Food Sciences Research, 2025, 12(2): 100-109 103 © 2025 by the authors; licensee Asian Online Journal Publishing Group Table 3. Effects of ensiling period on groundnut shell silage characteristics. Parameter Period pH Colour Aroma Week 3 4.98a Light brown Pleasant Week 5 4.58b Pale yellow Sweet Week 7 4.39c Pale yellow Sweet SEM 0.033 - - Note: Means with different superscripts (a, b, c) within the same column are significantly different (P<0.05). 3.1.3. Interaction Effect of Additives and Ensiling Period on Groundnut Shell Silage Characteristics Results of additives and the ensiling period on GNS silage characteristics are shown in Table 4. The result revealed that urea and yeast GNS treatment had a pale yellow colour with a sweet aroma. Control and yeast treatment had a combination of both pale yellow and light brown colours with a sweet and pleasant aroma in all the periods of ensiling. Meanwhile, sodium hydroxide had a light brown colour with a pleasant aroma and a pH range of 3.62–5.21 across all treatments and periods of ensiling. Table 4. Interaction effects between additives and ensiling period of groundnut shell (GNS) silage characteristic. Parameters Treatments Period pH Colour Aroma Untreated GNS 3 4.66 Light brown Pleasant 5 4.73 Light brown Pleasant 7 4.62 Pale yellow Sweet Urea+GNS 3 4.59 Pale yellow Sweet 5 4.55 Pale yellow Sweet 7 4.50 Pale yellow Sweet Yeast+GNS 3 4.16 Pale yellow Sweet 5 3.38 Pale yellow Sweet 7 3.62 Pale yellow Sweet Molasses+GNS 3 4.72 Light brown Pleasant 5 4.72 Pale yellow Sweet 7 4.20 Pale yellow Sweet NaOH+GNS 3 5.21 Light brown Pleasant 5 5.10 Light brown Pleasant 7 5.03 Light brown Pleasant SEM 0.075 T X P * - - Note: T x P = Treatment x period interaction. 3.1.4. Effect of Additives on Chemical Composition of Groundnut Shell Silage The results of additives on the chemical composition of GNS silage are shown in Table 5. The result revealed that there was a significant (p<0.05) difference among all the parameters evaluated. Percent Dry Matter (DM) of silage made from GNS (control) has the highest value of 92.60%, while the lowest value of 90.77% was recorded from the silage made from GNS (yeast). Treatment (urea) had the highest crude protein (CP) content at 8.97%, and the lowest CP at 4.33% was recorded in the control, followed by NaOH. Crude fibre (CF) was higher in the control at 51.42%, while the lowest value of 33.71% was recorded from silage made from GNS (urea). The treatment with yeast and molasses had the highest value of NFE, and the lowest value was recorded in the control. The lowest value of Acid Detergent Fibre (ADF) was recorded in the urea treatment, while the highest ADF was in the control. The lowest Neutral Detergent Fibre (NDF) was recorded in the urea treatment, and the highest NDF was in the control. Table 5. Effects of additives on chemical composition (%) of groundnut shell silage. Parameters Treatment DM Ash CP CF EE NFE ADF NDF Untreated GNS 92.60a 4.78b 4.33c 51.42a 0.99d 38.45d 57.71a 75.04a Urea+ GNS 90.89b 5.45a 8.97a 33.71d 3.41c 39.36c 41.25d 65.19d Yeast+ GNS 90.77bc 4.59c 7.15b 39.49c 4.88a 43.90a 52.09b 71.39b Molases+GNS 90.86c 3.91d 7.01b 46.88b 3.71b 42.58b 46.19 b 72.29b NaOH+GNS 90.81bc 3.91d 7.00b 47.88b 3.64b 38.47d 43.23b 67.24c SEM 0.032 0.37 0.210 0.157 0.063 0.204 0.427 0.431 Note: Means with different superscripts (a, b, c, d) within the same column are significantly different (P<0.05). DM: Dry matter, CP: Crude protein, CF: Crude fibre, EE: Ether extract, NFE: Nitrogen free extract, ADF: Acid detergent fibre, NDF: Neutral detergent fibre. 3.1.5. Effect of Ensiling Period on Chemical Composition of Groundnut Shell Silage The effects of the ensiling period on chemical compositions of GNS silage are shown in Table 6. The parameters evaluated are DM, ASH, CP, CF, EE, NFE, ADF, and NDF, and they were all significant (p<0.05) at all the ensiling periods. The DM percentage was highest at the 3rd week of the ensiling period (91.35%) compared to the 5th and 7th weeks, respectively. Ash content was highest at the 7th week (5.26%) and lowest at the 3rd week (3.84%). Crude protein (CP) content was highest at the 7th week (7.35%), while the lowest CP content was observed at the 3rd week (6.50%). Crude fiber (CF) content was highest at the 3rd week (47.36%) and lowest at the 7th week of the ensiling period (40.26%). Agriculture and Food Sciences Research, 2025, 12(2): 100-109 104 © 2025 by the authors; licensee Asian Online Journal Publishing Group Table 6. Effects of ensiling period on chemical composition (%) of GNS-treated silage. Parameter Period DM Ash CP CF EE NFE ADF NDF Week 3 91.35a 3.84a 6.50b 47.36a 2.78c 37.84b 72.06a 67.81a Week 5 91.24a 4.52b 6.82b 43.41b 3.03b 41.95a 70.88b 74.80b Week 7 91.06b 5.26c 7.35a 40.26c 4.17a 41.87a 68.06b 71.46c SEM 0.025 0.028 0.163 0.122 0.49 0.158 0.334 1.040 Note: Means with different superscripts (a, b, c) within the same column are significantly different (P<0.05). DM: Dry matter, CP: Crude protein, CF: Crude fibre, EE: Ether extract, NFE: Nitrogen-free extract, ADF: Acid detergent fibre, NDF: Neutral detergent fibre. 3.1.6. Interaction between Additives and Ensiling Period on Chemical Composition of Groundnut Shell Silage The effect of interaction between additives and the ensiling period on the chemical composition of GNS silage is shown in Table 7. Additives and the ensiling period significantly affect the chemical composition of silage. The percentage of dry matter (DM) in silage made without additives (control) at the 3rd week of the ensiling period was highest at 92.74%, while at the 7th week, yeast-treated silage had the lowest DM content at 90.57%. The percentage of ash shows an increasing trend as the ensiling period progresses, with the highest value recorded at the control at week 7 and the lowest at molasses at week 3. The crude protein (CP) content was highest in urea-treated silage at the 7th week, reaching 9.58%, and lowest in the control at 3.50% during the same period. The lowest crude fiber (CF) interaction was observed in urea at week 7, at 29.14%. The highest ether extract was found in yeast-treated silage at week 7, at 5.67%, while the lowest was in the control at week 3, at 0.45%. The nitrogen-free extract (NFE) was highest in molasses at week 7, at 45.94%, and lowest in the control at week 7, at 36.28%. These findings highlight the influence of different additives and the duration of ensiling on the chemical composition of silage, which is crucial for optimizing feed quality and nutritional value. The interaction between additives and ensiling period on the chemical composition of GNS was significantly (p<0.05) different for all parameters evaluated. 7. Interaction effects between additives and ensiling period on chemical composition (%) of groundnut shell silage. Parameters Treatment Period DM ASH CP CF EE NFE ADF NDF Untreated GNS 3 92.74 3.72 3.50 54.00 0.45 37.63 59.42 75.19 5 92.56 4.33 4.20 51.19 0.62 40.29 57.93 76.40 7 92.52 6.34 5.29 49.05 1.89 36.28 55.77 73.54 Urea +GNS 3 90.98 4.61 8.44 39.37 2.28 37.42 59.71 69.14 5 90.94 5.61 8.88 32.66 3.64 40.21 32.41 64.27 7 90.75 6.13 9.58 29.14 4.31 41.58 31.60 62.18 Yeast +GNS 3 90.81 4.18 7.24 43.26 4.18 42.03 57.23 76.39 5 90.92 4.43 7.38 38.15 4.78 45.29 45.37 73.64 7 90.57 5.15 8.02 37.08 5.67 44.30 53.66 68.35 Molasses + GNS 3 90.96 3.34 6.34 50.07 3.15 36.92 47.17 72.66 5 90.92 4.12 6.72 47.55 3.49 44.48 46.09 73.81 7 90.69 4.33 7.07 43.04 4.48 45.94 45.32 69.88 NaOH + GNS 3 90.93 4.21 7.18 47.55 3.95 38.00 44.41 67.78 5 90.92 4.32 7.08 43.04 4.48 41.68 41.93 65.51 7 90.76 4.46 7.28 42.21 5.24 38.03 53.63 68.08 SEM 0.055 0.633 0.364 0.273 0.109 0.354 0.740 0.747 T X P * * * * * * * * Note: T= Treatment x period interaction, 3= Weeks 3, 5= Weeks 5, 7= Weeks 7. 3.1.7. Dry Matter (DM) Disappearance (%) of Untreated Groundnut Shell The results of dry matter disappearance of untreated GNS at different ensiling period is presented in Figure 1. The untreated GNS disappearance curve revealed that the 7th week silage had the greatest disappearance values during 0-48 hours of incubation, followed by the 5th week, and finally, the least was the 3rd week silage. Figure 1. Dry matter disappearance (%) of untreated groundnut shell. Agriculture and Food Sciences Research, 2025, 12(2): 100-109 105 © 2025 by the authors; licensee Asian Online Journal Publishing Group 3.1.8. Dry Matter (DM) Disappearance (%) of Urea Treated Groundnut Shell The results of dry matter disappearance of urea treated GNS are shown in Figure 2. The urea dry matter curve revealed that GNS treated with urea and ensiled at 7th week produced slightly higher DM disappearance values after a 48-hour incubation period, followed by the 5th week, and the least was at the 3rd week ensiling period. Figure 2. Dry matter disappearance (%) of groundnut shell treated with urea. 3.1.9. Dry Matter Disappearances (%) of Groundnut shell Treated with Yeast Figure 3 the analysis revealed that GNS treated with yeast at the 7th week exhibited the highest dry matter (DM) disappearance, followed by the 5th week, while the lowest was recorded at the 3rd week ensiling period after a 48-hour incubation period. Figure 3. Dry matter disappearance (%) of groundnut shell treated with yeast. 3.1.10. Dry Matter Disappearance (DM) of Groundnut Shell Treated with Molasses The results of dry matter disappearance of molasses treated GNS at different ensiling period are shown in Figure 4. The dry matter disappearance curve revealed that molasses-treated GNS at 7th weeks produced the greatest DM disappearance after 48 hours, followed by 5th weeks, and the least was at three weeks after the 48- hour incubation period. Agriculture and Food Sciences Research, 2025, 12(2): 100-109 106 © 2025 by the authors; licensee Asian Online Journal Publishing Group Figure 4. Dry matter disappearance (%) of groundnut shell treated with molasses. 3.1.11. Dry Matter Disappearance (DM) of Groundnut shell Treated with NaOH The results of dry matter disappearance of NaOH treated GNS at different ensiling period are shown in Figure 5. The dry matter disappearance curve revealed that NaOH-treated GNS at 7th weeks produced the greatest DM disappearance after 48 hours, followed by 5th weeks, and the least was at three weeks after the 48-hour incubation period. Figure 5. Dry matter disappearance (%) of groundnut shell treated with NaOH. 3.1.12. Effect of Additives on Dry Matter Degradability of Groundnut Shell Silage The results of the rumen degradation characteristics of treated and untreated GNS silage are shown in Table 8. Groundnut shell shows no significant difference (p>0.05) between treatments. The results indicate that yeast has a higher quickly soluble fraction ‘a’ (45.55), while urea has a higher ‘b’ slowly degradable fraction (328.79). The degradation rate constant ‘c’ was higher in the control (0.048) and lower in yeast and molasses (0.002). The highest potential degradability (PD) was recorded in yeast (100%), and the lowest was in NaOH (88.61%). The highest effective degradability (ED2, ED5, and ED8) was recorded in molasses (67.50%, 53.17%, and 48.81%, respectively), and the lowest was obtained in the control (54.07%, 44.78%, and 41.58%, respectively). Table 8. Effect of additives on dry matter degradation characteristics of groundnut shell silage. Parameters Treatments A b C A B PD ED2 ED5 ED8 Untreated GNS 29.27 189.98 0.048 28.77 66.24 95.03 54.07 47.54 41.58 Urea + GNS 31.33 328.79 0.041 32.43 66.70 99.14 59.88 44.78 46.07 Yeast + GNS 45.55 271.32 0.041 30.18 69.81 100.00 57.74 49.58 46.73 Molasses+ GNS 23.58 286.82 0.002 35.42 54.61 90.67 67.50 53.17 48.81 NaOH + GNS 9.52 295.19 0.002 30.92 57.71 88.61 59.70 47.64 44.24 SEM 15.76 123.17 0.028 1.379 4.453 4.267 1.99 3.05 3.22 Note: Means with different superscripts within the same column are significantly different (P<0.05). a- quickly soluble fraction; b- slowly degradable fraction; c- degradation rate constant (Fraction/Hour); A- washing lost, B- rumen degradability fraction, PD- potential degradability; ED- effective degradability (%). Agriculture and Food Sciences Research, 2025, 12(2): 100-109 107 © 2025 by the authors; licensee Asian Online Journal Publishing Group 3.1.13. Effect of Ensiling Period on Dry Matter (DM) Degradation Characteristics of Groundnut Shell Silage The results of the effects of the ensiling period on DM degradation characteristics are presented in Table 9. The results revealed that no significant difference was observed for all the parameters evaluated. From the results obtained, period 7 had a higher value of the ‘a’ quickly soluble fraction; the ‘b’ slowly degradable fraction was higher at period 5, while the ‘c’ degradation rate constant was higher at period 3. The potential degradability (PD) obtained at the 7th week was higher (99.15%) compared to the 3rd and 5th weeks (92.25% and 92.67%, respectively). Table 9. Effect of ensiling period on dry matter (DM) degradation characteristics of groundnut shell silage. Period Parameters a B C A B PD ED2 ED5 ED8 Week 3 6.81 230.46 0.054 33.53 58.55 92.25 56.64 44.77 41.04 Week 5 43.68 400.94 0.003 29.13 63.32 92.67 60.87 50.17 46.96 Week 7 33.18 311.85 0.026 32.00 67.18 99.15 61.83 48.72 44.87 SEM 12.204 95.413 0.022 1.068 3.449 3.305 1.546 2.360 2.498 Note: Means with different superscripts within the same column are significantly different (P<0.05). a- quickly soluble fraction; b- slowly degradable fraction; c- degradation rate constant (Fraction/Hour); A- washing lost, B- rumen degradability fraction, PD- potential degradability; ED- effective degradability (%); 3.1.14. Interaction Effect between Additives and Ensiling Period on Dry Matter Degradation Characteristics of Groundnut Shell Silage Table 10 presents the interaction effects between additives and ensiling period on the dry matter (DM) degradation characteristics of groundnut shell silage. The results show that neither additives nor the ensiling period significantly affected parameters a, b, or c across treatments. However, urea- and yeast-treated silages at 7 weeks generally exhibited higher potential degradability (PD = 100%) compared to other treatments, while molasses-treated silage showed the highest effective degradability (ED2, ED5, and ED8). These findings suggest that treatment type and storage duration influence degradability patterns, with urea and yeast improving potential degradability and molasses improving effective degradability. Table 10. Interaction effect between additives and ensiling period on dry matter degradation characteristics of groundnut shell silage Treatment Period a B c A B PD ED2 ED5 ED8 Untreated GNS 3 30.00 348.59 0.001 26.37 73.63 100 54.08 40.03 36.37 5 36.67 113.04 0.006 32.77 52.33 85.10 53.17 43.86 41.20 7 21.15 108.31 0.125 27.23 72.77 100 54.97 49.53 47.17 Urea + GNS 3 50.19 164.41 0.141 22.07 66.67 100 51.53 43.73 40.97 5 39.39 323.71 0.002 29.33 70.47 100 63.07 49.33 45.70 7 39.36 397.48 0.001 27.10 72.90 100 64.50 49.87 46.07 Yeast +GNS 3 35.31 229.84 0.003 38.43 61.57 100 63.33 47.43 43.07 5 31.27 357.04 0.002 22.07 75.34 100 54.87 41.13 37.46 7 28.00 399.46 0.002 36.80 63.20 100 61.47 45.06 39.70 Molasses + GNS 3 10.23 162.67 0.119 34.53 49.83 85.33 59.23 51.63 47.93 5 41.16 244.76 0.003 36.87 48.73 86.33 70.50 53.93 49.50 7 39.80 453.04 0.002 34.87 65.27 100 72.76 53.97 49.00 NaOH + GNS 3 29.15 246.81 0.006 34.37 41.63 75.93 55.03 41.00 36.87 5 69.93 966.19 0.005 24.40 69.73 94.13 62.73 62.60 60.93 7 37.58 200.95 0.002 34.00 61.77 95.76 55.47 45.17 42.40 SEM 27.28 213.35 0.05 2.39 7.71 7.39 3.46 5.28 5.58 Note: Means with different superscripts within the same column are significantly different (P<0.05). a- quickly soluble fraction; b- slowly degradable fraction; c- degradation rate constant (Fraction/Hour); A- washing lost, B- rumen degradability fraction, PD- potential degradability; ED- effective degradability (%). 3.2. Discussion pH is widely used as a simple indicator of silage quality, with well-fermented silages typically exhibiting low pH values. Kung and Shaver [26] reported that tropical grass and legume silages generally have pH values ranging between 4.3 and 4.7. In this study, the pH of groundnut shell (GNS) silage decreased with increasing ensiling duration, reflecting progressive fermentation. Sodium hydroxide treated silage maintained a relatively higher pH (5.21), which agrees with Henderson et al. [27]. In contrast, urea-, yeast-, and molasses-treated silages had lower pH values (3.62–5.21), indicating effective fermentation and good preservation quality. The colour and aroma of GNS silage further supported these findings. All silages appeared pale yellow to light brown, with pleasant or sweet odours. According to Kung and Shaver [26] a sweet aroma is an indicator of well- fermented silage, while Oduguwa et al. [28] emphasized that silage resembling the original forage colour and having a pleasant smell reflects desirable fermentation. These observations suggest that additives contributed positively to the physical quality of GNS silage. Proximate composition results revealed slight variations across treatments, which may be attributed to differences in additives, crop variety, cultivation methods, and environmental factors, as previously noted by Larbi, et al. [29]. Untreated silages recorded higher dry matter (DM) content than treated silages, possibly due to reduced fermentation losses [30]. Urea and yeast treatments resulted in significantly higher crude protein (CP) contents, consistent with earlier studies demonstrating that ammoniation enhances protein levels in crop residues [31, 32]. In contrast, crude fibre contents decreased with urea, yeast, molasses, and NaOH treatments, supporting the view that these additives disrupt lignocellulosic bonds, thereby improving digestibility [33]. The fibre fractions (ADF and NDF) of GNS silage also declined with additive treatment and longer ensiling periods. This observation is in agreement with Tadesse et al. [34], who reported reductions in fibre fractions of ensiled crop residues following chemical and biological treatment. Such reductions suggest improved availability of nutrients for microbial fermentation in the rumen. Agriculture and Food Sciences Research, 2025, 12(2): 100-109 108 © 2025 by the authors; licensee Asian Online Journal Publishing Group The in sacco degradability trial demonstrated that both the ensiling period and additives influenced the degradability characteristics of GNS. Dry matter (DM) disappearance rates increased with longer incubation times, with the highest degradability observed after 48 hours of rumen incubation. Urea- and yeast-treated silages ensiled for 7 weeks showed markedly higher potential degradability (100%), indicating that these treatments improved rumen breakdown of the silage. Molasses-treated silages, however, recorded the highest effective degradability across different passage rates, suggesting that molasses enhanced the readily fermentable fraction of the silage. These findings are consistent with reports by Ørskov and McDonald [22] who highlighted the usefulness of the in sacco method in estimating degradability parameters. Similar improvements in degradability following urea treatment have also been reported in crop residues such as maize stover and wheat straw [35]. Yeast supplementation has likewise been associated with increased microbial activity and improved fibre utilization [36]. The present results confirm that biological and chemical additives can significantly enhance the degradability of groundnut shell, a by-product that is otherwise poorly utilized in animal feeding. Overall, the study demonstrates that both the ensiling period and additive type influence the fermentation quality, proximate composition, and degradability characteristics of GNS silage. Urea and yeast were most effective in improving crude protein and potential degradability, particularly after 7 weeks of ensiling, while molasses improved effective degradability. These findings suggest that groundnut shell, when properly treated and ensiled, can serve as a valuable feed resource for ruminant production. 4. Conclusion This study demonstrated that both additive type and ensiling duration significantly influence the fermentation quality, proximate composition, and degradability of groundnut shell silage. Urea and yeast treatments produced the highest crude protein contents and markedly improved potential degradability, particularly after seven weeks of ensiling. Molasses treatment enhanced effective degradability, while sodium hydroxide maintained higher pH values. Overall, the results confirm that groundnut shell, a widely available agricultural by-product, can be transformed into a valuable ruminant feed resource when properly ensiled with suitable additives. 4.1. Recommendations Based on the results and drawbacks of this research work, the following recommendations are made: Silage made from urea or yeast ensiled at the 7th week period is recommended for feeding farm animals. Further investigation needs to be conducted using feeding trials with groundnut shell ensiled with urea or yeast. References [1] A. Zarah, B. Bello, I. Mohammed, and F. Abbator, "Effect of agro-industrial by-products and crop residues based concentrate on the performance of Balami lambs," Journal of Agriculture, vol. 2, pp. 313-315, 2013. [2] A. Larbi et al., "Groundnut (Arachis hypogaea) for food and fodder in crop-livestock systems: Forage and seed yields, chemical composition and rumen degradation of leaf and stem fractions of 38 cultivars," Animal Feed Science and Technology, vol. 77, no. 1-2, pp. 33-47, 1999. https://doi.org/10.1016/s0377-8401(98)00238-7 [3] A. Akinfemi, O. Adu, and F. Doherty, "Conversion of sorghum stover into animal feed with white-rot fungi: Pleurotus ostreatus and Pleurotus pulmonarius," African Journal of Biotechnology, vol. 9, no. 11, 2010. [4] B. Soeharto, "Crop residues as feed for ruminants: A review of their palatability, degradability, and nutrient content," Journal of Animal Science and Technology, vol. 46, no. 2, pp. 134-142, 2004. [5] M. Jibrin, M. Amonye, N. Akonyi, and O. Oyeleran, "Design and development of a crop residue crushing machine," International Journal of Engineering Inventions, vol. 2, no. 8, pp. 28-34, 2013. [6] W. Chapple, M. Cecava, D. Faulkner, and T. Felix, "Effects of feeding processed corn stover and distillers grains on growth performance and metabolism of beef cattle," Journal of Animal Science, vol. 93, no. 8, pp. 4002-4011, 2015. https://doi.org/10.2527/jas.2015-9059 [7] B. C. Williams, M. F. Riedy, E. V. Williams, M. Gatti, and M. L. Goldberg, "The Drosophila kinesin-like protein KLP3A is a midbody component required for central spindle assembly and initiation of cytokinesis," The Journal of Cell Biology, vol. 129, no. 3, pp. 709-723, 1995. https://doi.org/10.1083/jcb.129.3.709 [8] R. Gates, T. Klopfenstein, S. Waller, W. Stroup, R. Britton, and B. Anderson, "Influence of thermo-ammoniation on quality of warm-season grass hay for steers," Journal of Animal Science, vol. 64, no. 6, pp. 1821-1834, 1987. https://doi.org/10.2527/jas1987.6461821x [9] E. R. Ørskov and M. Ryle, Energy nutrition in ruminants. Amsterdam: Elsevier, 1990. [10] M. Blummel and E. Ørskov, "Comparison of in vitro gas production and nylon bag degradability of roughages in predicting feed intake in cattle," Animal Feed Science and Technology, vol. 40, no. 2-3, pp. 109-119, 1993. https://doi.org/10.1016/0377- 8401(93)90150-i [11] A. Van Vuuren, S. Tamminga, and R. Ketelaar, "In sacco degradation of organic matter and crude protein of fresh grass (Lolium perenne) in the rumen of grazing dairy cows," The Journal of Agricultural Science, vol. 116, no. 3, pp. 429-436, 1991. https://doi.org/10.1017/s0021859600078242 [12] A. Kamalak, O. Canbolat, Y. Gurbuz, and O. Ozay, "Comparison of in vitro gas production technique with in situ nylon bag technique to estimate dry matter degradation," Czech Journal of Animal Science, vol. 50, pp. 60-67, 2005. [13] E. Olofin, "Some aspect of physical geography of Kano region and related human resources. Departmental Lecture note series Vol. 1 Pp 50," Geography Department, Bayero University, Kano, 2007. [14] National Population Commission (NPC), 2006 population and housing census of Nigeria. Abuja: National Population Commission, 2006. [15] Kano State Agricultural and Rural Development Authority (KNARDA), Kano state agricultural profile. Kano: KNARDA, 2001. [16] E. O. Valadares, S. C. Filho, F. N. Mendez, V. R. Rocha Junior, and E. R. Cappelle, Brazilian tables of composition of feed for cattle. CQBAL 2.0. Viçosa, MG: UFV, 2002. [17] S. Roy and D. Rangnekar, "Farmer adoption of urea treatment of cereal straws for feeding of dairy animals: A success in Mithila milkshed, India," Livestock Research for Rural Development, vol. 18, no. 8, pp. 1-8, 2006. [18] C. B. Gattass, M. G. Morais, U. G. P. Abreu, G. L. Franco, J. Stein, and B. Lempp, "Effect of yeast culture supplementation on ruminal fermentation of beef cattle," Journal of Zootechnology, vol. 37, no. 4, pp. 711-716, 2008. [19] O. J. Babayemi, O. A. Ekokoto, and U. A. Inyang, "Evaluation of Ensiled Cassava peels together With Albiza Samon pods," in Proceeding of the 34th Annual Conference of the Nigerian Society for Animal Production (NSAP), Uyo 544 – 546, 2009. [20] I. Muhammad, M. Abdu, G. Iyeghe-Erakpotobor, and K. Sulaiman, "Ensiling quality of Gamba fortified with tropical legumes and its preference by rabbits," Research Journal of Applied Sciences, vol. 4, no. 1, pp. 20-25, 2009. [21] E. R. Ørskov, F. D. Hovell, and F. Mould, "The use of the nylon bag technique for the evaluation of feedstuffs," Tropical Animal Production, vol. 5, no. 1, pp. 195–213, 1980. https://doi.org/10.1016/s0377-8401(98)00238-7 https://doi.org/10.2527/jas.2015-9059 https://doi.org/10.1083/jcb.129.3.709 https://doi.org/10.2527/jas1987.6461821x https://doi.org/10.1016/0377-8401(93)90150-i https://doi.org/10.1016/0377-8401(93)90150-i https://doi.org/10.1017/s0021859600078242 Agriculture and Food Sciences Research, 2025, 12(2): 100-109 109 © 2025 by the authors; licensee Asian Online Journal Publishing Group [22] E.-R. Ørskov and I. McDonald, "The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage," The Journal of Agricultural Science, vol. 92, no. 2, pp. 499-503, 1979. [23] J. E. Nocek, "In situ and in vitro degradation of protein and energy in ruminant feeds," Journal of Dairy Science, vol. 68, no. 5, pp. 1180–1192, 1985. [24] AOAC (Association of Official Analytical Chemists), Official methods of analysis, 17th ed. Gaithersburg, MD: AOAC International, 2000. [25] P. J. Van Soest and J. B. Robertson, Analysis of forages and fibrous foods: A laboratory manual for animal science 613. Ithaca, NY: Cornell University, 1985. [26] L. Kung and R. Shaver, "Interpretation and use of silage fermentation analysis reports," Focus on Forage, vol. 3, no. 13, pp. 1-5, 2001. [27] H. E. Henderson, D. R. Beattie, M. R. Geasler, and W. G. Bergen, "Molasses, minerals, ammonia and Pro-Sil additions to corn silage for feedlot cattle," Res. Rep. 136. pp. 1-22. Michigan State University, 1971. [28] B. Oduguwa, A. Jolaosho, and M. Ayankoso, "Effects of ensiling on the physical properties, chemical composition and minerals contents of guinea grass and cassava tops silage," Nigerian Journal of Animal Production, vol. 34, no. 1, pp. 100-106, 2007. [29] A. Larbi et al., "Fodder and tuber yields, and fodder quality of sweet potato cultivars at different maturity stages in the West African humid forest and savanna zones," Animal Feed Science and Technology, vol. 135, no. 1-2, pp. 126-138, 2007. https://doi.org/10.1016/j.anifeedsci.2006.05.021 [30] D. Patterson, T. Yan, F. Gordon, and D. Kilpatrick, "Effects of bacterial inoculation of unwilted and wilted grass silages. 2. Intake, performance and eating behaviour by dairy cattle," The Journal of Agricultural Science, vol. 131, no. 1, pp. 113-119, 1998. https://doi.org/10.1017/s0021859698005590 [31] I. Ali, J. Fontenot, and V. Allen, "Effects of feeding corn stover treated with different nitrogen sources on palatability and dry matter intake in sheep," Journal of Veterinary and Animal Science, vol. 2, no. 1, pp. 11-15, 2012. [32] A. A. Tesfaye, "The potential of urea-treated maize stover for growth performance of weaned crossbred calves," Agriculture and Natural Resources, vol. 39, no. 4, pp. 638–646, 2005. [33] A. Tolera and F. Sundstøl, "Supplementation of graded levels of Desmodium intortum hay to sheep feeding on maize stover harvested at three stages of maturity: 1. Feed intake, digestibility and body weight change," Animal Feed Science and Technology, vol. 85, no. 3-4, pp. 239-257, 2000. [34] A. Tadesse, Y. Fulpagare, and S. Gangwar, "Effect of urea treatment on chemical composition and oxalate content of sugarcane top," International Journal of Science and Nature, vol. 5, no. 1, pp. 15-18, 2014. [35] S. Chumpawadee, K. Sommart, T. Vongpralub, and V. Pattarajinda, "In sacco degradation characteristics of energy feed sources in Brahman-Thai native crossbred steers," Journal of Agricultural Technology, vol. 1, no. 2, pp. 192-206, 2005. [36] K. Phesatcha and M. Wanapat, "Study on ruminal degradability of local feeds using the nylon bag technique," Khon Kaen Agricultural Journal, vol. 40, no. Supplement 2, pp. 123–127, 2012. Asian Online Journal Publishing Group is not responsible or answerable for any loss, damage or liability, etc. caused in relation to/arising out of the use of the content. Any queries should be directed to the corresponding author of the article. https://doi.org/10.1016/j.anifeedsci.2006.05.021 https://doi.org/10.1017/s0021859698005590