The alternative resources constitute a viable option to mitigate the costs of pigs feeding in extensive and semi-extensive rearing houses (Lezcano et al. 2014 Lezcano, P., Berto, D., Bicudo, S., Curcelli, F., Gonzáles, P. & Valdivie, M. 2014. "Yuca ensilada como fuente de energía para cerdos en crecimiento". Avances en Investigación Agropecuaria, 18(3): 41-48, ISSN: 0188-7890. https://www.redalyc.org/pdf/837/83732353004.pdf. ). Ecuador have an excellent potential, as to the alternative foods production for their use in this animal category, among which is the guava fruit (Psidium guajaba L.). In tropical and subtropical areas, this crop is cultivated and harvest twice a year in February-May and August -November. The regions of higher cultivation are the provinces Orellana, Pastaza, Pichincha, Esmeraldas, Azuay, Zamora Chinchipe and Tungurahua, but the main production line is in the cantons of Baños, Mera, Pastaza, Santa Clara, Palora and Joya de los Sachas. In Pataza canton, this crop is established in the most part of the farms from agricultural farmers (Morocho 2017 Morocho, M. 2017. Estudio de factibilidad para la implementación de una planta procesadora de néctar de guayaba, (Psidium guajaba L) y su comercialización en el cantón centinela del Cóndor, provincia de Zamora Chinchipe. Engineering Thesis, Universidad Nacional de Loja, Loja, Ecuador, 100 p. ).
The commercial production of guava fruit begins in Ecuador from a third year, with an average of 3 t/ha/year, which reaches 26 t/ha/year in the eighth. In selected crops a production of 35 t/ha/year is achieved. The greatest part of the fruit is use for the production of jellies, yogurt, wines and jams. However, there is a surplus which not fulfill with the parameters for commercialization and it is not assess for animal feeding due to its high humidity content the changeable characteristics of the fruit (Marquina et al. 2008 Marquina, V., Araujo, L., Ruíz, J., Rodríguez-Malaver, A. & Vit, P. 2008. "Composición química y capacidad antioxidante en fruta, pulpa y mermelada de guayaba (Psidium guajava L.)". Archivos Latinoamericanos de Nutrición, 58(1), ISSN: 0004-0622. http://ve.scielo.org/scielo.php?script=sci_arttext&pid=S0004-06222008000100014. ), and, after harvested suffers the attack of microorganisms that causes the decomposition of this raw matter (MAGAP 2023 MAGAP (Ministerio de Agricultura Ganadería Acuacultura y Pesca). 2023. Productores de Pastaza negocian venta de productos a industria de Tungurahua, Available: https://www.agricultura.gob.ec/productores-de-pastaza-negocian-venta-de-productos-a-industria-de-tungurahua/#. ).
For the preserving of these resources for a long time and for their use in pigs feeding (Caicedo et al. 2019 Caicedo, W., Ferreira, F.N.A., Viáfara, D., Guamán, A., Sócola, C., Pérez, M., Díaz, L. & Ferreira, W.M. 2019. "Nutritive value and digestibility in growing pigs of baby banana (Musa acuminata AA) fermented in solid state". Livestock Research for Rural Development, 31(11), Article #170, ISSN: 2521-9952. Available: http://www.lrrd.org/lrrd31/11/orlan31170.html ) fermentative process can be used (silage). The traditional fermentative technique is performed with the use of lactic bacteria culture on the raw matter slightly chopped, under anaerobic conditions. However, in the fermentation of agricultural byproducts, today are applying inclusion variants of the draying material to improve the dry matter content and the nutrients concentration of the fermented food (Borrás-Sandoval et al. 2017 Borrás-Sandoval, L., Valiño, E. & Elías, A. 2017. "Evaluación del efecto de la inclusión de materiales fibrosos en la fermentación en estado sólido de residuos postcosecha de papa (Solanum tuberosum) inoculado con preparado microbial". Revista Electrónica de Veterinaria, 18(8): 1-16, ISSN: 1695-7504. https://www.redalyc.org/pdf/636/63652581011.pdf and Caicedo et al. 2019 Caicedo, W., Ferreira, F.N.A., Viáfara, D., Guamán, A., Sócola, C., Pérez, M., Díaz, L. & Ferreira, W.M. 2019. "Nutritive value and digestibility in growing pigs of baby banana (Musa acuminata AA) fermented in solid state". Livestock Research for Rural Development, 31(11), Article #170, ISSN: 2521-9952. Available: http://www.lrrd.org/lrrd31/11/orlan31170.html ).The objective of this study was to evaluate the chemical characteristics of the ripe guava fruit (Psidium guajaba L.) silage for their use in pigs.
Materials and Methods
⌅Location. The research was performed in the Microbiology and Bromatology laboratories from the Universidad Estatal Amazónica. The study was carried out in Pastaza canton, Pastaza province, Ecuador. This region has a subtropical humid climate, with high rainfalls (4000 to 4500 mm annuals), relative humidity of 87 % and altitude of 900 m o.s.l. The temperatures vary between 20 and 28 ºC (INAMHI 2014 INAMHI (Instituto Nacional de Meteorología e Hidrología). 2014. Anuario Meteorológico. Quito, Ecuador, p. 28, Available: https://drive.google.com/file/d/1aRysaX9teIQwI4E_U9vtR6XaNBNv4VL9/view. ).
Preparation of the ripe guava fruit silage. For the silage preparation ripe and fresh guava fruit was used, from Caicedo Agricultural Farm. After the harvest, the fruits were washed with drinking water for human consumption and they leave drained for 10 min. They were immediately milled in a hammer mill with 2cm sieve. Later the milled raw matter was taken to the Microbiology laboratory from Universidad Estatal Amazónica. To formulate the silage, there were combined chopped ripe fruit, wheat dust, sugar cane molasses, vitamin and mineral premixture, calcium carbonate and natural yogurt (table 1). All the raw matter was weighed in a CAMRY digital scales, model Ek9150k, from China, with 5000 g capacity and ± 1 g precision. The mixture was placed in 24 plastic micro-silos with 1kg capacity, whose content was analyzed in different conservation times (0, 1, 4, 8, 15 and 30 d). A total of four micro-silos per conservation time were evaluated, throwing out every time the respective measurements were performed.
| Raw matters | Inclusion, % |
|---|---|
| Chopped ripe guava | 90.0 |
| Wheat powder | 6.0 |
| Sugar cane molasses | 2.0 |
| Vitamins and minerals1premixture | 0.5 |
| Calcium carbonate | 0.5 |
| Natural yogurt | 1.0 |
1 Each kg contain: calcium 17 a 20%; phosphorus 18%; NaCl 0.5 a 1%; magnesium 3.0%; biotin 50 mg; zinc 8000 mg; manganese 1500 mg; iron500 mg; copper 2000 mg; iodine 160 mg; cobalt 30 mg; selenium 70 mg; vitamin A 300 000 UI; vitamin D3 50 000 UI; vitamin E 100 UI; calcium-phosphorus ratio 1.3:1; zinc-copper ratio 4:1
Determination of the chemical components of guava fruit silage. The chemical components of the silage were determined in the Bromatology Laboratory from Universidad Estatal Amazónica. For that three random samples of 1kg of the silage were taken, from the micro-silos of eight days post-elaboration. The time of the chemical characterization was established in function of Rodríguez (2008) Rodríguez, S. 2008. Plegable instructivo de divulgación a productores porcinos en Cuba. and Lezcano et al. (2014) Lezcano, P., Berto, D., Bicudo, S., Curcelli, F., Gonzáles, P. & Valdivie, M. 2014. "Yuca ensilada como fuente de energía para cerdos en crecimiento". Avances en Investigación Agropecuaria, 18(3): 41-48, ISSN: 0188-7890. https://www.redalyc.org/pdf/837/83732353004.pdf. suggestions. In the fermented food was determined the dry matter (DM), crude fiber (CF), ash, crude protein (CP), ether extract (EE) and nitrogen free extract (NFE), according to the AOAC (2005) AOAC (Association of Official Analytical Chemists). 2005. Official Method of Analysis. 18th Ed. Ed. Association of Official Analytical Chemists, Inc. Gaithersburg MD, USA, ISBN: 978-0-935584-87-5. recommendations . The gross energy (GE) was determined in an adiabatic calorimetric pump, Parr brand, model 1241, from United States. All the analyses were made in triplicate.
Checking of the pH in the guava fruit silage. The determination of the pH was performed with a standard portable meter, Milwaukee brand, model MW102, American production. The checking was made in 24 micro-silos at 0, 1, 4, 8, 15 and 30 d of conservation (four micro-silos in each study). The pH measurement was made by the Cherney and Cherney (2003) Cherney, J.H. & Cherney, D.J.R. 2003. Assessing silage quality. In: Silage science and technology. Buxton, D.R., Muck, R.E. & Harrison, J.H. (eds). Ed. American Society of Agronomy. Wisconsin, USA, pp. 141-198. procedure.
Experimental design and statistical analysis. For the analysis of the chemical components of the silage descriptive statistical was used and the mean, standard deviation and variation coefficient were determined. To analyze the pH data of the food a completely random design was applied. The treatments were the fermentation days 0, 1, 4, 8, 15 and 30 and Duncan (1955) Duncan, D.B. 1955. "Multiple Range and Multiple F Tests". Biometrics, 11(1): 1-42, ISSN: 0006-341X. https://doi.org/10.2307/3001478. test with (p ≤ 0.05) to contrast means was applied. All the analyses were carried out with the statistical program InfoStat (Di Rienzo et al. 2020 Di Rienzo, J.A., Casanoves, F., Balzarini, M.G., González, L., Tablada, M. & Robledo, C.W. 2020. InfoStat, Version 2020 (Windows). Grupo InfoStat, Universidad Nacional de Córdoba, Argentina. Available: https://www.infostat.com.ar/index.php?mod=page&id=46 ).
Results and Discussion
⌅The use of different raw matters and additives in a combination with the ripe guava fruit make a silage food of an appreciable nutritive quality for pigs feeding (table 2).
| Nutrients | Mean | Standard deviation | Variation coefficient , % |
|---|---|---|---|
| DM, % | 22.61 | 0.01 | 0.01 |
| CP, % | 13.51 | 0.10 | 0.20 |
| CF, % | 9.90 | 0.57 | 0.40 |
| SE, % | 6.08 | 0.01 | 0.02 |
| Ashes, % | 10.24 | 0.09 | 0.1 |
| NFE, % | 72.49 | 1.60 | 1.96 |
| GE, kJ g DM-1 | 18.54 | 3.33 | 2.76 |
The inclusion of the wheat powder as drying material improves the DM content of the silage, from 12 to 13 %, with respect to the fruit in natural state (Torres 2010 Torres, V. 2010. Determinación del potencial nutritivo y funcional de guayaba (Psidium guajaba L.), cocona (Solanum sessiliflorum Dunal) y camu camu (Myrciaria dubia Vaugh). Engineering Thesis, Escuela Politécnica Nacional, Quito, Ecuador, 140 p. ), which is beneficial to keep the food for a long time and avoid loses due to decomposing microorganisms. Nkosi et al (2016) Nkosi, B.D., Meeske, R., Langa, T., Motiang, M.D., Modiba, S., Mutavhatsindi, T.F., Malebana IM. & Groenewald, I.B. 2016. "Effects of bacterial inoculation on the fermentation characteristics and aerobic stability of ensiled whole plant soybeans (Glycine max (L.) Merr) ". South African Journal of Animal Science, 46(2): 129-138, ISSN: 2221-4062. https://www.ajol.info/index.php/sajas/article/view/137696. state that the high DM content in the silage limits the developing of putrefactive microorganisms. The increase in the protein value is due to the colony forming units (CFU) of lactic acid bacteria and yeasts which are develop during the fermentative process (Gunawan et al. 2015 Gunawan, S., Widjaja, T., Zullaikah, S., Ernawati, L., Istianah, N., Aparamarta, H.W. & Prasetyoko, D. 2015. "Effect of fermenting cassava with Lactobacillus plantarum, Saccharomyces cerevisiae, and Rhizopus oryzae on the chemical composition of their flour". International Food Research Journal, 22(3): 1280-1287, ISSN: 2231-7546. https://www.researchgate.net/publication/281728742. , Caicedo et al. 2020 Caicedo, W., Viáfara, D., Pérez, M., Ferreira, F.N.A., Pico, K., Cachago, K., Valle, S. & Ferreira, W.M. 2020. "Increase of protein and antioxidant activity of orito banana silage. Technical note". Cuban Journal of Agricultural Science, 51(3): 337-341, ISSN: 2079-3480. https://www.cjascience.com/index.php/CJAS/article/view/980/1240 and García et al. 2020 García, Y., Sosa, D., González, L. & Dustet, J.C. 2020. "Chemical, physical and microbiological characterization of fermented feed for use in animal production". Livestock Research for Rural Development, 32(7), Article #105, ISSN: 2521-9952. Available: http://www.lrrd.org/lrrd32/7/Yaneis32105.html. ). The increase in the concentrations of ash, ether extract, nitrogen free extracts and energy is due to the inclusion of different raw matters and additives which was made the silage (Borrás-Sandoval et al. 2017 Borrás-Sandoval, L., Valiño, E. & Elías, A. 2017. "Evaluación del efecto de la inclusión de materiales fibrosos en la fermentación en estado sólido de residuos postcosecha de papa (Solanum tuberosum) inoculado con preparado microbial". Revista Electrónica de Veterinaria, 18(8): 1-16, ISSN: 1695-7504. https://www.redalyc.org/pdf/636/63652581011.pdf and Fonseca-López et al. 2018 Fonseca-López, D., Saavedra-Montañéz, G. & Rodríguez-Molano, C.E. 2018. "Elaboración de un alimento para ganado bovino a base de zanahoria (Daucus carota L.) mediante fermentación en estado sólido como una alternativa ecoeficiente". Revista Colombiana de Ciencias Hortícolas, 12(1): 175-182, ISSN: 2011-2173. https://doi.org/10.17584/rcch.2018v12i1.7416. ).
The nutritional composition of the ripe guava fruit silage is similar to some types of silages from agricultural byproducts used in pigs: cassava root (Reina-Rivas et al. 2022 Reina-Rivas, J.J., Azum-Gonzales, J.L., Barcia, J.X. & Mendieta, J.D. 2022. "Uso de yuca (Manihot esculenta Crantz) ensilada como alternativa en la ceba de cerdos". Revista Colombiana Ciencia Animal, 14(1): e870, ISSN: 2027-4297. https://doi.org/10.24188/recia.v14.n1.2022.870 ), sweet potato tubers (Lezcano et al. 2015 Lezcano, P., Vázquez, A., Bolaños, A., Piloto, J., Martínez, M. & Rodríguez, Y. 2015. "Silage of alternative feeds of Cuban origin, a technical, economical and environmental option for the production of pork meat". Cuban Journal of Agricultural Science, 49(1): 65-69, ISSN: 2079-3480. http://scielo.sld.cu/scielo.php?script=sci_arttext&pid=S2079-34802015000100011. ) and banana (García et al. 2020 García, Y., Sosa, D., González, L. & Dustet, J.C. 2020. "Chemical, physical and microbiological characterization of fermented feed for use in animal production". Livestock Research for Rural Development, 32(7), Article #105, ISSN: 2521-9952. Available: http://www.lrrd.org/lrrd32/7/Yaneis32105.html. ).
The highest pH value was showed in the moment of the micro-silos elaboration (day zero) and was slightly decreased in 0.74 units towards the first day the fermentation process have been start. Among the 4 and 30 evaluation days, the pH was established in values lower to 4, without significant differences among the mentioned days. The results of the pH analysis in the ripe guava fruit silage are shown in table 3.
| Silage days | SE ± | P value | ||||||
|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 4 | 8 | 15 | 30 | |||
| pH | 4.75a | 4.01b | 3.74c | 3.78c | 3.75c | 3.76c | 0.05 | < 0.0001 |
abc Different letters show differences at the level of p < 0.05 (Duncan 1955 Duncan, D.B. 1955. "Multiple Range and Multiple F Tests". Biometrics, 11(1): 1-42, ISSN: 0006-341X. https://doi.org/10.2307/3001478. )
The highest pH values were showed in the 0 and 1 evaluation days. This is due to at the beginning of the fermentation process the lactic acid concentrations in the micro-silos are low or null because of the limited activity of the lactic acid bacteria (LAB).The changes in the pH are related with the amount of inoculum and soluble carbohydrates which are used in the silage formulation for the benefic microbial population reduce the pH efficiently, when increasing in the media the concentration of lactate and acetate (Ogiy et al. 2015 Ogiy, S., Chen, Y., Pasvolsky, R., Weinberg, Z.G. & Moshe, M. 2015. "High resolution melt analysis to confirm the establishment of Lactobacillus plantarum and Enterococcus faecium from silage inoculants during ensiling of wheat". Grassland Science, 62(1): 29-36, ISSN: 1744-6961. https://doi.org/10.1111/grs.12102. and Ogunade et al. 2018 Ogunade, I.M., Jiang, Y., Pech, 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 Dairy of Science, 101(3): 2048-2059, ISSN: 0022-0302. https://doi.org/10.3168/jds.2017-12876. ).
However to the previous, the pH was established between the 4 and 30 measurement days. This is satisfactory to achieve a good conservation of the product. Nkosi and Meeske (2010) Nkosi, B.D. & Meeske, R. 2010. "Effects of whey and molasses as silage additives on potato hash silage quality and growth performance of lambs". South African Journal of Animal Science, 40(3): 229-237, ISSN: 2221-4062. https://www.researchgate.net/publication/228858685. show that the pH should stabilized in the first 96h of started the fermentation to reduce the concentrations of butyric acid and ammoniac nitrogen, as to achieve a good aerobic stability and restrict the developing of proteolytic enzymes, enterobacteria and clostridiums that damage the silage (Álvarez et al. 2015 Álvarez, S., Méndez, P. & Martínez-Fernández, A. 2015. "Fermentative and nutritive quality of banana by-product silage for goats". Journal of Applied Animal Research, 43(4): 396-401, ISSN: 0971-2119. https://doi.org/10.1080/09712119.2014.978782. and Da Silva et al. 2018 Da Silva, N.C., Nascimento, C.F., Nascimento, F.A., De Resende, F.D., Daniel, J.L.P. & Siqueira, G.R. 2018. "Fermentation and aerobic stability of rehydrated corn grain silage treated with different doses of Lactobacillus buchneri or a combination of Lactobacillus plantarum and Pediococcus acidilactici". Journal of Dairy Science, 101(5): 4158-4167, ISSN: 0022-0302. https://pubmed.ncbi.nlm.nih.gov/29454688/. ).
The rapid pH stabilization is due to the lactic acid production because of the presence of Lactobacillus (Lopes et al. 2013 Lopes, M.P.C., Júnior, F.A.Z., Alberton, L.R., Otutumi, L.K., Silveira, A.P. & Meza, S.K.L. 2013. "Caracterização nutricional da silagem de bagaço de cana de açucar (Saccharum officinarum L.) adicionada ou não de soro de queijo e/ou grão de milho". Arquivos de Ciências Veterinárias e Zoologia, 16(1): 41-46, ISSN: 1982-1131. ).The inclusion of a carbon source (sugarcane molasses) of easily assimilation and the natural yogurt as inoculum source in the raw matter favors the growing of lactic bacteria and with this, the faster acidification of the medium (García et al. 2020 García, Y., Sosa, D., González, L. & Dustet, J.C. 2020. "Chemical, physical and microbiological characterization of fermented feed for use in animal production". Livestock Research for Rural Development, 32(7), Article #105, ISSN: 2521-9952. Available: http://www.lrrd.org/lrrd32/7/Yaneis32105.html. and Kim et al. 2021 Kim, D. H., Lee, K. D. & Choi, K. C. 2021. "Role of LAB in Silage Fermentation: Effect on Nutritional Quality and Organic Acid Production - An Overview". AIMS Agriculture and Food, 6(1): 216-234, ISSN: 2471-2086. https://doi.org/10.3934/agrfood.2021014. ).This allow to reduce and stabilize the silage pH (Ossa et al. 2010 Ossa, J.M., Vanegas, M.C. & Badillo, A.M. 2010. "Evaluación de la melaza de caña como sustrato para el crecimiento de Lactobacillus plantarum". Revista U.D.C.A Actualidad & Divulgación Científica, 13(1): 97-104, ISSN: 2619-2551. https://revistas.udca.edu.co/index.php/ruadc/article/view/713. and Cárdenas et al. 2018 Cárdenas, L.M., Gómez, J.A., Arenas, M. & Serna-Jiménez, J. 2018. "Evaluación de melaza como medio de cultivo para la producción de bacterias ácido-lácticas". UGCIENCIA, 23(1): 17-22, ISSN: 2346-0814. https://revistas.ugca.edu.co/index.php/ugciencia/article/view/919 ) and keep the nutrients in the food. It is important to highlight that the faster stabilization inhibits the development of decomposing microorganisms that causes undesirable fermentations, deterioration of nutrients and silage quality (Borreani et al. 2017 Borreani, G., Tabacco, E., Schmidt, R.J., Holmes, B.J. & Muck, R.E. 2017. "Silage review: Factors affecting dry matter and quality losses in silages". Journal of Dairy Science, 101(5): 3952-3979, ISSN: 0022-0302. https://doi.org/10.3168/jds.2017-13837. and Ávila and Carvalho 2020 Ávila, C.L.S. & Carvalho, B.F. 2020. "Silage fermentation - updates focusing on the performance of micro-organisms". Journal of Applied Microbiology, 128(4): 966-984, ISSN: 1364-5072. https://doi.org/10.1111/jam.14450. ).
Conclusions
⌅The ripe guava fruit silage had good nutritional composition, so it constitutes an alternative food with appreciable nutritive characteristics for their use in pig diets under the Ecuadorian Amazonia conditions. The silage pH was showed constant in the first 96h of started the fermentation process, which is beneficial to avoid undesirable fermentations and achieve good aerobic stability and food conservation for a long time.