ORIGINAL ARTICLE
Ruminal degradability and fecal digestibility of hydroponic fresh forage of maize (Zea mays) in domestic goats in Santa Elena, Ecuador
Degradabilidad ruminal y digestibilidad fecal del forraje verde hidropónico de maíz (Zea mays) en caprinos criollos en Santa Elena, Ecuador
N. Acosta,I R. Lima,II J. Avellaneda,III C. Mirabá,IV
]]> ICentro de Investigaciones Agropecuarias (CIAP), Universidad Estatal Península de Santa Elena. Campus La Libertad, vía principal Santa Elena- La Libertad, Ecuador.
ABSTRACT
Dry matter, organic matter and crude protein degradability and digestibility were assessed in hydroponic fresh forage hay of maize, cultivated with three nutritive solutions (Hoagland, La Molina and FAO)at 12 d of harvested. The experiment was developed from July to September, 2014 at “La Sevilla” farm located in San Marcos commune, canton and province of Santa Elena, Ecuador. Eight domestic goats were used (four fistulae fitted and without fistulae) which were adapted to the feed for 14 d. For determining ruminal degradability and fecal digestibility, 5 g of each sample were introduced in the rumen in nylon bags (45 – 50 µm) and at 0, 3, 6, 9, 12, 24, 48 and 72 h were assessed. Later they were removed and washed until attaining crystalline water and the bromatological analyses were carried out. Ruminal degradation parameters showed high levels of dry matter, organic matter and crude protein degradability. Results evidence that there were no differences in the degradability parameters for dry and organic matter which was demonstrated by the forage produced through different nutritive solutions. On evaluating the effect of the nutritive solution on the degradability parameters of the crude protein of the hydroponic fresh forage of maize, the “a” fraction and the effective rumen degradation with the FAO and Hoagland solutions were higher (P < 0.05) regarding that obtained with the solution La Molina. It is concluded that the hydroponic fresh forage of maize cultivated with three nutritive solutions exhibited high levels of degradability and fecal digestibility of the dry mater, organic matter and crude protein in goats. However, results of fecal digestibility of the nutrients studied show that the Hoagland and FAO solutions are the most promissory for producing this forage in the studied region.
Key words: degradability, digestibility, hydroponic fresh forage of maize.
RESUMEN
]]> Se evaluó la degradabilidad y digestibilidad de la materia seca, materia orgánica y proteína bruta del heno de forraje verde hidropónico de maíz, cultivado con tres soluciones nutritivas (Hoagland, La Molina y FAO) a 12 d de cosechado. El experimento se desarrolló de julio a septiembre de 2014 en la finca “La Sevilla”, situada en la comuna San Marcos, cantón y provincia de Santa Elena, Ecuador. Se utilizaron ocho caprinos criollos (cuatro fistulados y cuatro no fistulados) que se adaptaron al alimento durante 14 d. Para determinar la degradabilidad ruminal y la digestibilidad fecal, se introdujeron en el rumen 5 g de cada muestra en bolsas de nailon (45 – 50 µm) y se procedió a la evaluación a las 0, 3, 6, 9, 12, 24, 48 y 72 h. Luego, se retiraron y lavaron hasta lograr cristalinidad en el agua, y se realizaron análisis bromatológicos. Los parámetros de degradación ruminal mostraron niveles altos de degradabilidad de materia seca, materia orgánica y proteína bruta. Los resultados evidenciaron que no hubo diferencias en los parámetros de degradabilidad para la materia seca y la orgánica, lo que se constató por el forraje producido mediante diferentes soluciones nutritivas. Al evaluar el efecto de las soluciones nutritivas en los parámetros de degradabilidad de la proteína bruta del forraje verde hidropónico de maíz, la fracción “a” y la degradación efectiva en rumen con las soluciones FAO y Hoagland, fueron superiores (P < 0.05) con respecto al que se obtuvo con la solución La Molina. Se concluye que el forraje verde hidropónico de maíz cultivado con tres soluciones nutritivas mostró niveles altos de degradabilidad y digestibilidad fecal de la materia seca, materia orgánica y proteína bruta en caprinos. No obstante, los resultados de digestibilidad fecal de los nutrientes estudiados muestran que las soluciones Hoagland y FAO son las más promisorias para producir este forraje en la región estudiada.Palabras clave: degradabilidad, digestibilidad, forraje verde hidropónico de maíz.
INTRODUCTION
Santa Elena Peninsula is characterized by arid soils with sporadic rainfall that do not allow the adequate grassland growth for ruminant feeding. These conditions, repeated every year, maintain very low production standards compared to other ecological zones of Ecuador. Farmers due to the cited environmental conditions dedicate to goat cattle production under extensive management. Animals in this region graze large extensions searching for some feed for its nutrient supply. Hence, forage production with the utilization of hydroponic techniques was suggested as alternative for efficient production that will allow less dependence on climatological conditions, field availability and water. In addition the nutritive solutions added supply some nutritional factors.
The hydroponic fresh forage (HFF) is produced from the germination of viable seeds, previously selected, washed and disinfected, technically managed with irrigation and fertilized with standardized nutritive solutions that supply to the plant the necessary nutriments for its growth and development. Harvest is realized at 12 d guaranteeing high digestibility and nutritional quality, characteristics that make the forage fit for animal feeding.
In this study the kinetics of degradation and digestibility of the dry matter (DM), organic matter (OM) and crude protein (CP) of the hydroponic fresh forage of maize (Z. mays) was assessed in domestic goats in Santa Elena, Ecuador.
MATERIALS AND METHODS
]]> The experiment was developed from July to September, 2014 in “La Sevilla” farm located in San Marcos commune, canton and province of Santa Elena, Ecuador (05º 41’ 54” South latitude and 97º 77’35” West longitude), with meteorological conditions of 100 mm/year of rainfall, mean temperature 24º C, relative humidity 83 % and height of 13 masl. The hydroponic fresh forage of maize (HFFM) was cultivated with the utilization of three standardized nutritive solutions (Hoagland, La Molina and FAO). Harvesting was at 12 d of age, then hayed and stored in a ventilated place at 22 ºC until the beginning of the research study.Ruminal degradability of HFFM was determined with the use of four fistulated adult domestic goats in the rumen (in situ technique) fed HFFM in a maintenance diet for 14 d of adaptation. For the ruminal degradability studies, samples were ground until reaching a particle size of 1 mm. Five grams of each were weighed and introduced in the rumen in nylon bags of 45 – 50 µm of porosity for determining its degradation at 0, 3, 6, 9, 12, 24, 48 and 72 h (Ørskov and Mc Donald (1979). DM, OM and CP degradability was calculated by the equation:
D = a + b (1 – exp(-kfxt)), where:
t is the incubation time in hours
a is the soluble fraction
b is the potentially degradable fraction
kf is the degradation rate in hours
From the in sacco degradability, the effective rumen degradability (ERD) was calculated:
ERD = a + b x kf (kf + kp), where:
kp (0.03 per h) is the rate of ruminal passage (Ørskov and Mc Donald 1979)
]]> Bags were removed from the rumen and washed until attaining crystalline water. They were placed in the oven at 65 ºC for 48 h. Later, the bromatological analyses were realized for determining the degradation kinetics of the DM, OM and CP in the described times.In addition the HFFM digestibility was assessed through the in vivo technique of total collection of fecal feces (Bondi et al. 1989). The real or true digestibility coefficient (TDC) was calculated through the following formula:
TDC (%) = IF – (FM – EP)/IF x 100, where:
IF = ingested feed
FM = fecal material
EP = endogenous products
Four adult goats were introduced in metabolic cages and harnesses with devices for feces collection were placed to each one. Animals were adapted to voluntary HFFM intake for 14 d. Later, feces were collected during the following seven days. Samples were sent to the laboratory and fecal digestibility of DM, OM and CP were determined.
RESULTS AND DISCUSSION
The parameters of ruminal degradation (table 1) evidenced high ruminal degradability levels of DM, OM and CP. Results showed that there were no differences (P < 0.05) in the degradability parameters for DM and OM exhibited by the HFFM produced with the different nutritive solutions. Values obtained in this study are different to those found by Herrera et al. (2007), who evaluated the ruminal degradation of the DM of HFFM cultivated in a rice husk substrate and supplied to the animals with all its content (42.2 % at 48 h), very low values due to the lignin supply of the rice husks. Herrera et al. (2010) evaluated DM degradability of HFF of wheat harvested at 10 and 12 d obtaining at 96 h of ruminal incubation values of 76.5 and 66.8 %, respectively, similar to those obtained in this paper.
]]> In the case of OM degradability of HFFM, results obtained are comparable to those reported by Cerrillo et al. (2012) who estimated the ruminal degradation of the OM of HFF of wheat (83.1 and 7.7 %) and oat (71.2 and 65.5 %) harvested at 10 and 12 d, respectively.In this study, on evaluating the effect of the nutritive solutions on the degradability parameters of the CP, the “a” fraction and the ERD in the HFFM produced with the FAO and Hoagland solutions were superior (P < 0.05) than in the HFFM from La Molina solution. Herrera et al. (2010) on studying ruminal CP degradation of HFF harvested at 10 and 12 d reported values of 79.0 and 76.0 % respectively, similar to those found in the HFFM produced with the FAO and Hoagland solutions.
Regarding the fecal digestibility of DM, OM and CP there were differences (P < 0.01) between the HFFM produced with different solutions. Hoagland and FAO solutions were those of best results (table 2). In that respect, Herrera et al. (2007) assessed the DM digestibility of the HFFM cultivated in rice husk substrate and supplied completely to the animals. Digestibility values In this case were of 55.9 %. It is assumed that due to the high lignin content of the rice husks the forage is poorly digestible.
It is concluded that HFFM cultivated with three nutritive solutions showed high levels of degradability and fecal digestibility of DM, OM and CP in goats. However, fecal digestibility results of the studied nutrients reveal that Hoagland and FAO solutions are the most promissory for producing HFFM in the studied region.
REFERENCES
Bondi, A. A., Sanz, A. R. & Drori, D. 1989. Nutrición animal. España: Acribia, 546 p., ISBN: 978-84-200-0662-8, Available: <https://dialnet.unirioja.es/servlet/libro?codigo=159168>, [Accessed: February 12, 2016].
Cerrillo, S. M. A., Juárez, R. A. S., Rivera, A. J. A., Guerrero, C. M., Ramírez, L. R. G. & Barragán, H. B. 2012. ‘‘Producción de biomasa y valor nutricional del forraje verde hidropónico de trigo y avena’’. Interciencia, 37 (12), pp. 906–913, ISSN: 0378-1844.
Herrera, A. A. M., Depablos, A. L. A., López, M. R., Benezra, S. M. A. & Ríos, de Á. L. 2007. ‘‘Degradabilidad y digestibilidad de la materia seca del forraje Hidropónico de Maíz (Zea Mays). Respuesta animal en términos de consumo y ganancia de peso’’. Revista Científica, 17 (4), pp. 372–379, ISSN: 0798-2259.
Herrera, T. E., Cerrillo, S. M. A., Juárez, R. A. S., Murillo, O. M., Rios, R. F. G., Reyes, E. O. & Bernal, B. H. 2010. ‘‘Efecto del tiempo de cosecha sobre el valor proteico y energético del forraje verde hidropónico de trigo’’. Interciencia, 35 (4), pp. 284–289, ISSN: 0378-1844.
]]> Instituto Nacional de Meteorología e Hidrología. 2012. ‘‘Información hidrológica’’. Anuario Meteorológico, (52), p. 287, ISSN: 1390-3578.Ørskov, E. R. & McDonald, I. 1979. ‘‘The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage’’. The Journal of Agricultural Science, 92 (02), pp. 499–503, ISSN: 1469-5146, DOI: 10.1017/S0021859600063048.
Received: November 26, 2015
Accepted: April 1, 2016
N. Acosta, Centro de Investigaciones Agropecuarias (CIAP), Universidad Estatal Península de Santa Elena. Campus La Libertad, vía principal Santa Elena- La Libertad, Ecuador. Email: acoslones@yahoo.es
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