INTRODUCTION
The raw matter for feed manufacture, among which may be cited the corn, sorghum, wheat, soybean and cotton are increasingly less accessible to small and medium producers. This is due to the fact that they experience new costs in the market because of the climate change, the biofuels production and the high consumption by humans (Ren et al. 2014 and Gómez 2016). This environment forces to the search for alternative sources for animals feeding, including pigs (Caicedo et al. 2016).
In Pastaza province Ecuador, there is a great diversity of cultivations, among these is the “orito” banana Musa acuminata AA. This crop represents 5.67 % of the agricultural area of Pastaza (GADMP 2017). The banana fruit is a source rich in carbohydrates, beneficial fiber, iron, potassium, vitamin A, vitamin B6 and low in fat and proteins (Odenigbo et al. 2013). Health benefits are also reported due to its composition of total dietary fiber (TDF), total starch (TS), available starch (AS) and resistant starch (RS) and phenolic compounds when it has not matured (Sarawong et al.2014) . However, due to its high moisture content it is necessary to carry out drying processes for the meals production, and thus obtain improvements in the use of nutrients for pigs feeding (Sánchez et al. 2018).
The nutritional value of raw matters for pigs feeding can be expressed through the digestibility coefficient. Parra and Gómez (2009) state that regardless of the place and the technique used for the sample collection, several types of digestibility can be proven, and among these, the apparent digestibility (AD). The AD allows assuming what amount of the food was used by the animal. On the other hand, the age, health, body condition and breed of the animal can influence on the diet digestibility (Abeledo et al. 2014).
The objective of this study was to determine the chemical composition and apparent digestibility of nutrients of banana meal of “orito” (Musa acuminata AA) rejected in growing pigs.
MATERIALS AND METHODS
Location. The study was carried out in the Programa de Porcinos del Centro de Investigación, Posgrado y Conservación Amazónica (CIPCA) from the Universidad Estatal Amazónica (UEA). The CIPCA is located in the Ecuadorian Amazon Region, between the Pastaza and Napo provinces. This area has a semi-warm or humid subtropical climate, with rainfalls ranging between 4000 and 5000 mm per year. It is located at a height of 584 m o.s.l, with relative humidity of 87% and minimum and maximum average temperature of 18 to 36 ºC (Uvidia et al. 2014).
Elaboration of “orito” banana meal. The green “orito” banana used came from the San José parish of Pastaza canton, and do not fulfill with the size or the necessary weight established by the market for human consumption. Once purchased at the "Mercado Mariscal" collection center, they moved to the CIPCA, immediately a 3 % solution of hypochlorite was prepared in water to perform the washing for 10 minutes, rinsed and drained. Then it was left under cover for 2 hours and cut into side dish and were pre-dried under cover for 8 hours and then dried in an industrial rotary dryer (Burmester brand) at 70ºC for 2 hours. It was milled in a semi-industrial mill (TRAPS brand, TRF 300G model) with a mesh of 0.25 mm, packed in hermetic bags and stored for a week before use.
Management of animals and facilities. The pigs were managed in accordance with the guidelines for Animal Welfare of the Republic of Ecuador (AGROCALIDAD 2017) and the experimental protocol according to Sakomura and Rostagno (2007). For this study, 3 barrow male animals were used, from the commercial crossbreeding Largewhite x Duroc, with an initial average weight of 38 ± 2 kg, each pig constituted an experimental unit. The animals were housed in individual metabolic cages of 1.0 mx 0.40 m (0.4 m2) with a hopper feeder and a nipple drinker, located in a stable with walls 1.2 m high and concrete floor, the water was ad libitum, the average temperature in the building was 26°C.
Feeding management. The treatments consisted of three diets: a control diet T0 (corn and protein concentrate pigs); T20 and T40 (substitution of corn in 20 and 40 % for green “orito” banana meal). The diets were formulated according to the NRC (2012) suggestions for growing pigs (table 1). The intake of the animals was fitted as a metabolic weight unit (LW 0.75). The food was supplied twice a day in equal parts (8:00 am and 3:00 pm). The water was ad libitum.
Ingredients, % | Substitution levels of corn for “orito” banana meal , % | ||
---|---|---|---|
Control, T0 | T20 | T40 | |
Yellow corn | 55 | 35 | 15 |
Wheat meal | 9.0 | 9.0 | 9.0 |
“Orito” banana meal | - | 20 | 40 |
Protein concentrate pigs | 35 | 35 | 35 |
Mineral permixture pigs1 | 0.5 | 0.5 | 0.5 |
Sodium chloride | 0.5 | 0.5 | 0.5 |
Calcualtion of diets nutrients | |||
GE, kJ g DM-1 | 16.77 | 16.88 | 16.98 |
CP, % | 16.91 | 16.66 | 15.40 |
CF, % | 2.76 | 3.91 | 3.76 |
1Premixture of vitamins and minerals for growing pigs (Vit A, 2,300,000 UI; Vit D3, 466,667 UI; Vit E - 5,000 UI; Vit K3, 667 mg; Vit B1, 333 mg; Vit B2, 1,000 mg; Vit B6, 400 mg; Vit B12, 4.000 μg; Folic acid, 67 mg; Niacin, 6.660 mg; Pantothenic acid , 4.000 mg; Biotin, 17 mg; Choline, 43 g; Iron, 26.667 mg; Copper, 41.667 mg; Cobalt, 183 mg; Manganese, 16,667 mg; Zinc, 26,667 mg; Selenium, 67 mg; Iodine 267 mg; Antioxidante27 g; Vehicle qsp, 1,000 g); 2BHT; 3Calculating according to NRC (2012) and/or determined. Source: Elaboration of the authors.
Samples collection. The experiment consisted of three periods and divided into two phases, one of adaptation to the diets with duration of seven days and the other phase of five days for the faeces collection. The faeces were collected by the total collection method (Gutiérrez et al. 2012). After carrying out the daily weighing of feces, from each animal, was collected a specified sample of 100 g of fresh excreta/day, then there were stored in freezing at -20ºC. The calculation of the fecal outlet was made according to Ly et al. (2009). To determine the digestibility of the diet was taken into account: 100 - % of use of each nutrient.
Chemical analysis of samples and excreta. The nutrients determination was performed in the chemistry laboratory of the UEA. In samples of food and excreta were determined: dry matter (DM), crude fiber (CF), ash, crude protein (CP), ether extract (EE) and nitrogen-free extracts (NFE), according to the AOAC (2005) instructions. It was considered that the organic matter (OM) content was the result of subtracting from 100 the ash %. The gross energy (GE) was determined with an adiabatic calorimetric pump, Parr brand, model 1241. All analyzes were done in triplicate for each nutrient.
Experimental design. To analyze the chemical composition data (DM, OM, CP, CF, EE, NFE and GE) of “orito” banana, descriptive statistics were used and the mean and standard deviation were determined. The means of apparent digestibility of the DM, OM, CP, CF, NFE and GE were contrasted by the analysis of variance technique, according to 3 x 3 Latin square design (LSD). In the cases in which there were significant differences (P <0.05) the means were compared by the Duncan (1955) test. The analyzes were carried out with the use of the statistical program Infostat (Di Rienzo et al. 2012).
RESULTS
Chemical composition of green “orito” banana meal. The green “orito” banana meal (table 2) showed a high content of DM (93.3 %), OM (90.28 %), NFE (91.33 %) and GE (4061 kcal kg DM-1) and low in ash (3.92 %) , CP (2.52 %), CF (1.49 %) and EE (0.76 %).
Nutrients | Mean | SD |
---|---|---|
DM, % | 93.23 | 0.01 |
OM, % | 90.28 | 0.01 |
CP, % | 2.52 | 0.01 |
CF, % | 1.49 | 0.01 |
EE, % | 0.76 | 0.01 |
Ash, % | 3.92 | 0.01 |
NFE, % | 91.33 | 0.01 |
GE, kJ g DM-1 | 16.98 | 0.01 |
Apparent digestibility of nutrients from green “orito” banana meal. The apparent digestibility coefficients of the DM, OM, CP, CF, ELN and GE were high (table 3). The best apparent digestibility coefficients of the DM were obtained in the diets T0 (87.07 %) and T20 (86.23 %), without differences (P> 0.05) and the T0 diet exceeded (P <0.05) to T40 (85.75 %). The highest use (P <0.05) of OM (92.71 %) and CP (79.55 %) was evidenced in the diet T20, followed by T40 with OM (90.25 %) and CP (75.73 %) and, finally, diet T0 for OM (88.10 %) and CP (73.98 %). Regarding the use of the GE, the best use coefficients were reached in the diets T20 (51.97 %) and T40 (51.21 %) without differences (P> 0.05) and exceeded (P <0.05) the diet T0 (41.34 %). Respect to the NFE digestibility, there were no differences (P> 0.05) for the diets T20 (74.14 %) and T40 (73.37 %) and differed (P <0.05) from T0 (72.13 %). There were no differences (P> 0.05) between treatments for the use of GE, for T0 (85.97 %); T20 (86.97 %) and T40 (86.33 %), respectively.
Nutrients | Substitution levels of corn for green “orito” banana meal , % | SE± | P value | ||
---|---|---|---|---|---|
Control T0 | T20 | T40 | |||
DM, % | 87.07a | 86.23ab | 85.75b | 0.27 | P<0.0161 |
OM, % | 88.10c | 92.71a | 90.25b | 0.58 | P<0.0005 |
CP,% | 73.98c | 79.55a | 75.73b | 0.25 | P<0.0001 |
CF, % | 41.34b | 51.97a | 51.21a | 0.26 | P<0.0001 |
NFE, % | 72.13b | 74.14a | 73.37a | 0.41 | P<0.0001 |
GE, % | 85.97 | 86.97 | 86.33 | 0.28 | P=0.0730 |
a,b,c Different letters per row significantly differ (P <0.05) according to Duncan (1955)
DISCUSSION
Chemical composition of “orito” banana meal. The green “orito” banana meal showed high content of DM (93.3 %) and OM (90.28 %), which is satisfactory from the nutritional point of view and for its long-term conservation (Kaushal et al. 2011 and Digbeu et al. 2013). On the other hand, when meals do not have an adequate DM content, humidity drastically affects their useful life (Ohizua et al. 2017).
Banana in its natural state has low DM content, and when it comes into contact with decomposing microorganisms, it causes product damage through the production of toxins (Driehuis et al. 2018) and mycotoxins (Iheshiulor et al. 2011) that may cause diseases to animals (Carter and Peck 2015).
The content of NFE (91.33 %) and GE (4061 kcal kg DM-1) in the green “orito” banana meal were high. This is due to the high content of starch (80 %) and sugars (3.5 %) that this food have, which is widely used as an energy source for human and animal feeding (Diniz et al. 2014 and Martínez-Cardozo et al. 2016). On the other hand, this meal has a portion of resistant starch (Agama-Acevedo et al. 2012) so it is considered as a functional food for the prevention or reduction of cholesterol, constipation, diarrhea, control of blood glucose and ability to stimulate the proliferation of beneficial bacteria (Bezerra et al. 2013 and Eleazu et al. 2015).
The green “orito” banana meal showed low levels of CP (2.52 %), ash (3.92%), EE (0.76 %) and CF (1.49 %). However, these values are within the ranges found in other studies (Menezes et al. 2011, Bezerra et al. 2013 and Yangilar 2015). Famakin et al. (2016) show that banana meal have an appreciable content of phosphorus, calcium, potassium, iron, zinc, copper, sodium, magnesium, manganese and have low fiber content (Soto-Maldonado et al. 2018), ether extract (Menezes et al. 2011) and protein (Bezerra et al. 2013). However, when these are offered ripe, cooked, silage or dried, the voluntary intake of the animals is not affected (Ly 2004).
Apparent digestibility of nutrients from “orito” banana meal. The lowest DM digestibility coefficient was showed by the diet T40. This could be due to a low use of the minerals of the diet, the raw matters of vegetable origin have an appreciable phytic phosphorus content that is little available for monogastric animals (Steiner et al. 2007 and Rostagno et al. 2011). In this sense, Madrid et al. (2013), Varley et al. (2014) and Leiva (2015) show that phytases can be used to obtain a better use of minerals in products and byproducts of plant origin for growing pigs.
On the other hand, the inclusion with 20 and 40 % of green “orito” banana meal in the diet of growing pigs improved the digestibility coefficients of the OM, CP, EE, NFE and did not affect the GE digestibility in relation to the control diet. In this sense, Renaudeau et al. (2014) obtained high utilization rates of nutrients when including 20, 40 and 60 % of green banana meal in the diet of growing-fattening pigs, and recommended including up to 60 % of banana meal in the diet without affecting the productive rates of pigs. This confirms that green banana meal is an energy food with adequate nutrient content for pigs feeding. Hurtado et al. (2011) stated that the optimal use of nutrients is related to balanced diets with easily assimilable nutrients, which was corroborated in this research.
The high utilization rate of nutrients of the green “orito” banana meal could be due to the processing of chopped, dried and milled that the banana suffers before its use. Malavanh and Preston (2006) stated that the digestibility coefficients of the plant raw matters increase when they suffers drying processes, compared to those used in natural state (Ly and Delgado 2005). The best use of nutrients in raw matters is related to the inactivation of secondary metabolites (Apata and Babalola 2012 and Farfán-López and De Basilio 2014), and by the breaking of bonds of the constituent polysaccharides of the fiber, which leads to the formation of more soluble molecular fragments (Trejo-Márquez et al. 2016).
On the other hand, in growing pigs the fiber fermentation contributes to the energy metabolism for maintenance between 5 and 12 %. However, at this stage of development of the pig should not exceed 5 % of CF in the diet since it mainly affects the digestibility of protein and energy (Bertechini 2013). In this research, the level of CF of diets remained below 4 % and there was no a negative effect on the use of OM, CP, EE, NFE and GE respectively.
There are reports that the energy digestibility increases with the age of banana harvest, in practice 1150 degrees day is better than 750 and 900 degrees day (Renaudeau et al. 2014). This is related to a change in the chemical composition of the product since it increases the dry matter content and the starch of the banana (Ly 2004).
It is important to note that banana meal has a considerable content of non-digestible starch 24.82 % (Soto 2010) that can act as a prebiotic (Rivera-Quixchan et al. 2018) for the establishment of beneficial microorganisms (Dwivedi et al.2014). These microorganisms contribute to the use of nutrients through the production of enzymes: lipases, xylanases, amylases, proteases (Yüce et al.2017). As well as, antimicrobial compounds: hydrogen peroxide (H2O2), bacteriocins, diploccocins, lactalins, acidophyllines that and Staphylococcus aureus (Fernández et al. 2014 and Li et al. 2015) maintaining the intestinal health of animals (Liao and Nyachoti 2017).
The green “orito” banana meal showed high content of DM, OM, NFE, GE and did not affect the apparent digestibility coefficients of OM, CP, CF, NFE and GE when substituting corn in the diet in 20 and 40 %, guaranteeing an energetic food of appropriate nutritional characteristics for growing pigs.