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Revista mexicana de ciencias pecuarias
On-line version ISSN 2448-6698Print version ISSN 2007-1124
Rev. mex. de cienc. pecuarias vol.7 n.3 Mérida Jul./Sep. 2016
Articles
Forage production and quality of common vetch mixtures with barley, oat and triticale in four phenological stages
a Campo Experimental Zacatecas. INIFAP. Km. 24.5 Carretera Zacatecas-Fresnillo, 98500 Calera de Víctor Rosales, Zacatecas, México.
b Campo Experimental San Luis. INIFAP. San Luis Potosí. México.
c Centro de Investigación Regional Norte Centro. INIFAP. Blvd. José Santos Valdez 1200 Poniente. 27440, Matamoros, Coahuila. México. Correo electrónico: salinas.homero@hotmail.com. Correspondencia al último autor.
The objective was to determine forage yield and quality of vetch mixtures with barley, oat and triticale in two seeding ratios (65:35; 35:65) at four phenological stages. To this end, a randomized block design with factorial array (3x4x4) and four replications was established. The greatest dry matter yield was obtained from the oat - vetch mixture at the grain doughy stage of maturity (16.6 t ha-1 ; P<0.00), while the seed proportion with the highest production was from the oat-vetch (65:35) ratio with 19.9 t ha-1 during the dough grain stage. The highest amount of crude protein was obtained from the oat -vetch (178 g kg-1 MS) and triticale-vetch (161 g kg-1 MS) mixtures during booting stage. The monoculture vetch and oats-vetch (35:65) proportion, both had lower amounts of neutral detergent fiber at the mature grain stage (P<0.001). The oat, vetch and triticale monocultures showed the lowest acid detergent fiber during milky grain stage (P<0.001). The greatest percentage of TDN was observed in vetch monoculture and its mixtures with barley (65:35) during the milky grain stage, respectively (P<0.001). The monoculture vetch provided highest values for NEL and RFV (P<0.001). In conclusion, the forage yield and quality of vetch mixtures with barley, oat and triticale depend on the maturity stage. Also, the oat-vetch mixture showed the greatest dry matter yield and high CP concentration. In addition, forage relative value was higher during the mature grain stage.
Key words: Monocultures; Intercropping; Harvesting stage; Forage quality
Para determinar la producción y la calidad del forraje de la mezcla de veza común con cebada, avena, y triticale en dos proporciones de semilla (65:35; 35:65) durante cuatro etapas fenológicas, se estableció un experimento en un diseño de bloques completos al azar con arreglo factorial (3x4x4) con cuatro repeticiones. En mezclas de cultivos la mayor producción de materia seca (MS) la obtuvo la asociación avena-veza con 16.6 t ha-1 y en proporción de cultivos la avena-veza (65:35) produjo 19.9 t ha-1, durante la etapa grano masoso (P<0.001). La mayor cantidad de proteína cruda la obtuvieron las mezclas avena -veza (178 g kg-1 MS) y triticale- veza (161 g kg-1 MS) durante la etapa de embuche. Los menores valores de fibra detergente neutra los presentaron el monocultivo veza y su mezcla con avena (35:65), durante la etapa grano maduro (P<0.001). Las menores cantidades de fibra detergente ácida lo obtuvieron los monocultivos avena, veza y triticale durante la etapa grano lechoso (P<0.001). El mayor porcentaje de nutrientes digestibles totales lo obtuvo el monocultivo veza y su mezcla con cebada (65:35) durante la etapa grano lechoso, respectivamente (P<0.001). El contenido de energía neta de lactación y el valor relativo de forraje fue mayor para el monocultivo veza (P<0.001). Se concluye que la producción y calidad del forraje en mezcla de veza con cereales (cebada, avena y triticale) dependen de la etapa de cosecha. En este estudio, la mezcla avena-veza logró mayor producción de materia seca y mejor contenido de proteína cruda. Además, el valor relativo del forraje fue más alto durante la etapa grano maduro.
Palabras clave: Monocultivos; Cultivos asociados; Epoca de cosecha; Calidad del forraje
Introduction
Mixed cropping or also called intercropping is defined as the simultaneous growth of two or more species during a single growing season1. Historically, the type of annual intercrops widely recognized in the world is the combination of a cereal with a legume, by allowing the inclusion of legumes production and improving forage quality2. In this partnership, cereals characteristically provide high dry matter yields, but low crude protein content; this lowers its quality and nutritional value3. In comparison, legumes have acceptable forage yields; however, they are widely recognized as a rich source of crude protein4. One of the annual legumes widely used for intercropping with cereals is the common vetch or vetch (Vicia sativa L.), an annual legume with a climbing growth habit and high levels of crude protein5,6. With respect to cereals, a large number of species have been listed to be appropriate for combining them with vetch, among them are maize (Zea mays), oat (Oat sativa L.), barley (Hordeum vulgare L.), triticale (x Triticosecale Wittmack. Ex. A. Camus) and wheat (Triticum aestivum L. emend. Thell)7,8,9.
Previous studies have shown that barley produces more fodder than oat, triticale or wheat, when mixed with vetch8,10. In contrast, Knight and Goicoechea7 and Thomson et al8 found that the most suitable for mixing with vetch cereal is oat. However, Anil et al5 reported that triticale could be used as an alternative cereal for mixing with vetch.
Another factor that may modify the production and forage quality of the mixture is the seed ratio used for crop. Some authors suggest ranges varying from 20 to 80 kg ha-1 for cereals, while for common vetch values suggested fluctuate between 20 and 50 kg ha-1(11. Also, the harvest stage is another factor that may affect the production and quality of the forage. The plant quality continuously changes as it matures; in this state, the content of the cell wall increases; this causes more lignin buildup resulting in indigestible compound that consequently decreases forage quality(4). The vegetative stage has been suggested as the best harvest stage because it can be used for any livestock type and productive stage12.
In this context, the objective of this study was to measure the production and quality of forage mixture of common vetch with barley, oat and triticale, at two seed ratios (65:35; 35:65), within four phenological harvest stages.
Material and methods
Study site
The work was carried out in the Zacatecas Experimental Station belonging to the National Institute of Forestry, Agriculture and Livestock (INIFAP), located at 22° 54' N and 102° 39' W and 2,197 m asl, with an average temperature of 14.6 °C and annual rainfall of 416 mm, of which the majority occurs during the summer (June to September). The soil of the study area is classified as Kastanozem, pH 7.5, 1.26 % organic matter and with sandy loam texture13. The land where crops associations were planted was homogeneous in fertility, texture and slope.
Crop management and experimental design
A combination of crops was established in an area of 1.78 ha, divided into 0.81 ha for planting Barley-Vetch, 0.52 ha for Oat-Vetch and 0.45 ha for Triticale-Vetch. The varieties used were capuchona barley (Hordeum vulgare L.), chihuahua oat (Oat sativa L.), Nazas river triticale (x Triticosecale Wittmack. Ex. A. Camus) and common vetch (Vicia sativa L.).
Site preparation consisted of a fallow period, tracking and leveling. Sowing was done on wet soil by November 14, 2013 for barley-vetch mixture, and November 22 for oat-vetch and triticale-vetch mixtures. For this a precision seeder was used, with a seeding density of 50 kg cereal seed with 20 kg of vetch. The dose of 80-46-00 fertilizer was applied; the sources of these where from ammonium sulfate and triple superphosphate, applying all the phosphorous and half the nitrogen at planting, and the rest of nitrogen in the first supplementary irrigation. Four irrigations were applied by furrows irrigation at an interval of 20 d, including planting, providing approximately a total of 40 cm, this was estimated by measuring flow rate and time of irrigation.
The treatments were established with a completely randomized design with factorial arrangement (3x4x4). The first factor corresponded to three different cereal mixtures with vetch and were defined as follows: barley-vetch, oat-vetch and triticale-vetch. The second factor corresponded the mixture of cereals (barley, oat, triticale) with two vetch seed ratios defined at four levels: 100% monoculture cereal (barley, oat, triticale), cereal-vetch ratio of 65:35, cereal-vetch ratio of 35: 65, a 100% vetch monoculture and the third factor that corresponded to the growth stage of the crop that was defined by four phenological stages: booting stage, milky, doughy grain, and mature grain with four replicates per treatment. The experimental plots were 20 rows by 55 m in length with a spacing of 0.75 cm between them for barley + vetch mixture (825 m2) and for the mixtures of oat + vetch and triticale + vetch 20 rows that were 60 m long were used (900 m2).
Samplings dry forage yield
To estimate the production of green and dry fodder, two rows of each plot were used that were 3 m long and had a spacing of 0.75 m; the total area was 4.5 m2. Four samples were taken in each experimental plot, and these were carried out in a longitudinal to the surface of the plot. Each sampling was performed by cutting the forage with a sickle at a height of approximately 2 cm from the soil surface. To estimate the dry matter yield at each harvest, a 500 g sample of fresh forage was taken and placed to dry in an oven at 60 °C for 72 h, which was subsequently transformed to tons of dry matter per hectare. The cuts of forage in the booting stage were carried out at 85, 103 and 101 d after sowing (dap) for barley-vetch, oat- vetch and triticale- vetch, respectively association. For the milky grain stage cuts of barley-vetch, oat-vetch and triticale-vetch mixtures were made at 92, 130 and 129 dap, respectively. Doughy stage grain cuts of barley-vetch, oat-vetch and triticale-vetch mixtures were made at 106, 140 and 139 dap, respectively. In mature grain stage cuts of barley-vetch, oat-vetch and triticale-vetch mixtures were made at 118, 150 and 165 dap, respectively.
Nutritional quality
The forage samples used to calculate percentages of dry matter was processed with a Willy mill with a millimeter sieve. All samples were analyzed for percentage of crude protein (CP) using the Dumas combustion method AOAC14 using the LECO equipment. The neutral detergent fiber (NDF) and acid detergent fiber (ADF) were determined with the technique of detergents using an ANKOM fiber analyzer. The variables of total digestible nutrients (TDN), relative feed value (RFV) and net energy for lactation (NEL) were calculated using the equations adapted by Horroks and Vallentine16.
Data for all variables were analyzed using mixed models procedure set by the estimation method (RML) of SYSTAT 13, Chicago, IL17. The model included fixed effects of crop mixtures at three levels: barley-vetch, oat-vetch and triticale-vetch, with repetition as random factor; seeding ratios at four levels: monoculture cereal (barley, oats, triticale) 100 %, cereal-vetch ratio of 65:35 and cereal-vetch ratio of 35:65 and 100 % vetch as well as crop growth stage with four levels: boot stage, milky, doughy grain and mature grain and their interactions, and the random effects of repetition and residual. The comparison between treatments for all variables was made by Tukey test. Data is presented as an average.
Results
Dry matter yield
The mixed model analysis showed a significant effect of the mixture of cereals (oat, barley, triticale) with vetch on the production of dry matter (DM; P<0.001). Furthermore, the effect on the production of DM differ depending on the stage of harvest (P<0.001). Thus, the highest production of DM was obtained by oat-vetch mixture during the doughy grain stage, while the lowest production was found with barley-vetch mixture during the boot stage (Table 1).
Table 1 Differences in the production of DM, CP, ADF, NDF, TDN, NEL and RFV among crop associations in four phenological stages
![](/img/revistas/rmcp/v7n3//2448-6698-rmcp-7-03-00275-gt5.png)
DM= Dry matter; CP= Crude protein; ADF= Acid detergent fiber; NDF= Neutral detergent fiber; TDN= Total digestible nutrients; NEL= Net energy for lactation; and RFV= Relative feed value.
abcd Different letters represent significant differences among treatments (P<0.05).
The results showed differences in regard to the production of DM in monocultures (oat, barley, triticale) and the mixture of these cereals with vetch seed in two ratios (65:35, 35:65), (Table 2; P<0.001). Furthermore, the effect of the ratio of seed on the DM production differed depending on the stage of harvest (P<0.001). Monoculture oat (17.2 t ha-1) and its mixture with vetch (65:35; 19.9 t ha-1) had higher amounts of DM during the doughy grain stage, while the lower production was obtained with monocultures barley (2.4 t) and vetch (2.6 t).
Table 2 Differences in the production of DM, CP and NDF in monocultures (barley, oat and triticale) and the mixture of these cereals with vetch in two seed ratios (65:35, 35:65)
![](/img/revistas/rmcp/v7n3//2448-6698-rmcp-7-03-00275-gt6.png)
DM= Dry matter; CP= Crude protein; and NDF= Neutral detergent fiber.
abcdefghi Different letters represent significant differences among treatments (P<0.05).
Nutritional quality
Crude protein (CP) content among crop mixtures was different (P<0.05; Table 1). In fact, the effect of the mixture of crops on the content of CP differ depending on the stage of harvest. The highest content of CP was obtained with oat-vetch mixtures and triticale-vetch during the boot stage, while the least was present in the barley-vetch and oat-vetch grain mixtures during the doughy stage.
The results with respect to CP content evaluated as a monoculture (oat, barley, triticale) and the mixture of these cereals with vetch seed in two ratios (65:35, 35:65) showed differences (P<0.001; Table 2). Furthermore, the effect of the seed ratio with respect to CP content differed depending on the stage of harvest (P<0.001). Thus, the highest CP was found with the vetch monoculture (294 g kg-1 DM) during mature grain stage, followed by the seed ratio of oat-vetch (35:65; 175 g kg-1 DM) during the boot stage. Minor amounts of CP were obtained by the barley and oat monocultures during the mature stages grain (56 g) and doughy grain (60 g), respectively.
NDF was not different between crop mixtures (P>0.05; Table 1). There was also no effect between the mixture of crops and harvest stage on the NDF (P>0.05). However, there was a significant effect of seed ratio in the mixture on the NDF (P<0.001). Furthermore, the effect of seed ratio on NDF content differed depending on the stage of harvest (P<0.001; Table 2).
The least amount of NDF the vetch monoculture obtained (363 g kg-1 DM), followed oat-vetch ratio (35:65) with 407 g kg-1 DM, both data obtained during the mature grain stage, while NDF as much the present monoculture barley (622 g kg-1 DM) during grain doughy stage.
The content of ADF did not differ between crop mixtures (P>0.05; Table 1). However, there was an effect related to seed ratio in the mixtures with respect to ADF content (P<0.01). Furthermore, the effect of the seed ratio on ADF content differed depending on the stage of harvest (P<0.001; Table 3). Minor amounts of the ADF presented the oat monocultures (305 g kg-1 DM), vetch (306 g) and ratio (35:65) triticale-vetch (306 g) during the milky stage, while larger amounts presented the monoculture barley (416 g), and barley-vetch 65:35 ratio (409 g) during the dough grain stage.
Table 3 Differences in the production of ADF, TDN and NEL in monocultures (barley, oat and triticale) and the mixture of these cereals with two vetch seed ratios (65:35, 35:65)
![](/img/revistas/rmcp/v7n3//2448-6698-rmcp-7-03-00275-gt7.png)
ADF= Acid detergent fiber; TDN= Total digestible nutrients; and NEL= Net energy for lactation.
abcdef Different letters represent significant differences among treatments (P<0.05).
TDN content did not differ between crop mixtures (P>0.05; Table 1), but it was different in relation to the seed ratio in the mixture (P<0.001). In fact, the effect of the seed ratio on the content of TDN differ depending on the stage of harvest (P<0.01; Table 3). Thus, the highest amount of TDN was obtained by vetch monoculture with 66.7 % during the milky stage. Followed, monoculture barley (65.0 %) and its mixture with vetch (35:65; 64 %), both values obtained during the milky stage. The lowest percentage of TDN was obtained by vetch-triticale ratio (65:35), with 53.7 % during the boot stage. Followed by oat monoculture (54.4 %) and its mixture with vetch (65:35; 54.6 %), both during the boot stage. There was no interaction between the mix of crops and harvest stage on the content of TDN (P>0.05).
NEL values were not different between crop mixtures (P>0.05; Table 1). However, there was an effect of monocultures (barley, oat, triticale) and their mixture with vetch in two seed ratios (65:35; 35:65) on the content of NEL (P<0.001; Table 3). The highest NEL was found with the vetch monoculture with 1.62 Mcal kg-1 DM. There was no effect with harvest stage on the net energy of lactation (P>0.05), nor with the interaction between the seed ratio mixtures and harvest stage on NEL (P>0.05).
Relative feed value (RFV) did not differ between crop mixtures (P>0.05; Table 1). There was also no interaction between the cereal mixture and harvest stage on the RFV (P>0.05). However, there was an effect from monocultures (barley, oat and triticale) and mixtures of these cereals in two vetch seed ratios (65:35, 35:65; P<0.001). In addition, there was an effect of the harvest stage on the RFV (P<0.001). Furthermore, the effect of the seed ratio on RFV differ depending on the stage of harvest (P<0.05; Table 4). Thus, the vetch monoculture had higher values during the mature grain stage (167.2) and milky (152.0). It was followed by the oat monoculture with a value of 133.3. The lowest values were found for the triticale monoculture (82.0) and barley (84.6), followed by the ratios of triticale-vetch (65:35; 90.2) and barley-vetch (35:65; 91.8).
Table 4 Differences in the relative feed value (RFV) in monocultures (barley, oat and triticale) and the mixture of these cereals with two vetch seed ratios (65:35, 35:65)
Phenological stages | ||||
---|---|---|---|---|
Booting stage of grain | Milky grain | Doughy grain | Mature grain | |
Barley/100 | 116.4bcd | 113.6bcd | 84.6a | 94.7abc |
Vetch/100 | 140.2ef | 152.0fg | 110.4bcd | 167.2g |
Barley:veza/65:35 | 113.6bcd | 111.3bcd | 92.0ab | 95.6abc |
Barley:Vetch/35:65 | 109.0abc | 108.8abc | 91.8ab | 96.9abc |
Oat/100 | 94.7ab | 133.3de | 119.0bcd | 124.3de |
Oat:Vetch/65:35 | 92.0abc | 121.3cde | 126.8de | 121.0cde |
Oat:Vetch/35:65 | 101.5abc | 123.5cde | 121.5cde | 125.8de |
Triticale/100 | 92.0ab | 82.0a | 116.5bcd | 94.5abc |
Triticale:Vetch/65:35 | 90.2ab | 112.8bcd | 106.0abc | 105.5abc |
Triticale:Vetch/35:65 | 99.7abc | 121.3cde | 112.5bcd | 106.0abc |
abcde Different letters represent significant differences among treatments (P<0.05).
Discussion
The results show that forage production and nutritional quality of vetch mixture with cereals (barley, oats and triticale) and two seed ratios (65:35; 35:65) are associated with the phenological stage of harvest. Moreover, it was found that the oat-vetch mixture proved to be the association most suitable for crop DM production compared to triticale-vetch or barley-vetch mixtures. In particular, the ratio of oat-vetch (65:35) produced 40 % more DM during the milky-dough grain stage than the triticale-vetch mixture, and 80 % more than the barley-vetch mixture. These results agree with those obtained by Lithourgidis et al9; they demonstrated that the mixture of common vetch with oat (55:45) achieved higher production of DM than triticale -vetch mixture. In that study, oat-vetch mixture produced 18 % more dry matter than the mixture triticale-vetch. In addition, the vetch-oat mixture produced 8 % more dry forage than vetch monoculture. This is because oats shows greater complementarity with vetch because better use nitrogen fixed by the legume on the ground compared to other grasses. Another factor may be the physical ability of species to grow; it has been shown that weight and plant height are higher in oat-vetch mixtures than with barley-vetch or wheat-vetch18, furthermore oats grow better in competition; previous studies indicate that this crop shows a linear increase in competition with vetch as the density increases oat11. These qualities allow the oats have better growth and consequently increased production of dry matter19. For this reason, oat-vetch association is the best option for improving the dry matter production of vetch as reported in other studies11. However, the harvesting stage is another factor that strongly influences the production of crop DM. Studies carried out regarding the optimal time for cutting show that for highest yield and quality for growing oats is in the milky and doughy grain stages, harvesting up to 19 t ha-1 of dry matter, similar to the data obtained in the present study20.
The crude protein content in dry matter is important in assessing the nutritional quality of fodder21. In the present study, the CP varied depending on the type of mixture and at what harvesting stage it was evaluated. The highest amount of crude protein was found in the mixtures oat-vetch and triticale-vetch during booting stage; and in terms of seed mixture ratios, the vetch monoculture obtained the highest during the grain mature stage, followed by oat-vetch (35:65) ratio during the booting stage. One cause of the high concentration of CP in the booting stage is due to the capture of nitrogen. Studies indicate that during this stage, plants capture the highest amount of inorganic nitrogen due to the presence of many leaves22. In fact, some authors reported that during this time period the ratio of grain:foliage is greater (17:83), which allows greater amount of crude protein to be present in the plant (grain, 25.7 %; foliage 18.79 %)23. Data reported to nowadays indicate that the inclusion of vetch in cereals substantially improves CP content in the mixture, especially mixtures of oats and vetch4. The inclusion of vetch with the cereal, improved significantly the CP content of the mixture. However, the increase depended more on the stage of harvest and not the ratio of cereal seed as reported in other studies9,24.
The neutral detergent fiber represents the structural or cell wall in the forage. This variable is inversely related to the amount that an animal is able to consume. Thus, forages with low NDF values have high intake levels than those with higher values. Therefore, a low value of NDF is desirable for ruminants (4). In this study, the low values of NDF where presented in the vetch monoculture (363 g kg-1 DM) and its mixture with oat (35:65; 407 g) during the mature grain stage. Studies conducted in mixtures of oat with vetch indicate that the ratio of common vetch in oat is usually associated with an increase in the cellular content and a decrease in the NDF11,25,26. However, in this study, low values NDF found in vetch and its mixture with oat depend more on the stage of harvest than the ratio of vetch seed in the mixture. This probably can be attributed to the decline of NDF values with increasing maturity of the forage due to a dilution effect created by an increase in the ratios of grain relative to the forage4.
Acid detergent fiber mainly contains cellulose, lignin and silica4. ADF low values represent high energy content and digestibility, which are desirable for ruminants. In the present study, the ADF content of the seed ratios in mixtures depended on the stage of harvest, being monocultures oat, vetch and the ratio 35:65 triticale-vetch which showed fewer ADF during milky grain stage. Some reports indicate that the inclusion of vetch in cereals improves the nutritional quality of the mixture reducing the percentage of ADF compared to monoculture27. According to what was observed in this study, only to the extent triticale-vetch (35:65) could have reduced levels of ADF by the presence of vetch; however, other mixtures including vetch in cereals (oat and barley) did not change significantly the content of ADF mixtures9.
TDN content refers to the nutrients from the forage that are available to the animals, and these values are associated with ADF concentrations in the forage. In previous studies carried out on cereal mixtures (oat and triticale) with vetch indicate that the content of TDN decreases as the ratio of seed vetch increased in the mixture9. In the present study, the ratio of vetch seed in cereals did not reduce the concentrations of TDN, since the vetch monoculture and mixed with barley (65:35) were those who had higher amounts of TDN. It is likely that the high values of TDN reported in common vetch are attributed on one hand to the low values of ADF present in vetch, but mainly to the phenological stage in which it was harvested.
NEL was not affected by the mixture of crops, nor by the harvest phenological stage. Only the vetch monoculture (1.62 Mcal kg-1 DM) presented higher values of NEL than the cereals. These results differ from those by Lithourgidis et al9, who reported that the net energy of lactation was similar for oat-vetch and triticale-vetch mixtures and monocultures oat, triticale and vetch. Also, these same authors28 found no significant differences between mixtures of vetch with barley or wheat vetch in terms of NEL content. It is likely that the content of NEL found in this study was due to sampling at the different phenological harvesting stages of the crop, since in the study reported by Lithorurgidis, NEL was evaluated in the milky-dough grain state, whereas in the present study, there was no interaction between monocultures and the harvest stage.
RFV is the index that is used to predict consumption and energy value of forage, and this is derived from the digestibility of dry matter and dry matter intake29. Those forages with values greater than 151 are considered excellent30. In the present study, vetch was the monoculture that presented the highest values (167.2) during the whole grain stage, which is considered excellent in animal feed. It was followed by the monoculture of oat with a value of 133, which was not different from the vetch. Both values depended on the phenological stage of harvest.
Conclusions and implications
It can be concluded that the production and quality of vetch mixed forage with cereals (barley, oat and triticale) depend on the stage of harvest. In this study, oat-vetch mixture achieved higher production of dry matter and better crude protein content. In addition, the relative feed value was higher during the mature grain stage. These results suggest that oat-vetch mixture may be a viable alternative for the production of good quality forage for ruminant feed during the winter.
Acknowledgements
We thank the COFUPRO-Fundación Produce Zacatecas for providing financial support through the project entitled “Technology transfer in cutting forage production and its conservation (silage in milk production).”
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Received: May 15, 2015; Accepted: August 13, 2015