Effects of a commercial antibiotic and a microbial preparation on the productive performance and pigs health during fattening

Effects of a commercial antibiotic and a microbial preparation on the productive performance and pigs health during fattening

 

Efectos de un antibiótico comercial y un preparado microbiano en el comportamiento productivo y en la salud de los cerdos durante la ceba

 

 

L. Flores,I A. Elías,II F. Proaño,I G. Granizo,I Yolaine Medina,II Sandra López,I F. Herrera,II W. Caicedo,III

IEscuela Superior Politécnica de Chimborazo, Panamericana Sur km 1 1/2, Riobamba, Ecuador.
IIInstituto de Ciencia Animal, Apartado Postal 24, San José de las Lajas, Mayabeque, Cuba.
IIIUniversidad Estatal Amazónica, km 2 Vía a Napo, Pastaza, Ecuador.

 

 


ABSTRACT

To measure the influence of a Stafac (Virginiamicina at 2%, 1 kg.t-1) commercial antibiotic regarding to a microbial preparation in the productive performance and diarrheas occurrence during pig fattening, an experiment by a completely randomized design was conducted, with three treatments and four repetitions: T1) concentrate, T2) concentrate + commercial antibiotic,T3) concentrate + microbial preparation. A total of 120 barrow males were used, from Landrace x Large White cross, with Belga x Pietrain White sire, of 71 d of age, 28.62kg average weight± 2.66 kg. It was determined that, for final weight, with the concentrate plus the microbial preparation 98.41 kg of LW was obtained. This value was higher to that of the concentrate plus antibiotic and to the concentrate. For the daily weight gain and final weight gain, the best values corresponded to the concentrate plus microbial preparation, with 712.6 g and 69.84 kg respectively, which were above of the obtained for the concentrate plus antibiotic and the concentrate. In food conversion there were not significant differences between treatments. The group of animals fed with concentrate plus microbial preparation had lower number of diarrheas, with 9.25 of incidence. With the addition of this microbial preparation, better productive parameters and of health in pig fattening can be obtained, without using antibiotics.

Key words: microbial preparation, commercial antibiotic, fattening pig, whey.


RESUMEN

Para medir la influencia de un antibiótico comercial Stafac (Virginiamicina al 2%, 1 kg.t-1) con respecto a un preparado microbiano en el comportamiento productivo y ocurrencia de diarreas durante la ceba porcina, se condujo un experimento mediante un diseño completamente aleatorizado, con tres tratamientos y cuatro repeticiones: T1) concentrado solo, T2) concentrado más antibiótico comercial, T3) concentrado más preparado microbiano. Se utilizaron 120 machos castrados, del cruce Landrace x Large White, con padre  Blanco Belga x Pietrain, de 71 d de edad, 28.62 kg de peso promedio ± 2.66 kg. Se determinó que, para el  peso final, con el concentrado más el preparado microbiano se obtuvo 98.41 kg  de PV. Este valor resultó superior al del concentrado más antibiótico y al del concentrado solo. Para la ganancia de peso diaria y ganancia de peso final, los mejores valores correspondieron al concentrado más preparado microbiano, con 712.6 g y 69.84 kg respectivamente, que estuvieron por encima de los obtenidos para el concentrado más antibiótico y  el concentrado solo. Para la conversión alimentaria y conversión de proteína, los valores más eficientes correspondieron al  concentrado más preparado microbiano, con 3.24 y 540.97 g.kg PV-1 de proteína bruta (PB), respectivamente. En la conversión de energía no se encontraron diferencias significativas entre los tratamientos. El grupo de animales alimentados con concentrado más preparado microbiano tuvo menor número de diarreas,  con incidencia de 9.25. Con la adición de este preparado microbiano, se pueden obtener mejores parámetros productivos y de salud en ceba porcina, sin utilizar antibióticos.

Palabras clave: preparado microbiano, antibiótico comercial, ceba porcina, suero de leche.


 

 

INTRODUCTION

In Ecuador are used antibiotics in pig feeding that, in other countries, are considered in disuse because their application can create resistance to certain pathogenic bacteria. This not only reduces the number of antimicrobials available in the industry to control bacterial infections, but this resistance increases risks for human health.

Vondruskova et al. (2010) suggested that the continuous use of antibiotics may contribute to the bacteria reservoir resistant to drugs, able to transfer this property to pathogenic bacteria in animals and humans. The probiotics has consolidated as one of the natural alternatives to the use of growth promoters antibiotics, because they do not generate collaterals effects and produce better digestibility, weight gain and higher food conversion index (Gutiérrez et al. 2013).

Giang et al. (2011) manifested that by means of the appropriate combination of Bacillus, Saccharomyces probiotics strains and acid lactic bacteria, positive effects on growth, food conversion and nutrients digestibility in fattening pigs were verified.

Elias and Herrera (2008) informed of the obtaining and use of a product with probiotic activity, achieved from a simple biotechnological process, rich in lactobacillus, yeasts, organic acids of short carbonated chains and low pH. This product is able to controlling the E. coli development, reduce diarrheas incidence in animals and increase the liveweight gain.

In Ecuador there have been used microbial preparations with excellent probiotic activity, based on whey, sugar cane juice and pigs feces as bioacelerants. These preparations, when been products rich in organic acids, acid lactic bacteria and yeasts, improve the biopreparations quality (Díaz 2011).

The objectives of this research were to characterize chemical and microbiological the microbial preparation, to compare the nutrients content of the experimental diets and to evaluate the productive performance and of diarrheas during the fattening period.

 

MATERIALS AND METHODS

The experiment was developed in the Biotechnology and Animal Nutrition laboratories and in the Academic Pork Unit, of Cattle Sciences Faculty (CSF) from Chimborazo Higher Polytechnic School, in Ecuador (CHHPS) and it consisted on three stages:

Stage 1. Preparation and characterization of a microbial preparation. It lasted nine days. In plastic tanks (220L capacity) fresh whey, molasses, urea, mineral salt and water were mixed, according to Diaz (2011) recommendations, in percentages that are shown in (table 1).

The whey was taken from the CSF industrial dairy, CHHPS. The molasses contained 85 Brix degrees. The urea was obtained in commercial way and contained 46% of nitrogen. The mineral salt was commercially obtained and it was composed by 9% of calcium and 10% of phosphorous. The human consumption water was used and it was two hours resting before its use.

The mixture was homogenized and it was covered during 96h. For the product characterization five samples were taken (200 mL) by means of the pH determination (WPA portable potentiometer) and the organic acids content, according to Erwin et al. (1961) technique. It was also included the microorganisms recount: aerobics, mesophiles, lactic bacteria, coliforms, fungi and yeasts, according to Merck (2005) procedure. For the microbial preparation characterization the descriptive statistic was used, according Infostat (2012).

Stage 2.Comparison of nutrients content of the experimental diets. It lasted 30 d.  A concentrate that was considered as basic diet was formulated (table 2). This one  maintained the same raw matters, but it was different in their percentages for growth and fattening period, due to the animals nutritionals requirements, according to NRC reports (1998).

Table 3 shows the nutritional contribution of the experimented diets in the growing and fattening periods.

To estimate the nutritional influence that may cause the addition of the microbial preparation made by Diaz et al. (2013), regarding the addition of an antibiotic cited by Cromwell (2001), laboratory analysis were carried out for three treatments: basic concentrate, basic concentrate + microbial preparation(15 mL.kg LW-1) and basic concentrate + antibiotic(Stafac®; or Virginiamicina, in 1 kg.t-1 doses).

All treatments were subjected to proximal analysis, according to AOAC (2005).The in vitro digestibility of crude protein was determined by means of the pancreatine pepsin technique (Dierick et al. 1985) and true protein according to Bernstein (1983).For the comparison of  nutrients content of experimental diets, means of each treatment were used, after analyzing five samples.

Stage 3. Evaluation of productive indexes in fattening pigs. The initial weight, final weight, total and daily weight gain, dry matter conversion, protein conversion and energy conversion from the same conception of the treatments of stage 2 were evaluated. 

A total of 120 barrows pigs from Landrace-Large White x Belga-Pietrain cross were used, of 71d of age, of 28.62 kg LW ± 2.66 kg. Each experimental unit was composed of 10 pigs housed in 3 x 3.33 m collective pens; with density of a pig/m2. The food was offered every 24 h during the morning (8:00 a.m). 

For productive performance, the co-variable analysis in the variables final weight, total weight gain, daily weight gain, dry matter conversion, protein conversion and energy conversion was carried out. The initial weight was taken as concomitant variable, which not influence in the mentioned variables. That is why; variance analysis according to totally randomized design was carried out, according to InfoStat (2012), with three treatments and four repetitions per treatment. Duncan (1955) test for P < 0.05 was applied in necessary cases.

The theoretical suppositions of the variance analysis for number of diarrheas variable were analyzed Shapiro Wilk (1965) test for errors normality was used. The Levene (1960) test for the homogeneity variance that fulfills these suppositions was applied. That is why, it was not necessary to carry out its transformation (√x) by the statistical Software StatSoft, Inc. (2003). Later on, variance analysis was made according to initially foreseen design.

To measure the microbial preparation effect on the liver, pancreas and spleen weight of fattening pigs, a total of 12 pigs from Landrace-Large White x Belga-Pietrain cross were used. These animals were taken at random from the fattening pens, at 169d of age. The relative weight of these organs was calculated by the quocient between the weight of these organs and the final weight  of the animals. Variance analysis was carried out, according to totally randomized design, for three treatments, with four repetitions per treatment. Duncan (1955) test for P < 0.05 was  applied.

 

RESULTS AND DISCUSSION 

The microbial preparation showed 3.8 of pH, after 96 h of fermentation. The lactic acid content was of 0.122 mg.mL-1, 0.00367 mg.mL-1 of propionic acid and 0.00037 mg.mL-1 of butyric acid.The titratable acidity as lactic acid was of 3.26 %.The dry matter value was of 21.23%; total nitrogen, 1.383% and that of protein, 0.953%. The ammoniacal nitrogen content corresponded to 0.184 % and that of CP to 8.62 %.

There was total absence of totals salmonellas and coliforms. The molds and yeasts content was in 384 x 103 UFCmL-1, 8.9 Brix degrees, and acid lactic bacteria 43.12 x103 UFC.mL-1

When comparing the microbial preparation with Vitafert (Elias and Herrera 2008) some similarities in their microbiological and chemical composition were found. In this last, yeasts content oscillated between 107-108 UFC; that of lactobacillus, 109-1010 UFC; that of lactic acid, 40.5- and 54.04 mg.mL-1, and that of acetic between 13.51-25.82 mg.mL-1.

Comparison of the chemical composition of the experimental diets. Means of the treatments of nutrients content of experimental diets for growing stages are showed in table 4. The higher dry matter content took place in the concentrate, and the lower value was obtained for the concentrate plus microbial preparation.

Regarding ash content, the higher value was founded for the concentrate plus microbial preparation and the lower, for the concentrate plus the commercial antibiotic.

For protein, the higher value corresponded to the concentrate plus microbial preparation with 4.25 and 3.13 percentiles of difference regarding the concentrate plus the antibiotic, respectively. In table 4 it is show that for fat content the numeric difference is lower between the treatments means. The highest value was founded for the concentrate. Regarding fiber content, for the concentrate was higher and lower for the concentrate plus the microbial preparation.

The higher NFE content corresponded to the concentrate and the lower value, to the concentrate plus microbial preparation.

As to true protein, the highest value was in the concentrate plus microbial preparation, with 3.47 and 3.2 percentiles of difference in comparison with the concentrate plus antibiotic and with concentrate, respectively. As to CP digestibility, the best one was that of the concentrate plus microbial preparation. It was followed by the concentrate plus antibiotic, with 11.59 and 5.36 percentiles of difference, regarding the concentrate and the antibiotic, respectively.

In table 5 it is show that the higher dry matter content was for the concentrate and the lower for the concentrate plus the microbial preparation. The concentrate had the higher ash percent and the lower, the concentrate plus the microbial preparation.

For CP, the highest percentage corresponded to the microbial preparation, with difference above 6.01 and 4.43 percentiles relate to the concentrate and the concentrate plus antibiotic. In table 5 it is show that the higher fat content was in the concentrate plus microbial preparation and the lower, in the concentrate plus antibiotic. It is considered that the difference in the fat content between the concentrates is insignificant. According to NRC (1988), there were not found differences in post-weaning pigs performance, fed with concentrates that contained between 2 and 32 % of fat.

According to crude fiber content, the difference was lower between the treatment means, with higher fiber content in the concentrate. The lower value was founded in the concentrate plus antibiotic. For NFE, the concentrate obtained the higher percentage and the lower, the concentrate plus microbial preparation.

regarding to true protein, the highest concentration corresponded to the concentrate plus microbial preparation, higher in 5.63 and 4.33 percentiles regarding the concentrate, and to the concentrate plus antibiotic, respectively. As to CP digestibility, it was higher for the microbial preparation, and lower for the concentrate.

The lower content in DM was obtained with the microbial preparation addition in growing and fattening concentrates, regarding the other treatments. This was due to, possibly, to that the DM content of this latter was lower 21.23 %), and only contained 8.9 Brix degrees, meanly joined to the hydrolytic activity of acid lactic bacteria and yeasts, with CO2 and H2O production, as many authors have been informed in other foods(Aksu et al.2004, Nkosi 2009 and Weinberg et al. 2009).

In growing and fattening concentrates, the crude fiber content was considered lower: 9.05-12.19 and 10.69-11.96 %, respectively. This did not affect the intake either animals performance. In both cases, fiber values were lower to15 % of the diet, according the NRC (1998).That is why, the NFE decrease could be due to the bacteria  and yeasts quicker grow, added with the microbial preparation, that could be develop during the SSF process. A similar effect verified Elías et al. (1990) by means of the sugar cane SSF in the obtaining a food for animals, named Saccharina. Elías and Herrera (2008) also founded this kind of effect on other foods.

The reduction in NFE was directly related with the dispersion effect, due to the increase in CP (table 4 and 5). Likewise, it was founded higher content in true protein, that reached its higher value with the microbial preparation, where join to the mentioned hydrolytic effect, was possibly produce the protein synthesis, due to the microbial growth. To this respect, Elías et al. (1990) showed that the efficiency for the true protein synthesis in the soluble carbohydrates conversion process contents in the NFE was of 0.6 units.   

In the growth stage, the digestibility of the concentrate plus the microbial preparation increase in 5.36 percentiles, regarding the concentrate plus antibiotic. It was also increased in 11.59 percentiles with the concentrate. For fattening period, the digestibility of the concentrate plus the microbial preparation increased in 5.45 percentiles in relation to the concentrate plus antibiotic, and in 10.25 regarding the concentrate.

According to Díaz et al. (2013), this microbial preparation have great proteolytic enzymatic activity, that even with the higher number of acid lactic bacteria founded, it justifies  the increase in the obtained CP digestibility.

The Virginiamicina can reduce the concentration of Gram positive bacteria in pigs gastrointestinal tract and, in turn, can decrease the acid lactic production, ammonia and certain amines in the gastrointestinal tract (Vervaeke et al. 1979, Ravindran et al. 1984 and Cromwell 2001).A reduction in the intestinal concentration of ammonia and amines could reduce the digesta bypass rate, that can increase nutrients digestibility in pigs (Kass et al. 1980 and Kim et al. 2007).

Productive performance.The results obtained during the experiment regarding the final weight are showed in table 6. There were significant differences (P < 0.05) between treatments: the higher final weight was achieved with the microbial preparation, with difference of 8.13 and 13.43 kg de LW regarding to the commercial antibiotic and to the control. For total weight gain, there were significant differences (P < 0.05) between treatments. The higher value was founded for the microbial preparation, with difference of 8.27 and 13.48 kg, regarding to the commercial antibiotic and to the control. In daily weight gain there were significant differences (P < 0.05) between treatments. The highest daily weight gain was determined for the microbial preparation, with difference of 0.11 and 0.17 kg regarding to the commercial antibiotic and to the control, respectively.

For the variables dry matter intake per day, protein intake per day and energy intake per day, it was not carried out statistical analysis because there was not intra-treatments variability. Only the each treatment means were informed. The higher dry matter intake was for the microbial preparation, because when incorporating the product to the concentrate it is added dry matter of this last. The protein intake per day was higher for the microbial preparation, since the concentrate plus the product had CP higher percentage, and the dry matter intake is higher. The energy intake per day was highest in the microbial preparation, since there was higher dry matter ingestion.

According to the dry matter and protein conversion, there were significant differences (P < 0.05) between the treatments (table 6). The most efficient values were reached with the microbial preparation (0.52 and 0.19 kg of difference), while the dry matter intake per day regarding to the control and the antibiotic was 85.43 and 33.98 g.kg LW-1, respectively. For the energy conversion, there were significant differences (P < 0.05).

Reid et al. (2003) stated that the probiotics are refers to a group of non pathogenic organisms that, when are ingested in enough quantity, they produce beneficial effects on the host health. Probiotics are microorganisms live cultures that can benefit the host animal when improving the microbial balance in the intestine. The obtained results in the 99 d of experimental research agree with researches carried out by other authors.   Beruvides (2009) studied the effect of different Vitafer levels inclusion on the productive performance and of health in pig fattening. Rondón et al. (2013) informed the Lactobacillus salivarius C 65 probiotic effect on the productive and health indicators of suckling pigs. Thacker (2013) researched alternatives to antibiotics as growth promoters for its use in pig production. Wang et al. (2011) used the dietetics suplementation with the Lactobacillus fermentum 15007 probiotic and the Aureomycin antibiotic and they differentially affected the small intestine proteomics in growing pigs.

In table 7 is clearly showed that in the diarrheas incidence per animal had significant differences between the treatments with the lower number of diarrheas for the microbial preparation.

According to Corcionivoschi et al. (2010), the action mechanisms of the probiotic bacteria and its effect on the fight against digestive disorders in animals have been demonstrated and supported in many scientific researches. The probiotic bacteria are used in a wide range of nutrition techniques to support the host organism during the physiological tension, to reduce stress due to the technology and to face diarrheal syndromes.

Table 8 shows the results obtained from relative weight of pancreas, liver and spleen at 99 days of experimentation. There were no differences among treatments for relative weight. For relative weight of liver, there were differences (P 0.0351) between the microbial preparation and the two remaining treatments. For relative weight of spleen, there were differences (P 0.0007) between the microbial preparation and the two remaining treatment, and the highest value was obtained with the inclusion of the studied product.

The values obtained in this study agree with other researchers. Pino and Dihigo (2006) observed a significant increase (P 0.05) of liver weight (30%) regarding the control in pre-fattening pigs treated with a probiotic additive. This could be caused by the increase of their activity because this organ performs numerous functions for animal welfare. Ayala et al. (2010), evaluated a commercial probiotic, the used dose was 5kg/t, and they found increase in the liver relative weight of 25kg LW piglets in relation to the control.

Ayala et al. (2008) found higher weight of the spleen in animals treated with a commercial probiotic (a microbiological combination of two pure strains L.acidophilus CN CM27/6R and L. rhamnosus CN CM MA 27/6B) and Martinez (2011) explained that the presence of dead and live strains in the composition of grains dehydrated with soluble favors the increase of the spleen relative weight, which could be due to the probiotic effect.

It is concluded that the microbial preparation, when having organic acid of short chain, lactic acid bacteria and yeasts, have low pH, that is why  have probiotics properties. This improve the nutritional quality of diets, since the CP digestibility is better, and they are also higher the productive parameters, and lower the number of diarrheas in fattening
pigs.

From these results, future researches are recommended with this microbial preparation to determine their action in the cecum fermentation.

 

REFERENCES

Aksu, T., Baytok, E. & Bolat, D. 2004. ‘‘Effects of a bacterial silage inoculant on corn silage fermentation and nutrient digestibility’’. Small Ruminant Res., 55: 249.

AOAC 2005. Official Methods of Analysis. 18th ed., Gaithersburg, MD, USA: Assoc. Off. Agric. Anal. Chem. Inc.

Beruvides, A. 2009. Efecto de la inclusión de diferentes niveles de Vitafer en el comportamiento productivo y de salud en ceba porcina. M.Sc. Thesis, Instituto de Ciencia Animal.

Corcionivoschi, N., Drinceanu, D., Mircea, I., Deirdre Stack, D., Ştef, L., Julean, C. & Bourke, B. 2010. ‘‘The Effect of Probiotics on Animal Health’’. Animal Sci. Biotechnol., 43: 35.

Cromwell, G. L. 2001. ‘‘Antimicrobial and promicrobial agents’’. In: Lewis A. J. & Shoulthern L. L. (eds.), Swine Nutrition, 2nd ed., Boca Raton, FL: CRC Press, pp. 421–426.

Díaz, B. 2011. ‘‘Aprovechamiento biotecnológico de residuos agroindustriales para alimentación de animales zootécnicos’’. Rev. Colombiana de Ciencias Pecuarias, 4: 145.

Díaz, B. 2013. ‘‘Nutritional and economical efficiency of three biosilages from agroindustrial wastes in beef cattle’’. Cuban Journal of Agricultural Science, 47: 143.

Dierick, M. A., Decuypere, J. & Henderichx, H. 1985. ‘‘Protein digestion in pig measured in vivo’’. In: Just A., Jorgensen H. & Fernández J. (eds.), Proceedings of the 3rd International Seminar on Digestive Physiology in the Pig, pp. 239–332.

Di Rienzo, J. A., Casanoves, F., Balzarini, M. G., González, L., Tablada, M. & Robledo, C. W. 2012. InfoStat. version 2012, [Windows], Universidad Nacional de Córdoba, Argentina: Grupo InfoStat, Available: <http://www.infostat.com.ar/>.

Duncan, D. B. 1955. ‘‘Multiple range and multiple F tests’’. Biometrics, 11: 1.

ECUAQUIMICA 2000. Pecutrin® saborizado. Minerales + Vitaminas A, D3, E. Suplemento mineral más vitaminas ADE. no. 1AB-630-AGROCALIDAD, Available: <http://www.ecuaquimica.com/pdf_ganaderia/Pecutrin.pdf>, [Consulted: February 1, 2015].

Elías, A. & Herrera, F. 2008. Producción de alimentos para animales a través de procesos biotecnológicos sencillos con el empleo de microorganismos beneficiosos activados (MEBA). Vitafer. La Habana, Cuba: Instituto de Ciencia Animal.

Elías, A., Lezcano, O., Lezcano, P., Cordero, J. & Quintana, L. 1990. ‘‘A review on the development of a protein sugar cane enrichment technology through solid state fermentation (Saccharina)’’. Cuban Journal of Agricultural Science, 24: 1.

Erwin, E., Marco, G. & Emery, E. 1961. ‘‘Volatile fatty acid analysis of blood and rumen fluid by gas chromatography’’. J. Dairy Sci., 44: 1788.

Giang, H., Viet, T., Ogle, B. & Lindberg, J. 2011. ‘‘Growth performance, digestibility, gut environment and health status in weaned piglets fed a diet supplemented with a complex of lactic acid bacteria alone or in combination with Bacillus subtilis and Saccharomyces boulardii’’. Livestock Sci., 143: 132.

Gutiérrez, L., Montoya, O. & Vélez, J. 2013. ‘‘Probióticos: Una alternativa de producción limpia y de reemplazo a los antibióticos promotores de crecimiento en la alimentación animal’’. Producción + limpia, 8: 135.

Kass, L., van Soest, P., Pond, W., Lewis, B. & McDowell, R. 1980. ‘‘Utilization of dietary fiber from alfalfa by growing swine. I. Apparent digestibility of diet components in specific segments of the gastrointestinal tract’’. J. Anim. Sci., 50: 175.

Kim, B., Lindemann, M., Cromwell, G., Balfagon, A. & Agudelo, J. 2007. ‘‘The correlation between passage rate of digesta and dry matter digestibility in various stages of swine’’. Livest. Sci., 109: 81.

King´s College 1961. Agricultural biochemistry and nutrition. England: Newcastle upon tyne, 5 p.

Levene, H. 1960. Robust tests for the equality of variance. Contributions to Probability and Statistics. Stanford University Press, 278-292 p.

Merk 2005. Catálogo de productos, técnicas y servicios en medios de cultivo para microbiología. Alemania, 45-49 p.

Nkosi, B. D., Meeske, R., Palic, D., Langa, T., Leeuro, K. J. & Gtoenewald, J. B. 2009. ‘‘Effects of ensiling whole crop maize with bacterial inoculants on the fermentation, aerobic stability, and growth performance of lambs’’. Anim. Feed. Sci. Tech., 154: 193.

NRC 1998. Nutrient Requirement of Domestic Animal. Nutrient Requirement of swine. Washington D.C.: Nat. Acad. Sci., 85-90 p.

Ravindran, V., Kornegay, E. & Webb, K. 1984. ‘‘Effects of fiber and virginiamycin on nutrient absorption, nutrient retention and rate of passage in growing swine’’. J. Anim. Sci., 59: 400.

Reid, G., Jass, J., Sebulsky, M. T. & McCormick, J. K. 2003. ‘‘Potential uses of probiotics in clinical practice’’. Clin. Microbiol. Rev., 16: 658.

Rondón, A., Ojito, Y., Arteaga, F., Laurencio, M., Milián, G. & Pérez, Y. 2013. ‘‘Probiotic effect of Lactobacillus salivarius C 65 on productive and health indicators of lactating piglets’’. Cuban Journal of Agricultural Science, 47: 403.

Shapiro, S. & Wilk, B. 1965. ‘‘An analysis of variance test for normality (complete samples)’’. Biometrika, 52: 602.

StatSoft Inc. 2003. STATISTICA (data analysis software system). version 7.

Thacker, P. 2013. ‘‘Alternatives to antibiotics as growth promoters for use in swine’’. Journal of Animal Science and Biotechnol, 4: 6.

Vervaeke, I., Decuypere, Dierick, N. & Henderickx, H. 1979. ‘‘Quantitative in vitro evaluation of the energy metabolism influenced by virginiamycin and spiramycin used as growth promoters in pig nutrition’’. J. Anim. Sci., 49: 846.

Vondruskova, H., Slamova, R., Trckova, M., Zraly, Z. & Pavli, I. 2010. ‘‘Alternatives to antibiotic growth promoters in prevention of diarrhea in weaned piglets’’. Veterinary Medicine, 55: 2000.

Wang, X., Yang, F., Liu, C., Zhou, H., Wu, G., Qiao, S., Li, D. & Wang, J. 2011. ‘‘Dietary Supplementation with the Probiotic Lactobacillus fermented I5007 and the Antibiotic Aureomycin Differentially Affects the Small Intestinal Proteomes of Weanling Piglets1– 3’’. The J. Nut., 111: 9.

Weinberg, Z., Shatz, O., Chen, Y., Yosef, E., Nikbahat, M., Ben Ghedalia, D. & Miron, J. 2009. ‘‘Effect of lactic acid bacteria inoculants on in vitro digestibility of wheat and corn silages’’. J. Dairy Sci., 90: 4754.

 

 

Received: November 19, 2014
Accepted: May 5, 2015

 

 

L. Flores, Escuela Superior Politécnica de Chimborazo, Panamericana Sur km 1 1/2, Riobamba, Ecuador. Email: luisgerardofloresmancheno@yahoo.es

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