The modern animal exploitation is characterized by a high productive intensity, regardless of the species. This makes the animals to undergo constant stressing situations that may result into a higher frequency of disease appearance and decrease of productive levels (Hernández et al. 2015 and Jaque et al. 2015), being the gastrointestinal processes some of the most outstanding problems affecting the profitability of the exploitation system used.
Due to the current intensive management methods, farm animals are very sensitive to enteric bacterial unbalances in the gastrointestinal tract, which leads to an insufficient nutrient conversion and growth delay (Pérez et al. 2015). For counteracting these problems, for years, diets have been supplemented with antibiotics, which proved to be effective in the decrease of diarrheas and as animal growth promoters (Milián et al. 2017a). However, their excessive use resulted in the development of pathogenic strains resistant to these antimicrobials. Therefore, it is necessary the study and introduction of practices of feeding and managing of different products that contribute to avoid these negative effects (Linares 2015).
The World Organization for Animal Health (OIE) 2014 works on introducing new products and technologies into animal production systems for obtaining healthy food that allows high productions with a proper economical sustainability and biological guarantee for protecting animals and humans. Among these products, there are the zootechnical additives with probiotic effect, which represent a potentially significant and safe therapeutic progress (Pérez et al. 2015, Pérez et al. 2016 and Milián et al. 2017b). It is known the existence of some zootechnical additives with positive response in different species of economic interest. However, the unusual practice of zootechnical additives in Cuba generates negative effects on productive, physiological and health performance in different pig categories. Therefore, the objective of this study was to evaluate the zootechnical additive VITAFERT in the productive performance and health of pre-fattening piglets.
Materials and Methods
This study was carried out in the Centro Porcino Gelpis of Matanzas province, located in the epizootiological quadrant 036-117-59. The experiments were conducted during the months between January and March, 2017.
A total of 200 pigs were used of a commercial crossing, in the prefattening category, which were crossbred from crossing York-Land (YL), Large White-Landrace (LWxL) females and Duroc Jersey males, and L-35 females and castrated males in the same proportion. The evaluate animals had a mean weight of 7 kg, liveweight was estimated to 100 % of the animals with use of a KERN diameter model scale. Periodically, disinfection, disinsection and pest control were performed in order to fulfill the rules for this type of breeding system, reaching a favorable health state of the unit.
Four treatments and five repetitions were performed, with a completely randomized design under commercial production conditions. Levels of Vitafert were used at a rate of 0, 5, 10 and 15mL/kg of liveweight (LW), respectively. Vitafert was produced according to the methodologies of Elías and Herrera (2008), substituting final molasses for raw sugar for animal intake. For producing the product, plastic tanks of 220 L, wood spatulas for stirring and raw matters (maize, soybean meal, urea, mineral salt, ammonia sulfate, raw sugar for animal intake and 1L of natural yogurt) were used. The additive was added to the concentrate a few minutes before providing it to the animals.
The animals under study were fed according to the regulations of the Manual de Crianza Porcina (MCP 2008) and the zootechnical additive Vitafert was added. The provided food was the initial concentrate in pellet shape and nutrient contribution was calculated (table 1).
Procedure for evaluating biological activity in each sampling is described as follows:
Productive indicators:
Weight increase
IP-1 = PF - PI
Where: PF: final weight; PI: initial weight
Food conversion
CA = CaxIP-1
Where: (Ca: food intake) Daily mean gain
DMG = PF - PI x 43 days-1
Health indicators. Mortality and incidence of diarrheas were the evaluated health factors, with a daily observation to verify the existence or not of these indicators. For classifying diarrheas, the clinic was taken into account and samples were taken to the lab for confirmation of their diagnosis.
Statistical processing. For the analysis of results, the statistical software INFOSTAT, version 2012 (Di Rienzo et al. 2012) was used. In the case of productive indicators, an analysis of variance of simple classification was applied. For classifying diarrheas, an analysis of variance was used through contingency tables to demonstrate the interaction between treatments and types of diarrheas, applying comparison test of Duncan (1955) for P<0.05 in the necessary cases. The test CompaPro- version 1 (2007) with a 95 % of reliability to establish the existence of statistical differences for the incidence of diarrheas per days and mortality.
Results and Discussion
Table 2 shows the results obtained in the performance of productive indicators of pre-fattening piglets, housed in Flat Decks. There is an improve of indicators measured among treatments regarding to control group (P<0.01) and among treatments (G-I: 5mL/kg of LW, G-II: 10mL/kg of LW and G-III: 15mL/kg of LW), with the best performance in G-III.
These results could be related to the production of lactic acid, acetic and antibacterial substances by Lactobacillus spp., and digestive enzymes that generate the yeasts within Vitafert, according to Elías and Herrera (2008), which could allow to maintain a favorable state of eubiosis for the animal. Similar results were obtained by Rondón et al. (2013) and Rodríguez (2017), with the evaluation of the zootechnical additives PROBIOLACTIL®, SUBTILPROBIO® and PROBIOLEV® in other categories of zootechnical interest, obtaining improvement in the productive indicators.
Recent researches (Milián et al. 2017a b and Rodríguez 2017) demonstrated that Bacillus genus produces LFB 112 bacteriocin and the lepopeptides Surfactin and Mycosubtilin that inhibit the development of positive Gram and negative Gram bacteria, germs involved in animal diseases of zootechnical interest, such as E. coli, Salmonella, C. perfringens, Streptococcus spp., S. aureus, Pasteurella multocida, and P. aeruginosa, which makes promising the use of Vitafert from the presence of this microorganism in its composition.
Other authrs like Quemac (2014), in pigs treated with probiotics (Rhodopseudomonas spp., Lactobacillus spp., and Saccharomyces spp.), obtained differences regarding weight increase, daily mean gain and conversion. Likewise, Sánchez (2016), after applying a nutraceutical additive with probiotic effect, obtained improvement for these indicators.
Studies carried out by Contino et al. (2008), in pre-fattening stages, treated with Sorbial probiotic and a daily frequency, reported a significant improvement (p<0.05) of liveweight increase and daily mean gain (DMG) regarding control. Similarly, Pérez (2008) found increses of weight and DMG in rearing and pre-fattening animals with the use of the zootechnical additive PROBIOLEV®.
Results of this study in productive indicators may be compared to those of Flores et al. (2015) and Iser (2016), who state that one of the favorable mechanisms of probiotics is that they are able to perform synthesis of compounds that are deficient in the animal diet, such as vitamins of B complex, essential amino acids, digestive enzymes, minerals, acetates and other substances necessary for growth and development of animals. In addition, they improve palatability of food and increase its intake.
Weight gains obtained with the highest levels of inclusion of the microbial preparation agree with recommendations of the Grupo Porcino (GRUPOR 2010) in intensive rearing systems with the use of concentrated food.
Table 3 and 4 show the results of diarrhea incidence during the experimental stage, demonstrating that the interaction treatments and diarrhea classification was significant. There are differences among all treatments regarding control. G- I and G- II showed no differences between them. The lowest incidence of diarrheas was achieved in G-III. Results of this study coincide with those reported by Hou et al. (2015), which demonstrated that Lactobacillus, specifically Lactobacillus reuteri, when it is provided to pigs, produces a decrease of diarrheas.
Cortés and Gómez (2011) determined that the use of probiotics in diets for pigs during the first life stages has a beneficial effect on the improvement of nutrient absorption in the small intestine. This is demonstrated in the improvement of zootechnical parameters and in the decrease of diarrhea occurrence. Giang et al. (2012), when supplemented diets with a complex of acid lactic bacteria, alone and combined with B. subtilis and S. boulardii, improved productive indicators of post-weaning pigs.
Martínez (2009) obtained a decrease of infectious and digestive diarrhea incidence with the inclusion of Vitafert formulated with final molasses and inclusion levels of 5 and 10 mL/kg of liveweight. In this same sense, results agree with those stated by López (2000), who expressed that there are many reasons for the use of organic acids on pig diets, especially during rearing and weaning stages, because they help to reduce gastric and intestinal pH under 4.2, which improves digestibility of proteins in the diet, and influences gastric emptying and mobility. On the other hand, Ayala et al. (2014) added that the action of these acids inhibit, at a great extent, the growth of pathogenic bacteria. In this context, Blanchard and Wright (2000) referred that a more favorable environment is produced for the development of beneficial bacteria like lactobacilli and streptococcus.
Table 5 shows the effects of the zootechnical additive Vitafert on mortality of pre-fattening piglets, with differences between control group and experiments with an increase of this indicator in the control group. There was a dead pig in the treatment that used the lowest dose of Vitafert. However, in the treatment that used Vitafert in 10 and 15 mL, there were no deaths, which evidences the effectiveness of the product to decrease mortality in pre-fattening stages, and this could be used as a preventive alternative. These results coincide with recent studies of Díaz et al. (2014), Flores et al. (2015, 2016) and García et al. (2016), who show the positive effect of including zootechnical additives in diets for pigs as excellent improvers of health and productive indicators.
Results of health indicators should be analyzed with a multifactorial approach in which their action start from the presence of microorganisms like lactic bacteria and yeasts. Rodríguez (2017) demonstrated that yeasts are able to adhere to the intestinal epithelium, colonize it and exert their activity with positive effect on productive indicators. Rondón et al. (2013) specified that lactic bacteria, generally, have the ability of preventing adherence and colonization of pathogenic microorganisms in the wall of the gastrointestinal tract, to preserve their function as protective barrier and inhibit cell functions of some pathogens like E. coli and Salmonella. In addition, lactic bacteria may decrease potential pathogens in the intestinal lumen, due to the antimicrobial substances they produce (bacteriocins and organic acids) and, therefore, improve the productive performance of pigs.
From the results of this research, it can be concluded that the addition of the zootechnical additive Vitafert improves productive performance and health of pre-fattening piglets, being the dose of 15 mL/kg of liveweight the one with the best effect.