Evaluación de la eficacia de aditivos basados en aceites esenciales frente a un desafío oral de Escherichia coli K88 en lechones de destete

Montoya Pérez, Daniel
Martín Orue, Susana María (dir.) ; Castillejos Velázquez, Lorena (dir.)

Manuel Fondevila Camps (ponente)

Universidad de Zaragoza, VET, 2019
Producción Animal y Ciencia de los Alimentos department, Producción Animal area

Máster Universitario en Nutrición Animal

Abstract: Phytogenic feed additives are characterized to contain botanic compounds biologically active with organoleptic and medical properties. Globally their use in feeding strategies or as alternative to growth promoters for animal production has increased, especially during the weaning period. The high stress and the abrupt feeding changes experienced by the piglet in this period have a negative impact on voluntary feed intake, which may promote the presence of enteropathies that affect piglet performance and increase mortality rates. The main objective of this study was to evaluate the potential of two phytogenic feed additives in weanling pigs to enhance gut health at early life stages and to fight intestinal pathogens. To achieve the objective, a trial was designed to evaluate the potential of two different phytogenic feed additives in weanling piglets in front of an Enterotoxigenic Escherichia coli K88 (ETEC K88) oral challenge. In brief, 96 weanling piglets were transported to the University facilities from commercial farm with mothers that did not received E. coli vaccination. Animals were distributed in 4 rooms of 8 pens each (32 pens, three animals per pen). The experiment included four treatment groups with eight replicates per each including: (i) a control group with plain diet (T1); (ii) the same plain diet supplemented with ZnO (2500 ppm Zn) (T2); (iii) supplemented with phytogenic 1 (1kg/tm) (T3); (iv) or supplemented with phytogenic 1 (1kg/tm) plus phytogenic 2 (1.5 kg/tm) (T4). Pigs were fed over 16 days ad libitum with the experimental diets. After an adaptation period, animals were orally challenged with ETEC K88 and one animal per pen was euthanized at day 8 post-inoculation (PI). In this experiment, main parameters assessed were animal performance, clinical signs, bacterial loads in the gut, immune response and intestinal morphology. In general terms, we were not able to find significant differences in performance comparing the phytogenic diets to the plain diet, although some trends could be found. ZnO supplementation increased (P = 0.03) average daily gain (ADG) in the 0-4 PI period compared to pigs fed treatment T1, and treatments T3 & T4 showed intermediate values. The same pattern was observed with gain:feed ratio (G:F; P = 0.03) in the same period. Additionally, some significant effects were found in other parameters. The numbers of lactobacilli in feces and colon digesta on day 8 PI were the highest (P = 0.0007; P = 0.03, respectively) with diets supplemented with phytogenics (T3 & T4) and the lowest with the diet including ZnO (T2). The ratio lactobacilli:coliformrs in feces on day 8 PI was significantly increased (P=0.002) by the inclusion of the T3 treatment when compared to T1 and T2, showing T4 intermediate values. Phytogenics did not affect the serological concentration of TNF-α. There was a trend at day 4 PI in Pig-MAP to decrease with T4 (P=0.07). Villus:crypt (VH:CD) ratio was significantly increased (P=0.009) by the inclusion of ZnO and also by the T4 treatment compared to T1, showing T3 intermediate values. In conclusion, both tested phytogenics could help the piglet to fight the ETEC challenges after weaning considering the numerical improvements observed in performance immediately after the challenge. This better response could be due to an improved microbiota balance suggested by the increased ratio of lactobacilli:coliforms observed in feces on day 8 PI, particularly in the T3 treatment. Additionally the phytogenic T4 shows enhanced anti-inflammatory properties with reductions in Pig-MAP serological levels concomitant with an improvement in the intestinal architecture (VH:CD ratio).

Tipo de Trabajo Académico: Trabajo Fin de Master