ABSTRACT An experiment was carried out to study the effect of different eubiotics on productive characteristics, intestinal integrity, as well as the content of enterobacteria in the cecum of broiler chickens. A completely randomized design with five treatments and 8 replicates of 25 birds each was used. In total 1000 mixed broiler chickens from Ross308 strain, one day old were obtained from a commercial hatchery. The birds were housed on concrete floors in a conventional house. A sorghum+soybean meal control diet was used, to which the additives under study were added. The treatments were distributed as follows: T1 = Control diet without antibiotic or eubiotic; T2 = T1 + bacteriophages; T3 = T1 + antibiotic; T4 = T1 + probiotic; T5 = T1 + symbiotic. The results obtained at 49 days of age for weight gain and feed conversion rate improved (p<0.05) with the addition of the antibiotic and eubiotics. A lower (p<0.05) intestinal density was observed with the probiotic. The height, width, and area of villi in duodenum was higher (p<0.05) when antibiotic and eubiotics were included. In the histological score, in duodenum, the antibiotic and eubiotics resulted with a higher score (p<0.05), associated to a physiological and controlled inflammation response that allowed improving productivity. Finally, the relative expression of enterobacteria, such as Lactobacillus salivarius, allowed associating positive changes in the microbiome and better productive parameters when including the symbiotic, with comparable results to the antibiotic when including the eubiotics.

Abstract: Exogenous phytase could influence dietary protein availability by variation in using dose. The objective of the present study was to determine if incremental dosing of an evolved E.coli 6-phytase would lead to improvements in lysine availability through evaluating performance and bone status in Bovans White layers. A total of 182 layers were placed in individual cages and distributed to 13 treatments: a 3 × 4 factorial arrangement with three levels of digestible lysine (dLys - 0.67, 0.77, and 0.87 %) and four doses of phytase (0, 300, 1 200, and 4 800 FTU/kg) in 0.12 % available P (avP) diets. Additionally, one phytase-free control treatment was included with 0.25 % avP and 0.87 % dLys. Productive parameters were recorded for 25 weeks, from 39 week-old. At the end, abdominal fat deposition and the tibia were sampled; in bone was determined breaking strength and bone ash. Layers fed 1 200 FTU/kg phytase increased egg production percentage (F3,169= 2.01, p = 0.111), abdominal fat deposition (F3,169= 2.52, p = 0.059), bone breaking strength (F3,169= 4.29, p = 0.006) and bone ash weight (F3,169= 3.62, p = 0.014) compared with non-phytase inclusion. Furthermore, 1 200 FTU/kg phytase decreased incidence of broken eggs and soft-shell eggs (F3,169= 2.9, p = 0.036). Phytase and dLys levels influenced egg mass and bone ash concentration (F12,169= 1.86, p = 0.043). FCR and body weight loss was reduced with phytase inclusion (respectively: F12,169= 2.43, p = 0.006, and F12,169= 2.24, p = 0.012). Phytase-free control diet increased egg weight (F12,169= 3.70, p < 0.001), but gave greater BW loss (F12,169= 17.79, p < 0.001), less abdominal fat content (F12,169= 5.85, p < 0.001), and no effect on other variables (p > 0.07). In conclusion, 1 200 FTU/kg of phytase improved productive performance and preserved body weight and bone status, without equivalence of phytase inclusion for dLys level, even with higher doses.

ABSTRACT. To determine the saturation point of absorption and cutaneous deposition of yellow xanthophylls (XA) in broilers, two hundred and sixteen Ross 308 chickens (108 males and 108 females) were sorted by sex and randomly assigned to 6 dietary treatments containing 6 replications of 6 birds each. Treatments consisted of increasing levels of xanthophylls from Aztec marigold flower (Tagetes erecta) (65, 92, 119, 146, 173, and 200 ppm). Weight gain, feed consumption, and feed conversion were measured weekly. Plasma pigment levels and skin yellowness in live birds were measured twice per week. Growth performance was analysed through ANOVA for a 6X2 factorial arrangement, where the first factor was the XA adding at six levels, and the second factor was sex at two levels. Pigment plasma concentration and skin yellowness were fitted into a multiple linear regression model. Results indicated that the highest levels of plasma xanthophylls and skin yellowness were found after 28 d of feeding. Skin yellowness increased by 2.24 b* for every d of xanthophylls consumption. In the females, skin yellowness was 1.35 b* higher than in the males. Increasing dietary xanthophylls by 10 ppm was reflected in 0.83 b* of increase in skin yellowness.

RESUMEN. Para evaluar el punto de saturación en la absorción y depósito cutáneo de xantofilas amarillas (XA) en pollos de engorda, doscientos dieciséis pollos (108 machos y 108 hembras) Ross 308 fueron asignados aleatoriamente a 6 tratamientos, cada uno con seis réplicas con seis aves cada una. Los tratamientos consistieron en adicionar al alimento seis niveles diferentes de XA de flor de cempasúchil (Tagetes erecta) (65, 92, 119, 146, 173, y 200 ppm). La ganancia de peso, consumo de alimento y conversión alimenticia se midieron semanalmente. Los niveles de pigmento plasmático y amarillamiento cutáneo en aves vivas se midieron dos veces por semana. La ganancia de peso se analizó con ANOVA mediante un arreglo factorial 6x2 (primer factor los niveles de XA y el segundo factor el sexo). La concentración plasmática de pigmento y el amarillamiento en piel se analizaron mediante un modelo lineal de regresión múltiple. Los resultados indicaron que los mayores niveles de XA en plasma y piel se encontraron después de 28 días de alimentación. El amarillamiento en piel aumentó 2,24 b* por cada día de consumo de XA. En las hembras, el amarillamiento en piel fue 1,35 b* mayor que en los machos. El aumento de 10 ppm de XA en la dieta se reflejó en un incremento de 0,83 b* de amarillamiento en piel.

Two experiments were conducted in broiler chickens from 21 to 49 d of age to evaluate the plasmatic level, deposition, and digestibility of xanthophylls (XA) from marigold flower (Tagetes erecta) after infection with vaccine strains of Eimeria spp. In Experiment 1, 432 birds were assigned to 4 treatments: 1) non-infected control; 2) 8.32 x 10(4) sporulated Eimeria oocysts (SEO)/bird; 3) 17.82 x 10(4) SEO/bird, and 4) 49.92 x 10(4) SEO/bird. In Experiment 2, 400 broilers were assigned to 4 treatments: 1) non-infected control; treatments 2 to 4 were challenged with 8.32 x 10(4) SEO/bird. The birds received 85, 108, 141, and 162ppm of total dietary XA from d 35 to 49 for treatments 1 to 4, respectively. Both experiments contained 4 replications (2/sex) per treatment. In Experiment 1, the SEO dose was associated with the reduction in body weight gain (BWG), skin yellowness units (b*), and plasma xanthophylls (PX). In both sexes, b* increased by 1.36/d of XA consumption. For every 10(4) SEO, PX decreased by 0.8 μg/ml/d, and 0.06b*. In Experiment 2, no difference was detected in PX or b* at 49 d between treatments. XA digestibility decreased by 15 units in the infected birds. Results suggest that XA digestion and absorption are similar between males and females. However, females have a greater ability for skin XA deposition. After a mild Eimeria spp. infection, it is possible to achieve adequate skin yellowness (SY) levels if the infected birds are treated immediately and receive at least 62 mg of dietary XA/bird for 14 d.

Se evaluó el nivel plasmático, depósito cutáneo y digestibilidad de xantófilas (XA) de flor de cempasúchil (Tagetes erecta) en pollos infectados por vía oral con cepas vacunales de Eimeria spp. En el experimento 1 se probaron diferentes dosis infectantes: 1) testigo no infectado; 2) 8,32 x 10(4) ooquistes esporulados de Eimeria (OEE)/ave; 3) 17,82 x 10(4) OEE/ave, y 4) 49,92 x 10(4) OEE/ave; en el experimento 2 se utilizó una dosis infectante y diferentes dosis de pigmento en la dieta: 1) testigo no infectado; y los tratamientos 2 a 4 se desafiaron con 8,32 x 10(4) OEE/ave, las aves fueron tratadas, y se proporcionaron 85, 108, 141, o 162 ppm de XA totales en la dieta en los grupos 1 a 4, del día 35 al 49 de edad. Cada experimento tuvo 4 réplicas (2/sexo) por tratamiento. En el Experimento 1 la dosis de OEE se asoció con la reducción en la ganancia de peso, unidades de amarilleamiento cutáneo (b*), y nivel de xantófilas plasmáticas (XP). Por cada 10(4) OEE las XP disminuyeron 0,80 mg/ml/d, y 0,06 en b*. En el Experimento 2 la digestibilidad de las XA disminuyó 15 unidades en las aves infectadas y los niveles de XP o b* fueron similares entre tratamientos al final de la prueba. Se sugiere que la digestión y absorción de XA es entre sexos, pero la hembra deposita más XA cutáneas. Después de una infección moderada por Eimeria es posible lograr niveles comercializables de amarilleamiento cutáneo (SY) mediante un tratamiento y al menos 62 mg de XA/ave/14 d.