J. F. Pérez

University of Barcelona, Barcino, Catalonia, Spain

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Publications (71)87.02 Total impact

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    ABSTRACT: An experiment was conducted to evaluate the influence of different Ca sources (limestone, Ca chloride, and Lipocal, a fat-encapsulated tricalcium phosphate, TCP: ) in conjunction with 4 dietary levels of non-phytate P ( NPP: ) on performance, ileal digestibility of Ca and P, and bone mineralization in broiler chickens. Calcium sources were also evaluated in vitro to measure acid-binding capacity ( ABC: ) and Ca solubility at different pH values. Ca chloride showed the highest solubility of Ca, with TCP showing the highest ABC. Ross male broiler-chicks were sorted by BW at 1 d post-hatch and assigned to 5 cages per diet with 5 birds per cage. Twelve diets were arranged in a 3 × 4 factorial of the 3 Ca sources and 4 levels of NPP (0.3%, 0.35%, 0.4% or 0.45%) consisting of 4 added P levels (Ca(H2PO4)2) with a high dose of phytase (1,150 U/kg) in all diets. On d 14 post-hatch, 3 birds were euthanized, and ileal digesta and the right tibia were collected to determine ileal Ca and P digestibility and bone mineralization, respectively. Feed intake ( FI: ) and weight gain ( WG: ) on d 14 was higher (P < 0.01) with TCP and limestone than with Ca chloride. Added P increased the tibia weight and tibia ash content in chicks fed TCP up to 0.4% NPP and limestone up to 0.35% NPP. Calcium ileal digestibility was higher (P < 0.01) with Ca chloride (73.7%) than with limestone (67.1%) or TCP (66.8%), which increased (P < 0.05) with added levels of P from monocalcium phosphate. Phosphorus ileal digestibility was not affected by the Ca source and increased (P < 0.001) with added levels of NPP. It can be concluded that starting broilers responded better to low-soluble Ca sources compared to high-soluble sources. A level of 0.35%-0.40% NPP with a high dose of phytase (1,150 U/kg) in diets including limestone or TCP is sufficient to guarantee performance and bone formation for broiler chickens from d 0 to d 14. © 2015 Poultry Science Association Inc.
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    ABSTRACT: The potential of a prebiotic oligosaccharide lactulose, a probiotic strain of Lactobacillus plantarum, or their synbiotic combination to control post-weaning colibacillosis in pigs were evaluated using an enterotoxigenic Escherichia coli (ETEC) K88 oral challenge. Seventy-two weanlings were fed four diets: a control diet (CTR), supplemented with L. plantarum (2 × 10(10) CFU ⋅ day(-1)) (LPN); with 10 g ⋅ kg(-1) lactulose (LAC) or a combination of both treatments (SYN). After 7 days the pigs were orally challenged. Six pigs per treatment were euthanized on days 6 and 10 post challenge (PC). Inclusion of lactulose improved the average daily gain (ADG) (P < 0.05), increased lactobacilli (P < 0.05) and the percentage of butyric acid (P < 0.02) in the colon. An increase in the ileum villous height (P < 0.05) and a reduction of the Pig Major Acute-phase Protein (Pig-MAP) in serum (P < 0.01) were observed also. The inclusion of the probiotic increased numbers of L. plantarum in the ileum and colon (P < 0.05) and in the total lactobacilli in the colon and trend to reduce diarrhoea (P = 0.09). The concentration of ammonia in ileal and colonic digesta was decreased (P < 0.05) and the villous height (P < 0.01) and ileal goblet cells (P < 0.05) increased at day 10 PC. A decrease in plasmatic TNF-α (P < 0.01) was also seen. Positive effects of both additives were combined in the SYN treatment resulting in a complementary synbiotic with potential to be used to control post-weaning colibacillosis.
    Applied and Environmental Microbiology 06/2014; 80(16). DOI:10.1128/AEM.00770-14 · 3.95 Impact Factor
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    ABSTRACT: Traditionally, feeding highly digestible ingredients and including in-feed antibiotics as growth promoters has been recommended in piglets diets. However, the ban of in-feed antibiotics as growth promoters in many countries, together with the increases in price of many ingredients, favours the study of less complex diets in the post-weaning (PW) period. In this respect, the inclusion of dietary fibre (DF) as a mean to overcome problems associated with the weaning process might be of value. In PW piglet feed, functional characteristics of fibrous ingredients are likely more important than the chemical composition of the fibrous ingredients. This article reviews the functional effects of DF on the digestive tract of piglets during the PW period. Evidence presented in this review indicates that moderate levels of insoluble fibre sources preferably as coarse particle size and when pigs have a compromised health status, might have positive effects promoting gut health during the first two weeks after weaning. These positive effects might be associated with enhanced maturation of the gastrointestinal tract (GIT) as well as with the physical effect of DF on the growth of intestinal microbiota and the blocking of the adhesion of pathogenic bacteria to the GIT mucosa. On the other hand, inclusion of soluble and rapid fermentable fibre sources in the diet for the first two weeks after weaning, especially with early weaning in farms with poor health status, might be contraindicative due to the limited digestive capacity of the piglets. Once the pigs adapt to solid feed, higher amounts of soluble and fermentable fibre sources, can be gradually included in the diet to promote healthy fermentation of undigested nutrients and better absorption of SCFA by the colon mucosa. Under poor hygiene conditions, the level of fermentable fibre and CP content of the PW diets should be limited to avoid intestinal dysbiosis, which might increase the risk of post-weaning diarrhoea (PWD).
    Animal Feed Science and Technology 03/2014; DOI:10.1016/j.anifeedsci.2013.12.013 · 2.09 Impact Factor
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    ABSTRACT: The prebiotic lactulose, a probiotic strain of Lactobacillus plantarum (L. plantarum) and a synbiotic combination of these two agents were evaluated as growth promoters in 25–39- day old commercial weaning pigs. Ninety-six weaning pigs were allocated into 32 pens, taking initial weight into account, and distributed into four groups as follows: a control diet (CTR), the same diet supplemented daily with L. plantarum (109 CFU/mL sprayed on top; 20 mL/pig) (LPN); 10 g/kg lactulose (LAC) or a combination of both treatments (SYN). At day 14, eight piglets from each group were euthanized and proximal colon digesta was sampled for luminal pH, short-chain fatty acids (SCFA) and lactic acid concentrations. Deoxyribonucleic acid was extracted from colonic digesta and the microbial community was profiled by terminal restriction fragment length polymorphism analysis (T-RFLP) and qPCR. Blood urea nitrogen (BUN) and acute-phase proteins (Pig-MAP) were measured. Lactulose treatment (LAC) improved feed intake (P<0.05), average daily gain (P<0.01), feed:gain ratio (P<0.05) and reduced BUN (P<0.01). Both, LAC and LPN treatment, decreased the Enterobacteriaceae:Lactobacillus spp. ratio in the colonic luminal contents (P<0.05). Moreover LPN treatment promoted a decrease in the percentage of branched fatty acids (P<0.01) suggesting a reduction in proteolytic microbial activity. Microbial profiling of colonic luminal contents by T-RFLP revealed changes in some microbial species. Terminal restriction fragments (TRFs) compatible with Bifidobacterium thermoacidophilum were more frequently detected in experimental diets compared to CTR (P<0.05). Pigs receiving SYN diet demonstrated the combined positive effects of individual LAC and LPN treatment although we were not able to show a specific increase in the probiotic strain with the inclusion of lactulose. Collectively, these data suggest the combination of lactulose and L. plantarum acts as a complementary synbiotic, but not as a synergistic combination.
    Animal Feed Science and Technology 10/2013; 185(3-4):160-168. DOI:10.1016/j.anifeedsci.2013.07.009 · 2.09 Impact Factor
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    ABSTRACT: Enterotoxigenic Escherichia coli (ETEC) K88 is the most prevalent enteropathogen in weaned piglets, with the ability to express fimbria F4 and specifically attach to intestinal receptors in the young piglet. The prevention of ETEC K88 adhesion to the epithelium by interfering in this fimbria-receptor recognition provides an alternative approach to prevent the initial stage of disease. The aim of this study is to screen, among different feed ingredients (FI), their ability to reduce ETEC K88 attachment to the porcine intestinal epithelial cell-line (IPEC-J2). The selected FI consisted of products of a vegetable or dairy origin, and microbial by-products, which could be suitable to be included in piglet's diet. Incubation of a mixture of each FI extract with the bacteria on IPEC-J2 monolayer was allowed. After washing with PBS to remove the non-adhered bacteria, the culture medium was added to grow the adhered bacteria and, simultaneously, to keep the cells alive. Then, the bacterial growth was monitored in a spectrophotometer reader for 12h. Casein glycomacropeptide (CGMP), locust bean (LB), exopolysaccharide (EPS) and wheat bran (WB) reduced the number of attached ETEC K88 to IPEC-J2, but no anti-adhesive effect was found for soybean hulls, sugar-beet pulp, locust gum, fructooligosaccharides, inulin, mushroom, mannanoligosaccharides or the fermented product from Aspergillus oryzae. The lineal analysis of dose responses demonstrated lineal activity (P<0.0001) for CGMP, LB, EPS and WB. These in vitro results suggest CGMP, LB, EPS and WB as good candidates to be included in piglet's diet with supported functional activity against colibacillosis.
    Veterinary Microbiology 08/2013; 167(3-4). DOI:10.1016/j.vetmic.2013.07.035 · 2.73 Impact Factor
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    ABSTRACT: Flavour cues present in amniotic fluid are used in mammals to find their mother early, but they are also useful for having contact with environmental flavours before birth. Three experiments have been performed to evaluate if piglets, during lactation and post-weaning, have the ability to prefer natural or artificial cues previously added to the gestating diets. For 7 min, pigs, in pairs, were offered a triple-choice stimulus through a Triple-U-Testing Arena among maternal amniotic fluid, alien amniotic fluid or water (Experiment 1) or among a flavour added to the late-gestation diet, a control flavour and water (Experiment 2). The same prenatal strategy was used to study the piglet's preference for flavoured or unflavoured creep feed during the suckling period (Experiment 3). Suckling piglets preferred amniotic-fluid flavours from their own mother over an alien amniotic fluid and they also preferred specific flavour cues given to the sows during late gestation (anise and milky-cheese). However, prenatal flavour exposure did not improve the preference of piglets for a flavoured compared to an unflavoured creep feed diet. Pre-natal exposure to flavours via maternal diet influences the piglet's preferences for new flavours, probably through a positive association between flavours and the hedonic reward of the uterine experience and a familiarity effect. Nevertheless, our results do not exclude alternative routes of exposure of the newborn piglets to sow feed odours. Preferences acquired before birth seem to be long-lasting. This may be an important factor to reduce neophobia for specific flavours in young pigs.
    Animal Feed Science and Technology 07/2013; 183(3-4):160-167. DOI:10.1016/j.anifeedsci.2013.04.023 · 2.09 Impact Factor
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    ABSTRACT: High doses of Zn are widely used for prevention and treatment of diarrhoea in weaning piglets; however, the mechanism of action of Zn against diarrhoea is still not well understood. The objective of this study was to evaluate whether weaning induces Zn deficiency in piglets. Eight litters of primiparous sows were selected for the experiment, and 3 piglets presenting similar weights were selected within each litter. Two of the three selected piglets from each litter were weaned at 21d of age and fed two different diets: a commercial control diet (WCt) and the same diet plus 2000 ppm of Zn as ZnO (WZn). The third selected pig from each litter was kept unweaned (Uw) with the sow and the rest of the litter. All 24 selected animals were killed at 28 d of age, and blood, gastrointestinal content, liver, pancreas and spleen were sampled for Zn, Fe and Cu analysis (mg/kg or L of sample). Data were analysed using anova including treatment as a fixed factor. Weaned pigs fed WCt diet presented a lower Zn concentration in plasma than Uw animals (0.76 ± 0.091 vs. 1.10 ± 0.099 mg/L, p = 0.05). Zinc levels in liver, pancreas and spleen were not affected by weaning. Total concentration of Zn was higher in gastrointestinal contents of weaned animals fed WCt diet than in Uw pigs (p ≤ 0.001 for stomach, jejunum, ileum, caecum and colon). Supplementation with high doses of ZnO increased levels of Zn in gastrointestinal content (p < 0.001), liver (p < 0.001) and pancreas (p < 0.001) compared to WCt diet. It also increased plasma Zn to non-deficient levels (1.32 ± 0.086), but the increase was not as marked as in other locations and final concentration was not different than that in Uw animals (p = 0.231). Weaning creates a Zn deficiency situation in weaned pigs as observed by plasma Zn concentrations. ZnO supplementation counteracts Zn deficiency.
    J Anim Physiol a Anim Nutr 05/2013; 97:6-12. DOI:10.1111/jpn.12046 · 1.32 Impact Factor
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    ABSTRACT: Pigs can learn to prefer a flavor if it has been previously associated to positive consequences. The aim of this experiment was to study flavor preferences conditioned by the postingestive effect of nutrients in pigs. In total, 240 weanling piglets were allocated in 24 pens (10 piglets/pen) and distributed to 2 groups of animals (12 pens per group). Pigs in Group 1 (G1) were trained during 8 d with one flavor [positive conditioned stimulus (CS+)] into a protein solution [4% porcine digestible peptides (PDP)] on odd days and another flavor [negative conditioned stimulus (CS-)] into 100 mM of monosodium glutamate (MSG) solution on even days (5-L bottle for 24 h). In the second group of pigs [Group 2 (G2)], CS+ was mixed into a 4% sucrose solution in odd days and CS-into 1% sucrose +0.08% saccharine on even days. Therefore, treatments were defined as CS+, the flavor associated with PDP or sucrose, on odd days, which were assumed to have a higher postingestive effect than MSG or saccharine + sucrose, the ingredients associated to CS-. Concentration of ingredients in the solutions were chosen to ensure that hedonic attraction for PDP and MSG solutions and for sucrose and saccharine + sucrose were similar (checked in previous double-choice studies). The amount of solution offered during training period was prepared to be totally consumed each day to equalize flavors intake. Flavors (0.0375% anise or garlic) were counterbalanced across replicates to act as CS+ or CS-. Double-choice test between flavors dissolved in water (CS+ and CS-) were performed by selecting 2 pigs/pen on days 1, 6, and 8 after the training period. Solution intake was measured after 30 min. Piglets showed higher intakes for CS+ than CS-in G2 [212 vs. 76 mL and 168 vs. 86 mL (P < 0.05) and 195 vs. 78 mL (P = 0.15)] on days 1, 6, and 8, respectively. Differences between CS+ and CS-consumption were observed in G1 on day 8 (231 vs. 130 mL; P < 0.05). In conclusion, weanling pigs can acquire flavor preferences through associative learning between a flavor and postingestive effects of some nutrients.
    Journal of Animal Science 01/2013; 90(Supplement 4):381-383. DOI:10.2527/jas.51308 · 1.92 Impact Factor
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    ABSTRACT: Physiological state or dietary nutrient content can be determinants of the sensory perception with consequences for feed preferences. The aim of the present study was to assess whether the preference for protein or carbohydrate of piglets is affected by dietary energy density. In total, 240 weanling piglets (28 d old; initial BW 7.2 +/- 1.1 kg) were allocated to 24 pens (10 pigs/pen) according to BW. Piglets were split up into 2 groups and had ad libitum access to a high energy (HE; 3.90 Mcal DE/kg; crude fat 129 g/kg) or a low energy (LE; 3.35 Mcal DE/kg; crude fat 60 g/kg) diet with similar CP content (190 g/kg). Piglet performance and preference for protein [porcine digestible peptides (PDP; Palbio 62SP, Bioiberica, Palafolls, Spain) 20 g/L] or carbohydrate (sucrose 20 g/L) solutions were measured on days 14 and 21 after weaning using a double-choice test (DCHT). The LE diet promoted a higher (P < 0.05) ADFI and ADG than the HE diet. Final BW on day 21 was higher (P < 0.001) for piglets fed the LE diet than piglets fed the HE diet (12.8 vs. 11.5 kg). Preference (P > 0.05) was not observed for protein or carbohydrate solutions on day 14 or 21 in piglets fed the LE diet. On the other hand, piglets fed the HE diet had higher (75% on day 14 and 65% on day 21; P < 0.01) preference for the sucrose solution. Dietary energy level and consequent nutrient imbalances, such as dietary protein-to-energy ratio, may affect feed preference for protein or carbohydrate solutions in piglets.
    Journal of Animal Science 01/2013; 90(Supplement 4):71-73. DOI:10.2527/jas.49994 · 1.92 Impact Factor
  • XV Jornadas sobre Producción Animal. AIDA, ITEA, Zaragoza, Spain; 01/2013
  • IUNS 20th International Congress of Nutrition, Granada, Spain; 01/2013
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    Proceedings of The Nutrition Society 01/2013; 72(OCE3). DOI:10.1017/S0029665113001420 · 4.94 Impact Factor
  • XIV Biennial Conference of the Australasian Pig Science Association (APSA)., Melbourne, Australia.; 01/2013
  • 46th International Congress of the International Society for Applied Ethology, Viena, Austria.; 01/2012
  • 46th International Congress of the International Society for Applied Ethology, Vienna, Austria.; 01/2012
  • ASAS Annual Meeting, Phoenix, Arizona, USA.; 01/2012
  • ASAS Annual Meeting, Phoenix, Arizona, USA.; 01/2012
  • ASAS Annual Meeting, Phoenix, Arizona, USA.; 01/2012
  • ASAS Annual Meeting, Phoenix, Arizona, USA.; 01/2012

Publication Stats

666 Citations
87.02 Total Impact Points


  • 2004–2015
    • University of Barcelona
      Barcino, Catalonia, Spain
  • 1995–2014
    • Autonomous University of Barcelona
      • • Faculty of Veterinary
      • • Centre de Recerca en Sanitat Animal (CReSA)
      Cerdanyola del Vallès, Catalonia, Spain
  • 1997
    • University of Zaragoza
      • Departamento de Producción Animal y Ciencia de los Alimentos
      Zaragoza, Aragon, Spain