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1.
Regul Toxicol Pharmacol ; 99: 213-224, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30266242

RESUMEN

The current study presents a safety evaluation of a novel glucuronoxylan hydrolase (EC 3.2.1.136) from Bacillus subtilis produced in Bacillus licheniformis. The glucuronoxylan hydrolase preparation did not exhibit irritative potential to the eye and skin when applied in in vitro models. The glucuronoxylan hydrolase preparation was non-mutagenic and non-clastogenic in in vitro tests. Oral administration of the glucuronoxylan hydrolase preparation to rats did not cause any adverse effect in a 90-days subchronic toxicity study. A tolerance study was performed with broiler chickens and confirmed that this glucuronoxylan hydrolase is safe for broiler chickens when fed at the maximum recommended dose, as well as at the 10 times higher dose. In conclusion, there are no safety concerns with using this novel glucuronoxylan hydrolase as a feed additive as it is toxicologically inert and the glucuronoxylan hydrolase is well tolerated by broiler chickens. The beneficial safety evaluation of glucuronoxylan hydrolase is consistent with the fact that this type of enzyme is ubiquitous in nature.


Asunto(s)
Alimentación Animal/microbiología , Fermentación/fisiología , Hidrolasas/metabolismo , Xilanos/metabolismo , Animales , Bacillus subtilis/metabolismo , Pollos , Masculino , Ratas , Ratas Wistar , Piel/efectos de los fármacos
2.
Front Psychol ; 13: 882898, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35783757

RESUMEN

The new contexts of literary education allow for the creation of digital reading and writing practices related to what specialised literature calls digital literature. Among these practices and with an eminently theoretical content and with an example of this content, in this paper, we want to focus our gaze on cyberpoetry, conceived as an exercise in literary creativity that firstly involves use of technology and specific software for the digital creation of poetic texts and, last but not least, knowledge and mastery of poetic language and the literary conventions linked thereto. From this point of view, in initial teacher training, we work with future teachers to create cyberpoems with a dual purpose: on the one hand, to reflect on what literary reading in digital format entails and to rehearse reading mediation processes that can be carried out with this type of literature, and, on the other, to begin in the digital creation of cyberpoems that, later, may be presented and worked in a real context of the school classroom. In this paper, we present digital practices of literary reading that have been created by student teachers in initial training. The creation of these practices has been carried out with the Genially tool. For data collection, the URL of each creation is accessed in order to analyse them. The analysis of the data follows the parameters of the qualitative methodology, specifically based on three categories of analysis for each digital creation: multimodality, hypertextuality and the interaction of each digital reading proposal. The conclusions of all this allow us to affirm that the creation of cyberpoems is an exercise in literary creativity that has to take into account the digital dimension of the literary text and its reading comprehension in a multimodal environment. Thus, the teacher in initial training carries out a digital literary mediation exercise, of a creative type, which he will later carry out in his pedagogical practice.

3.
Front Microbiol ; 13: 982712, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36545207

RESUMEN

Introduction: Very little is known about the impact of n-3 long-chain fatty acids (n-3 LCFAs) on the microbiota of sows and their piglets. The aim of this study was to evaluate the effect of n-3 LCFA in sow diets on the microbiota composition of sows' feces, colostrum, and milk as well as that of piglets' feces. Methods: Twenty-two sows were randomly assigned to either a control or an n-3 LCFA diet from service to weaning. Sows' and piglets' performance was monitored. The gestating and lactating sows' microbiomes in feces, colostrum, and milk were characterized by 16s ribosomal RNA gene sequencing. The fecal microbiome from the two lowest (>800 g) and the two highest birth weight piglets per litter was also characterized, and the LPS levels in plasma were analyzed at weaning. Results and Discussion: n-3 LCFA increased microbiota alpha diversity in suckling piglets' and gestating sows' feces. However, no effects were observed in colostrum, milk, or lactating sows' feces. Dietary n-3 LCFA modified the microbiota composition of gestating sows' feces, milk, and suckling piglets' feces, without affecting lactating sows' feces or colostrum. In gestating sows' feces and milk, the decrease in genus Succinivibrio and the increase of Proteobacteria phylum, due to the increased genera Brenneria and Escherichia, respectively, stand out. In the feces of suckling piglets, the higher abundance of the beneficial genus Akkermansia and Bacteroides, and different species of Lactobacillus are highlighted. In addition, positive correlations for families and genera were found between lactating sows' feces and milk, milk and suckling piglets' feces, and lactating sows' feces and suckling piglets' feces. To conclude, dietary n-3 LCFA had a positive impact on the microbiome of suckling piglet's feces by increasing microbial diversity and some beneficial bacteria populations, had a few minor modifications on the microbiome of milk and gestating sows' feces and did not change the microbiome in lactating sows' feces or colostrum. Therefore, this study shows the effect of dietary n-3 LCFA on the microbiota of sows, colostrum, milk, and suckling piglets during the lactation period providing crucial information on the microbiota status at the early stages of life, which have an impact on the post-weaning.

4.
Front Physiol ; 13: 884925, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36148301

RESUMEN

Fast optimisation of farming practices is essential to meet environmental sustainability challenges. Hologenomics, the joint study of the genomic features of animals and the microbial communities associated with them, opens new avenues to obtain in-depth knowledge on how host-microbiota interactions affect animal performance and welfare, and in doing so, improve the quality and sustainability of animal production. Here, we introduce the animal trials conducted with broiler chickens in the H2020 project HoloFood, and our strategy to implement hologenomic analyses in light of the initial results, which despite yielding negligible effects of tested feed additives, provide relevant information to understand how host genomic features, microbiota development dynamics and host-microbiota interactions shape animal welfare and performance. We report the most relevant results, propose hypotheses to explain the observed patterns, and outline how these questions will be addressed through the generation and analysis of animal-microbiota multi-omic data during the HoloFood project.

5.
Animals (Basel) ; 11(1)2021 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-33440734

RESUMEN

The current study was conducted to examine the effects of deoxynivalenol (DON) at different levels (5 and 15 mg/kg feed) on the metabolism, immune response and welfare parameters of male broiler chickens (Ross 308) at 42 days old. Forty-five 1 day-old broiler chickens were randomly distributed into three different dietary treatments: (1) control, (2) DON-contaminated diet with 5 mg DON/kg of feed (guidance level), and (3) DON-contaminated diet with 15 mg DON/kg of feed. Five replicated cages with three birds each were used for each treatment in a randomized complete block design. The results showed that DON was detected in excreta of birds fed contaminated diets compared with controls. The metabolite DON-3 sulphate (DON-3S) was detected in plasma and excreta in both treated groups, as well as in the liver (but only at 15 mg/kg feed). The increase in the level of DON decreased the hemoglobin concentration (p < 0.001), whereas the erythrocyte counts were only decreased at 15 mg DON/kg feed. No effect of DON on the responses to common vaccines was observed. In plasma, interleukin 8 levels in both contaminated groups were significantly higher than in the control group. The expression of interleukin 6, interleukin 1ß and interferon-γ increased in jejunum tissues of broilers fed 5 mg/kg of DON compared with controls. The stress index (heterophil to lymphocyte ratio) was not affected by DON-contaminated diets compared with controls. The plasma corticosterone level was significantly lower in both DON groups compared with controls. In conclusion, DON-3S could be used as a specific biomarker of DON in different biological matrices, while the immune response in broiler chickens is stimulated by the presence of DON at the guidance level, but no adverse effect was observed on physiological stress parameters.

6.
Toxins (Basel) ; 13(3)2021 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-33803037

RESUMEN

Deoxynivalenol (DON), a trichothecene mycotoxin produced by Fusarium species, is the most widespread mycotoxin in poultry feed worldwide. Long term-exposure from low to moderate DON concentrations can produce alteration in growth performance and impairment of the health status of birds. To evaluate the efficacy of mycotoxin-detoxifying agent alleviating the toxic effects of DON, the most relevant biomarkers of toxicity of DON in chickens should be firstly determined. The specific biomarker of exposure of DON in chickens is DON-3 sulphate found in different biological matrices (plasma and excreta). Regarding the nonspecific biomarkers called also biomarkers of effect, the most relevant ones are the impairment of the productive parameters, the intestinal morphology (reduction of villus height) and the enlargement of the gizzard. Moreover, the biomarkers of effect related to physiology (decrease of blood proteins, triglycerides, hemoglobin, erythrocytes, and lymphocytes and the increase of alanine transaminase (ALT)), immunity (response to common vaccines and release of some proinflammatory cytokines) and welfare status of the birds (such as the increase of Thiobarbituric acid reactive substances (TBARS) and the stress index), has been reported. This review highlights the available information regarding both types of biomarkers of DON toxicity in chickens.


Asunto(s)
Alimentación Animal/microbiología , Bienestar del Animal , Pollos/crecimiento & desarrollo , Metabolismo Energético , Microbiología de Alimentos , Fusarium/metabolismo , Tricotecenos/toxicidad , Crianza de Animales Domésticos , Animales , Biomarcadores/sangre , Pollos/inmunología , Pollos/metabolismo , Fusarium/crecimiento & desarrollo , Estado de Salud , Factores de Tiempo , Tricotecenos/metabolismo
7.
Microorganisms ; 8(2)2020 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-31973199

RESUMEN

The reduction of antimicrobial resistance is a major challenge for the scientific community. In a few decades, infections by resistant bacteria are forecasted to be the main cause of death in the world. The withdrawal of antibiotics as growth promoters and their preventive use in animal production is essential to avoid these resistances, but this may impair productivity and health due to the increase in gut inflammation. This reduction in productivity aggravates the problem of increasing meat demand in developing countries and limits the availability of raw materials. Probiotics are promising products to address this challenge due to their beneficial effects on microbiota composition, mucosal barrier integrity, and immune system to control inflammation. Although many modes of action have been demonstrated, the scientific community is not able to describe the specific effects that a probiotic should induce on the host to maximize both productivity and animal health. First, it may be necessary to define what are the innate immune pathways acting in the gut that optimize productivity and health and to then investigate which probiotic strain is able to induce the specific effect needed. This review describes several gaps in the knowledge of host-microbiota-pathogen interaction and the related mechanisms involved in the inflammatory response not demonstrated yet in poultry.

8.
Poult Sci ; 99(9): 4496-4504, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32867993

RESUMEN

This experiment was conducted to evaluate the chemical composition and standardized ileal amino acid digestibility of corn grain and to use these data to develop prediction equations for estimating total amino acids (TAAs) and standardized ileal digestible amino acids (SIDAAs) for broiler chickens. Four types of corn grains were obtained from different origins (Brazil, Ukraine, Russia, and Iran). Eighty-day-old Ross 308 male broiler chicks were fed a standard diet until day 18, and experimental diets were fed from 19 to 24 D of age. Five dietary treatments consisted of 4 semi-purified diets containing corn from each origin as the only source of amino acid (AA) and a N-free diet for determination of basal endogenous AA losses. Assay diets contained 939 g of test corn/kg. The concentration of crude protein and gross energy ranged from 7.58 to 8.39% (coefficient of variation [CV] = 4.72%) and 4,121 to 4,621 kcal/kg (CV = 5.09%), respectively. There was significant variation among the 4 corn grains in standardized ileal digestibility (SID) for CP, Phe, Leu, Asp, Glu, Ser, Gly, Ala, and Tyr (P ≤ 0.05). The results of linear regression showed that linear prediction equations based on protein content can be used to predict the TAA and SIDAA contents (e.g., TLys = 0.041 × CP, adj R2 = 95.9, standard error of prediction [SEP] = 0.05; SIDLys = 0.0356 × CP, adj R2 = 96, SEP = 0.051). Inclusion of other proximate components of test samples into the regression equation increased the R2 value and decreased the SEP value (e.g., TLys = 0.329 × crude fiber [CF] ‒ 0.209 × Ash, adj R2 = 99.9, SEP = 0.005; SIDLys = â€’1.1591 + 0.836 × CF ‒ 0.055 × Ash, adj R2 = 99.9, SEP = 0.001). The concentration of TAA and SIDAA was highly correlated (adj R2 > 89%) for most AA and showed that the amount of SIDAA could be predicted from its total concentration with a high degree of accuracy (e.g., SIDLys = 0.0023 + 0.861 × TLys, adj R2 = 99.9, SEP = 0.0001). In conclusion, this in vitro assays and equations accurately predicted TAA and SIDAA corn grain samples for broiler chickens and can serve as a reference analysis to develop calibration equations for rapid feed quality evaluation methods such as near-infrared reflectance spectroscopy.


Asunto(s)
Aminoácidos , Fenómenos Fisiológicos Nutricionales de los Animales , Pollos , Íleon , Zea mays , Aminoácidos/metabolismo , Alimentación Animal/análisis , Animales , Pollos/metabolismo , Dieta/veterinaria , Íleon/metabolismo , Masculino , Zea mays/química
9.
Animals (Basel) ; 10(10)2020 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-33023213

RESUMEN

The present study with 1-day-old male broilers (Ross 308) was conducted to evaluate the effects of deoxynivalenol (DON) at different levels (5 and 15 mg/kg feed) on growth performance, relative weight of organs, morphology of the small intestine, serum biochemistry, and welfare parameters of broiler chickens. Forty-five broiler chicks were randomly divided into three different experimental groups with five replicates each: (1) control group received a non-contaminated diet, (2) contaminated diet with 5 mg DON/kg of feed, and (3) contaminated diet with 15 mg DON/kg of feed for 42 days. Results showed that feed artificially contaminated with DON at guidance level (5 mg/kg diet) did not affect growth performance parameters. However, 15 mg/kg reduced body weight gain and altered feed efficiency. DON at two assayed levels significantly increased the absolute and relative weight of thymus and the relative weight of gizzard and decreased the absolute and the relative weight of the colon. Compared to controls, both doses affected small intestine morphometry parameters. In terms of biochemical indicators, DON at 5 mg/kg reduced the creatine kinase level and at 15 mg/kg DON reduced the cholesterol level. Furthermore, DON at 15 mg/kg induced more fear in broilers compared to broilers fed the guidance level. It was concluded that even the guidance level of DON did not affect the chickens' performance. However, its toxic effect occurred in some organs and biochemical parameters.

10.
Poult Sci ; 99(10): 4947-4957, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32988531

RESUMEN

The objective of this experiment was to determine total amino acid (TAA) content, standardized ileal digestibility (SID) of crude protein, and standardized ileal amino acid digestibility in 9 sources of soybean meal (SBM) of different origin and to subsequently establish equations for predicting the TAA content and concentration of standardized ileal digestible amino acids (SIDAA) based on their protein content and other proximate components. Concentration of SIDAA of the samples was also predicted using TAA values. A total of 160 1-day-old male broiler chicks were randomly assigned to 10 dietary treatments consisted of 9 semipurified diets containing one SBM (200 g of crude protein/kg) as the only source of dietary amino acid (AA) and one N-free diet to determine endogenous ileal AA flow. The birds were fed with a standard diet from 0 to 18 D of age, and experimental diets were fed from 19 to 24 D of age. The fitness of the models of the study was tested using the adjusted coefficient of determination (R2) value, P-value regression and coefficients, and standard error of prediction (SEP). The coefficient of SID for Lys and Cys among SBM varied from 86.7 to 96.3 and 74.1 to 89.3, respectively, with significant difference (P < 0.05). In equations based on protein content, the adjusted R2 value ranged from 40.7 (Ile) to 99.6 (Met) and 37.2 (Met + Cys) to 99.6 (Met) for TAA content and concentration of SIDAA, respectively. Inclusion of other proximate components of test samples (e.g., crude fiber, neutral detergent fiber, acid detergent fiber, ash, gross energy, and so on) into the regression equation increased the adjusted R2 value and decreased the SEP. The results of linear regression revealed that it is possible to satisfactorily estimate the TAA content and concentration of SIDAA of SBM through its protein content and other proximate components, but the prediction equations based on other proximate components were more accurate in terms of reflecting the measured results; however, additional time and costs were associated with this approach. It is also possible to estimate the concentration of SIDAA through TAA values with reasonable accuracy and lower SEP.


Asunto(s)
Aminoácidos , Fenómenos Fisiológicos Nutricionales de los Animales , Pollos , Contenido Digestivo , Glycine max , Aminoácidos/análisis , Aminoácidos/metabolismo , Alimentación Animal/análisis , Animales , Dieta/veterinaria , Digestión , Contenido Digestivo/química , Masculino , Distribución Aleatoria , Glycine max/química
11.
Front Immunol ; 11: 482, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32528460

RESUMEN

Development of semi-automated devices that can reduce the hands-on time and standardize the production of clinical-grade CAR T-cells, such as CliniMACS Prodigy from Miltenyi, is key to facilitate the development of CAR T-cell therapies, especially in academic institutions. However, the feasibility of manufacturing CAR T-cell products from heavily pre-treated patients with this system has not been demonstrated yet. Here we report and characterize the production of 28 CAR T-cell products in the context of a phase I clinical trial for CD19+ B-cell malignancies (NCT03144583). The system includes CD4-CD8 cell selection, lentiviral transduction and T-cell expansion using IL-7/IL-15. Twenty-seven out of 28 CAR T-cell products manufactured met the full list of specifications and were considered valid products. Ex vivo cell expansion lasted an average of 8.5 days and had a mean transduction rate of 30.6 ± 13.44%. All products obtained presented cytotoxic activity against CD19+ cells and were proficient in the secretion of pro-inflammatory cytokines. Expansion kinetics was slower in patient's cells compared to healthy donor's cells. However, product potency was comparable. CAR T-cell subset phenotype was highly variable among patients and largely determined by the initial product. TCM and TEM were the predominant T-cell phenotypes obtained. 38.7% of CAR T-cells obtained presented a TN or TCM phenotype, in average, which are the subsets capable of establishing a long-lasting T-cell memory in patients. An in-depth analysis to identify individual factors contributing to the optimal T-cell phenotype revealed that ex vivo cell expansion leads to reduced numbers of TN, TSCM, and TEFF cells, while TCM cells increase, both due to cell expansion and CAR-expression. Overall, our results show for the first time that clinical-grade production of CAR T-cells for heavily pre-treated patients using CliniMACS Prodigy system is feasible, and that the obtained products meet the current quality standards of the field. Reduced ex vivo expansion may yield CAR T-cell products with increased persistence in vivo.


Asunto(s)
Inmunoterapia Adoptiva/métodos , Subgrupos de Linfocitos T/inmunología , Linfocitos T/inmunología , Centros Médicos Académicos , Adolescente , Adulto , Automatización , Reactores Biológicos , Proliferación Celular , Células Cultivadas , Niño , Citotoxicidad Inmunológica , Femenino , Humanos , Memoria Inmunológica , Masculino , Sistemas de Atención de Punto , Adulto Joven
12.
Anim Sci J ; 89(6): 895-905, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29603498

RESUMEN

The objective of this study was to assess the effects of a probiotic strain Clostridium butyricumMIYAIRI 588 (CBM588) on broiler and weaned piglet health and zootechnical performance. Five field studies were carried out in broilers and five in weaned piglets under European feed additive guidelines. Each study followed a randomized blocked design with two treatments: Control (basal diet) and CBM588 supplemented groups. The zootechnical performance parameters selected were body weight, daily gain, feed intake and feed efficiency (feed:gain). Broilers fed diets with CBM588 gained significantly more weight (+2%, p < .001) and exhibited significantly better feed efficiency (-1.6%, p < .001) in comparison with Controls. Similarly, analysis of pooled data of weaned piglet trials showed that CBM588-fed piglets were significantly heavier than Controls (+2.6%, p = .014), exhibited significantly higher mean daily gain (+4.7%; p = .004), and significantly improved feed efficiency (-4.2%, p = .001). In addition to the zootechnical efficacy studies, the preventive effect of CBM588 on necrotic enteritis (NE) was assessed in a natural challenge model in broilers where CBM588 reduced the incidence and severity of NE lesions. These data indicate the potential of CBM588 to improve broiler and weaned piglet zootechnical performance, and to make a positive contribution to animal health.


Asunto(s)
Fenómenos Fisiológicos Nutricionales de los Animales , Ácido Butírico/metabolismo , Pollos/crecimiento & desarrollo , Pollos/fisiología , Clostridium butyricum , Suplementos Dietéticos , Enterocolitis Necrotizante/prevención & control , Enterocolitis Necrotizante/veterinaria , Enfermedades de las Aves de Corral/prevención & control , Probióticos/administración & dosificación , Enfermedades de los Porcinos/prevención & control , Porcinos/crecimiento & desarrollo , Porcinos/fisiología , Alimentación Animal , Animales , Peso Corporal , Clostridium butyricum/metabolismo , Ingestión de Alimentos , Destete
13.
Meat Sci ; 93(3): 517-24, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23273459

RESUMEN

Sixteen gilts were fed a control (4% of sunflower oil) or an experimental diet (4% conjugated linoleic acid (CLA) oil). CLA had no effect on intramuscular fat (IMF) content neither in longissimus thoracis (LT) nor in semimembranosus (SM) muscles but increased liver weight, reduced perirenal fat and tended to reduce backfat between the last 3th-4th lumbar vertebrae. Despite the fact that 9c,11t and 10t,12c CLA isomers were included in the same proportion in the diet, the 9c,11t and 9c,11c were the isomers more deposited in all tissues. Addition of CLA in the diet affected fatty acid composition in a tissue specific manner, increasing percentages of SFA in all tissues, reducing percentages of MUFA in LT and LT subcutaneous fat, and of PUFA in LT subcutaneous fat, liver and SM. The FA modification by dietary CLA in LT IMF was reflected in the different lipid fractions, SFA and MUFA mainly in the neutral lipid fraction, and PUFA in the polar fraction.


Asunto(s)
Tejido Adiposo/metabolismo , Distribución de la Grasa Corporal , Dieta , Grasas de la Dieta/farmacología , Ácidos Grasos/metabolismo , Ácidos Linoleicos Conjugados/farmacología , Carne/análisis , Animales , Grasas de la Dieta/metabolismo , Femenino , Ácidos Linoleicos Conjugados/metabolismo , Hígado/metabolismo , Músculo Esquelético/metabolismo , Grasa Subcutánea/metabolismo , Porcinos
14.
Meat Sci ; 91(4): 448-53, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22429803

RESUMEN

Several reports show that intramuscular fat (IMF) and/or marbling affect the sensory acceptability of meat. The aim of the present work was to (1) investigate using Spanish consumers the eating and visual acceptability of pork with different levels of IMF, (2) understand more about this acceptability by studying segments of consumers and (3) determine which fresh pork characteristics are important at the point of purchase. Loin section (n = 40) were sorted into four IMF groups: 0.96 ± 0.30% (G1), 2.11 ± 0.07% (G2), 3.72 ± 0.26% (G3), and 5.78 ± 0.19% (G4). Consumers (n = 200) evaluated the acceptability, tenderness and juiciness of cooked loin chops from each IMF group and then ranked raw chops according to visual preference. Two groups of consumers--'lean loin lovers' (55.5%) and 'marbled loin lovers' (44.5%)--were identified based on their visual preferences; however, according to their eating acceptability scores, all the consumers preferred loins with higher IMF levels. Accordingly, the minimum IMF content recommended to ensure a good taste is between 2.2% and 3.4%.


Asunto(s)
Comportamiento del Consumidor , Grasas de la Dieta , Preferencias Alimentarias , Carne/análisis , Gusto , Percepción Visual , Tejido Adiposo , Adolescente , Adulto , Anciano , Animales , Culinaria , Femenino , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético , España , Porcinos , Adulto Joven
15.
Arch Anim Nutr ; 59(1): 53-9, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15889652

RESUMEN

An experiment was conducted to determine the efficacy of a so-called consensus phytase preparation produced by Hansenula polymorpha on growth, tibia and toe ash and P retention of young turkeys. A total of 192 female turkeys (BUT 9 strain) were placed into 96 batteries at two per cage and assigned to one of eight diets: A negative control containing 2.5 g non-phytate P per kg feed (T-1); T-1 plus 125, 250, 500, 1000 or 10 000 phytase units (U) per kg feed, respectively, (T-2 to T-6); T-1 plus 0.5 or 1.0 g Pi/kg feed as dicalcium phosphate dihydrate (DCP), respectively, (T-7 and 8). The experiment lasted 32 d, and excreta were collected and weighed between 26 and 29 d of age. Feed was also weighed during this period in order to calculate P retention. Performance was calculated for the 0 to 32 d period. At the end of the experiment one bird per pen was killed for tibia and toe ash content determination, except for T-2, T-3, and T-7. Body weight, FCR, toe and tibia ash, and P retention responded to phytase or Pi supplementation. Using linear or quadratic models for comparing performance of the treatments containing supplemental Pi with phytase treatments, an equivalence between phytase and Pi was calculated. Body weight, toe ash, tibia ash and P retention showed a significant response to phytase supplementation. The values of equivalence for body weight, toe ash, tibia ash and P retention were 251, 597, 391 and 390 U to 1 g Pi/kg feed. At 10 000 U/kg feed there was a significant response in terms of weight gain and P retention, indicating that turkeys respond to levels greater than 1 000 U/kg feed.


Asunto(s)
6-Fitasa/administración & dosificación , Fósforo/metabolismo , Pichia/enzimología , Pavos/crecimiento & desarrollo , 6-Fitasa/metabolismo , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Peso Corporal , Calcificación Fisiológica/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Femenino , Minerales , Distribución Aleatoria , Tibia/química , Pavos/metabolismo , Aumento de Peso
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