24 research outputs found
Role of a family 11 carbohydrate-binding module in the function of a recombinant cellulase used to supplement a barley based diet for broiler chickens
Cellulases and xylanases display a modular architecture that comprises a catalytic
module linked to one or more non-catalytic carbohydrate-binding modules (CBMs). CBMs have been
classified into 52 different families, based on primary structure similarity. These non-catalytic modules
mediate a prolonged and intimate contact of the enzyme with the target substrate eliciting efficient
hydrolysis of the target polysaccharides.
2. A study was undertaken to investigate the importance of a family 11 CBM, displaying high affinities
for barley -glucans, in the function of recombinant derivatives of cellulase CtLic26A-Cel5E of
Clostridium thermocellum used to supplement a barley-based diet for broiler chicken.
3. The results showed that birds fed on diets containing the recombinant CtLic26A-Cel5E modular
derivatives or the commercial enzyme mixture RovabioTM Excel AP displayed improved performance
when compared with birds fed on diets not supplemented with exogenous enzymes.
4. It is suggested that the enzyme dosage used in this study (30 U/kg of basal diet), was probably too
high for the efficacy of the family 11 CBM to be noticed. It remains to be established if the targeting
effect resulting from the incorporation of CBMs in plant cell wall hydrolases may be effective at lower
exogenous enzyme dosages
Crop -glucanase activity limits the effectiveness of a recombinant cellulase used to supplement a barley-based feed for free-range broilers
1. The supplementation of diets rich in soluble polysaccharides with microbial cellulases
and hemicellulases decreases digesta viscosity and promotes broiler performance.
2. In contrast, recent experiments suggest that polysaccharidases are ineffective for improving the
nutritive value of pasture biomass used by free-range broilers. However, the feasibility of using cellulases
and hemicellulases to improve the utilisation of cereal-based feeds by pastured poultry remains to be
established.
3. A study was undertaken to investigate the capacity of a recombinant cellulase from Clostridium
thermocellum to improve the nutritive value of a barley-based feed for free-range pastured broilers of the
RedBro Cou Nu RedBro M genotype.
4. The results show that supplementation of a barley-based diet with a recombinant -glucanase had
no effect on the performance of free-range broilers, foraging in legume-based diets from d 28 to 56.
In addition, the results confirm that the lack of effect of the recombinant enzyme in improving the
nutritive value of the barley-based feed does not result from enzyme proteolysis or inhibition in the
gastrointestinal tract.
5. Significantly, -glucanase activity was identified in the crop of non-supplemented animals. The data
suggest that endogenous cellulases originated both from the barley-based feed and from the crop
microflora.
6. The results presented here suggest that in older birds of slow-growing genotypes associated with
free-range production systems, previously unknown sources of -glucanases, such as the feed and
microbial symbiotic microflora, can affect the effectiveness of exogenous enzymes added to the feed
Influence of dietary Chlorella vulgaris and carbohydrate-active enzymes on growth performance, meat quality and lipid composition of broiler chickens
Article in pressHerein, we investigated the effect of
Chlorella vulgaris as ingredient (10% of incorporation) in
broiler diets, supplemented or not with 2 formulations of
Carbohydrate-Active enZymes (CAZymes; Rovabio
Excel AP and a mixture of recombinant CAZymes,
composed by an exo-b-glucosaminidase, an alginate
lyase, a peptidoglycan N-acetylmuramic acid deacetylase
and a lysozyme), on growth performance, meat quality,
fatty acid composition, oxidative stability, and sensory
traits. One hundred twenty 1-day-old Ross 308 male birds
were randomly assigned to one of the 4 experimental diets
(n 5 30): corn-soybean meal–basal diet (control), basal
diet with 10% C. vulgaris (CV), CV supplemented with
0.005% of a commercialCAZymecocktail (Rovabio Excel
AP), (CV1R), and CV supplemented with 0.01% of a 4-
CAZyme mixture previously selected (CV 1 M) during
the experimental period lasted from day 21 to day 35.
Body weight gain and feed conversion rate of broilers were
not affected by C. vulgaris but digesta viscosity increased more than 2-fold (P , 0.001) relative to the control. In
addition, neither cooking loss, shear force, juiciness, flavor
nor off-flavor was impaired by dietary treatments
(P.0.05). By contrast, the dietary C. vulgaris increased
tenderness, yellowness (b*) and total carotenoids in
breast and thigh meats. However, no additional protective
effect against lipid oxidation was observed in meat
with the inclusion of microalga. Chlorella vulgaris, independently
of CAZymes, had a minor impact on meat fatty
acid composition but improved the proportion of some
beneficial fatty acids. In summary, our data indicate a
slight improvement of broiler meat quality and lipid
nutritional value, without impairment of broilers’ growth
performance, thus supporting the usefulness of this
microalga in poultry diets, up to this high level of incorporation.
By contrast, the selected CAZyme mixtures
used do not significantly improve the release of microalga
nutrients in poultry diets, through the disruption of
microalga cell wall, which warrants further researchinfo:eu-repo/semantics/acceptedVersio
A PRND polymorphism in Churra do Campo portuguese sheep breed
Prion-like Doppel gene (PRND) is located downstream from priori protein gene (PRNP). Doppel protein is not related to prion disease but to male fertility. Our previous analysis of PRND coding region in 460 animals from 8 Portuguese sheep breeds, by multiple restriction fragment-single strand conformation polymorphism (MRFSSCP), revealed a synonymous substitution (78G>A). An association was found between identified PRND polymorphism and PRNP genotypes, determined by primer extension and grouped into 5 grades of increasing scrapie susceptibility-R1 to R5: PRND was monomorphic (GG) in animals with most resistant ARR/ARR PRNP genotype-R1; higher frequency of heterozygotes (GA) was significantly associated with ARQ/AHQR4. Therefore, EU selection programme to eradicate scrapie in sheep, based on PRNP genotypes, may reduce genetic diversity, with hypothetical repercussions on reproduction. The aim of current work was to evaluate 78G>A PRND polymorphism in highly endangered Churra do Campo Portuguese sheep breed. From a total of 73 animals analysed (16 R1, 36 R3, 18 R4, 3 R5), 72 were GG and 1 GA, the later being ARQ/ARQ (R4). Low incidence of PRND polymorphic variants in this breed may be explained by mating involving small number of related animals, and particular differences in distribution of PRNP genotypes
Impact of dietary incorporation of Spirulina (Arthrospira platensis) and exogenous enzymes on broiler performance, carcass traits and meat quality
This study assessed the effect of Spirulina
(Arthrospira platensis), individually and in combination
with exogenous enzymes, on growth
performance, carcass traits, and meat quality of broiler
chickens. One hundred and twenty Ross 308 male
chickens were allocated into 40 battery brooders, with 3
birds per cage, and fed ad libitum a corn-based diet
during the first 21 D of the trial. The experimental period
lasted from day 21 to 35, during which birds were fed 4
different diets: a corn-soybean basal diet, taken as the
control group, a basal diet containing 15% Spirulina
(MA), a basal diet containing 15% Spirulina plus 0.005%
Rovabio Excel AP (MAR), and a basal diet containing
15% Spirulina plus 0.01% lysozyme (MAL). Body weight
gain (P , 0.001) and feed conversion rate (P , 0.001)
were improved in control chickens, when compared with
those fed with Spirulina. In addition, Spirulina increased
the length of duodenum plus jejunum in relation to the
other treatment (P , 0.01). Chickens on the MAL diet showed a considerable increase in digesta viscosity
(P , 0.05) compared with the control group. Breast and
thigh meats from chickens fed with Spirulina, with or
without the addition of exogenous enzymes, had higher
values of yellowness (b*) (P , 0.001), total carotenoids
(P , 0.001), and saturated fatty acids (P , 0.001),
whereas n-3 polyunsaturated fatty acid (P , 0.01) and
a-tocopherol (P , 0.001) decreased, when compared
with the control. In conclusion, the incorporation of 15%
Spirulina in broiler diets, individually or combined with
exogenous enzymes, reduced birds’ performance through
a higher digesta viscosity, which is likely associated with
the gelation of microalga indigestible proteins. In addition,
cell wall of Spirulina was successfully broken by the
addition of lysozyme, but not by Rovabio Excel AP.
Therefore, we anticipate that the combination of lysozyme
with an exogenous specific peptidase could improve
the digestibility of proteins from this microalga and
avoid their detrimental gelationinfo:eu-repo/semantics/publishedVersio
Parâmetros de qualidade da carne de cordeiros submetida aos processos de maturação e injeção de cloreto de cálcio
Pesquisa e quantificação do agonista beta2-adrenérgico salbutamol (Albuterol) no plasma sanguíneo
A utilização de agonistas Beta2-adrenérgicos (por exemplo, clenbuterol, salbutamol, ractopamina, etc.) para fins ilegais, de aceleração do crescimento em animais de talho, é um gravíssimo problema da Saúde Pública Veterinária.info:eu-repo/semantics/publishedVersio
Serum adipokine profile and fatty acid composition of adipose tissues are affected by conjugated linoleic acid and saturated fat diets in obese Zucker rats
Funding: The authors acknowledge Clinica Médica e Diagnóstico Dr Joaquim Chaves (Alge´s, Portugal) for the technical assistance regarding the serum lipids determination. The present study was supported by FCT POCTI/CVT/2002/44 750 and PTDC/CVT/2006/66 114 grants. S. V. M., P. A. L. and S. P. A. are the recipients of FCT individual fellowships SFRH/BD/2005/2256, SFRH/BPD/2005/23 931 and SFRH/ BD/2007/37 793, respectively. S. V. M., P. A. L. and C. M. A. performed the animal experiment, tissue sampling, laboratory work and prepared the manuscript. P. O. R. was responsible for Luminex xMAP analysis. S. P. A. and R. J. B. B. were responsible for fatty acid analysis. R. M. A. P. performed the biochemistry serum profile. S. V. M. and R. J. B. B. performed the statistical analysis. M. F. C. and J. A. M. P. were responsible for interpretation of the results, preparation of the manuscript and design of the study.Conjugated linoleic acid (CLA) has been reported as having body fat lowering properties and the ability to modulate the inflammatory system in several models. In the present study, the effects of CLA added to saturated fat diets, from vegetable and animal origins, on the serum adipokine profile of obese Zucker rats were assessed. In addition, the fatty acid composition of epididymal and retroperitoneal adipose tissues was determined and a principal component analysis (PCA) was used to assess possible relationships between fatty acids and serum metabolites. Atherogenic diets (2% cholesterol) were formulated with palm oil and ovine fat and supplemented or not with 1% of a mixture (1:1) of cis-9, trans-11 and trans-10, cis-12-CLA isomers. CLA-fed animals exhibited lower daily feed intake, final body and liver weights, and hepatic lipids content. Total and LDL-cholesterol levels were increased in CLA-supplemented groups. CLA also promoted higher adiponectin and lower plasminogen activator inhibitor-1 (PAI-1) serum concentrations. In contrast to palm oil diets, ovine fat increased insulin resistance and serum levels of leptin, TNF-α and IL-1β. Epididymal and retroperitoneal adipose tissues had similar deposition of individual fatty acids. The PCA analysis showed that the trans-10, cis-12-CLA isomer was highly associated with adiponectin and PAI-1 levels. Summing up, CLA added to vegetable saturated enriched diets, relative to those from animal origin, seems to improve the serum profile of adipokines and inflammatory markers in obese Zucker rats due to a more favourable fatty acid composition. © 2009 The Authors.publishersversionpublishe
Seasonality as experienced in the market and the resulting variation in the amino acid and elemental composition of chub mackerel (Scomber colias)
Chub mackerel (Scomber colias) is an underutilised fish species, abundant in the Atlantic Ocean. Its amino acid
profile and elemental composition are still insufficiently studied. Accordingly, these aspects were studied on a
monthly basis. The most abundant essential amino acids, lysine and leucine, had contents ranging from 1270 ±
40 mg/100 g in August to 1820 ± 96 mg/100 g in November and from 1210 ± 36 mg/100 g in August to 1570 ±
20 mg/100 g in March, respectively. The other essential amino acids’ contents varied between 500 and 1200 mg/
100 g. Essential amino acids represented between 41.9 % and 44.6 % of all amino acids. As a result of high
histidine content in S. colias, three weekly meals (160 g/meal) guarantee all human histidine requirements.
Regarding elemental composition, K was the most abundant, varying its content between 331 ± 3 mg/100 g and
499 ± 4 mg/100 g. The other studied elements’ order of abundance was P > Na > Mg > Ca > Fe > Zn. Under
optimal conditions, consumption of a 160 g daily meal of S. colias may provide at most 20 % of the Fe and 30 %
of the Zn requirements. Therefore, though not an outstanding Fe and Zn source, S. colias can give a significant
contribution to these elements’ requirementsHighlights: - Lys & Leu were the most abundant essential amino acids in Scomber colias; - In S. colias, 41.9–44.6 % of the total amino acids were essential amino acids; - Glu, Asp, Arg, Cys, Tyr, & Ile had a seasonal variation in S. colias; 3 weekly 160 g meals of S. colias may cover histidine requirements; - A 160 g meal of S. colias everyday may cover up to 20 % of Fe & 30 % of Zn. needs.This work was supported by national funds through FCT - Fundação
para a Ciência e a Tecnologia, I.P., within the scope of projects New Food4ThoughtPTDC/SAUNUT/30455/2017 (Exploitation of the bioac tive nutrients’ potential for the prevention of Alzheimer’s Disease and
cognitive aging through in vitro assays, in vivo verification, and in silico
quantification of the health benefits) and CIISA (Project UIDB/00276/
2020). Researchers were supported by the following Post-Doctoral
Grants: Ref.: SFRH/BPD/102689/2014 (“Fundação para a Ciência e a
Tecnologia”, FCT) for the author Carlos Cardoso and DIVERSIAQUA
(MAR2020, Ref.: 16-02-01-FEAM-66) for the author Claudia ´ Afonso.
The author Ana Gomes-Bispo also acknowledges FCT and IPMA for the
DL57/2016 Junior Researcher Contractinfo:eu-repo/semantics/publishedVersio
Assessing the effect of dietary inulin supplementation on gastrointestinal fermentation, digestibility and growth in pigs: A meta-analysis
International audienceInulin has been reported to improve the homeostasis in the gastrointestinal tract (GIT) of pigs by modulating the intestinal microbiota and fermentation. The present study aimed to quantify the relationship between dietary inulin and microbial response variables in digesta from the GIT and feces of weaned, growing and finishing pigs using a meta-analytical approach. We further examined the effect of dietary inulin on the coefficients of ileal (CLAD) and total tract apparent digestibility (CTTAD) of nutrients and ADG. Pig's starting body weight was considered the main inclusion criterion. Missing information about explanatory variables and few values available for response variables reduced the number of studies included. From the 33 included articles published between 2000 and 2016, individual sub-datasets for fermentation metabolites, bacterial abundances, CIAD, CTTAD and performance were built. Prediction models on the effect on inulin were computed accounting for inter- and intra-study variability. Dietary inulin levels ranged from 0.1 to 25.8%, whereby the median and mean inulin levels were 0.1-2% and 3-4%, respectively. Few of the investigated fermentation response variables were influenced by dietary inulin. Strong negative relationships were found between dietary inulin and gastric pH in weaned pigs (R-2 = 0.81; P < 0.001; n = 12), colonic enterobacteria (R-2 = 0.50; P < 0.001; n = 19) and fecal lactobacilli (R-2 = 0.41; P < 0.001; n = 26) throughout all production phases, whereas observed negative relationships between inulin and colonic bifidobacteria and fecal enterobacteria and Escherichia coli were of minor physiological relevance (P < 0.05). Moreover, increasing inulin levels negatively correlated with the CTTAD of crude protein (R-2 = 0.83; P < 0.001; n = 15), but they did not influence average daily gain of pigs. Best-fit models indicated that dietary crude protein amplified the effect of inulin on CTTAD of crude protein and gastric pH, but counteracted the inulin effect on fecal E. coli (P < 0.05). Accordingly, both pig's body weight and inulin decreased gastric pH and fecal lactobacilli but counteracted the inulin effect on colonic bifidobacteria and fecal E. coli (P < 0.05). In conclusion, this study supported a stimulatory effect of dietary inulin on gastric acid secretion, which may be favorable GIT health in weaned pigs. However, due to limiting information provided in the original studies, like dietary fructans or fibers, low numbers of observation and low inulin levels, relationships should be regarded as trends