Graziela Drociunas Pacheco

Chronic ingestion of deoxynivalenol and fumonisin, alone or in interaction, induces morphological and immunological changes in the intestine of piglets

Deoxynivalenol (DON) and fumonisins (FB) are mycotoxins produced by Fusarium species, which naturally co-occur in animal diets. The gastrointestinal tract represents the first barrier met by exogenous food/feed compounds. The purpose of the present study was to investigate the effects of DON and FB, alone and in combination, on some intestinal parameters, including morphology, histology, expression of cytokines and junction proteins. A total of twenty-four 5-week-old piglets were randomly assigned to four different groups, receiving separate diets for 5 weeks: a control diet; a diet contaminated with either DON (3 mg/kg) or FB (6 mg/kg); or both toxins. Chronic ingestion of these contaminated diets induced morphological and histological changes, as shown by the atrophy and fusion of villi, the decreased villi height and cell proliferation in the jejunum, and by the reduced number of goblet cells and lymphocytes. At the end of the experiment, the expression levels of several cytokines were measured by RT-PCR and some of them (TNF-α, IL-1β, IFN-γ, IL-6 and IL-10) were significantly up-regulated in the ileum or the jejunum. In addition, the ingestion of contaminated diets reduced the expression of the adherent junction protein E-cadherin and the tight junction protein occludin in the intestine. When animals were fed with a co-contaminated diet (DON+FB), several types of interactions were observed depending on the parameters and segments assessed: synergistic (immune cells); additive (cytokines and junction protein expression); less than additive (histological lesions and cytokine expression); antagonistic (immune cells and cytokine expression). Taken together, the present data provide strong evidence that chronic ingestion of low doses of mycotoxins alters the intestine, and thus may predispose animals to infections by enteric pathogens.

Phytic acid protects porcine intestinal epithelial cells from deoxynivalenol (DON) cytotoxicity

The purpose of this study was to evaluate the effects of phytic acid (IP(6)) as a possible inhibitor of cellular damage induced by toxic substances such as mycotoxins on a porcine intestinal epithelial cell line (IPEC-1). We first observed that a dose of 5 mM phytic acid decreases cell viability and transepithelial electrical resistance (TEER) of cell monolayer. We next investigate the effect of non-cytotoxic dose of phytic acid on the deoxinivalenol (DON) induced decreased TEER. We showed that treatment with 0.5 mM or 1.0 mM phytic acid restores the decrease in TEER caused by 25 μM DON. In conclusion this study demonstrates that phytic acid decreased the negative effects of deoxynivalenol on the membrane integrity of the IPEC-1 intestinal epithelial cell line.

Efeito da ractopamina na performance e na fisiologia do suíno

O objetivo deste trabalho foi avaliar a inclusao de diferentes niveis de ractopamina em racoes de suinos em fase de terminacao, durante 21 dias pre-abate, sobre as caracteristicas de desem- penho, carcaca, qualidade de carne e sobre parâmetros fisiologicos e sanguineos indicado- res de bem-estar. Foram utilizados 36 suinos comerciais, 18 machos castrados e 18 femeas, com peso medio inicial de 87,0±5,02 kg, alimenta- dos ad libitum com racoes isonutrientes, com 0, 10 e 20 ppm de ractopamina. O delineamento experimental foi em blocos casualizados, fatorial 3 x 2, com seis repeticoes para os parâmetros de desempenho e 12 repeticoes para os demais parâmetros. Houve efeito linear (p<0,05) positivo para o ganho de peso e para a conversao alimen- tar e efeito quadratico (ponto de minima de 9,4 ppm de ractopamina) para o consumo de racao. Para os parâmetros de carcaca houve efeito quadratico para o rendimento de carcaca (com ponto de maxima para 9,5 ppm de ractopamina). O valor de a*(componente vermelho-verde), c*(indice de saturacao) e marmoreio apresentaram efeito linear negativo. O diâmetro da fibra muscular do musculo L. dorsi e o ângulo de tonalidade (h*) apresentaram efeito linear positivo para os niveis de ractopamina. Outros parâmetros relacionados a qualidade da carne nao foram influenciadas pelos tratamentos, resultando em carnes livres de PSE e DFD. A ractopamina pode ser utilizada nas racoes de suinos ate 20 ppm com efeitos positivos no desempenho e na carcaca, sem alteracoes no comportamento dos animais e comprometimentos na qualidade da carne.

Desempenho e características de carcaça de suínos submetidos a diferentes programas de restrição alimentar na fase dos 30 aos 118 kg

The aim of this work was evaluate the animal performance, the carcass characteristics and the weight of the organs of digestive system of pigs submitted to different periods of feed restriction. A total of 40 barrows, Landrace × Large White were distributed to randomized block design, to four feed restriction programs, five replications and two animal per experimental unit. Four restrict programs were evaluated: one control, with ad libitum feeding during the 86 days of experiment, and others three, with restriction of 20% in the feed intake in relation to control group, during 21 days, at 30, 50 or 70 kg BW. Performance characteristics as daily feed intake, daily weight gain and the feed conversion of the animals were evaluated. Carcass characteristics, as hot and cold carcass weights, length and carcass dressing, subcutaneous fat thickness, Longissimus dorsi muscle depth, lean meat yield, lean meat amount and loin eye area were evaluated. Also were evaluated organs weights, as liver, stomach, small and large intestine. The costs of each program were evaluated to observe their viability. Feed conversion, considering total experimental period, was better for the animals kept on feed restriction from 70 kg BW. The carcass characteristics evaluations and organs weights did not differ among feed restriction programs. The costs analysis showed a better relation for feed restriction from 70 kg BW. In all feeding programs, the feed restriction followed by ad libitum feeding promoted a compensatory gain effect for all treatments.

Farelo de gérmen de milho desengordurado associado à fitase

The objective of this study was to evaluate the effect and the interaction of phytic acid (used in fattening pig diets, mainly through of defatted corn germ meal (FGMD)), and phytase on performance, serum profile and carcass traits. Thirty two pigs from a commercial line Pen Ar Lan averaging 60.31±5.32 kg (SD) of initial body weight were used. Animals were fed ad libitum during 29 days and it was measured the average daily feed intake, average daily gain and feed conversion ratio. Blood samples were taken at 14th day of the experiment and a complete blood count and serum phosphorus, calcium, iron, triglycerides, choles-terol and urea concentrations were performed. Levels of phosphorus and calcium in faeces also were evaluated. A greater feed intake was observed when FGMD was included in the diets (p<0.05). However, the other performance variables, carcass and hematological parameters were not influenced by both FGMD and phytase factors (p£0.05). Barrows had a greater urea excretion, carcass weight and backfat thickness than females (p<0.05). In other hand, females had a greater meat yield of the chilled carcass compared to barrows (p<0.05). Finally, when the phytase was added on feed, pigs had a lower level of phosphorus and calcium in faeces (p<0.05). In conclusion, diets containing higher levels of phytic acid (with FGMD as ingredient) did not affect the parameters studied.