Differential expression of miRNAs associated with pectoral myopathies in young broilers: insights from a comparative transcriptome analysis.

INTRODUCTION: White Striping (WS) and Wooden Breast (WB) pectoral myopathies are relevant disorders for contemporary broiler production worldwide. Several studies aimed to elucidate the genetic components associated with the occurrence of these myopathies. However, epigenetic factors that trigger or differentiate these two conditions are still unclear. The aim of this study was to identify miRNAs differentially expressed (DE) between normal and WS and WB-affected broilers, and to verify the possible role of these miRNAs in metabolic pathways related to the manifestation of these pectoral myopathies in 28-day-old broilers. RESULTS: Five miRNAs were DE in the WS vs control (gga-miR-375, gga-miR-200b-3p, gga-miR-429-3p, gga-miR-1769-5p, gga-miR-200a-3p), 82 between WB vs control and 62 between WB vs WS. Several known miRNAs were associated with WB, such as gga-miR-155, gga-miR-146b, gga-miR-222, gga-miR-146-5p, gga-miR- 29, gga-miR-21-5p, gga-miR-133a-3p and gga-miR-133b. Most of them had not previously been associated with the development of this myopathy in broilers. We also have predicted 17 new miRNAs expressed in the broilers pectoral muscle. DE miRNA target gene ontology analysis enriched 6 common pathways for WS and WB compared to control: autophagy, insulin signaling, FoxO signaling, endocytosis, and metabolic pathways. The WS vs control contrast had two unique pathways, ERBB signaling and the mTOR signaling, while WB vs control had 14 unique pathways, with ubiquitin-mediated proteolysis and endoplasmic reticulum protein processing being the most significant. CONCLUSIONS: We found miRNAs DE between normal broilers and those affected with breast myopathies at 28 days of age. Our results also provide novel evidence of the miRNAs role on the regulation of WS and in the differentiation of both WS and WB myopathies. Overall, our study provides insights into miRNA-mediated and pathways involved in the occurrence of WS and WB helping to better understand these chicken growth disorders in an early age. These findings can help developing new approaches to reduce these complex issues in poultry production possibly by adjustments in nutrition and management conditions. Moreover, the miRNAs and target genes associated with the initial stages of WS and WB development could be potential biomarkers to be used in selection to reduce the occurrence of these myopathies in broiler production.

Post-weaning piglets fed with different levels of fungal mycotoxins and spray-dried porcine plasma have improved weight gain, feed intake and reduced diarrhea incidence.

Mycotoxins are responsible for economic losses in the swine production industry, especially during post-weaning, when piglets are physiologically immature. Spray-dried porcine plasma (SDPP), added to pig diets, may help reduce losses due to mycotoxins. This work investigates the effects of SDPP in post-weaning piglets fed with diets containing natural contaminants or with more contaminants (co-contamination by mycotoxins). Fifty-six castrated weaned piglets were used in a randomized 2 (0 and 6% of SDPP) x 2 (natural contamination or co-contamination with mycotoxin) factorial design, with seven experimental units of two piglets each. The natural contaminants were 0.95 µg/kg aflatoxins +450 µg/kg fumonisins. The co-contaminated diet contained 300 µg/kg aflatoxins +8000 µg/kg fumonisins. Animals were fed 15 days with experimental diets. Feed intake, weight gain, feed efficiency, diarrhea incidence, and economic feasibility of SDPP treatement were evaluated in three periods of five days each. There was no interaction (P < 0.05) between mycotoxins levels and SDPP. Feed intake, weight gain and feed efficiency were higher (P < 0.05) in diets supplemented with SDPP. Animals fed with SDPP showed lower (P < 0.05) diarrhea incidence in the 1-10 day and 1-15 day periods. The experimental dose of mycotoxins reduced (P < 0.05) weight gain at 11-15 days. SDPP proved to be economical feasible over the total experimental period (1-15 days). Spray-dried plasma improved weight gain, feed intake and reduced diarrhea incidence in piglets post-weaning, but did not correlate with various levels of mycotoxins.

Interaction between live vaccines for coccidiosis and phytogenic compounds in the diet of broilers.

This study aimed to determine whether live vaccines alone or associated with phytogenic compounds supplied via feed could improve performance, intestinal health, serum biochemistry, and coccidiostatic action in broilers up to 42 days of age, challenged with Eimeria spp., compared with a traditional anticoccidial program. We used 800 birds divided into five treatments of eight repetitions each (n = 20): NC - Negative control (absence of additives in the feed and without coccidian challenge); PC - Positive control (absence of additives and with coccidian challenge at 21 days); AAP - Anticoccidial additives program, including salinomycin and nicarbazine, with coccidian challenge at 21 days of life; VAC - Vaccination on day 1 of life (Hipracox HIPRA®) against coccidiosis and subsequent coccidian challenge at 21 days; VAC + BPC - Vaccination (day 1 of life), the addition of 200 ppm of blend phytogenic compound (BPC) based on carvacrol and cinnamaldehyde to the diet, with coccidian challenge at 21 days of life. The birds in the AAP group more significant weight gain and greater body weight at 21 days than the NC and 42 days of age than the NC and VAC + BPC groups. The excretion of Eimeria oocysts in the excreta of birds was higher in PC than in NC, and in the litter, PC had higher counts than NC, AAP, and VAC + BPC. A higher mean score of intestinal lesions for Eimeria acervulina was observed in VAC and VAC + BPC birds, while for Eimeria maxima, the highest score was found in PC. Higher serum levels of total protein due to the increase in globulins were observed in birds of AAP and VAC than NC. Our findings suggest that vaccination for coccidiosis shortly after the birth of chicks allows performance similar to the conventional coccidiosis control program via diet.

Parasites of Auchenipterus osteomystax (Osteichthyes, Auchenipteridae) from two different environments, Rosanas reservoir and upper Paraná river floodplain, Brazil - DOI: 10.4025/actascibiolsci.v31i1.833

Surumanha, Auchenipterus osteomystax Miranda-Ribeiro, 1918 is an insectivorous species that inhabits benthopelagic freshwater environments. In order to know the parasitic fauna and aspects of the host-parasite relationship in surumanhas from Rosanas hydroelectric reservoir and the upper Paraná river floodplain, 36 specimens from the reservoir and 41 specimens from the floodplain were collected, using gill nets. The parasitic fauna of the hosts from the different environments presented low similarity; among ten parasite species present in A. osteomystax, only two were observed in both environments. It was observed significant difference in the prevalence of the metacercariae of Strigeidae in relation to the sex of the hosts from the floodplain, indicating that males are more parasitized. Clinostomum complanatum was the only species that presented significant negative correlation with the relative condition factor (kn) of the host, indicating possible pathogenicity.

Ecological aspects of Diplectanum piscinarius (Platyhelminthes, Monogenea) parasite of gills of Plagioscion squamosissimus (Osteichthyes, Sciaenidae) in the Upper Paraná River floodplain, Brazil - DOI: 10.4025/actascibiolsci.v27i3.1279 / Aspectos ecológicos de Diplectanum piscinarius (Platyhelminthes, Monogenea) parasita de brânquias de Plagioscion squamosissimus (Osteichthyes, Sciaenidae) da plan. inund. Alto rio Paraná, B - DOI: 10.4025/actascibiolsci.v27i3.1279

Thirty-nine specimens of Plagioscion squamosissimus Heckel, 1840 were collected through nets of different mesh sizes in the Upper Paraná River floodplain. The occurrence of Diplectanum piscinarius Kritsky and Thatcher, 1984 was registered and it presented mean abundance of 31, mean intensity of 31.8 and prevalence of 97%. This paper also brings an ecological analysis of some aspects of the host-parasite relationship between D. piscinarius and P. squamosissimus. There were not significant differences between the prevalence and intensity of parasitism of males and females. There were not correlations between abundance and prevalence and the standard length of the hosts; and between relative condition factor (Kn) and abundance. From the results it is possible to assume that there are few physiological and behavioral differences between male and female hosts. Physiological changes probably do not occur during the development of the hosts and parasites do not seem to be very pathogenic

Trinta e nove espécimes de Plagioscion squamosissimus Heckel, 1840 foram coletados com redes de espera de diferentes malhagens na planície de inundação do Alto rio Paraná. Foi registrada a ocorrência de Diplectanum piscinarius Kritsky e Thatcher, 1984, que apresentou abundância média igual a 31, intensidade média 31,8 e prevalência 97%. Realizou-se uma análise ecológica de alguns aspectos da relação parasita-hospedeiro entre D. piscinarius e P. squamosissimus. Não houve diferenças significativas entre prevalência e intensidade de parasitismo em machos e fêmeas. Não houve correlações entre abundância e prevalência com o comprimento padrão dos hospedeiros e entre o fator de condição relativo com a abundância. Através dos resultados, é possível supor que, provavelmente, existem poucas diferenças fisiológicas e comportamentais entre hospedeiros machos e fêmeas, não ocorrem mudanças fisiológicas durante o desenvolvimento dos hospedeiros e o parasita exibe baixa patogenicidade