Gustavo Castro

La morfometría es una herramienta para cuantificar y analizar la variación morfológica en el tamaño y forma de los animales. El objetivo del estudio fue contribuir a la caracterización morfométrica del cerdo criollo araucano para conocer algunas de sus características funcionales y etnológicas. Se estudiaron 58 cerdos (27 hembras y 31 machos), con edades entre 4 a 48 meses, localizados en tres veredas de Arauca, oriente de Colombia. Se obtuvieron 11 medidas corporales individuales y se construyeron tres índices. Se aplicó estadística descriptiva y un análisis univariado para medir el efecto ambiental sobre las medidas corporales e índices, usando la edad como covariable. Los cerdos presentaron una variabilidad media en las medidas corporales asociada con una mediana armonía. Los cerdos se consideran dolicocéfalos, mesolíneos y no aptitud cárnica. Las hembras tendían a ser más grandes que los machos. La vereda fue el único efecto que influyó sobre la combinación lineal de las variables morfológicas e índices. Dada la variabilidad de las medidas según las veredas se podría inferir que en los cerdos araucanos estudiados se presentan biotipos distintos.

Background: Feral swine (Sus scrofa) are highly invasive and threaten animal and human health in the Americas. The screwworm (Cochliomyia hominivorax) is listed by the World Organization for Animal Health as a notifiable infestation because myiasis cases affect livestock, wildlife, and humans in endemic areas, and outbreaks can have major socioeconomic consequences in regions where the screwworm has been eradicated. However, a knowledge gap exists on screwworm infestation of feral swine in South America, where the screwworm is endemic. Here, we report screwworm infestation of feral swine harvested in Artigas Department (Uruguay), where the Republic of Uruguay shares borders with Brazil and Argentina.Methods: Myiasis caused by the larvae of screwworm were identified in feral swine with the support and collaboration of members of a local feral swine hunting club over a 3-year period in the Department of Artigas. Harvested feral swine were examined for the presence of lesions where maggots causing the myiasis could be sampled and processed for taxonomic identification. The sites of myiasis on the body of infested feral swine and geospatial data for each case were recorded. The sex and relative size of each feral swine were also recorded. Temperature and precipitation profiles for the region were obtained from public sources.Results: Myiases caused by screwworms were recorded in 27 of 618 the feral swine harvested. Cases detected in males weighing > 40 kg were associated with wounds that, due to their location, were likely caused by aggressive dominance behavior between adult males. The overall prevalence of screwworm infestation in the harvested feral swine was associated with ambient temperature, but not precipitation. Case numbers peaked in the warmer spring and summer months.Conclusions: This is the first report on myiasis in feral swine caused by screwworm in South America. In contrast to myiasis in cattle, which can reach deep into host tissues, screwworms in feral swine tended to cause superficial infestation. The presence of feral swine in screwworm endemic areas represents a challenge to screwworm management in those areas. Screwworm populations maintained by feral swine may contribute to human cases in rural areas of Uruguay, which highlights the importance of the One Health approach to the study of this invasive host species–ectoparasite interaction.Graphical

This study assessed the effect of bran rice inclusion in the diet on the productive behavior and carcass characteristics of Pampa Rocha piglets. Sixteen animals were used from weaning up to 42 days and 77 days of age, which were housed in boxes in a deep bed system of wheat straw. A randomized complete block design with two treatments and four replications was used. Treatments consisted of diets with different lipid content (T0 = 0 % rice bran; T15 = 15 % rice bran). Productive behavior was evaluated through analysis of variance and comparison of means for daily food consumption (DC), daily weight gain (DG) and conversion efficiency (CE). Weight and backfat thickness were the evaluated carcass traits, and they were analyzed through a comparison of means per treatment. The DG and CE showed differences during week 5, although they showed no differences in the experimental period average. For DC, no differences were recorded during the weeks or the average of the experimental period. Carcass traits did not differ statistically between treatments. Based on the results, rice bran could be considered as an alternative in the preparation of ration for piglets.

Within the last two decades, several high-impact viruses have emerged in the global swine population, including porcine reproductive and respiratory syndrome virus (PRRSV). In Uruguay, the more recent serological survey for PRRSV and other notifiable diseases such as Aujeszky's disease virus (ADV) and classical swine fever virus (CSFV) dated from year 2000. The main purpose of this study was to update our information on the infection status of PRRSV, ADV and CSFV in Uruguayan pig herds, in order to keep informed about the epidemiological situation of these notifiable infections in the country. For serological testing, a total of 524 swine serum samples collected during the period 2014–2016 were assayed by commercial ELISAs. Our results revealed the (unexpected) presence of PRRSV antibodies in Uruguayan domestic swine herds and confirmed the absence of ADV and CSFV antibodies in all of the assessed samples. Following such initial finding, PRRSV antibodies were further investigated in 23 retrospective samples collected during 2010-2014. Thirteen of these 23 samples resulted seropositive. Subsequently, a molecular detection approach in frozen serum samples was implemented to confirm PRRSV infection, and viral RNA was identified by reverse transcription–nested polymerase chain reaction (RT-nPCR). Fourteen of 86 evaluated 2014–2016 samples resulted positive for viral RNA, while molecular analysis of four retrospective samples also revealed the presence of PRRSV type 2. Viral isolation of selected samples was carried out in porcine alveolar macrophages (PAM) and MARC 145 simian kidney cells, and the virus identity was confirmed by cytopathic effect (CPE) and immunofluorescence assay (IFA) using specific monoclonal antibodies for PRRSV nucleocapsid. Data reported here evidence for the first time the circulation of PRRSV type 2 in Uruguay, and retrospective serology results suggest that the virus has been infecting pigs in this country at least since 2011.

In this study, we genetically characterized the Uruguayan pig breed Pampa Rocha. Genetic variability was assessed by analyzing a panel of 25 microsatellite markers from a sample of 39 individuals. Pampa Rocha pigs showed high genetic variability with observed and expected heterozygosities of 0.583 and 0.603, respectively. The mean number of alleles was 5.72. Twenty-four markers were polymorphic, with 95.8% of them in Hardy Weinberg equilibrium. The level of endogamy was low (F_IS = 0.0475). A factorial analysis of correspondence was used to assess the genetic differences between Pampa Rocha and other pig breeds; genetic distances were calculated, and a tree was designed to reflect the distance matrix. Individuals were also allocated into clusters. This analysis showed that the Pampa Rocha breed was separated from the other breeds along the first and second axes. The neighbour-joining tree generated by the genetic distances D_A showed clustering of Pampa Rocha with the Meishan breed. The allocation of individuals to clusters showed a clear separation of Pampa Rocha pigs. These results provide insights into the genetic variability of Pampa Rocha pigs and indicate that this breed is a well-defined genetic entity.