Blastocystis is frequently reported in fecal samples from animals and humans worldwide, and a variety of subtypes (STs) have been observed in wild and domestic animals. In Colombia, few studies have focused on the transmission dynamics and epidemiological importance of Blastocystis in animals. In this study, we characterized the frequency and subtypes of Blastocystis in fecal samples of domestic animals including pigs, minipigs, cows, dogs, horses, goats, sheep, and llama from three departments of Colombia. Of the 118 fecal samples included in this study 81.4% (n = 96) were positive for Blastocystis using a PCR that amplifies a fragment of the small subunit ribosomal RNA (SSU rRNA) gene. PCR positive samples were sequenced by next generation amplicon sequencing (NGS) to determine subtypes. Eleven subtypes were detected, ten previously reported, ST5 (50.7%), ST10 (47.8%), ST25 (34.3%), ST26 (29.8%), ST21 (22.4%), ST23 (22.4%), ST1 (17.9%), ST14 (16.4%), ST24 (14.9%), ST3 (7.5%), and a novel subtype, named ST32 (3.0%). Mixed infection and/or intra -subtype variations were identified in most of the samples. Novel ST32 was observed in two samples from a goat and a cow. To support novel subtype designation, a MinION based sequencing strategy was used to generate the full-length of the SSU rRNA gene. Comparison of full-length nucleotide sequences with those from current valid subtypes supported the designation of ST32. This is the first study in Colombia using NGS to molecularly characterize subtypes of Blastocystis in farm animals. A great diversity of subtypes was observed in domestic animals including subtypes previously identified in humans. Additionally, subtype overlap between the different hosts examined in this study were observed. These findings highlight the presence of Blastocystis subtypes with zoonotic potential in farm animals indicating that farm animals could play a role in transmission to humans.

The objective of this study was to validate the use of exogenous gonadotropin (PG600) treatment for stimulating estrus in noncyclic gilts and to compare lifetime productivity of gilts recorded as having natural (NAT) versus PG600-induced (PG600) first estrus in a commercial setting. Prepubertal Camborough gilts ( = 4,489) were delivered to a gilt development unit (GDU) with the goal of delivering known cyclic breeding-eligible females to the sow farm (SF). A boar exposure area (BEAR) was designed to facilitate stimulation and detection of puberty by providing fence line and direct contact (15 min daily) with mature boars over an intensive 28-d period, starting at approximately d 160 (d 0). At d 14, nonpubertal gilts were mixed in new pen groups. At d 23, noncyclic "opportunity" gilts with no record of vulval development and required to meet breeding targets, were eligible for treatment with PG600 to induce puberty. Overall, 77.6% ( = 3,475) of gilts exhibited standing estrus (NAT = 2,654; PG600 = 821) and were eligible for shipping to the SF at approximately 35 d, and 76.6% of gilts that were administered PG600 exhibited the standing reflex within 13 d of treatment. Ultimately, 72.0% of gilts entering the GDU were delivered to the SF as breeding-eligible females. Considering the gilts delivered, a greater proportion of NAT than PG600 gilts were successfully bred ( < 0.001) and had better farrowing rates to first service, and overall farrowing rates (including gilts that returned to estrus and were rebred) were greater for NAT compared to PG600 gilts ( < 0.001) . Farrowing rates at second and third parity were similar between NAT and PG600 gilts; however, at fourth parity, a greater proportion of NAT gilts farrowed. In comparison, considering only gilts served, there was no difference ( > 0.05) in the proportion of NAT and PG600 gilts farrowing a third litter, but a greater proportion of NAT than PG600 gilts farrowed their fourth litter ( < 0.001). There was no difference between NAT and PG600 gilts for litter size at parity 1 through 4 or total pigs born over 4 parities ( > 0.05). A negative correlation ( < 0.0001) was detected between age at puberty and lifetime growth rate at puberty, and growth rate classification affected age and weight at puberty. However, retention rates and total sow productivity to parity 4 were not affected by growth rate classification at puberty.

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It was carried out an investigation at the central region of Venezuela from January to June 2014 with the aim to determine the prevalence of coccidian Cystoisospora suis in intensive swine herds. For parasitic determination 572 litters were selected with signsof diarrhea. Likewise, 1.712 fecal samples were also collected in mature pigs. Stoolsamples were cultured in a 2.5% potassium dichromate solution and later processedby coprological technique. The results of this investigation indicated that C. suis was observed in 55 herds (82.1%) and 210 litters (36.7%) with the highest prevalence values in first two weeks of age (P < 0.05). Regarding to mature pigs, there was a significant correlation (rho = 0.35; P < 0.05) among oocysts excretion in piglets and sows, suggesting that sows may act as infection sources. Sows parity was statistically correlated with the prevalence values in litters as in lactating sows (P < 0.05). This might indicate that as parity increase, prevalence decreases in these groups. Probably these findings are associated with unknown immunologic mechanisms. It is concluding that C. suis is broadly distributed in Venezuela and it could be controlled by improving conditions sanitary herd, however, non elucidated immunologic mechanisms might be involved in the protozoa transmission cycle.

RESUMENEl objetivo del estudio fue determinar la prevalencia de parásitos gastrointestinales en bovinos del departamento del Cesar, Colombia. Se colectaron 862 muestras fecales en 27 fincas de doble propósito de dos municipios. Los animales fueron estratificados en tres grupos etarios: 0-12, 12-24 y >24 meses. Las muestras se procesaron mediante las técnicas coprológicas de McMaster, Dennis y Baermann. Se identificaron los géneros de los parásitos según morfología de sus huevos o larvas infectivas. La prevalencia global de parásitos gastrointestinales fue de 83.2%, siendo los valores más altos para Eimeria sp (77.9%), Strongyloides sp (10.8%) y Haemonchus sp (8.5%). No se encontró asociación estadística por efecto de los municipios, pero se observó por efecto del grupo etario en la prevalencia de Eimeria sp, Strongyloides, Haemonchus y Trichostrongylus (p<0.05).Palabras clave: gastrointestinal; helmintos; parásitos; vacunos ABSTRACTThe objective of the study was to determine the prevalence of gastrointestinal parasites in bovines from the department of Cesar, Colombia. Faecal samples were collected (n=862) from 27 dual-purpose cattle farms in two municipalities. The animals were stratified into three age groups: 0-12, 12-24 and >24 months. The samples were processed using the coprological techniques of McMaster, Dennis and Baermann. The genera of the parasites were identified according to the morphology of their eggs or