Effect of COQ9 and STAT5A polymorphisms on reproductive performance in a Holstein cow herd in Mexico.

Coenzyme Q9 (COQ9), a coenzyme Q (CoQ) precursor, is an essential component of the mitochondrial electron transport chain that drives adenosine triphosphate production. COQ9 polymorphism 18:25527339 is characterized by substitution of guanine (allele G) for adenine (allele A), which modifies the function of the protein encoded by the gene. In Holsteins, allele A has been associated with better reproductive performance in terms of the conception rate, number of services per conception (SPC) and days open (DO). The signal transducer and activator of transcription (STAT) protein is a transcription factor activated in the presence of cytokines and growth factors. STAT5A polymorphism 19:42407732 in exon 8 has been associated with higher fertility and embryonic survival rates. The objective of this study was to determine the relationship of COQ9 and STAT5A polymorphisms with reproductive parameters [calving to first heat interval (CFHI), DO and SPC]. Blood samples were taken from 112 lactating Holstein from a herd in México for allele genotyping by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). To estimate the association between reproductive parameters and genotypes, a linear mixed-effect model was performed. The COQ9 AG genotype was associated significantly with lower SPC (P<0.05) but not with DO or CFHI. No significant association with any reproductive parameter was found for STAT5A. Our findings suggest that the COQ9 18:25527339 polymorphism is a useful molecular marker for improvement of reproductive performance in dairy herds.

A novel simple genotyping assay for detection of the 'Gait keeper' mutation in DMRT3 and allele frequencies in Azteca and Costa Rican Saddle Horse breeds.

The 'Gait keeper' mutation in the DMRT3 gene alters locomotion and gait patterns in horses. This mutation (C>A) has been found in all gaited breeds of horses analyzed but is absent in most non-gaited breeds. We developed a new mutagenically separated polymerase chain reaction (MS-PCR) based method for simple detection of horse DMRT3 genotype. Our method was applied in a preliminary study to determine DMRT3 allele frequencies in 78 Azteca horses (AZ) and 53 Costa Rican Saddle Horses (CRSH). We found a wild-type C allele frequency of 100% in the AZ horses. For the CRSH, the wild-type C frequency and mutant A allele frequency were 88.7% and 11.3%, respectively.

Effect of aqave oliqofructose feed on eqq production from layinq hens / Efecto de oligofructosa de agave en dietas de gallinas ponedoras en la producción de huevos

ABSTRACT Objective. To determine egg production in laying hens treated with oligofructose from agave. Materials and methods. Eighteen weeks old Hy-line W-36 hens (n = 300) were distributed randomly into 3 treatment groups: no feed supplementation (control) or feed supplementation with 0.1% of 0.2% oligofructose from agave (OFA). Hens were monitored from development until 30 weeks of egg laying. Results. A significant (p<0.05) increase in the percent of egg-laying hens as well as increased in egg weight and egg quality occurred in hens from the OFA treatment groups relative to the control hens. Significantly lower levels (p<0.05) of fecal putrescine were observed in hens from the OFA treatment groups. Conclusions. The oligofructose from agave may be used as an alternative feed additive in laying hens.

RESUMEN Objetivo. Determinar la producción de huevos en gallinas tratadas con oligofructosa de agave (OFA). Materiales y métodos. Se utilizaron 300 gallinas de la línea genética Hy-line w-36, de 18 semanas de nacidas, distribuidas aleatoriamente en tres tratamientos con cuatro repeticiones de 25 gallinas cada uno. Los tratamientos consistieron en tres niveles de OFA, 0, 0.1 y 0.2% en alimento. La prueba duró desde las 18 hasta las 30 semanas de postura. Resultados. Se presentó un incremento significativo (p<0.05) en el porcentaje de postura y peso del huevo, así como en índices de calidad del huevo a favor de tratamientos con OFA. Se encontraron valores significativamente (p<0.05) más bajos de putrescina fecal en las gallinas tratadas con OFA. Conclusiones. El uso de la OFA en gallinas ponedoras puede ser una alternativa como aditivo en la alimentación.

Diagnosis and prevalence of Theileria equi horses in western Mexico by nested PCR.

Theileria equi infection prevalence was calculated from 1000 blood samples obtained from apparently healthy horses in western Mexico. Samples were sent to the Animal Biotechnology Laboratory of the University of Guadalajara (Mexico) for T. equi diagnosis. Nested polymerase chain reaction (nPCR) was used as a diagnostic method to detect pathogen DNA. Using primers for the merozoite antigen-1 (EMA-1) gene, 19.70±2.47% of the horses (95% CI, 17.23-22.17%) tested positive for T. equi. There was no significant association between gender and T. equi infection. However, prevalence was higher among stabled horses (25.81%) than that among grazing horses (15.02%). The positivity rate was also higher among Quarter Horse (24.70%), Lusitano (35.90%), and Costa Rican Saddle Horse (47.37%) breeds than that among the other seven breeds investigated in this study. The percentage of T. equi infection was higher among adult horses (≥ 4years old, 25.05%) than that among colts and fillies (2-4years old, 15.48%), yearlings (1-2years old, 10.49%), and foals (<1year old, 10.34%). This is the first study of T. equi infection prevalence among horses in Mexico by nPCR . The results indicate that the equine piroplasmosis (EP) caused by T. equi is enzootic in western Mexico.

Genotyping of friesian horses to detect a hydrocephalus-associated c.1423C>T mutation in B3GALNT2 using PCR-RFLP and PCR-PIRA methods: Frequency in stallion horses in México.

Hydrocephalus in Friesian horses is an autosomal recessive hereditary disease that can result in an abortion, a stillbirth, or euthanization of a newborn foal. Here, the hydrocephalus-associated c.1423C > T mutation in B3GALNT2 gene was detected with PCR-RFLP and PCR-PIRA methods for horse genotyping. A preliminary genotyping survey was performed on 83 randomly selected Friesian stallion horses to determine the current allele frequency in Mexico. The frequency of the mutant T allele was 9.6%.

New test for endothelin receptor type B (EDNRB) mutation genotyping in horses.

Lethal white foal syndrome (LWFS) is an autosomal recessive disease of neonatal foals characterized by a white hair coat and a functional intestinal obstruction. Traditional techniques for identifying the dinucleotide mutation (TC→AG) of the endothelin receptor B gene (EDNRB) associated with LWFS are time-consuming. We developed a new technique based on mutagenically separated polymerase chain reaction (MS-PCR) for simple detection of the EDNRB genotype in horses.

Estudio citogenético y anatomopatológico del síndrome freemartin en bovinos (Bos taurus) / Cytogenetic and anatomopathological studies of the freemartin syndrome in cattle (Bos taurus)

A través del análisis citogenético se diagnosticaron como freemartin cinco individuos seleccionados de un total de 10 bovinos (Bos taurus) que tenían el antecedente de proceder de partos múltiples heterosexuales; asimismo, se estudiaron anatomopatológicamente dos de estos individuos. La presencia de quimerismo cromosómico (60,XX/60,XY) caracterizó a los animales estudiados, excepcionalmente un individuo freemartin mostró tan sólo células 60,XY, en tanto que los hallazgos anatomopatológicos de dos freemartin estudiados hasta su sacrificio exhibieron masculinización del tracto reproductor con únicamente tejido testicular en las gónadas.