Chronic inflammatory and degenerative endometrial lesions in subfertile Criollo Limonero cattle; a B. taurus Latin-American breed threatened with extinction; A case-control study.

Criollo Limonero is a tropical Bos taurus breed for sustainable dual purpose (milk and beef) production in the South-American tropics, which is currently threatened with extinction. The objective was to perform a clinical evaluation and histopathological assessment of uterine biopsy samples of repeat breeder (RB) Criollo Limonero cattle to determine the occurrence of pathological conditions as potential causes of subfertility. Twenty-four Criollo Limonero cattle [18 cows (5-13 years old) and 6 heifers (6-7.5 years old)] that had failed to conceive after four or more services were considered for this study. Additionally, five cows with history of adequate reproductive performance were used as a control group. Animals were submitted to physical exam, vaginoscopy, and ultrasonographical evaluation of the reproductive tract. Uterine biopsy samples were collected for histopathological evaluation. Vaginoscopy revealed that 41.7% of the RB cattle had abnormal vaginal secretions, while abnormal secretions were not observed in any control cow. Ultrasonographical examination of the uterus revealed the presence of free uterine fluid in 20.8% of the RB animals, while none of the control cows had fluid in the uterine lumen. In addition, ovarian cysts were observed in 25.0% of the RB animals. Histopathological evaluation of the endometrial biopsies revealed that mononuclear leukocyte infiltration, dilated uterine glands, and periglandular fibrosis were the most prevalent lesions in the sub-fertile animals. Chronic endometritis characterized by inflammatory (mononuclear leukocyte infiltration) and degenerative (dilated glands and periglandular fibrosis) endometrial lesions, and ovarian cysts were the most frequent reproductive pathologies observed in the studied subfertile Criollo Limonero cattle, suggesting a strong association with their reduced fertility.

Factores que afectan el número de dientes incisivos al nacer en becerros criollo limonero: desgaste dentario hasta los 12 meses de edad / Factors affecting the number of incisive teeth at birth in criollo limonero calves: teeth waste unitel 12 months of age old

Los objetivos de este estudio fueron determinar el número de dientes incisivos al nacer en becerros Criollo Limonero y las variables que lo influencian, así como, caracterizar la secuencia de desgaste en relación con la edad. Desde su nacimiento y hasta los 12 meses de edad, se observó mensualmente en la dentadura incisiva de 216 becerros Criollo Limonero el número de dientes al nacer, tipo de desgaste y magnitud del desgaste. Todos los becerros nacieron en la Estación Local Carrasquero-INIA, Zulia, Venezuela. El número de dientes al nacer fue analizado mediante distribución de frecuencias. Para analizar los factores que influencian el número de incisivos al nacer se practicó un ANAVA con un modelo estadístico que incluyó las variables sexo del becerro, familia de la madre y familia del padre, condición corporal pre-parto y el número de partos de la madre. 70,8% de los becerros nacieron con 6 dientes incisivos y un 2,3% con 4 dientes. Todos los becerros presentaron sus dientes por pares. Las hembras nacieron con más dientes (6 vs 5; P<0,02) que los machos, y los becerros nacidos de madres con ³ 6 partos presentaron más dientes (5,8 ± 0,3 vs 4,9 ± 0,2; P<0,04) que aquellos nacidos de hembras con £ 5 partos. La interacción sexo del becerro x número de partos de la madre tendió afectar el número de dientes al nacer (P>0,10). El desgaste dentario se inició con rasamiento leve a los 6 meses en pinzas, primeros y segundos medianos, este tipo de desgaste se acentuó a los 9 meses y se hizo marcado a los 12 meses de edad. Se concluyó que los becerros Criollo Limonero nacen predominantemente con 6 dientes, y que el número de dientes incisivos al nacer parece estar más influenciado por factores no genéticos como el sexo del becerro y el número de partos de la madre.

The objectives of this study were to determine the number of incisive teeth at birth in Criollo Limonero calves, factors influencing number of incisive teeth at birth and teeth waste until 12m age old. Incisive teeth from 216 Criollo Limonero calves owned by the Estación Local Carrasquero-INIA, Zulia, Venezuela were monthly observed from birth to 12 m age old. Likewise, type of teeth waste and its magnitude were monthly recorded. The number of incisive teeth at birth was analyzed by frequency distribution. In order to analyze the factors influencing the number of incisive teeth at birth, a statistical model that included the variables calf gender, dam and sire family, prepartum body condition score, and parity was built, and an ANOVA was performed. Most (70.8%) of calves were born with 6 incisive teeth, while 21.3% borh with 4 teeth. All calves had their teeth in pairs. Female calves were born with more (6 vs 5; P<0.02) teeth than male calves. Calves from dams with parity ³ 6 had more (5.8 ± 0.3 vs 4.9 ± 0.2; P<0.04) incisive teeth than those from dams with parity £ 5. The interaction calf gender x parity tended (P>0.10) to have an influence on number of incisive teeth at birth. Mild teeth waste started at 6m age old in front, first, and second lateral teeth. Mild teeth waste became more evident at 9m age old, and strong teeth waste was evident at 12m age old. It was concluded that Criollo Limonero calves are predominatly born with 6 incisive teeth and this number seems to be more influenced by non-genetic factors such as calf gender and parity.

Pedigree analysis in criollo limonero

Con el objetivo de continuar el programa de conservación genética de la raza Criollo Limonero, se realizó un estudio para evaluar la variabilidad genética del rebaño, utilizando 2552 registros genealógicos disponibles entre los años 1985 y 2003 en la Estación Local Carrasquero, ubicada en el sector playa Bonita, municipio Mara, al norte del estado Zulia-Venezuela. Se determinó la consanguinidad de cada animal y la consanguinidad global del rebaño (fh), el promedio de relación de parentesco (AR), los parámetros de la probabilidad de orígen del gen, el número de fundadores (NF), el número efectivo de fundadores (fe), el número efectivo de ancestros (fa), número de genomas fundadores (Ng) y el número de fundadores que explican el 50 por ciento (F50) de la variabilidad genética. La fh en el año 2003 fue de 0,35 por ciento y el AR 3,4 por ciento, el NF 386, fe 63,5, fa 38, Ng 27,71; y el valor de F50 fue 18. La fh no tuvo un incremento marcado a pesar que el AR indicó que existe una alta relación entre los individuos de la población, por lo que los apareamientos deben planificarse para evitar el apareamiento de animales emparentados. Los valores de probabilidad de origen de los genes indican que la población ha perdido variabilidad genética por un efecto de cuello de botella y por deriva genética aunque este deterioro no se refleje en un incremento en la consanguinidad. Aun existe una cantidad importante de diversidad que debe preservarse, dada la importancia que representa este germoplasma para la región y el país.

In order to continue the genetic program for the conservation of the Criollo Limonero population, a study was carried out to evaluate the genetic variability of this local breed. For this purpose, 2552 genealogical records from the Criollo herd at the Carrasquero Local Station (INIA) located at Playa Bonita, Mara County, North of Zulia State-Venezuela, during the 1985-2003 period were used. Global inbreeding of the herd (fH) and animal inbreeding were determined; in addition, Average of relatedness (AR), probabilities of gene origin, number of founders (NF), effective number of founders (fe), effective ancestors number (fa), genome founders number (Ng ) and number of founders explaining 50% (F50) of the genetic variability. For the year 2003 fH was 0.35%, whereas AR, NF, fe, fa, Ng and F50 were 3.4%, 386, 63.5, 38, 27.71 and 18 respectively. Even though AR showed a high relationship among the individuals in the herd, fH did not have a significant increase. For this reason, mates should be planned carefully in order to avoid related mates. Probabilities of gene origin suggest that genetic variation has decreased in this population due to a bottleneck effect and genetic drift, without increasing inbreeding. An important genetic diversity exists in this population which should be preserved, given the importance of this genetic resource for the region and the country.

Milk Yield and reproductive performance of crossbred holstein x criollo limonero cows / Producción de leche y comportamiento reproductivo de vacas cruzadas Holstein × Criollo Limonero

Records from ½ Criollo Limonero + ½ Holstein (F1) and backcrosses, ¾ Criollo Limonero + » Holstein (R) handled in a Venezuelan humid tropical forest zone were analyzed to compare their productive and reproductive performance. The analyzed variables were: age at first calving (AFC), interval from calving to conception (ICC), calving interval (CI), services per conception (SC), gestation length (GL), calf birth weight (CBW), lactation length (LL), milk at 90 d (M90), total milk yield (TMY), and milk adjusted to 305 d (M305). No statistical differences (P > 0.05) were found between F1 and R for AFC (3.4 ± 0.1 vs 3.2 ± 0.1 years), SC (1.6 ± 0.1 vs 1.7 ± 0.1), GL (both 280d), CBW (both 34 ± 0.6 kg), M90 (919 ± 99 vs 813 ± 105 kg), TMY (2093 ± 176 vs 1964 ± 176 kg) or for M305 (2424 ± 146 vs 2430 ± 151kg), respectively. However, the F1 cows had ICC (258 ± 18 vs 173 ± 22 d; P < 0.004) and CI (577 ± 21 vs 474 ± 25 d; P < 0.001) longer than R, respectively. Year of birth affected (P < 0.05) to AFC, (P < 0.03) to ICC, and (P < 0.01) to CI, M90, TMY, and M305. Environmental effects were found for GL, M90, TMY, M305, and LL. Although no differences between genotypes were found for milk yield, R cows had better reproductive performance than the F1 cows.

Con el objetivo de comparar el comportamiento productivo y reproductivo, se analizaron los registros de vacas ½ Criollo Limonero + ½ Holstein (F1) y retrocruces ¾ Criollo Limonero + » Holstein (R) manejadas en una zona de bosque húmedo tropical venezolana. Se analizaron las variables edad al primer parto (AFC), intervalo parto-concepción (ICC), intervalo entre partos (CI), servicios por concepción (SC), duración de la gestación (GL), peso al nacer de los becerros (CBW), longitud de lactancia (LL), producción de leche total (TMY), a los 90 días (M90) y ajustada a 305 días (M305). No se hallaron diferencias significativas (P > 0,05) entre F1 y R para AFC (3,4 ± 0,1 vs 3,2 ± 0,1 años), SC (1,6 ± 0,1 vs 1,7 ± 0,1), GL (ambos 280d), CBW (ambos 34 ± 0,6 kg), M90 (919 ± 99 vs 813 ± 105 kg), TMY (2093 ± 176 vs 1964 ± 176 kg) ni M305 (2424 ± 146 vs 2430 ± 151kg), respectivamente. No obstante, las F1 tuvieron ICC (258 ± 18 vs 173 ± 22 d; P < 0,004) e CI (577 ± 21 vs 474 ± 25 d; P < 0,001) más prolongados que las R, respectivamente. El año de nacimiento afectó (P < 0,05) a AFC, (P < 0,03) ICC, y (P < 0,01) a CI, M90, TMY, y M305. Se hallaron efectos climáticos sobre GL, M90, TMY, M305, y LL. Aunque sin diferencias en producción de leche, las R tuvieron mejor desempeño reproductivo.