ABSTRACT
Crossbred cattle are commonly used for milk production in the tropics, combining the potential benefits of pure breeds with the heterosis effects of the offspring. However, no comprehensive assessment of lifetime productivity for crossbred versus purebred cattle in low-altitude tropical environments has been carried out. The present study compares the lifetime productivity of purebred Holstein (HO, n = 17,269), Gyr (GY4, n = 435), and Brahman (BR4, n = 622) with crossbreds Gyr × Holstein (GY × HO, n = 5521) and Brahman×Holstein (BR × HO, n = 5429) cows from dairy farms located in low and medium altitude tropical regions in Costa Rica. The production traits of interest were age at first calving (AFC), days open (DO), milk production per lactation (TMP), lactation length (LLEN), age at culling (ACUL), and number of lactations (NLAC). Estimates of heterosis were also calculated. The AFC for GY × HO crosses (33-34 months) was not significantly different (p > .05) from HO (33.8 months). For BR × HO crosses, a significant (p < .05) decrease in AFC (BR3HO1 35.6 months, BR2HO2 34.5 months, and BR1H03 33.3 months) was observed as the fraction of HO breed increased. Estimates of heterosis for AFC were favourable for both crosses, of a magnitude close to 3%. The DO for F1 crosses (GY2HO2 94 days; BR2HO2 96 days) was significantly (p < .05) lower than HO (123 days). Estimates of heterosis for DO were also favourable and above 15% for both crosses. The TMP and LLEN were higher for HO (TMP = 5003 kg; LLEN = 324 days) compared with GY × HO (TMP = 4428 to 4773 kg; LLEN = 298 to 312 days) and BR × HO (TMP = 3950 to 4761 kg; LLEN = 273 to 313 days) crosses. Heterosis for TMP was favourable but low for both crosses, with a magnitude below 3.0%. The NLAC for HO (4.6 lactations) was significantly (p < .05) lower than F1 (GY2HO2, 5.8 lactations; BR2HO2, 5.4 lactations). Heterosis for NLAC was above 6.0% for both crosses. Overall, estimates of lifetime income over feed costs per cow on average were USD 2637 (30.3%) and USD 734 (8.4%) higher in F1 GY × HO and BR × HO, respectively, compared to HO. In conclusion, crossbred animals, specifically those with Gyr and Brahman genetics, extend the productive lifespan, increasing economic returns.
Subject(s)
Hybrid Vigor , Lactation , Milk , Tropical Climate , Animals , Cattle/genetics , Cattle/physiology , Lactation/genetics , Lactation/physiology , Female , Costa Rica , Breeding , Hybridization, Genetic , Altitude , Crosses, GeneticABSTRACT
Aspergillosis is a disease caused by some species of the fungus Aspergillus, occurring in both mammals (including humans) and birds, the latter being the most susceptible group. Aspergillus must be considered a public health concern as it affects the poultry industry economically and is an occupational risk to its workers. A retrospective study of fungal isolates from the lungs of chickens (Gallus gallus), analyzed between 2008 and 2021 at the Mycology Laboratory, School of Veterinary Medicine, Universidad Nacional, Heredia, Costa Rica was performed to report the prevalence of Aspergillus spp. in poultry farms in Costa Rica and their associated factors. A total of 1113 cases were received, of which 31% (n = 392; 95% CI: 28.3−33.7) were positive for fungal isolation. Aspergillus was the most frequently detected genus, and the most frequent sections were Fumigati (n = 197/392, 50.3%), Flavi (n = 90/392, 22.9%), and Nigri (n = 50/392, 12.7%). Significant effects (p < 0.05) related to the year, geographical origin, purpose, and age were identified in relation to the Aspergillus infection. The identified factors are explained by climatic variations in the tropics and the particularities of the birds. Future research including molecular characterization and antifungal susceptibility tests in animals, humans, and the environment, are needed to better understand the risks of the diseases caused by those fungi in this country.
ABSTRACT
The aim was to determine the relationship between kinematic parameters of boar spermatozoa and fertility rates of sow, as well as to assess the effect of sperm clusters on the fertility capacity of the ejaculate. Semen samples were collected from 11 sexually mature boars. Samples were analyzed by an ISAS®v1 CASA-Mot system for eight kinematic parameters. Ejaculate clusters were characterized using multivariate procedures, such as principal factors (PFs) analysis and clustering methods (the k-means model). Four different ejaculate clusters were identified from two kinematic PFs which involved linear trajectory and velocity. There were differences (p < 0.05) between the sperm kinematic variables by sire line. There was no statistical difference (p > 0.05) between dam lines and ejaculate clusters in fertility variables. The discriminant ability of the different kinematics of sperm variables to predict litter size fertility was analyzed using receiver operating characteristics (ROC) curve analysis. Curvilinear velocity (VCL), average path velocity (VAP), amplitude of lateral head displacement (ALH), and beat-cross frequency (BCF) showed significant, albeit limited, predictive capacity for litter size fertility variables (range: 0.55-0.58 area under curve, AUC). The kinematic analysis of the ejaculates in clusters did not have a predictive capacity for litter size variables.
ABSTRACT
Resumen Justificación: alrededor del mundo las cardiopatías congénitas ocupan las primeras causas de mortalidad infantil. En Costa Rica son el grupo de defectos congénitos más frecuentes, con una prevalencia de 6 x 1000 nacimientos (IC95 % 5 -7 x 1000 nacimientos), que representan cerca del 13 % de la mortalidad infantil. El objetivo del estudio fue analizar la supervivencia a cinco años de edad de los niños nacidos con defectos cardiacos en Costa Rica. Métodos: se analizó una cohorte retrospectiva de 543 niños nacidos con cardiopatías congénitas entre enero de 2006 y junio de 2007 en Costa Rica; utilizando los registros médicos y la base nacional de defunciones se brindó un seguimiento mínimo de 5 años en todos los casos. Se obtuvo estimados de supervivencia de Kaplan-Meier al mes, año y cinco años de vida, y se evaluaron factores pronóstico empleando el modelo de riesgos proporcionales de Cox. Se estimaron riesgos relativos crudos y ajustados con su respectivo intervalo de confianza del 95 %. Resultados: la prevalencia de cardiopatías congénitas fue de 5,14 por 1000 nacimientos (IC95 % 4,73-5,60; n: 543) para el período de estudio. La mortalidad fue del 27,9 % (IC 95 % = 24,21- 31,73; n: 152). La supervivencia acumulada al año y cinco años fue del 76,1 % y el 72,4 %, respectivamente, frente al 99,1 % y 98,8 % sobrevivencia de la cohorte de nacimientos nacional (con y sin cardiopatía) de la misma edad. La edad temprana al diagnóstico, severidad, cardiopatías congénitas múltiples y la asociación de defectos congénitos mayores se asociaron significativamente (p≤0,05) a una menor probabilidad de supervivencia. Conclusiones: la cohorte de niños con cardiopatías congénitas estudiada presentó una alta mortalidad al año y cinco años. El peor pronóstico de supervivencia fue para aquellos que necesitaban una cirugía cardíaca a temprana edad.
Abstract Background: Around the world, congenital heart defects occupy the first causes of infant mortality. In Costa Rica heart malformations are the most frequent group of birth defects, with a prevalence of 6 x 1000 births (95% CI 5-7 x 1000 births). They represent about 13% of infant mortality and are. the leading cause of death due to birth defects. The objective of this study is to analyze the survival of children with CC in Costa Rica. Methods: A retrospective cohort of 543 children born with CC between January 2006 and June 2007 in Costa Rica was analyzed. Using medical records and the national database of deaths, a minimum follow-up of 5 years was given in all cases. Kaplan-Meier survival estimates were obtained at month, year and five years of life. Prognostic factors were assessed using the Cox proportional hazards model. Raw and adjusted relative risks were estimated with their respective 95% confidence interval. Results: The prevalence of CC was 5.14 per 1000 births (95% CI: 4.73-5.60; n: 543) for the study period. Mortality was 27.9% (95% CI: 24.21-31.73; n: 152). Cumulative survival at one year and five years was 76.1% and 72.4%, respectively, compared to 99.1% and 98.8% of survival in the same national birth cohort (with and without CC), at the same age. Early age at diagnosis, severity, multiple CC and the association of major BD were significantly associated (p≤0.05) with a lower probability of survival. Conclusions: The cohort of children with congenital heart disease studied had a high mortality rate at one year and five years. The worst prognosis of survival was for those who needed cardiac surgery at an early age.
Subject(s)
Infant, Newborn , Infant , Child, Preschool , Child , Costa Rica , Heart Defects, Congenital/mortalityABSTRACT
OBJETIVO: Identificar las tendencias y el impacto de los diferentes tipos de defectos congénitos (DC) en la tasa de mortalidad infantil (TMI) y neonatal (TMN) en Costa Rica para el período 1981-2010. MÉTODOS: Se analizaron datos del Centro Centroamericano de Población, que utiliza las versiones 9 y 10 de la Clasificación Internacional de Enfermedades para clasificar las causas de defunción. Se analizaron tendencias de mortalidad infantil, neonatal y residual. Para cada grupo de DC se construyó un modelo de regresión Poisson Log Lineal. Se obtuvieron las TMI y las TMN y los riesgos relativos correspondientes a las tres décadas 1981-1990, 1991-2000 y 2001-2010, con sus intervalos de confianza de 95% (IC95%). Los estimados se compararon mediante chi cuadrado de Wald. RESULTADOS: Al comparar la década de 1980 con la del 2000, la TMN y la TMI por DC presentó una disminución significativa de 2,37 (IC95%: 2,26-2,48) a 2,13 (2,03-2,23) y de 4,13 (3,99-4,27) a 3,18 (3,05-3,31), respectivamente. Los grupos de DC que registraron una reducción significativa en la TMI fueron: sistema nervioso, digestivo y circulatorio. Con excepción del sistema circulatorio, estos grupos experimentaron una caída significativa en la TMN. En el resto de los grupos se registró un aumento significativo o no hubo cambio. CONCLUSIONES: Se ha producido una disminución de la TMI y la TMN por DC, aunque proporcionalmente estas tasas han crecido debido a un mayor descenso de las otras causas. Esta reducción es mucho menor en la mortalidad neonatal. Se debe fortalecer la prevención primaria y la atención neonatal de los DC.
OBJECTIVE: Identify trends for different types of birth defects and their impact on infant (IMR) and neonatal (NMR) mortality rates in Costa Rica from 1981 to 2010. METHODS: Infant, neonatal, and postneonatal mortality trends were analyzed, using data from the Central American Population Center, which uses the International Classification of Diseases, versions 9 and 10, to classify causes of death. For each group of birth defects, a Poisson log-linear regression model was constructed. IMR and NMR, relative risk, and 95% confidence intervals (95%CI) were calculated for the three decades (1981-1990, 1991-2000, and 2001-2010). Estimates were compared using Wald chi square. RESULTS: Comparison of the 1980s and the 2000s found a significant decrease in NMR and IMR from birth defects in these decades, from 2.37 (95%CI: 2.26-2.48) to 2.13 (2.03-2.23) and from 4.13 (3.99-4.27) to 3.18 (3.05-3.31), respectively. Reduction in IMR was significant for birth defect groups for nervous, digestive, and circulatory systems. There was also a significant drop in NMR for nervous and digestive system groups. All other groups experienced a significant increase or no change. CONCLUSIONS: IMR and NMR from birth defects have decreased, although these rates have increased proportionately due to a greater decline in other causes. This reduction is much smaller for neonatal mortality. Primary prevention and neonatal care of birth defects should be strengthened.
Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Congenital Abnormalities/mortality , Cause of Death , Congenital Abnormalities/classification , Costa Rica/epidemiology , Infant Mortality/trends , International Classification of Diseases , Retrospective Studies , RiskABSTRACT
OBJECTIVE: Identify trends for different types of birth defects and their impact on infant (IMR) and neonatal (NMR) mortality rates in Costa Rica from 1981 to 2010. METHODS: Infant, neonatal, and postneonatal mortality trends were analyzed, using data from the Central American Population Center, which uses the International Classification of Diseases, versions 9 and 10, to classify causes of death. For each group of birth defects, a Poisson log-linear regression model was constructed. IMR and NMR, relative risk, and 95% confidence intervals (95%CI) were calculated for the three decades (1981-1990, 1991-2000, and 2001-2010). Estimates were compared using Wald chi square. RESULTS: Comparison of the 1980s and the 2000s found a significant decrease in NMR and IMR from birth defects in these decades, from 2.37 (95%CI: 2.26-2.48) to 2.13 (2.03-2.23) and from 4.13 (3.99-4.27) to 3.18 (3.05-3.31), respectively. Reduction in IMR was significant for birth defect groups for nervous, digestive, and circulatory systems. There was also a significant drop in NMR for nervous and digestive system groups. All other groups experienced a significant increase or no change. CONCLUSIONS: IMR and NMR from birth defects have decreased, although these rates have increased proportionately due to a greater decline in other causes. This reduction is much smaller for neonatal mortality. Primary prevention and neonatal care of birth defects should be strengthened.
