Efecto de la raza y el manejo sobre la vida productiva del bovino lechero en Costa Rica
Archivos
Fecha
2004
Autores
Cedeño, D.A
Vargas Leitón, Bernardo
Título de la revista
ISSN de la revista
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Editor
Universidad de Córdoba
Resumen
Se analizó el efecto de factores raciales y de
manejo sobre la longitud de la vida productiva en
ganado lechero de Costa Rica utilizando la metodología de análisis de sobrevivencia. Se utilizó
información proveniente de ganaderías lecheras,
abarcando el periodo comprendido entre 1985
hasta 2002, e incluyendo los grupos raciales
Holstein (n=28986), Jersey (n=14064), Guernsey
(n=1054), Pardo Suizo (n=1684), ½Holstein x
½Jersey (n=4707), Bos indicus x Pardo Suizo
(n=737), y Holstein x Pardo Suizo (n=946). La
vida productiva esperada varió desde 2,81±0,17
años (Bos Indicus x Pardo Suizo) hasta 4,26±0,06
años (Holstein x Jersey). Las curva de sobrevivencia de los grupos Holstein x Jersey, Holstein
x Pardo Suizo y Jersey fueron más elevadas que
las demás, mientras que la del grupo Bos indicus
x Pardo Suizo fue más baja. Se compararon
además las curvas de sobrevivencia de 15 ganaderías Holstein. Se observó un rango de variación en la vida productiva esperada desde
2,76±0,08 años hasta 5,72±0,22 años. La variabilidad observada entre ganaderías fue mayor
que entre razas, lo que parece indicar que los factores ambientales tienen mayor efecto que los
factores raciales sobre la vida productiva. El
promedio de vida productiva de las ganaderías
analizadas no se correlacionó de manera significativa con su promedio de producción de leche a
305-d (r=0,06, p<0,82) o el intervalo entre partos
(r=0,14, p<0,60). Se concluye que existe una alta
variación en la vida productiva esperada de la
población estudiada, la cual es principalmente
causada por la gran variación existente en las
tasas de descarte involuntario, y en menor grado
debido a factores raciales
This study analyzed the effect of breed type and management factors on herd life in dairy cattle of Costa Rica using survival analysis. Information was obtained from commercial dairy farms between years 1985 to 2002, and included the following breed types: Holstein (n= 28986), Jersey (n= 14064), Guernsey (n= 1054), Brown Swiss (n= 1684), ½Holstein x ½Jersey (n= 4707), Bos Indicus x Brown Swiss (n= 737), and Holstein x Brown Swiss (n= 946). Expected herd-life for the different breed types ranged from 2.81±0.17 years for Bos indicus x Brown Swiss up to 4.26±0.06 years for Brown Swiss x Holstein. The survival curve for the groups Holstein x Jersey, Holstein x Pardo Suizo and Jersey were higher than the others, while the curve Bos indicus x Pardo Suizo was lower. The survival curves of 15 Holstein farms were also compared. Herd-life in these farms ranged from 2.76±0.08 up to 5.72±0.22 years. The range of variation in expected herd-life obtained for the farms was higher than the range observed between breeds, which seems to indicate that environmental factors have a higher effect than the racial factors on length of herd-life. At the farm level, expected herd-life was not significantly correlated to either 305-d milk yield (r=0.06, p<0.82) or calving interval (r=0.14, p<0.60). It is concluded that expected herd-life is highly variable within the available population, which is mainly caused by high and variable culling rates between farms, and to a lesser extent, due to differences in breed type.
This study analyzed the effect of breed type and management factors on herd life in dairy cattle of Costa Rica using survival analysis. Information was obtained from commercial dairy farms between years 1985 to 2002, and included the following breed types: Holstein (n= 28986), Jersey (n= 14064), Guernsey (n= 1054), Brown Swiss (n= 1684), ½Holstein x ½Jersey (n= 4707), Bos Indicus x Brown Swiss (n= 737), and Holstein x Brown Swiss (n= 946). Expected herd-life for the different breed types ranged from 2.81±0.17 years for Bos indicus x Brown Swiss up to 4.26±0.06 years for Brown Swiss x Holstein. The survival curve for the groups Holstein x Jersey, Holstein x Pardo Suizo and Jersey were higher than the others, while the curve Bos indicus x Pardo Suizo was lower. The survival curves of 15 Holstein farms were also compared. Herd-life in these farms ranged from 2.76±0.08 up to 5.72±0.22 years. The range of variation in expected herd-life obtained for the farms was higher than the range observed between breeds, which seems to indicate that environmental factors have a higher effect than the racial factors on length of herd-life. At the farm level, expected herd-life was not significantly correlated to either 305-d milk yield (r=0.06, p<0.82) or calving interval (r=0.14, p<0.60). It is concluded that expected herd-life is highly variable within the available population, which is mainly caused by high and variable culling rates between farms, and to a lesser extent, due to differences in breed type.
Descripción
Palabras clave
RAZAS, GANADO DE LECHE, DAIRY CATTLE, PRODUCCIÓN DE ANIMALES, MEJORAMIENTO GENÉTICO, GENETIC IMPROVEMENT, ANIMAL PRODUCTION, COSTA RICA