Resumen de The association between mastitis and reproductive performance in seasonally-calved dairy cows managed on a pasture-based system

C.I. Gómez Cifuentes, A.I. Molineri, M.L. Signorini, Daniel E. Scandolo, Luis Fernando Calvinho

• español

  El objetivo de este trabajo fue determinar asociación entre mastitis clínicas, subclinicas y condición corporal con la performance reproductiva de vacas en un sistema de partos estacional bajo condiciones de pastoreo. Se analizo informacion de 182 vacas paridas durante 2008. Se realizo Chi cuadrado y regresión logística con prenez al final de la temporada de servicios y numero de servicios como variables dependientes. Las mastitis clínicas, subclinicas y la condición corporal, así como otras posibles variables asociadas fueron analizadas como variables independientes. Numero de lactancia, tipo de parto, intervalo entre parto a inicio de temporada de servicio y condición corporal estuvieron asociadas con preñez. Las vacas con una o dos lactancias (P = 0,031), aquellas sin problemas en el parto (P = 0,003) y las que tuvieron mayor cantidad de dias entre el parto y el inicio de la temporada de servicios (P = 0.001) y las que tuvieron una condición corporal > 2.5 (P = 0.007) tuvieron mas probabilidad de quedar preñadas. Las mastitis subclinicas afectaron la performance reproductiva aumentando el numero de servicios (P = 0.03). Ademas la temporada de servicios influyo sobre el numero de servicios recibidos por vaca, ya que aquellas paridas en verano necesitaron mas servicios para quedar prenadas (P = 0.046). Las mastitis clinicas no estuvieron asociadas con preñez (P = 0.863). La información obtenida puede ser utilizada para mejorar la performance reproductiva de rodeos bajo condiciones pastoriles y sistemas de servicios estacionados.

• English

  The objective of this study was to assess association between clinical, subclinical mastitis, body condition score and the reproductive performance of cows under seasonally calving conditions in a pasture-based management system. Data from 182 cows calved during 2008 were analyzed. Chi-square and logistic regression were performed considering pregnancy at the end of breeding season and number of services as dependent variables, whereas clinical and subclinical mastitis and other variables related to the animal that could have an effect on the dependent variables (e.g. parity, BCS, concurrent diseases) were considered as independent variables. Lactation number, calving difficulty, interval from calving to the beginning of breeding season and body condition score had a significant effect on pregnancy at the end of breeding season. Cows with one or two lactations (P = 0.031), those with no difficulty at calving (P = 0.003), those with more days from calving to the beginning of breeding season (P = 0.001), and those with body condition score > 2.5 (P = 0.007) were most likely to become pregnant. Subclinical mastitis affected reproductive performance increasing the number of services (P = 0.03). Also, breeding season influenced number of services, since summer-calving cows needed more services to become pregnant (P = 0.046). Clinical mastitis was not associated with pregnancy as a final measure of reproductive performance (P = 0.863). Although subclinical mastitis influenced reproductive performance, several parameters related to reproductive and nutritional management, significantly affected the outcome variables under experimental conditions of this study. This information can be valuable to improve reproductive performance in similar management systems.