Efecto de diferentes estrategias de manejo durante el período destete – encarnerada en ovejas sobre las variables productivas, sanitarias y reproductivas

The aim of this study was to evaluate the effect on sanitary, productive and reproductive aspects in different strategies in the sheep 's management during the dry period. It was held from the 14th of January 2021 to the 19th of May at the Centro de Investigación y Experimentación Dr Alejandro Gallinal (CIEDAG) of Secretariado Uruguayo de la Lana, in Cerro Colorado, Florida, Uruguay. Nevertheless, the experiment will be continually held for the next two years.

There were 210 Corriedale ewes that were classified at weaning according to its liveweight (PV), condition scoring (CC), dentition and reproductive antecedents. All animals considered were homogeneously allocated in three randomly selected treatments with two repetitions each one. The treatments were: control treatment, grazing nature pastures in a continue stocking rate (4 animals/ha); confinement in an area of 11,1m²/animal with water and shade administration and a diet of pasture hay; confinement in a diet base on 200 grames/animal/day of corn and hay.

Before establishing the confinement, the animals were dosed with an anthelmintic of known efficiency and submitted to a General Objective Exam (GOE) to ensure sanitary status. The treatments started at the weaning and lasted 39 days, at its end a flushing started for 30 days with a diet based on Festuca arundinacea and Lotus corniculatus pasture. On the 15th day of the flushing the mating started for 41 days with 3 rams per 100 ewes.

The aspects evaluated were: parasite status with HPG, liveweight, condition scoring, blood metabolites, pregnancy, prolificacy and twin rates. The hypothesis is that the different strategies resulted in different condition scoring and liveweight evolution, that could be verified in different blood metabolites evolution. However, the different treatments involve could not result in different reproductive rates as long as the animals could recover live weigh and condition scoring during the mating. In sanitary terms, if the environmental conditions are the required the animals confined could present lower HPG results than the one grazing.