TECHNOLOGICAL LEVEL EFFECT ON HIGH BLOOD MILKING ANIMAL´S PERFORMANCE IN A DUAL PURPOSE SYSTEM.

Abstract

Technological level effect on crossbred animal's performance was studied in a dual purpose farm of chiriqui, Panama. It was evaluated two technological levels (NT): ST or study of the traditional farm system, and SM or study of the improved farm system, including twice milking. Breed groups (GR) were: >75% Holstein blood (HOC) and >75% Brown Swiss blood (PSC). Data set were analized by fixed linear models. Age was included as covariate. During SM, lactation length was shortened in both GR (78 days in HOC and 190 days in PSC), but non-adjusted total milk yield and daily milk yield increased 22.6% and 49.6% in HOC, and 21.7% and 32.1% in PSC, respectively. Lactation curve traits were also modified by NT (P<0.01). Time of peak lactation was shortened (25 days in HOC and 10 days in PSC) during SM, but milk yield at peak lactation (46% in HOC and 22.7% in PSC) and adjusted 280-d milk yield (19.3% in HOC and 7.7% in PSC) were increased significantly. Age at first calving decreased in 14 moths during SM. Daily gain and weight at eight months of the calves increased 71.8% and 51.5% in SM, respectively. Total calf mortality  decreased 6.5%, but stillbirths was reduced only in 1.5%. Inclusion of technologies and twice milking increased milk yield and improved reproductive efficiency mainly in HOC.