Manejo reprodutivo e sanitário na bacia leiteira da região central do Rio Grande do Sul

The growth of the dairy production occurred from studies conducted with practical application in the farm. The aim of these studies was to evaluate the relationship of production systems with reproductive efficiency and milk quality of dairy cows in the central region of the RS/Brazil. In the first study, data from 150 holstein cows were investigated to detect the occurrence of postpartum disease within the first 45 days of lactation. Also, the effect of different production system levels highly specialized (n=50), specialized (n=50) and not specialized (n=50) and the pregnancy rate after the first artificial insemination (AI) were analyzed. Thirty-five percent (53/150) of females were diagnosed with postpartum disorders and 65% (97/150) remained healthy. At day 60 after AI, 41% (61/150) of the cows were pregnant. The occurrence of postpartum diseases decreased conception rate in the cows with post partum (P=0.0011) and only 30% (16/53) were pregnant at 60d. The pregnancy rate from all health cows was 46% (45/97). The two diseases with the highest incidence level were uterine infection (49%) and mastitis (30%).The combined conception rate of healthy cows from all systems was higher than those with postpartum disease (46.3% vs. 26.4%, P=0.0227). In all three systems, highly specialized, specialized, and not specialized, there was a correlation between sickness and the delay in conception (P=0.0018, P=0.0005 and P=0.0140), respectively. None of the production systems effectively reduced the occurrence of postpartum disease. These analyze of milk samples were collected from milk tanks (n=69) and from individual cows (n=3517) on highly specialized (HS, n=3), specialized (S, n=5) and not specialized (NS, n=7) production systems. Composition, somatic cell count (SCC) and urea nitrogen (UN) was analyzed in the different production systems, seasons and ranges allowed by the Federal Normative Instruction 51/2002 (IN51). Mean SCC of the tank samples was 604.900 cells mL-1. Only 42% (n=29/69) of the milk samples obtained ...