Effects of winter supplementation and antiparasite treatment on the productive performance of milk herd in the central-south region of Chile

During the winter of 1994, a survey of productive and reproductive paramete rs was undertaken in the south-central part of Chile (8th Region) on 71 cow s provided by four small farms with low production (<3000 1/year). A low fo od intake was recorded (8.6+/-0.2-12.4+/-0.2 kg DM/day) and, as a result, t he cows calved with poor body condition score (1.9+/-0.04 points on the sca le of one-to-five, had milk production between 10.5+/-0.4 and 12.8+/-0.6 1/ day, had a delayed start of ovulatory activity (78.2+/-4.6 days) and an int erval between calving and conception of 120.3+/-4.6 days. In addition, low levels of packed cell volume (PCV) and hemoglobin (HEM) were found, which w ere considered to be a combined effect of low feed ingestion and parasitic infection by Fasciola hepatica. To improve the productive and reproductive parameters, treatments were unde rtaken in three of the four small farms; a parasiticide treatment was used against the F: hepatica at the beginning of the winter and the availability of forage was increased via the use of supplementary green oats. Spring cr ops were also cultivated: corn for silage and oats with peas to make hay. The antiparasite treatment and supplementation of forage was associated wit h better body condition score at calving, improved hematological parameters , increased milk production (17%), reduced number of days to conception (12 0 vs. 91) and increased conception rate at first service (36 vs. 60%). In t he fourth small farm where no interventions were undertaken, the parameters obtained during 1994 remained unchanged. (C) 1999 Elsevier Science B.V. Al l rights reserved.