ChileanJAR

The effect of concentrate supplementation on grazing behavior of lactating dairy cows was studied. The study was conducted at Vista Alegre Experimental Farm (39º48’ S lat; 73º13’ W long), owned by Universidad Austral de Chile, located in Valdivia. Twelve Holstein-Friesian cows managed under a rotational strip grazing system on an improved permanent pasture were used. A latin square design was used, with three periods (of 23 days), three treatments and four blocks per treatment. The three treatments studied were: T1: only grazing, without supplement; T2: grazing plus a concentrate based on sugar beet pulp (6 kg cow^-1 d^-1); and T3: grazing plus a concentrate based on cereal grain (6 kg cow^-1 d^-1). In the last week of each period, the grazing behavior of each of the animals was recorded every ten minutes for 24 h. It was observed that grazing time was 45 min lower in the supplemented treatments, with no differences being found between the treatments with supplementation. The biting rate was reduced by the supplementation, the treatment without supplementation having 5000 more bites per day. Total dry matter intake and milk production were higher in the supplemented treatments, however pasture dry matter intake was decreased by supplementation.