Ewes production in a pasture of star grass ( Cynodon nlemfuensis) fertilized with swine lagoon effluent

Abstract

A study was carried out to evaluate the effect of fertilizing star grass ( Cynodon nlemfuensis) with effluents from swine lagoon on weight gain of Pelibuey ewes. Two stocking rates (69.4 ewes ha −1 versus 97.2 ewes ha −1) and two rest periods (21 days versus 28 days), were compared using eight paddocks of 720 m 2 each (two replicates per treatment). The paddocks were fertilized with 300 kg ha −1 of N, divided in three applications and were irrigated during the dry season. Ewes were allowed to graze for 24 h per day, with water and a mineral supplement freely available. Live weight was recorded at 28 day intervals. Herbage mass, crude protein and neutral detergent fiber (NDF) concentration were evaluated in plots ( 2 m×1 m) with 300 and 450 kg ha −1 of N, cutting every 21 or 28 days, in four replicates. Weight gains were higher ( P<0.01) at medium than at high stocking rates (53.4 g per day versus 40.5 g per day). Weight gain per hectare was higher ( P<0.01) for the resting interval of 21 days as compared with 28 days (3.7 kg ha −1 per day versus 3.2 kg ha −1 per day). The application of swine lagoon effluent on star grass increase dry matter production and allows an increase in stocking rate.