The effect of sward height and its direction of change on the herbage intake, diet selection and performance of weaned lambs grazing ryegrass swards

abonos agneau altura application rates azote cordero diet dieta digestibilidad digestibility dose d'application engrais feed intake fertilizers gain de poids ganancia de peso gramineas graminee grasses grazing grazing systems hauteur height lambs liveweight gain lolium perenne nitrogen ovin ovinos pastoreo prise alimentaire (animaux) selective grazing sheep sistemas de pastoreo weight gain