-This study was designed to investigate the effect of early weaning and concentrate supplementation on performance and metabolic profile of lambs in four production systems on pasture: suckling lambs not supplemented until slaughter; suckling lambs supplemented with concentrate in creep feeding until slaughter; early weaned lambs not supplemented until slaughter; early weaned lambs supplemented with concentrate until slaughter. Performance was assessed by average daily gain (ADG) and body condition score (BCS) measurements. Concentrate supplementation has similar response to suckling on the performance and metabolic profile of animals, and may be considered an efficient strategy to improve the nutritional status of early weaned lambs.

No abstract

Objetivou-se analisar os custos e a rentabilidade de sistemas de produção de ovinos em pastagem sob três estratégias de suplementação de cordeiros lactentes: (1) creep grazing de trevo branco; (2) creep feeding; e (3) sem suplementação. Utilizaram-se dois métodos de análise financeira: análise anual (de curto prazo) e de fluxo de caixa (de longo prazo). Os custos foram segmentados em variáveis, fixos, operacionais e totais. O fator de produção que exerceu maior influência no custo variável da produção foi a alimentação, e no custo total foi o custo de oportunidade do capital imobilizado. O sistema com creep grazing não apresentou resultados econômico-financeiros superiores aos com creep feeding.

No abstract

-The influence of early weaning and concentrate supplementation strategies on sward characteristics, forage chemical composition and lamb productivity were evaluated in four production systems on Tifton-85 pasture: suckling lambs not supplemented until slaughter; suckling lambs supplemented with concentrate in creep feeding until slaughter; early-weaned lambs not supplemented until slaughter; and early-weaned lambs supplemented with concentrate until slaughter. Structural, morphological and productive characteristics of pasture were measured. The forage was chemically analyzed to estimate its composition. Lambs average daily gain and productivity were calculated. Sward height, forage and morphological components mass were lower in systems without weaning. Forage production was higher in systems with supplementation. Higher levels of neutral and acid detergent fiber were observed in forage ingested by lambs in creep feeding and by weaned and unsupplemented lambs. Average daily gain was higher for lambs in creep feeding (275 g/d) and lower for the weaned and unsupplemented animals (57 g/d). Productivity was higher for weaned and supplemented lambs (21 kg lamb body weight, BW gain/ha/d). Lower productivity was observed in systems without supplementation (5 kg lamb BW gain/ha/d on average). Ewes modify the sward conditions improving the pasture characteristics and the quality of forage produced. Changes in sward conditions affect the chemical composition of forage ingested by lambs. Early weaning may be an alternative to maximize pasture utilization in small areas. Concentrate supplementation may increase lamb performance and productivity in grazing systems. If the objective is to improve lamb individual performance, creep feeding should be used.