Resumo

ROVIRA, P.J.. Desempeño productivo de novillos sobre pasturas templadas con suplementación energética en autoconsumo. Rev. vet. [online]. 2012, vol.23, n.1, pp.3-7. ISSN 1669-6840.

Self-feeding of supplements to livestock can be a useful practice among those producers limited on time and labor resources to handle daily supplementation of cattle. The objective of the study was to evaluate self-feeding of an energetic supplement on the performance of steers (326±23 kg) grazing high quality temperate pastures. Treatments were: 1) control group without supplementation, 2) hand-fed daily supplementation at 1% of body weight (BW), 3) restricted self-feeding supplementation at 1% BW loading the feeder once a week, 4) self-feeding supplementation ad-libitum. The ration used in self-feeding treatments contained 10% salt to limit food intake. Feed intake in self-feeding ad-libitum supplementation (6.7 kg/a/d) was greater than that registered in supplemented treatments at 1% BW either hand-fed (3.6 kg/a/d) or restricted self-feeding (3.7 kg/a/d). In this last treatment, the feeder was empty during 2 to 3 days per week to adjust feed intake at 1% BW. The final BW and average daily gain of supplemented animals (382±29 kg and 1.012±0.546 kg/a/d, respectively) were greater (p 0.05). Conversion efficiency of the supplement, expressed as the amount of supplement (kg) required to gain 1 kg of live weight above the performance of the control group, tended to worsen in self-feeding treatments (5.2 and 6.9 kg restricted and ad-libitum, respectively) compared to the hand-fed daily supplementation (4.7 kg). Supplemented animals registered a greater rib eye area and fat (intramuscular and subcutaneous) than animals in the control group. Self-feeding supplementation is a useful strategy to cope with the high cost and/or lack of labor in livestock operations although supplement feed conversion can be negatively affected due to the high intake of ration and its associated salt

Palavras-chave : cattle; supplementation; self-feeding; salt.

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