Estimation of dry matter intake by lambs managed on different leaves allowance of Brachiaria-grass using internal and external markers

ABSTRACT

It aimed to estimate the forage intake by lambs managed in different leaf allowances on Brachiaria-grass using internal and external markers. Forty-eight Texel lambs with 17.52 ± 3.48 kg were evaluated which were 12 testers and 36 regulators. The lambs were kept in twelve paddocks, subdivided into four treatments based on green leaf allowance (60, 75, 90, and 105 g/kg of BW). The experimental design was completely randomised. To estimate dry matter intake (DMI), the following markers were used: indigestible dry matter (iDM); indigestible neutral detergent fibre (iNDF); indigestible acid detergent fibre (iADF); lignin in indigestible acid detergent (iADL) and titanium dioxide (TiO₂). Comparisons between intake markers were made using Chromic Oxide (Cr₂O₃) as a control marker. The leaves allowance tested did not alter the voluntary intake by lambs kept in Brachiaria-grass pasture. Comparison between the control intake marker (Cr₂O₃) and the other markers by Dunnett's test showed that, regardless of green leaf allowance, the Cr₂O₃, TiO₂ and iADL markers provided similar estimates of DMI, but with lower values than the other markers. External marker TiO₂ and the internal iADL were demonstrated to be more suitable for estimating the dry matter intake in grazing lambs regardless of the leaf allowance.

KEYWORDS:

• Chromic oxide
• indigestible acid detergent lignin
• indigestible dry matter
• indigestible fibre
• titanium dioxide

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior –CAPES [grant no 001]; Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul [grant no 23/200.145/2011]; Conselho Nacional das Fundações Estaduais de Amparo à Pesquisa [grant no 563988/2010-0].