Abstract

RIBEIRO, T.; FERRAZ-DE-OLIVEIRA, M. I.; MENDES, C.  and  D'ABREU, M. C.. Study for the validation of the n-alkane technique to estimate feed intake and digestibility in Alentejano pigs. Rev. de Ciências Agrárias [online]. 2007, vol.30, n.1, pp.296-302. ISSN 0871-018X.

The plant epicuticular n-alkanes have been used with success as faecal markers for the estimation of intake and digestibility in ruminants, but few reports have been published with pigs, particularly, “Alentejano” pigs. The aim of this experiment is to validate the n-alkanes technique for the estimation of diet intake and digestibility in pigs of the “Alentejano” breed. An experiment was carried out with eight male “Alentejano” pigs (average LW 58 kg), housed in metabolic cages, in a controlled environment room. The animals were given a diet composed by 3kg of acorns and 400 g of grass per day, distributed into two meals (9:30 am and 5:30 pm). The animals were randomly distributed in two groups of four animals each. Animals in group 1 received one small cake per day containing 100 mg of C32 and 150 mg of C36 and in group 2 received two small cakes per day containing 50 mg of C32 and 75 mg of C36. Faecal samples were collected daily, for ten days, from the first day of alkanes administration, to determine the pattern of excretion of the markers. Also per rectum faecal samples were taken, every four hours, during three days, to determine daily variation of faecal n-alkanes concentration. Moreover, total faecal collection was carried out, for 5 days, to determine faecal n-alkane recoveries. The faecal excretion of the artificial n-alkanes stabilized on the fifth day after the first dosing of the alkanes. No daily variation was observed in the faecal concentrations of even-chain and odd chain n-alkanes, therefore indicating that, in similar experimental conditions, intake and digestibility estimates can be based upon only one daily faecal sample collection. The C32 and C36 recoveries were 107% and 110% respectively and those of C27, the C29, the C31 were 75,1% 133,9% and 91,5% respectively. Given the high mean standard error (10,7) obtained, those recoveries were not significantly (P>0,05) different.

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